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Objectives: Digital breast tomosynthesis (DBT) plus digital mammography (DM) in screening is problematic due to increased radiation by the double exposure. Synthesised two-dimensional mammography (s2D) calculated from DBT datasets at no additional dose appears a sensible alternative compared to adding DM. This systematic review and meta-analysis focuses on screening performance outcomes in women screened with DBT plus s2D compared to DM alone.Methods: PubMed was searched from January 1, 2010, to September 2, 2020. Studies comparing DBT plus s2D to DM alone in breast cancer screening were included. Pooled risk ratios (RR) were estimated for cancer detection rates (CDR), recall rates, interval cancer rates (ICR), biopsy rates, and positive predictive values for recalls (PPV-1), for biopsies recommended (PPV-2), and for biopsies performed (PPV-3). Sensitivity analyses were performed using the leave-one-out approach. Risk of bias (RoB) was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool.Results: Twelve papers covering 414,281 women were included from 766 records identified. CDR is increased ([RR, 95% CI] 1.35, 1.20-1.52), recall rates are decreased (0.79, 0.64-0.98), and PPV-1 is increased (1.69, 1.45-1.96) when using DBT plus s2D compared to DM alone. ICR and biopsy rates did not differ, but PPV-2 respectively PPV-3 increased with DBT plus s2D (1.57, 1.08-2.28 respectively 1.36, 1.17-1.58). Overall RoB of studies was assessed to be low.Conclusion: Results show improved diagnostic outcomes with DBT plus s2D compared to DM alone and underline the value of DBT in combination with s2D in breast cancer screening.Key Points: • DBT plus s2D is associated with higher CDR, lower recall rates, and a higher PPV-1 compared to DM alone in breast cancer screening. • No differences in biopsy rates were found between screening modalities, but PPV-2 and PPV-3 were higher in women screened with DBT plus s2D compared to DM alone. • We identified inconsistent results of ICR in two studies comparing DBT plus s2D to DM alone-resulting in no differences when pooling ICR in meta-analysis. [ABSTRACT FROM AUTHOR]

The objective of this paper is to compare the accuracy of standard, non-contrast endosonography (EAS) with contrast-enhanced endosonography (CE-EAS) in the diagnosis of anal fistulas. The group consisted of 126 patients (mean age: 43.1 years) with the clinical diagnosis of anal fistula. For anal endosonography, a Bruel & Kjaer unit with a 7.0-MHz transducer was used with a 3% solution of hydrogen peroxide as the contrast agent (1, 2, 3). In each case, EAS and CE-EAS diagnoses of the type and complexity of anal fistula, as well as the location of the internal opening, were determined. Results showed that CE-EAS was significantly more accurate in diagnosing the type of anal fistulas than NC-EAS (97 vs. 94%, respectively; P=02275), and in differentiating simple from complex tracks (92 vs. 75%, respectively; P<0.00001). CE-EAS was much more accurate in patients with recurrent fistulas (57 vs. 92%, respectively; P<0.00006), whereas in a subgroup of primary tracks, both methods were of comparable accuracy. Sensitivities of CE-EAS and EAS for internal opening were 89 and 65%, respectively. The conclusion of this paper is that CE-EAS significantly increases the accuracy of standard non-contrast EAS and is especially beneficial for the differentiation between simple and complex tracks. [ABSTRACT FROM AUTHOR]

The hypothesis was that when a hospital-wide Picture Archive and Communications System (PACS) is used, preparation for clinico-radiological meetings is faster, and more images are available, than when a conventional film system is used. This paper reports a study which compared the preparation time by radiologists when film was used with the time for the same activity when a hospital-wide PACS was used at Hammersmith Hospital for the preparation of the respirator medicine and hepato-biliary meeting. It was found that when PACS was used the time per patient to prepare for the respiratory medicine session was reduced by 11.1 min and that similarly, 16 min per patient was saved in the preparation of the hepato-biliary sessions. The number of images which were unavailable for the session was reduced when PACS was in operation, but this reduction was not shown to be statistically significant. The introduction of PACS at Hammersmith Hospital has significantly reduced the time spent by radiologists in preparing for the two clinico-radiological sessions studied and, if this is extended to the other numerous sessions held each week, contributes to a considerable saving of staff time within the radiology department. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to characterize and quantify the vascularization and hemodynamic characteristics of head and neck tumors (HNT) with a dynamic 3D time-resolved echo-shared angiographic technique (TREAT) using the regular contrast agent (CA) bolus. Sixteen patients with HNT underwent 3D-TREAT during the CA administration on a 1.5-T magnetic resonance (MR) scanner. Using a parallel imaging acceleration factor of 2, 20 3D data sets at a temporal resolution of 2.3 s/frame were acquired. The quality of tumor delineation, vascularization type, and enhancement pattern were evaluated. Quantitative assessment included measurement of the contrast-to-noise ratio (CNR), determination of signal-intensity-over-time (SIT) curves, time-to-peak enhancement within the carotid arteries and the tumor, and the delay between both. TREAT was compared to conventional digital subtraction angiography (DSA) in six patients. Tumor delineation with TREAT was very good or good in 11/16 patients, and better with TREAT than with DSA in 3/6 cases. The CNR was significantly different for glomus tumors versus hypovascularized malignant tumors with TREAT (p=0.0001), but not on T1-weighted gradient echo (T1w GE) images. Qualitative assessment of tumor vascularization on dynamic TREAT shows good correlation (r=0.75) to quantitative SIT curves. We conclude that TREAT imaging permits the characterization of tumor vascularity and holds promise as a supplementary diagnostic tool in the differential diagnosis of HNT. [ABSTRACT FROM AUTHOR]

To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development. [ABSTRACT FROM AUTHOR]

The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force F(z) (in millinewtons) was evaluated by determining the deflection angle beta [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force F(rot) was qualitatively determined using a five-point scale. beta was found to be >45 degrees in 13(15) devices at 1.5(3) T and translational force F(z) exceeded gravitational force F(g) on the particular object [F(z) 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. F(z) was found to be up to 24.1(47.5)-fold higher than F(g) at 1.5(3) T. Corresponding to this, F(rot) on the objects was shown to be high at both field strengths (> or = +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles <45 degrees , but F(rot) was found to be > or = +3 at both field strengths. For the remaining objects, beta was below 45 degrees and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of F(z). The implications of these results for orthodontic patients undergoing MRI are discussed. [ABSTRACT FROM AUTHOR]

This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/alpha/ST: 600 ms/28 ms/180 degrees /6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/alpha: 0.8/1.9 ms/40 degrees ), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P<0.0001). Severe morphological changes led to perfusion defects (97%, P<0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients. [ABSTRACT FROM AUTHOR]

The aim of this paper was to assess the diagnostic value of magnetic resonance (MR) fluoroscopy in the study of oesophageal motility disorders and to compare MR fluoroscopy results with those of manometry and barium contrast radiography. Twenty-five subjects referred for dysphagia and three patients in follow-up after pneumatic dilatation of the lower oesophageal sphincter to treat severe achalasia underwent esophageal manometry, barium contrast radiography and MR fluoroscopy. Examinations were performed on a 1.5 T scanner. Dynamic turbo- fast low angle shot (turbo-FLASH) sequences acquired during oral contrast agent administration were used to perform MR fluoroscopy. MR fluoroscopy correctly diagnosed achalasia in nine patients, uncoordination of esophageal body motility in ten and scleroderma oesophagus in one. Diagnostic performance was satisfactory, with a sensitivity of 87.5% and a specificity of 100% in the general depiction of motility alterations. Our work demonstrates that MR fluoroscopic examination in subject affected by oesophageal motility disorders is feasible and can properly depict motility and morphology alterations, achieving correct diagnosis in the majority of cases. Studies on larger populations are necessary to obtain statistically significant results. [ABSTRACT FROM AUTHOR]

Accurate determination of left ventricular (LV) myocardial function is fundamental for clinical diagnosis, risk stratification, and estimation of prognosis in patients with ischemic and nonischemic cardiomyopathy. Primarily, multi-detector-row spiral CT (MDCT) of the heart aimed at detecting coronary artery obstruction and cardiac morphology. Multiple studies have demonstrated that retrospectively, ECG-gated MDCT determination of LV volumes and consequently global LV function parameters is feasible in good agreement with established imaging modalities such as cineventriculography, echocardiography, and cine magnetic resonance imaging (CMR). Post-processing tools allow fast and semi-automatic determination of LV function parameters from MDCT data in analogy to known CMR evaluation approaches. Although MDCT is not considered to be first-line modality for LV function assessment, this technique provides accessory dynamic information in patients undergoing MDCT coronary angiography, contributing to combined assessment of cardiac morphology and function without need of additional radiation exposure. MDCT regional LV wall motion analysis at rest is feasible, but further improvement in temporal resolution seems mandatory to match results obtained from competing modalities. This paper will discuss the diagnostic potential of MDCT for assessment of LV function with regards to accuracy and clinical applications, as well as limitations, particularly in comparison with CMR as modality of reference. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe our experience with endovascular obliteration of duodenal varices in patients with liver cirrhosis and portal hypertension. Balloon-occluded transvenous retrograde and percutaneous transhepatic anterograde embolizations were performed for duodenal varices in five patients with liver cirrhosis, portal hypertension, and decreased liver function. All patients had undergone previous endoscopic treatments that failed to stop bleeding and were poor surgical candidates. Temporary balloon occlusion catheters were used to achieve accumulation of an ethanolamine oleate-iopamidol mixture inside the varices. Elimination of the varices was successful in all patients. Retrograde transvenous obliteration via efferent veins to the inferior vena cava was enough to achieve adequate sclerosant accumulation in three patients. A combined anterograde-retrograde embolization was used in one patient with balloon occlusion of afferent and efferent veins. Transhepatic embolization through the afferent vein was performed in one patient under balloon occlusion of both efferent and afferent veins. There was complete variceal thrombosis and no bleeding was observed at follow-up. No major complications were recorded. Endovascular obliteration of duodenal varices is a feasible and safe alternative procedure for managing patients with portal hypertension and hemorrhage from this source. [ABSTRACT FROM AUTHOR]

Unlabelled: Lymphnodes status in cervical carcinoma is important in therapeutic planning, and the role of Computed Tomography (CT) and Magnetic Resonance (MR) is controversial: this paper aims to evaluate their accuracy in diagnosing nodal metastases in patients with cervical carcinoma. We reviewed, retrospectively and blindly, CT and MR of 62 patients, before surgical lymphnode resection: 45 of these patients had pre-surgical chemotherapy. Lymphnodes were defined metastatic by CT and MRI when larger than 1 cm short axis. Both diagnoses by the original routine reports and by a second blind expert were compared with pathological reports.Results: combining the reading results of both observers CT showed a sensitivity of 64.6% and specificity of 93.3%; MRI a sensitivity of 72.9% and specificity of 93.1%. Positive Predictive Value was 50.8% for CT and 53% for MR, while Negative Predictive Value was 96% both for CT and MR. The expert Radiologist reviewing the films obtained better results. Inter-observer variability in the lower quadrants was high for each imaging technique (kappa for CT: 0.71; kappa for MRI: 0.84). Both imaging techniques showed similar screening accuracy in identifying nodal metastases. The radiologist's experience is important in determining the performance of the imaging technique. Anyway, CT and MRI are only moderately sensitive for detection of nodal metastases and the clinical impact of their results in patient's management is limited. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to compare the influence of detector collimation on the signal-to-noise ratio (SNR) for a 5.0 mm reconstructed slice thickness for four multi-detector row CT (MDCT) units. SNRs were measured on Catphan test phantom images from four MDCT units: a GE LightSpeed QX/I, a Marconi MX 8000, a Toshiba Aquilion and a Siemens Volume Zoom. Five-millimetre-thick reconstructed slices were obtained from acquisitions performed using detector collimations of 2.0-2.5 mm and 5.0 mm, 120 kV, a 360 degrees tube rotation time of 0.5 s, a wide range of mA and pitch values in the range of 0.75-0.85 and 1.25-1.5. For each set of acquisition parameters, a Wiener spectrum was also calculated. Statistical differences in SNR for the different acquisition parameters were evaluated using a Student's t-test (P<0.05). The influence of detector collimation on the SNR for a 5.0-mm reconstructed slice thickness is different for different MDCT scanners. At pitch values lower than unity, the use of a small detector collimation to produce 5.0-mm thick slices is beneficial for one unit and detrimental for another. At pitch values higher than unity, using a small detector collimation is beneficial for two units. One manufacturer uses different reconstruction filters when switching from a 2.5- to a 5.0-mm detector collimation. For a comparable reconstructed slice thickness, using a smaller detector collimation does not always reduce image noise. Thus, the impact of the detector collimation on image noise should be determined by standard deviation calculations, and also by assessing the power spectra of the noise. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training ( P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow ( P<0.001 and P=0.03, respectively), but increased for the trainee ( P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases. [ABSTRACT FROM AUTHOR]

The causes of stress urinary incontinence are not completely known. Recent papers have stressed the importance of more anatomical information, which may help to elucidate the mechanism of stress urinary incontinence. The purpose of this study was to evaluate the prevalence of lesions of the urethral support mechanism and lesions (defects and scars, thinning) of levator ani muscle with endovaginal MRI in a case-control study. Forty women (median age 52 years, age range 40-65 years)--20 patients with stress urinary incontinence (cases) and 20 age-matched healthy volunteers (controls)--underwent endovaginal MRI: axial, coronal, and sagittal T2-weighted turbo spin echo. The examinations were evaluated for the presence of lesions of urethral supporting structures and levator ani and scar tissue of the levator ani. The thickness of the levator ani muscle was measured. Lesions of the urethral support system and levator ani were significantly more prevalent in cases than in controls ( p<0.01). Median levator ani thickness in patients was significantly lower than in healthy controls [2.5 mm (range 0.9-4.1 mm) vs 3.9 mm (range 1.4-7 mm)] ( p<0.01). This study indicates a relationship between stress urine incontinence and the presence of lesions of the urethral support and levator ani and levator ani thinning. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to describe the MR imaging findings of right adrenal hemorrhage after orthotopic liver transplantation. Twenty-seven orthotopic liver transplantation patients underwent MR studies of the liver and/or biliary system. Patients were referred to MR examination because of suspected biliary complications ( n=22) or for evaluation of mass lesions ( n=5). The standard MR protocol included T1-weighted spin-echo (SE) or gradient-recalled echo (GRE) images and T2-weighted turbo SE (TSE) images with fat suppression. In addition, cholangiography pulse sequences and/or contrast-enhanced T1-weighted images were obtained according to specific indications. In 2 patients a right adrenal mass was detected at MR imaging. Three to 4 weeks after transplantation, the lesions were markedly hyperintense on T2-weighted images and showed a hypointense capsule. Follow-up MR examinations revealed a slight decrease in size and a change in morphology. Computed tomography examinations of these 2 patients, obtained 10 weeks after transplantation, showed resolution of the hemorrhage and transformation into a cystic lesion in one case and a complete resolution of the hemorrhage and a normal right adrenal gland in the other case. Adrenal hemorrhage after liver transplantation shows typical MR features and should not be mistaken for an adrenal tumor or a postoperative abscess. [ABSTRACT FROM AUTHOR]

The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed. [ABSTRACT FROM AUTHOR]

Objectives: To perform an online survey about the use of magnetic resonance arthrography (MRA) in clinical practice.Methods: We administered an online survey to all 1,550 members of the European Society of Musculoskeletal Radiology (ESSR) about MRA asking ten different questions. Subgroup analysis was performed between general and orthopaedic hospitals using χ2 and Mann-Whitney U statistics.Results: One-hundred forty-eight answers were included (148/1,550, 9.5% of ESSR members). A median of 3,000 (interquartile range: 1,567.5-5,324.5) musculoskeletal MR examinations and a median of 125.5 MRAs (50.75-249) per institution were performed in 2016. Ratio between MRA and musculoskeletal MR was 4.7% (1.6%-9.0%). Using MRA, the most investigated joint was the shoulder followed by the hip (96.6%). The most common indications were the evaluation of instability, labrum, and rotator cuff (85.1%). Fluoroscopy represented the preferred injection guidance. A self-prepared mixture of Gadolinium/saline is preferred in general hospitals, while pre-diluted Gadolinium-based syringes are mainly used in orthopaedic hospitals (P=.010). The number of MRA performed at orthopaedic hospitals (284;83.75-449.50) was higher (P=.006) than that performed at general hospitals (115.50;44.75-234.25).Conclusions: One out of twenty MR examinations is a MRA, with higher prevalence in orthopaedic hospitals. The shoulder and the hip are the most investigated joints. Instability, labrum, and cuff are the most common indications.Key Points: • The most common MRAs are shoulder and hip (96.6% of answers). • Most common clinical indications for MRA are instability, labrum, and rotator cuff (85.1% of answers). • Fluoroscopy represents the preferred guidance to inject joints (61.0% of answers). • The median number of MRA performed at orthopaedic hospitals (n=284) was significantly higher (P=.006) than that performed at general hospitals (n=115.50). • A self-prepared mixture of Gadolinium/saline solution is preferred in general hospitals (64.8%) compared to orthopaedic hospitals (36.0%; P=0.010). [ABSTRACT FROM AUTHOR]

Objectives: To propose national diagnostic reference levels (DRLs) for interventional radiology and to evaluate the impact of the procedural complexity on patient doses.Methods: Eight interventional radiology units from Spanish hospitals were involved in this project. The participants agreed to undergo common quality control procedures for X-ray systems. Kerma area product (KAP) was collected from a sample of 1,649 procedures. A consensus document established the criteria to evaluate the complexity of seven types of procedures. DRLs were set as the 3rd quartile of KAP values.Results: The KAP (3rd quartile) in Gy cm2 for the procedures included in the survey were: lower extremity arteriography (n = 784) 78; renal arteriography (n = 37) 107; transjugular hepatic biopsies (THB) (n = 30) 45; biliary drainage (BD) (n = 314) 30; uterine fibroid embolization (UFE) (n = 56) 214; colon endoprostheses (CE) (n = 31) 169; hepatic chemoembolization (HC) (n = 269) 303; femoropopliteal revascularization (FR) (n = 62) 119; and iliac stent (n = 66) 170. The complexity involved the increases in the following KAP factors from simple to complex procedures: THB x4; BD x13; UFE x3; CE x3; HC x5; FR x5 and IS x4.Conclusions: The evaluation of the procedure complexity in patient doses will allow the proper use of DRLs for the optimization of interventional radiology.Key Points: • National DRLs for interventional procedures have been proposed given level of complexity • For clinical audits, the level of complexity should be taken into account. • An evaluation of the complexity levels of the procedure should be made. [ABSTRACT FROM AUTHOR]

Objectives: Intravenous application of contrast media is part of a wide spectrum of diagnostic procedures for better imaging quality. Clinical avoidance of contrast-enhanced imaging is an ever-present quandary in patients with impaired kidney function. The objective of this study was to estimate the risk for acute kidney injury (AKI), dialysis and mortality among patients undergoing contrast-enhanced CT compared to propensity score-matched controls (i.e. contrast-unenhanced CT). Selected cohort studies featured high-risk patients with advanced kidney disease and critical illness.Methods: This review was designed to conform to the Preferred Reporting Items in Systematic Reviews and Meta-Analysis (PRISMA) guidelines. PubMed was searched from August 2021 to November 2021 for all-language articles without date restriction. A random-effects model (DerSimonian and Laird method) was used for meta-analysis.Results: Twenty-one articles were included, comprising data of 169,455 patients. The overall risk of AKI was similar in the contrast-enhanced and unenhanced groups (OR: 0.97 [95% CI: 0.85; 1.11], p = 0.64), regardless of baseline renal function and underlying disease. Substantial heterogeneity was detected (I2 = 90%, p ≤ 0.0001). Multivariable logistic regression identified hypertension (p = 0.03) and estimated glomerular filtration rate (eGFR) ≤ 30 mL/min/1.73 m2 (p = 0.0001) as factors associated with greater risk of post-contrast AKI.Conclusions: Based on propensity score-matched pairs obtained from 21 cohort studies, we found no evidence for increased risk for AKI, dialysis or mortality after contrast-enhanced CT among patients with eGFR ≥ 45 mL/min/1.73 m2. In congruence with the emerging evidence in the literature, caution should be exercised in patients with hypertension and eGFR ≤ 30 mL/min/1.73 m2.Key Points: • The application of contrast media for medical imaging is not associated with higher odds for AKI, induction of renal replacement therapy, or mortality. Many comorbidities traditionally associated with greater risk for acute kidney injury do not appear to predispose for renal decline after contrast media exposure. • Underlying hypertension and eGFR less than or equal to 30 mL/min/1.73 m2 seem to predispose for post-contrast acute kidney injury. • Propensity score matching cannot account for unmeasured influences on AKI incidence, which needs to be addressed in the interpretation of results. [ABSTRACT FROM AUTHOR]

Objectives: To determine the performance of diagnostic algorithm of adding hepatobiliary phase (HBP) images in Gd-EOB-DTPA-enhanced MRI for the detection of hepatocellular carcinoma (HCC) measuring up to 3 cm in patients with chronic liver disease.Methods: We searched multiple databases from inception to April 10, 2020, to identify studies on using Gd-EOB-DTPA-enhanced MRI for the diagnostic accuracy of HCC (≤ 3 cm) in patients with chronic liver disease. The diagnostic algorithm of Gd-EOB-DTPA-enhanced MRI with HBP for HCC was defined as a nodule showing hyperintensity during arterial phase and hypointensity during the portal venous, delayed, or hepatobiliary phases. For gadoxetic acid-enhanced MRI without HBP, the diagnostic criteria were a nodule showing arterial enhancement and hypointensity on the portal venous or delayed phases. The data were extracted to calculate summary estimates of sensitivity, specificity, diagnostic odds ratio, likelihood ratio, and summary receiver operating characteristic (sROC) by using a bivariate random-effects model.Results: Twenty-nine studies with 2696 HCC lesions were included. Overall Gd-EOB-DTPA-enhanced MRI with HBP had a sensitivity of 87%, specificity of 92%, and the area under the sROC curve of 95%. The summary sensitivity of Gd-EOB-DTPA-enhanced MRI with HBP was significantly higher than that without HBP (84% vs 68%, p = 0.01).Conclusion: Gd-EOB-DTPA-enhanced MRI with HBP showed higher sensitivity than that without HBP and had comparable specificity for diagnosis of HCC in patients with chronic liver disease.Key Points: • Hypointensity on HBP is a major feature for diagnosis of HCC. • Extending washout appearance to the transitional or hepatobiliary phase on Gd-EOB-DTPA provides favorable sensitivity and comparable specificity for diagnosis HCC. • The summary sensitivity of gadoxetic acid-enhanced MRI with HBP was significantly higher than that without HBP (84% vs 68%, p = 0.01) for diagnosis of HCC in patients with chronic liver disease. [ABSTRACT FROM AUTHOR]

Objectives: The multicenter study aimed to explore the relationship between the growth pattern of liver metastases on preoperative MRI and early recurrence in patients with colorectal cancer liver metastases (CRCLM) after surgery.Methods: A total of 348 CRCLM patients from 3 independent centers were enrolled, including 130 patients with 339 liver metastases in the primary cohort and 218 patients in validation cohorts. Referring to the gross classification of hepatocellular carcinoma (HCC), the growth pattern of each liver metastasis on MRI was classified into four types: rough, smooth, focal extranodular protuberant (FEP), and nodular confluent (NC). Disease-free survival (DFS) curve was constructed using the Kaplan-Meier method.Results: In primary cohort, 42 (12.4%) of the 339 liver metastases were rough type, 237 (69.9%) were smooth type, 29 (8.6%) were FEP type, and 31 (9.1%) were NC type. Those patients with FEP- and/or NC-type liver metastases had shorter DFS than those without such metastases (p < 0.05). However, there were no significant differences in DFS between patients with rough- and smooth-type liver metastases and those without such metastases. The patients with FEP- and/or NC-type liver metastases also had shorter DFS than those without such metastases in two external validation cohorts. In addition, 40.5% of high-risk-type (FEP and NC) liver metastases converted to low-risk types (rough and smooth) after neoadjuvant chemotherapy.Conclusion: The FEP- and NC-type liver metastases were associated with early recurrence, which may facilitate the clinical treatment of CRCLM patients.Key Points: • In the primary cohort, patients with FEP- and NC-type metastases had shorter disease-free survival (DFS) and a higher intrahepatic recurrence rate than patients without such metastases in the liver. • In the primary cohort, there were no significant differences in DFS or intrahepatic recurrence rate between patients with rough- and smooth-type metastases and those without such metastases in the liver. • High-risk patients had shorter DFS and a higher intrahepatic recurrence rate than low-risk patients in primary and external validation cohorts. [ABSTRACT FROM AUTHOR]

Objective: To develop a quantitative Response Evaluation Criteria in Solid Tumors (qRECIST) for evaluating response to neoadjuvant therapy (nT) in ESCCs relying on multiparametric (mp) MRI.Methods: Patients with cT2-T4a/N0-N3/M0 ESCC undergoing pre-nT and post-nT esophageal mpMRI before radical resection were prospectively included. Images were reviewed by two experienced radiologists. qRECIST was redefined using four methods including conventional criterion (cRECIST) and three model-dependent RECIST relying on quantitative MRI measurements at pre-nT, post-nT, and delta pre-post nT, respectively. Pathological tumor regression grades (TRGs) were used as a reference standard. The rates of agreement between four qRECIST methods and TRGs were determined with a Cronbach's alpha test, area under the curve (AUC), and a diagnostic odds ratio meta-analysis.Results: Ninety-one patients were enrolled. All four methods revealed high inter-reader agreements between the two radiologists, with a Kappa coefficient of 0.96, 0.87, 0.88, and 0.97 for cRECIST, pre-nT RECIST, post-nT RECIST, and delta RECIST, respectively. Among them, delta RECIST achieved the highest overall agreement rate (67.0% [61/91]) with TRGs, followed by post-nT RECIST (63.8% [58/91]), cRECIST (61.5% [56/91]), and pre-nT RECIST (36.3% [33/91]). Especially, delta RECIST achieved the highest accuracy (97.8% [89/91]) in distinguishing responders from non-responders, with 97.3% (34/35) for responders and 98.2% (55/56) for non-responders. Post-nT RECIST achieved the highest accuracy (93.4% [85/91]) in distinguishing complete responders from non-pCRs, with 77.8% (11/18) for pCRs and 94.5% (69/73) for non-pCRs.Conclusion: The qRECIST with mpMRI can assess treatment-induced changes and may be used for early prediction of response to nT in ESCC patients.Key Points: • Quantitative mpMRI can reliably assess tumor response, and delta RECIST model had the best performance in evaluating response to nT in ESCCs, with an AUC of 0.98, 0.95, 0.80, and 0.82 for predicting TRG0, TRG1, TRG2, and TRG3, respectively. • In distinguishing responders from non-responders, the rate of agreement between delta RECIST and pathology was 97.3% (34/35) for responders and 98.2% (55/56) for non-responders, resulting in an overall agreement rate of 97.8% (89/91). • In distinguishing pCRs from non-pCR, the rate of agreement between MRI and pathology was 77.8% (11/18) for pCRs and 94.5% (69/73) for non- pCRs, resulting in an overall agreement rate of 91.2% (83/91). [ABSTRACT FROM AUTHOR]

Objectives: To compare patient satisfaction, procedural variables, and safety with transradial access (TRA) and transfemoral access (TFA) in patients undergoing transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).Materials and Methods: From February 2019 to August 2021, 130 patients undergoing TACE for HCC were randomly allocated to the TRA (n = 65) or TFA (n = 65) group. Vascular closure devices were not used after TFA-TACE. All patients completed the post-catheterization questionnaire and 8-item Short-Form Health Survey 1 day after TACE.Results: Technical success rate, crossover rate, contrast agent dose, fluoroscopy time, procedure time, air kerma, dose-area product, length of hospital stay, and total cost were similar between the two groups (all p > 0.05). The incidence and severity of adverse events were also similar between the two groups (all p > 0.05). However, overall discomfort, difficulty going to the bathroom, difficulty feeding or self-caring, difficulty walking, general health, physical function, role physical function, social function, mental health, and role emotional function were better in the TRA group than in the TFA group (all p < 0.001). Consequently, more patients preferred the current access for their next procedure in the TRA group than in the TFA group (90.8% vs. 24.6%; p < 0.001).Conclusion: In patients undergoing TACE for HCC, using TRA instead of TFA can improve patient satisfaction without compromising procedural variables and safety.Key Points: • Transradial access (TRA) enabled early ambulation after transarterial chemoembolization (TACE), resulting in significant increase in activities of daily living and health-related quality of life (HRQoL) compared to transfemoral access (TFA) when vascular closure devices were not used. • Procedural variables (contrast agent dose, fluoroscopy time, procedure time, air kerma, dose-area product, length of hospital stay, and total cost) were not significantly different between patients who received TRA-TACE and TFA-TACE. • The incidence and severity of adverse events were similar between patients who received TRA-TACE and TFA-TACE. [ABSTRACT FROM AUTHOR]

Objectives: To develop and validate an optimal model based on the 1-mm-isotropic-3D contrast-enhanced StarVIBE MRI sequence combined with clinical risk factors for predicting survival in patients with esophageal squamous cell carcinoma (ESCC).Methods: Patients with ESCC at our institution from 2015 to 2017 participated in this retrospective study based on prospectively acquired data, and were randomly assigned to training and validation groups at a ratio of 7:3. Random survival forest (RSF) and variable hunting methods were used to screen for radiomics features and LASSO-Cox regression analysis was used to build three models, including clinical only, radiomics only and combined clinical and radiomics models, which were evaluated by concordance index (CI) and calibration curve. Nomograms and decision curve analysis (DCA) were used to display intuitive prediction information.Results: Seven radiomics features were selected from 434 patients, combined with clinical features that were statistically significant to construct the predictive models of disease-free survival (DFS) and overall survival (OS). The combined model showed the highest performance in both training and validation groups for predicting DFS ([CI], 0.714, 0.729) and OS ([CI], 0.730, 0.712). DCA showed that the net benefit of the combined model and of the clinical model is significantly greater than that of the radiomics model alone at different threshold probabilities.Conclusions: We demonstrated that a combined predictive model based on MR Rad-S and clinical risk factors had better predictive efficacy than the radiomics models alone for patients with ESCC.Key Points: • Magnetic resonance-based radiomics features combined with clinical risk factors can predict survival in patients with ESCC. • The radiomics nomogram can be used clinically to predict patient recurrence, DFS, and OS. • Magnetic resonance imaging is highly reproducible in visualizing lesions and contouring the whole tumor. [ABSTRACT FROM AUTHOR]

The aim of this paper is to examine signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality of cardiac CINE imaging at 1.5 T and 3.0 T. Twenty volunteers underwent cardiac magnetic resonance imaging (MRI) examinations using a 1.5-T and a 3.0-T scanner. Three different sets of breath-held, electrocardiogram-gated (ECG) CINE imaging techniques were employed, including: (1) unaccelerated SSFP (steady state free precession), (2) accelerated SSFP imaging and (3) gradient-echo-based myocardial tagging. Two-dimensional CINE SSFP at 3.0 T revealed an SNR improvement of 103% and a CNR increase of 19% as compared to the results obtained at 1.5 T. The SNR reduction in accelerated 2D CINE SSFP imaging was larger at 1.5 T (37%) compared to 3.0 T (26%). The mean SNR and CNR increase at 3.0 T obtained for the tagging sequence was 88% and 187%, respectively. At 3.0 T, the duration of the saturation bands persisted throughout the entire cardiac cycle. For comparison, the saturation bands were significantly diminished at 1.5 T during end-diastole. For 2D CINE SSFP imaging, no significant difference in the left ventricular volumetry and in the overall image quality was obtained. For myocardial tagging, image quality was significantly improved at 3.0 T. The SNR reduction in accelerated SSFP imaging was overcompensated by the increase in the baseline SNR at 3.0 T and did not result in any image quality degradation. For cardiac tagging techniques, 3.0 T was highly beneficial, which holds the promise to improve its diagnostic value. [ABSTRACT FROM AUTHOR]

Detection and characterization of intraorbital foreign bodies (IFB) is fundamental in acute trauma setting, preventing inflammatory sequelae or complications related to IFB movements when a MRI study is planned. Papers concerning plain film and CT sensibility in IFB detection show controversial results. For this reason we investigated plain film, CT and MRI sensibility in the evaluation of IFB. For an in vitro model, specimens of dry and fresh wood, glass, iron, plastic and graphite were immersed in animal lard and in a 0.9% sodium chloride plus 3.5 g/dl human serum albumin solution. Specimens of different size and nature where also implanted into enucleated pig eyes. Air bubbles were introduced also. Plain film, CT and MRI investigation were performed. Plain films underestimated intraocular IFB as plastic, fresh or dry wooden IFB were not demonstrated. The CT study was always able to depict and differentiate IFB according to the attenuation values. Severe artefacts prevented demonstration of iron, glass and graphite IFB on MRI, whereas plastic or wooden IFB were always detected. Despite radiographs have been suggested as a prerequisite for MR imaging, because our results showed plain film to underestimate radiolucent IFB, we suggest CT as the modality of choice when IFB has to be ruled out. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the prediction performance of deep convolutional neural network (DCNN) based on ultrasound (US) images for the assessment of breast cancer molecular subtypes.Methods: A dataset of 4828 US images from 1275 patients with primary breast cancer were used as the training samples. DCNN models were constructed primarily to predict the four St. Gallen molecular subtypes and secondarily to identify luminal disease from non-luminal disease based on the ground truth from immunohistochemical of whole tumor surgical specimen. US images from two other institutions were retained as independent test sets to validate the system. The models' performance was analyzed using per-class accuracy, positive predictive value (PPV), and Matthews correlation coefficient (MCC).Results: The model achieved good performance in identifying the four breast cancer molecular subtypes in the two test sets, with accuracy ranging from 80.07% (95% CI, 76.49-83.23%) to 97.02% (95% CI, 95.22-98.16%) and 87.94% (95% CI, 85.08-90.31%) to 98.83% (95% CI, 97.60-99.43) for the two test cohorts for each sub-category, respectively. In terms of 4-class weighted average MCC, the model achieved 0.59 for test cohort A and 0.79 for test cohort B. Specifically, the DCNN also yielded good diagnostic performance in discriminating luminal disease from non-luminal disease, with a PPV of 93.29% (95% CI, 90.63-95.23%) and 88.21% (95% CI, 85.12-90.73%) for the two test cohorts, respectively.Conclusion: Using pretreatment US images of the breast cancer, deep learning model enables the assessment of molecular subtypes with high diagnostic accuracy.Trial Registration: Clinical trial number: ChiCTR1900027676 KEY POINTS: • Deep convolutional neural network (DCNN) helps clinicians assess tumor features with accuracy. • Multicenter retrospective study shows that DCNN derived from pretreatment ultrasound imagine improves the prediction of breast cancer molecular subtypes. • Management of patients becomes more precise based on the DCNN model. [ABSTRACT FROM AUTHOR]

Objectives: Brain imaging is particularly difficult to learn and to teach. This study aimed to evaluate the performance of teaching brain imaging through drawing method in medical faculty students.Methods: We conducted a prospective, interventional, randomized, single-blind study in third-year voluntary medical students between December 2016 and June 2019. Eighty medical students received a theoretical training on brain imaging interpretation and were subsequently randomized into two groups ("teaching through drawing" and "standard teaching"). An initial evaluation was carried out to assess the students' basic level. Three teaching and training sessions were spread over 2 months in each group. One month after the third teaching session, students were evaluated by an examiner who was blind to the student's group. The same comprehensive evaluation grid has been used for the initial and final students' evaluations to give an objective score out of 20 points. Students' scores were compared between groups using the t test and effect sizes were measured using Cohen's d.Results: Students' mean age was 21.1 years old. In total, 61.3% were female. Regarding initial evaluation, scores did not differ significantly between both groups (10.1 ± 2.0 versus 9.9 ± 1.9, p = 0.65), thus confirming the homogeneity of the students' basic level. The scores obtained from the final evaluation were significantly higher for the "teaching through drawing" students than for the "standard teaching" students (14.7 ± 2.7 vs 13.2 ± 2.0, p = 0.009, Cohen's d = 0.62).Conclusions: This study provides class II evidence that the method of drawing alone can improve brain imaging comprehension and analysis in medical faculty students.Key Points: • The method of drawing can improve brain imaging analysis in medical faculty students. • A large majority of students were satisfied by the method of brain imaging teaching through drawing. [ABSTRACT FROM AUTHOR]

Objectives: Right ventricular (RV) function is considered the major determinant of prognosis in patients with chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this meta-analysis was to evaluate RV remodelling and function following balloon pulmonary angioplasty (BPA) in patients with inoperable CTEPH or persistent/recurrent pulmonary hypertension (PH) after pulmonary endarterectomy (PEA).Methods: We reviewed all studies evaluating RV function by cardiac magnetic resonance (CMR) and/or echocardiography pre- and post-BPA from PubMed/Medline prior to 15 December 2019. Ten (299 patients) of the 29 studies retrieved met the inclusion criteria: 5 CMR and 5 echocardiography studies. The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines.Results: Pooled data from CMR studies revealed BPA resulted in a significantly decreased RV end-diastolic volume index (weighted mean difference (WMD) - 28.33 ml/m2, p < 0.00001) and RV end-systolic volume index (WMD - 29.06 ml/m2, p < 0.00001) accompanied by an increased RV ejection fraction (RVEF, WMD 8.97%, p < 0.00001). Data from the echocardiography studies showed BPA resulted in decreased RV basal diameter (WMD - 0.37 cm, p = 0.0009) and an increase of RV fractional area change (WMD 5.97 %, p = 0.003), but improvements of tricuspid annular plane systolic excursion (TAPSE) and S' were not significant.Conclusions: BPA improves RVEF and decreases RV volumes in patients with inoperable CTEPH or persistent/recurrent PH after PEA.Key Points: • Balloon pulmonary angioplasty improves RVEF and decreases RV volumes in patients with inoperable CTEPH or persistent/recurrent PH after PEA. [ABSTRACT FROM AUTHOR]

Objectives: Ultrasound (US)-guided fine needle aspiration cytology (FNAC) and thyroglobulin measurement (FNA-Tg) are two common methods for confirming lymph node metastases (LNM) in patients with differentiated thyroid carcinoma (DTC). This study aimed at comparing the diagnostic performance of FNAC, FNA-Tg alone, and in combination by means of a meta-analysis.Methods: Eligible articles were selected according to predefined criteria, and their quality was evaluated as per the QUADAS-2 checklist. We calculated pooled sensitivity (Se), specificity (Sp), positive/negative likelihood ratio, and diagnostic odds ratio (DOR), and plotted the summary receiver operating characteristic (SROC) curve using the Meta-DiSc1.4 software.Results: Twenty-one studies pooling 1662 malignant and 1279 benign LNs from 2712 patients with DTC were included. The results showed that FNAC was more specific (pooled Sp, 0.98) while FNA-Tg was more sensitive (pooled Se, 0.94). FNAC and FNAC+FNA-Tg performed better postoperatively than FNA-Tg, while FNA-Tg performed better preoperatively. The combination of FNAC and FNA-Tg could achieve a better diagnostic performance than each alone (DOR 446.00, area under the curve [AUC] 0.9862), no matter preoperatively (DOR 378.14, AUC 0.9879) or postoperatively (DOR 788.72, AUC 0.9930). Besides, the combination of FNAC and FNA-Tg/serum-Tg ratio obtained a higher Sp (0.98) than the combination of FNAC and FNA-Tg.Conclusion: The addition of FNA-Tg, especially the FNA-Tg/serum-Tg ratio, to FNAC could increase the diagnostic performance of LNM in both preoperative and postoperative patients with DTC. Since one test or test combinations could perform differently according to the clinical situation, the best-fitting test should be chosen accordingly.Key Points: • FNAC is more specific than FNA-Tg while FNA-Tg is more sensitive than FNAC. • The combination of FNAC and FNA-Tg could achieve a better diagnostic performance than either alone, no matter preoperatively or postoperatively. • The combination of FNAC and FNA-Tg/serum-Tg ratio could reach a higher Sp than the combination of FNAC and FNA-Tg. [ABSTRACT FROM AUTHOR]

Objective: This study aims to determine the risk factors, patterns, and long-term survival outcomes of late recurrence after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) within the Milan criteria and develop a nomogram to predict the recurrence-free survival (RFS).Materials and Methods: This retrospective study included patients with HCC within the Milan criteria, who received RFA at three hospitals in China from January 2011 to December 2016. The clinical variables were assessed by univariate and multivariate Cox regression analyses.Results: A total of 398 patients were included. The median follow-up was 58.7 months (range: 24.1-96.0). Ninety-eight patients had late recurrence. Furthermore, 14 patients (14.29%) had local tumor progression (LTP) alone, 43 patients (43.88%) had intrahepatic distant recurrence (IDR) alone, 15 patients (15.31%) had extrahepatic recurrence (ER) alone, three patients (3.06%) had both LTP and IDR, six patients (6.12%) had both LTP and ER, and 17 patients (17.35%) had both IDR and ER. Patients without late recurrence had better long-term overall survival (OS) compared to those with late recurrence (p < 0.001). Male gender, multiple tumors, and cirrhosis were the independent risk factors of late recurrence. A well-discriminated and calibrated nomogram was constructed to predict the probability of RFS.Conclusion: Male gender, multiple tumors, and cirrhosis are the independent risk factors of late recurrence after RFA for HCC within the Milan criteria. Late recurrence might mainly occur from de novo HCC under the background of cirrhosis. An individualized surveillance and prevention strategy for HCC patients after RFA should be developed.Key Points: • In the present retrospective study of 398 patients, male gender, multiple tumors, and cirrhosis were the independent risk factors of late recurrence (> 2 years) of HCC after RFA. • The most common pattern of late recurrence was intrahepatic distant recurrence alone (n = 43, 43.88%). Late recurrence might mainly occur from de novo HCC under the background of cirrhosis. • A prognostic nomogram was built to predict the individualized recurrence-free survival after RFA, which achieved good calibration and discriminatory ability with a concordance index of 0.763. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to systematically evaluate the diagnostic accuracy of CT-determined resectability following neoadjuvant treatment for predicting margin-negative resection (R0 resection) in patients with pancreatic ductal adenocarcinoma (PDAC).Methods: Original studies with sufficient details to obtain the sensitivity and specificity of CT-determined resectability following neoadjuvant treatment, with a reference on the pathological margin status, were identified in PubMed, EMBASE, and Cochrane databases until February 24, 2020. The identified studies were divided into two groups based on the criteria of R0 resectable tumor (ordinary criterion: resectable PDAC alone; extended criterion: resectable and borderline resectable PDAC). The meta-analytic summary of the sensitivity and specificity for each criterion was estimated separately using a bivariate random-effect model. Summary results of the two criteria were compared using a joint-model bivariate meta-regression.Results: Of 739 studies initially searched, 6 studies (6 with ordinary criterion and 5 with extended criterion) were included for analysis. The meta-analytic summary of sensitivity and specificity was 45% (95% confidence interval [CI], 19-73%; I2 = 88.3%) and 85% (95% CI, 65-94%; I2 = 60.5%) for the ordinary criterion, and 81% (95% CI, 71-87%; I2 = 0.0%) and 42% (95% CI, 28-57%; I2 = 6.2%) for the extended criterion, respectively. The diagnostic accuracy significantly differed between the two criteria (p = 0.02).Conclusions: For determining resectability on CT, the ordinary criterion might be highly specific but insensitive for predicting R0 resection, whereas the extended criterion increased sensitivity but would decrease specificity. Further investigations using quantitative parameters may improve the identification of R0 resection.Key Points: • CT-determined resectability of PDAC after neoadjuvant treatment using the ordinary criterion shows low sensitivity and high specificity in predicting R0 resection. • With the extended criterion, CT-determined resectability shows higher sensitivity but lower specificity than with the ordinary criterion. • CT-determined resectability with both criteria achieved suboptimal diagnostic performances, suggesting that care should be taken while selecting surgical candidates and when determining the surgical extent after neoadjuvant treatment in patients with PDAC. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to compare manganese-DPDP (Mn-DPDP) and gadolinium chelate (Gd-DTPA) contrast agents for enhancement of the normal pancreas. A total of 14 patients with focal liver disease underwent Mn-DPDP- and Gd-DTPA-enhanced 1.5 T MR examinations using spoiled gradient-echo (FLASH) technique at two separate times. Contrast agents were injected according to the currently recommended practices; Gd-DTPA was injected as a rapid bolus injection in a dosage of 0.1 mmol/kg, and Mn-DPDP was injected as a slow IV injection in a dosage of 5 mumol/kg. Quantitative region of interest measurements were made in 11 patients, and percent contrast enhancement of the pancreas and pancreas-fat signal-to-noise ratios (SNR) were determined for each agent. Images were also evaluated qualitatively by consensus reading of two investigators and overall scan quality was rated on a scale from 1 (poor) to 4 (very good). Enhancement of the pancreas immediately post Gd-DTPA was significantly higher than 15 min post Mn-DPDP (73.3 vs 36.3%; p = 0.003). On postcontrast images the pancreas-fat SNR measurements were 7.7 (i.e., pancreas higher in signal than fat) and -6.1 for Gd-DTPA and Mn-DPDP, respectively, which was significantly different (p < 0.001). Image quality was rated as 3.1 and 2.5 for Gd-DTPA- and Mn-DPDP-enhanced images, respectively. The normal pancreas enhances significantly more with Gd-DTPA than with Mn-DPDP administered under the conditions of this study. Overall image quality is also greater on the Gd-DTPA-enhanced images. [ABSTRACT FROM AUTHOR]

Objective: The objective was to identify barriers and facilitators to the implementation of artificial intelligence (AI) applications in clinical radiology in The Netherlands.Materials and Methods: Using an embedded multiple case study, an exploratory, qualitative research design was followed. Data collection consisted of 24 semi-structured interviews from seven Dutch hospitals. The analysis of barriers and facilitators was guided by the recently published Non-adoption, Abandonment, Scale-up, Spread, and Sustainability (NASSS) framework for new medical technologies in healthcare organizations.Results: Among the most important facilitating factors for implementation were the following: (i) pressure for cost containment in the Dutch healthcare system, (ii) high expectations of AI's potential added value, (iii) presence of hospital-wide innovation strategies, and (iv) presence of a "local champion." Among the most prominent hindering factors were the following: (i) inconsistent technical performance of AI applications, (ii) unstructured implementation processes, (iii) uncertain added value for clinical practice of AI applications, and (iv) large variance in acceptance and trust of direct (the radiologists) and indirect (the referring clinicians) adopters.Conclusion: In order for AI applications to contribute to the improvement of the quality and efficiency of clinical radiology, implementation processes need to be carried out in a structured manner, thereby providing evidence on the clinical added value of AI applications.Key Points: • Successful implementation of AI in radiology requires collaboration between radiologists and referring clinicians. • Implementation of AI in radiology is facilitated by the presence of a local champion. • Evidence on the clinical added value of AI in radiology is needed for successful implementation. [ABSTRACT FROM AUTHOR]

Objectives: To analyse clinical and radiological changes from disease onset to exacerbation in coronavirus infectious disease-19 (COVID-19) patients.Methods: We reviewed clinical histories of 276 patients with confirmed COVID-19 pneumonia and extracted data on patients who met the diagnostic criteria for COVID-19 severe/fatal pneumonia and had an acute exacerbation starting with mild or common pneumonia.Results: Twenty-four patients were included. Of these, 8% were smokers, 54% had been to Wuhan, and 46% had comorbidities. Before acute exacerbation, elevated lactate dehydrogenase (232.9 ± 88.7) was present, and chest CT scans showed the number of involved lobes was 4 (2-5) and total CT score was 6 (2-8). Following acute exacerbation, patients were likely to have more clinical symptoms (p < 0.01) and abnormal laboratory changes (p < 0.01). The number of involved lobes and CT score after an exacerbation significantly increased to 5 (5-5) and 12 (9-14), respectively. Receiver operating characteristic (ROC) curve showed that, when the cutoff value of CT score was 5, the sensitivity and specificity for severe pneumonia were 90% and 70%, respectively. CT findings of ground glass opacity with consolidations (91.7%), bilateral distribution (100.0%), and multifocal lesion (100.0%) were features in found in patients after exacerbation.Conclusions: There are significant changes in clinical, laboratory, and CT findings in patients from disease onset to exacerbation. An increase in the number of involved lobes or an increased CT score from the baseline may predict poor clinical outcomes. Combining an assessment of CT changes with clinical and laboratory changes could help clinical teams evaluate the prognosis.Key Points: • The common chest CT signs of COVID-19 pneumonia after exacerbation were ground glass opacity (GGO) with consolidation, bilateral distribution, and multifocal lesions. • An increase in number of involved lobes or an increased CT score from the baseline may predict a poor clinical outcome. • Worsened symptoms and abnormal laboratory results are also associated with poor prognosis. [ABSTRACT FROM AUTHOR]

Objectives: To assess whether with recent MR technology current patient preparation literature recommendations for female pelvic MRI are still valid and how they are influencing the position of the female pelvic organs, image quality, and diagnostic confidence.Methods: This prospective study was performed in two centres. The effects of bladder filling (empty, moderate, full; n = 26), fasting, saturation band (n = 25), and menstrual cycle (n = 25) were assessed in healthy subjects in centre 1, while the effect of intravenous glucagon application was evaluated in 20 patients with benign conditions in centre 2. Images of the pelvis were acquired using 1.5-T MRI with T2-weighted turbo spin echo imaging in sagittal and (angulated) transaxial planes. The analysis was conducted hierarchically using paired Wilcoxon tests with an alpha significance level of 0.05.Results: Urinary bladder filling influenced the cervix-to-uterine angle (p < 0.001) but had no clear effect on image quality (p > 0.05). A moderately full bladder provided the best delineation of fat between the bladder and uterus (p = 0.0009). A full bladder resulted in highest ovarian displacement (p = 0.0059). Timing within the menstrual cycle did not influence the depiction of zonal anatomy (p > 0.05). Fasting (p < 0.02) and saturation bands (p < 0.001) had a positive effect on image quality. Glucagon was associated with decreased MRI artefacts (p = 0.002).Conclusion: Fasting, antispasmodic agents, and saturation bands improved MR image quality and are recommended for female pelvic MRI. Urinary bladder filling influenced the cervix-to-uterine angle, but had no clear effect on image quality.Key Points: • Fasting, saturation band, and glucagon injection significantly reduced bowel movement artefacts. • Depiction of the anatomical details of the uterus was not influenced by the timing of MRI within the menstrual cycle. • Although bladder filling did not impact diagnostic capabilities in healthy volunteers, in clinical practice, it may be useful to examine patients with a moderately full bladder, to reduce diagnostic inaccuracies. [ABSTRACT FROM AUTHOR]

Objectives: To build models based on conventional logistic regression (LR) and machine learning (ML) algorithms combining clinical, morphological, and hemodynamic information to predict individual rupture status of unruptured intracranial aneurysms (UIAs), afterwards tested in internal and external validation datasets.Methods: Patients with intracranial aneurysms diagnosed by computed tomography angiography and confirmed by invasive cerebral angiograph or clipping surgery were included. The prediction models were developed based on clinical, aneurysm morphological, and hemodynamic parameters by conventional LR and ML methods.Results: The training, internal validation, and external validation cohorts were composed of 807 patients, 200 patients, and 108 patients, respectively. The area under curves (AUCs) of conventional LR models 1 (clinical), 2 (clinical and aneurysm morphological), and 3 (clinical, aneurysm morphological and hemodynamic characteristics) were 0.608, 0.765, and 0.886, respectively (all p < 0.05). The AUCs of ML models using random forest (RF), multilayer perceptron (MLP), and support vector machine (SVM) were 0.871, 0.851, and 0.863, respectively. There were no difference among AUCs of conventional LR, RF, and SVM (all p > 0.05/6), while the AUC of MLP was lower than that of conventional LR (p = 0.0055).Conclusion: Hemodynamic parameters play an important role in the prediction performance of the models. ML methods cannot outperform conventional LR in prediction models for rupture status of UIAs integrating clinical, aneurysm morphological, and hemodynamic parameters.Key Points: • The addition of hemodynamic parameters can improve prediction performance for rupture status of unruptured intracranial aneurysms. • Machine learning algorithms cannot outperform conventional logistic regression in prediction models for rupture status integrating clinical, aneurysm morphological, and hemodynamic parameters. • Models integrating clinical, aneurysm morphological, and hemodynamic parameters may help choose the optimal management. [ABSTRACT FROM AUTHOR]

Objectives: To prospectively compare unenhanced quiescent-interval single-shot MR angiography (QISS-MRA) with contrast-enhanced computed tomography angiography (CTA) for contrast-free guidance in transcatheter aortic valve intervention (TAVI).Methods: Twenty-six patients (mean age 83 ± 5 years, 15 female [58%]) referred for TAVI evaluation underwent QISS-MRA for aortoiliofemoral access guidance and non-contrast three-dimensional (3D) "whole heart" MRI for prosthesis sizing on a 1.5-T system. Contrast-enhanced CTA was performed as imaging gold standard for TAVI planning. Image quality was assessed by a 4-point Likert scale; continuous MRA and CTA measurements were compared with regression and Bland-Altman analyses.Results: QISS-MRA and CTA-based measurements of aortoiliofemoral vessel diameters correlated moderately to very strong (r = 0.572 to 0.851, all p ≤ 0.002) with good to excellent inter-observer reliability (intra-class correlation coefficient (ICC) = 0.862 to 0.999, all p < 0.0001) regarding QISS assessment. Mean diameters of the infrarenal aorta and iliofemoral vessels differed significantly (bias 0.37 to 0.98 mm, p = 0.041 to < 0.0001) between the two modalities. However, inter-method decision for transfemoral access route was comparable (κ = 0.866, p < 0.0001). Aortic root parameters assessed by 3D whole heart MRI strongly correlated (r = 0.679 to 0.887, all p ≤ 0.0001) to CTA measurements.Conclusion: QISS-MRA provides contrast-free access route evaluation in TAVI patients with moderate to strong correlations compared with CTA and substantial inter-observer agreement. Despite some significant differences in minimal vessel diameters, inter-method agreement for transfemoral accessibility is strong. Combination with 3D whole heart MRI facilitates unenhanced TAVI guidance.Key Points: • QISS-MRA and CTA inter-method agreement for transfemoral approach is strong. • QISS-MRA is a very good alternative to CTA and MRA especially in patients with Kidney Disease Outcomes Quality Initiativestages 4 and 5. • Combination of QISS-MRA and 3D "whole heart" MRI facilitates fully unenhanced TAVI guidance. [ABSTRACT FROM AUTHOR]

Objectives: To develop a multisequence MRI-based radiomics signature for the preoperative prediction of the muscle-invasive status of bladder cancer (BCa).Methods: This retrospective study involved 106 eligible patients from two independent clinical centers. All patients underwent a preoperative 3.0 T MRI scan with T2-weighted image (T2WI) and multi-b-value diffusion-weighted image (DWI) sequences. In total, 1404 radiomics features were extracted from the largest region of the reported tumor locations on the T2WI, DWI, and corresponding apparent diffusion coefficient map (ADC) of each patient. A radiomics signature, namely the Radscore, was then generated using the recursive feature elimination approach and a logistic regression algorithm in a training cohort (n = 64). Its performance was then validated in an independent validation cohort (n = 42). The primary imaging and clinical factors in conjunction with the Radscore were used to determine whether the performance could be further improved.Results: The Radscore, generated by 36 selected radiomics features, demonstrated a favorable ability to predict muscle-invasive BCa status in both the training (AUC 0.880) and validation (AUC 0.813) cohorts. Subsequently, integrating the two independent predictors (including the Radscore and MRI-determined tumor stalk) into a nomogram exhibited more favorable discriminatory performance, with the AUC improved to 0.924 and 0.877 in both cohorts, respectively.Conclusions: The proposed multisequence MRI-based radiomics signature alone could be an effective tool for quantitative prediction of muscle-invasive status of BCa. Integrating the Radscore with MRI-determined tumor stalk could further improve the discriminatory power, realizing more accurate prediction of nonmuscle-invasive and muscle-invasive BCa.Key Points: • DWI is superior to T2WI sequence in reflecting the heterogeneous differences between NMIBC and MIBC, and multisequence MRI helps in the preoperative prediction of muscle-invasive status of BCa. • Co-occurrence (CM), run-length matrix (RLM), and gray-level size zone matrix (GLSZM) features were the favorable feature categories for the prediction of muscle-invasive status of BCa. • The Radscore (proposed multisequence MRI-based radiomics signature) helps predict preoperatively muscle invasion. Combination with the MRI-determined tumor stalk further improves prediction. [ABSTRACT FROM AUTHOR]

Objectives: To retrospectively evaluate the different performances of T1-SE and T1-GE sequences in detecting hypointense lesions in multiple sclerosis (MS), to quantify the degree of microstructural damage within lesions and to correlate them with patient clinical status.Methods: Sixty clinically isolated syndrome (CIS) and MS patients underwent brain magnetic resonance imaging (MRI) on 1.5-T and 3-T scanners. We identified T2 fluid-attenuated inversion recovery hyperintense lesions with no hypointense signal on T1-SE/T1-GE (a), hypointense lesions only on T1-GE (b), and hypointense lesions on both T1-SE and T1-GE sequences (c). We compared mean lesion number (LN) and volume (LV) identified on T1-SE and T1-GE sequences, correlating them with Expanded Disability Status Scale (EDSS); fractional anisotropy (FA) and mean diffusivity (MD) values inside each lesion type were extracted and normal-appearing white matter (NAWM).Results: Thirty-five patients were female. Mean age was 39.2 (± 7.8); median EDSS was 3 (± 2). There were 23 CIS, 21 relapsing-remitting (RR), and 16 progressive MS. T1-GE and T1-SE LN and LV were significantly different (p < 0.001), both correlating with EDSS. Both FA and MD metrics resulted significantly different among the three lesion groups and NAWM (p < 0.001). FA and MD values extracted from (b) and (c) showed statistically significant differences (p < 0.001), while for (a) and (b), the differences were not significant (p = 0.31 for FA and p = 0.62 for MD).Conclusion: T1-SE hypointense lesions demonstrated a more pronounced degree of microstructural damage. T1-weighted sequence type must be more carefully evaluated in clinical and research settings.Key Points: • T1-weighted spin-echo (T1-SE) images detect chronic hypointense lesions (so called black holes) associated with more severe microstructural changes. • In the last years, three-dimensional (3D) T1-weighted gradient-echo (T1-GE) sequences are often utilized in lieu of T1-SE acquisition, more so at 3 T or higher fields. • T1-weighted sequence type must be more carefully evaluated in clinical and research settings in the definition of "black holes" in MS, in order to avoid the overestimation of the effective severe tissue damage. [ABSTRACT FROM AUTHOR]

Objectives: This study was conducted in order to compare the effect of field of view (FOV) size on image quality between ultra-high-resolution CT (U-HRCT) and conventional high-resolution CT (HRCT).Methods: Eleven cadaveric lungs were scanned with U-HRCT and conventional HRCT and reconstructed with five FOVs (40, 80, 160, 240, and 320 mm). Three radiologists evaluated and scored the images. Three image evaluations were performed, comparing the image quality with the five FOVs with respect to the 160-mm FOV. The first evaluation was performed on conventional HRCT images, and the second evaluation on U-HRCT images. Images were scored on normal structure, abnormal findings, and overall image quality. The third evaluation was a comparison of the images obtained with conventional HRCT and U-HRCT, with scoring performed on overall image quality. Quantitative evaluation of noise was performed by setting ROIs.Results: In conventional HRCT, image quality was improved when the FOV was reduced to 160 mm. In U-HRCT, image quality, except for noise, improved when the FOV was reduced to 80 mm. In the third evaluation, overall image quality was improved in U-HRCT over conventional HRCT at all FOVs. Noise of U-HRCT increased with respect to conventional HRCT when the FOV was reduced from 160 to 40 mm. However, at 240- and 320-mm FOVs, the noise of U-HRCT and conventional HRCT showed no differences.Conclusions: In conventional HRCT, image quality did not improve when the FOV was reduced below 160 mm. However, in U-HRCT, image quality improved even when the FOV was reduced to 80 mm.Key Points: • Reducing the size of the field of view to 160 mm improves diagnostic imaging quality in high-resolution CT. • In ultra-high-resolution CT, improvements in image quality can be obtained by reducing the size of the field of view to 80 mm. • Ultra-high-resolution CT produces images of higher quality compared with conventional HRCT irrespective of the size of the field of view. [ABSTRACT FROM AUTHOR]

Objectives: This study was conducted in order to evaluate the feasibility of a newly developed half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence for T2-weighted MRI of the female pelvis, in which scanning and post-processing filtering techniques were optimized to minimize blurring and the resultant reduction in signal-to-noise ratio (SNR) was compensated by signal averaging of multiple excitations (multi-NEX), and to compare its image quality with that of a conventional turbo spin echo (TSE) sequence.Methods: Fifty females with gynecological disease were prospectively enrolled. They underwent pelvic MRI including sagittal T2-weighted imaging obtained with multi-NEX HASTE (mHASTE) and TSE with acquisition times of 1 m 9 s and 3 m 26 s, respectively. At the prospective reading, mHASTE was reviewed first, and any changes in the image interpretation detected during the subsequent TSE reading were recorded. The SNR and tissue contrast were quantitatively measured. Two radiologists independently assessed tissue conspicuity and overall image quality considering noise, artifacts, and blurring, and visual grading characteristics (VGC) analysis was performed to compare the two sequences.Results: Adding TSE to mHASTE did not change image interpretations in any case. mHASTE produced an equivalent SNR and significantly higher contrast between the myometrium and junctional zone (p < 0.05) compared with TSE. The area under the VGC curve (AUCVGC) showed that the conspicuity of the uterus, ovaries, and lesions and the overall image quality were significantly higher on mHASTE than on TSE for both readers (AUCVGC, 0.740-0.880; p < 0.01).Conclusion: mHASTE is a feasible option for T2-weighted MRI of the female pelvis, as it allows faster and higher-quality image acquisition than conventional TSE.Key Points: • High-quality T2-weighted imaging is essential for magnetic resonance imaging of the female pelvis. • A new HASTE sequence was developed, in which a parallel imaging technique, a wide bandwidth, and a post-processing filter were used to minimize blurring, and the resultant reduction in the signal-to-noise ratio was compensated using signal averaging of multiple excitations (multi-NEX). • Multi-NEX HASTE allows fast and high-quality T2-weighted image acquisition. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to investigate the utility of compressed sensing time-of-flight magnetic resonance angiography (CS TOF-MRA) for diagnosing intracranial and cervical arterial stenosis by using digital subtraction angiography (DSA) as the reference standard.Methods: Thirty-seven patients with head and neck arterial stenoses who underwent CS TOF-MRA and DSA were retrospectively enrolled. The reconstructed resolution of CS TOF-MRA was 0.4 × 0.4 × 0.4 mm3. The scan time was 5 min and 2 s. The image quality of CS TOF-MRA was independently ranked by two neuroradiologists in 1031 arterial segments. The luminal stenosis grades on CS TOF-MRA and DSA were analyzed in 61 arterial segments and were compared using the Wilcoxon signed-rank test. The ability of CS TOF-MRA to predict moderate to severe stenosis or occlusion was analyzed.Results: The image quality of most arterial segments (95.2%) on CS TOF-MRA was excellent. Arterial segments with low image quality were mainly the V3-4 segments of the vertebral artery. The majority of arterial stenoses (62.3%) were located in the cervical internal carotid artery. The luminal stenosis grades of CS TOF-MRA were concordant with that of DSA in 50 of 61 segments (p = 0.366). CS TOF-MRA had a sensitivity of 84.4% and a specificity of 88.5% for predicting moderate to severe stenosis. For detecting occlusion lesions, it had a sensitivity of 100% and a specificity of 94.1%.Conclusion: CS TOF-MRA provides adequate image quality within a reasonable acquisition time and is a reliable tool for diagnosing head and neck arterial steno-occlusive disease.Key Points: • CS TOF-MRA provides a relatively large coverage (16 cm), high resolution (0.4 × 0.4 × 0.4 mm3) and good image quality of head and neck arteries within 5 min and 2 s. • The diagnostic accuracy of CS TOF-MRA in the assessment of moderate to severe stenosis and occlusion was comparable with that of DSA. • Arterial segments with low image quality were mainly the V3 and V4 segments of the vertebral artery. [ABSTRACT FROM AUTHOR]

Objectives: (1) To assess the methodological quality of radiomics studies investigating histological subtypes, therapy response, and survival in patients with renal cell carcinoma (RCC) and (2) to determine the risk of bias in these radiomics studies.Methods: In this systematic review, literature published since 2000 on radiomics in RCC was included and assessed for methodological quality using the Radiomics Quality Score. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool and a meta-analysis of radiomics studies focusing on differentiating between angiomyolipoma without visible fat and RCC was performed.Results: Fifty-seven studies investigating the use of radiomics in renal cancer were identified, including 4590 patients in total. The average Radiomics Quality Score was 3.41 (9.4% of total) with good inter-rater agreement (ICC 0.96, 95% CI 0.93-0.98). Three studies validated results with an independent dataset, one used a publically available validation dataset. None of the studies shared the code, images, or regions of interest. The meta-analysis showed moderate heterogeneity among the included studies and an odds ratio of 6.24 (95% CI 4.27-9.12; p < 0.001) for the differentiation of angiomyolipoma without visible fat from RCC.Conclusions: Radiomics algorithms show promise for answering clinical questions where subjective interpretation is challenging or not established. However, the generalizability of findings to prospective cohorts needs to be demonstrated in future trials for progression towards clinical translation. Improved sharing of methods including code and images could facilitate independent validation of radiomics signatures.Key Points: • Studies achieved an average Radiomics Quality Score of 10.8%. Common reasons for low Radiomics Quality Scores were unvalidated results, retrospective study design, absence of open science, and insufficient control for multiple comparisons. • A previous training phase allowed reaching almost perfect inter-rater agreement in the application of the Radiomics Quality Score. • Meta-analysis of radiomics studies distinguishing angiomyolipoma without visible fat from renal cell carcinoma show moderate diagnostic odds ratios of 6.24 and moderate methodological diversity. [ABSTRACT FROM AUTHOR]

Introduction: A systematic review and meta-analysis were performed to determine the diagnostic performance of dynamic contrast-enhanced computed tomography (DCE-CT) for the differentiation between malignant and benign pulmonary nodules.Methods: Ovid MEDLINE and EMBASE were searched for studies published up to October 2018 on the diagnostic accuracy of DCE-CT for the characterisation of pulmonary nodules. For the index test, studies with a minimum of a pre- and post-contrast computed tomography scan were evaluated. Studies with a reference standard of biopsy for malignancy, and biopsy or 2-year follow-up for benign disease were included. Study bias was assessed using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies). The sensitivities, specificities, and diagnostic odds ratios were determined along with 95% confidence intervals (CIs) using a bivariate random effects model.Results: Twenty-three studies were included, including 2397 study participants with 2514 nodules of which 55.3% were malignant (1389/2514). The pooled accuracy results were sensitivity 94.8% (95% CI 91.5; 96.9), specificity 75.5% (69.4; 80.6), and diagnostic odds ratio 56.6 (24.2-88.9). QUADAS 2 assessment showed intermediate/high risk of bias in a large proportion of the studies (52-78% across the domains). No difference was present in sensitivity or specificity between subgroups when studies were split based on CT technique, sample size, nodule size, or publication date.Conclusion: DCE-CT has a high diagnostic accuracy for the diagnosis of pulmonary nodules although study quality was indeterminate in a large number of cases.Key Points: • The pooled accuracy results were sensitivity 95.1% and specificity 73.8% although individual studies showed wide ranges of values. • This is comparable to the results of previous meta-analyses of PET/CT (positron emission tomography/computed tomography) diagnostic accuracy for the diagnosis of solitary pulmonary nodules. • Robust direct comparative accuracy and cost-effectiveness studies are warranted to determine the optimal use of DCE-CT and PET/CT in the diagnosis of SPNs. [ABSTRACT FROM AUTHOR]

Objectives: To compare the scan acquisition time, radiation dose, subjective and objective image quality of two dual-source CT scanners (DSCT) for detection of acute pulmonary embolism.Methods: Two hundred twenty-one scans performed on the 2nd-generation DSCT and 354 scans on the 3rd-generation DSCT were included in this large retrospective study. In a randomized blinded design, two radiologists independently reviewed the scans using a 5-point Likert scale. Radiation dose and objective image quality parameters were calculated.Results: Mean acquisition time was significantly lower in the 3rd-generation DSCT (2.81 s ± 0.1 in comparison with 9.7 s ± 0.15 [mean ± SD] respectively; p < 0.0001) with the 3rd generation 3.4 times faster. The mean subjective image quality score was 4.33/5 and 4/5 for the 3rd- and 2nd-generation DSCT respectively (p < 0.0001) with strong interobserver reliability agreement. DLP, CTDIvol, and ED were significantly lower in the 3rd than the 2nd generation (175.6 ± 63.7 mGy cm; 5.3 ± 1.9 mGy and 2.8 ± 1.2 mSv in comparison with 266 ± 255 mGy.cm; 7.8 ± 2.2 mGy and 3.8 ± 4.3 mSv). Noise was significantly lower in the 3rd generation (p < 0.01). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM), a dose-insensitive index for CNR, were significantly higher in the 3rd-generation DSCT (33.5 ± 23.4; 29.0 ± 21.3 and 543.7 ± 1037 in comparison with 23.4 ± 17.7; 19.4 ± 16.0 and 170.5 ± 284.3).Conclusion: Objective and subjective image quality are significantly higher on the 3rd-generation DSCT with significantly lower mean acquisition time and radiation dose.Key Points: • The 3rd-generation DSCT scanner provides an improved image quality, less perceived artifacts, and lower radiation dose in comparison with the 2nd-generation DSCT, when operating in dual-energy (DE) mode. • The 3.4-times-faster 3rd-generation DSCT scanner can be of particular value in patients with chronic lung diseases or breathing difficulties that prevent adequate breathhold. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the prognostic value of late gadolinium enhancement (LGE) in myocarditis and clinically suspected myocarditis.Methods: The study was registered in PROSPERO (CRD42019144976). A systematic search of PubMed, Ovid Medline, Embase, Web of Science and the Cochrane Central Register of Controlled Trials was completed. Major adverse cardiac event (MACE) was defined as the combination of all-cause mortality or cardiovascular death, resuscitated cardiac arrest, heart transplantation, appropriate implantable cardioverter-defibrillator shock, rehospitalisation following a cardiac event and recurrent acute myocarditis. Combined outcome was defined as the combination of all adverse events. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the prognostic value of LGE.Results: Eight articles including 1319 patients (mean age, 38.8 ± 12.9 years) were included in the meta-analysis. The study showed that positive LGE was strongly associated with an increased risk of combined outcome (pooled OR, 5.85; 95% CI, 2.88 to 11.86; p < 0.001) and of MACE (pooled OR, 4.57; 95% CI, 2.18 to 9.59; p < 0.001). Additionally, in a subgroup analysis with mean ejection fraction (EF) point of 50%, the pooled ORs for the combined outcome were 6.46 for left ventricular EF (LVEF) > 50% and 7.90 for LVEF ≤ 50%, and the pooled ORs for MACE were 9.03 and 3.45, respectively. After 3 years of follow-up, the worse outcomes occurred mainly in patients with positive LGE.Conclusion: Positive LGE is a powerful prognosticator of adverse outcome in myocarditis and clinically suspected myocarditis, irrespective of LVEF.Key Points: • Forty-four percent to 100% of myocarditis patients have positive late gadolinium enhancement. • Positive LGE was a powerful prognosticator of adverse outcome in myocarditis and clinically suspected myocarditis, irrespective of LVEF. • LGE-CMR is important tool for risk stratification in myocarditis and clinically suspected myocarditis. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT.Methods: Bi-institutional review identified 67 adults (mean age, 47 years; 23 M/44 F) with pathologically proven HEH and pretreatment multiphasic CT (n = 67) and/or MR (n = 30) and/or FDG-PET-CT (n = 13).Results: HEHs were multifocal in 88% (59/67). Mean size of the dominant mass was 4.1 cm (range, 1.4-19 cm). The tumors were located in the peripheral, subcapsular regions of the liver in 96% (64/67). Capsular retraction was present in 81% (54/67 cases) and tumors were coalescent in 61% (41/67). HEH demonstrated peripheral ring enhancement on arterial phase imaging in 33% (21/64) and target appearance on the portal venous phase in 69% (46/67). Persistent peripheral enhancement on the delayed phase was seen in 49% (31/63). On MR, multilayered target appearance was seen on the T2-weighted sequences in 67% (20/30) and on the diffusion-weighted sequences in 61% (11/18). Target appearance on hepatobiliary phase of MRI was seen in 57% (4/7). On pre-therapy FDG-PET-CT, increased FDG uptake above the background liver parenchyma was seen in 62% (8/13).Conclusion: HEHs typically manifest as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. Peripheral arterial ring enhancement and target appearance on portal venous phase are commonly seen on CT. Similarly, multilayered target appearance correlating with its histopathological composition is typically seen on multiple sequences of MR including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced multiphasic MR.Key Points: • Hepatic epithelioid hemangioendotheliomas manifest on CT and MR as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. • Enhancement pattern on contrast-enhanced CT and MR can vary but peripheral ring enhancement on arterial phase and target appearance on portal venous phase are commonly seen. • Retrospective two-center study showed that cross-sectional imaging may help in the diagnosis. [ABSTRACT FROM AUTHOR]

Objectives: This study was conducted in order to assess the performance of the Liver Imaging Reporting and Data System (LI-RADS) treatment response (TR) (LR-TR) categorization on gadoxetic acid-enhanced MRI (Gd-EOB-MRI) for detecting viable tumors in hepatocellular carcinoma (HCC) treated with locoregional treatment (LRT) and to investigate the added value of ancillary features (AFs) to conventional enhancement-based criteria.Methods: This retrospective study included 183 patients with Gd-EOB-MRI after LRT for HCC and appropriate reference standards for tumor viability (84 viable and 99 nonviable). Two independent radiologists assigned per-lesion mRECIST and TR categories (TR-nonviable, TR-equivocal, or TR-viable) according to the LR-TR algorithm and modified LR-TR algorithms including mLR-TR(TP) allowing transitional phase (TP) washout and mLR-TR(AF) allowing category adjustment by applying AFs. Diagnostic performances of imaging criteria were compared using the Cochran's Q test with post hoc analysis.Results: For detecting viable tumors, LR-TR-viable resulted in sensitivities of 64.5%/39.3% and specificities of 98.0%/98.0% in reviewers 1/2. In comparison to LR-TR-viable, mRECIST-viable, mLR-TR(TP)-viable, and mLR-TR(AF)-viable showed significantly higher sensitivities (92.9%/94.0%, 77.4%/56.6%, and 86.9%/83.3% in reviewers 1/2) (ps < 0.001). The specificity of mRECIST-viable (73.7%/62.6%) was significantly lower than that of LR-TR-viable (ps < 0.001), while those of mLR-TR(TP)-viable and mLR-TR(AF)-viable were greater than 95% (98.0%/96.0% and 97.0%/96.0%), statistically equivalent to LR-TR-viable (ps > 0.05). TR-equivocal was least assigned on mLR-TR(AF) (1.1%/7.7%) than LR-TR (15.8%/32.2%) or mLR-TR(TP) (6.6%/23.5%) in both reviewers.Conclusion: The LR-TR algorithm on Gd-EOB-MRI provides a specific diagnosis of viable tumor but with limited sensitivity. By applying AFs in the category adjustment, more sensitive and confident diagnosis can be achieved without significant loss of specificity.Key Points: • The LI-RADS treatment response (LR-TR) algorithm on Gd-EOB-MRI provides a highly specific diagnosis of viable HCC but with limited sensitivity. • The inferior sensitivity of LR-TR-viable category to that of mRECIST can be improved by applying ancillary features in the category adjustment. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of image quality of coronary CT angiography (CCTA) on the diagnostic performance of a machine learning-based CT-derived fractional flow reserve (FFRCT).Methods: This nationwide retrospective study enrolled participants from 10 individual centers across China. FFRCT analysis was performed in 570 vessels in 437 patients. Invasive FFR and FFRCT values ≤ 0.80 were considered ischemia-specific. Four-score subjective assessment based on image quality and objective measurement of vessel enhancement was performed on a per-vessel basis. The effects of body mass index (BMI), sex, heart rate, and coronary calcium score on the diagnostic performance of FFRCT were studied.Results: Among 570 vessels, 216 were considered ischemia-specific by invasive FFR and 198 by FFRCT. Sensitivity and specificity of FFRCT for detecting lesion-specific ischemia were 0.82 and 0.93, respectively. Area under the curve (AUC) of high-quality images (0.93, n = 159) was found to be superior to low-quality images (0.80, n = 92, p = 0.02). Objective image quality and heart rate were also associated with diagnostic performance of FFRCT, whereas there was no statistical difference in diagnostic performance among different BMI, sex, and calcium score groups (all p > 0.05, Bonferroni correction).Conclusions: This retrospective multicenter study supported the FFRCT as a noninvasive test in evaluating lesion-specific ischemia. Subjective image quality, vessel enhancement, and heart rate affect the diagnostic performance of FFRCT.Key Points: • FFRCTcan be used to evaluate lesion-specific ischemia. • Poor image quality negatively affects the diagnostic performance of FFRCT. • CCTA with ≥ score 3, intracoronary enhancement degree of 300-400 HU, and heart rate below 70 bpm at scanning could be of great benefit to more accurate FFRCTanalysis. [ABSTRACT FROM AUTHOR]