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Background: Anti-fibrotic drugs for interstitial pulmonary fibrosis (IPF) have been developed. Physicians are becoming increasingly aware of the need for better diagnosis of IPF. Purpose: To evaluate whether a computer-aided system can improve the diagnostic performance of general radiologists in detecting the usual interstitial pneumonia (UIP) pattern on computed tomography (CT). Material and Methods: We included 60 CT datasets from 30 patients with IPF and 30 with idiopathic fibrosing non-specific interstitial pneumonia (fNSIP), all diagnosed by a multidisciplinary diagnosis (MDD) procedure that included surgical biopsy. We analyzed the CT data using a computer-aided system (Gaussian histogram normalized correlation: GHNC). Five general radiologists with <6 years of experience each interpreted these CT scans with and without the GHNC results. We compared the likelihoods of a UIP-pattern diagnosis with the likelihood of the same diagnosis by MDD using the average area under the curve (AUC) of the receiver operating characteristics (ROC). We also evaluated the association between the radiologists' diagnosis and survival using the Kaplan–Meier method. Results: In the ROC analysis, the AUC increased significantly from 0.731 without GHNC to 0.829 with GHNC (P = 0.0396). The diagnosis without GHNC was not significantly associated with survival for any radiologist, but the UIP diagnosis with GHNC was significantly associated with a worse prognosis for four out of five radiologists. Conclusion: The computer-aided system could increase the confidence level of UIP-pattern diagnosis by non-expert radiologists. [ABSTRACT FROM AUTHOR]

Background: As guidelines endorse the use of computed tomography (CT) for examining coronary artery disease (CAD), it is important to compare the advantages and disadvantages of the novel photon counting detector CT (PCD-CT) technology with the established energy integrating detector CT (EID-CT). Purpose: To compare the image quality of coronary computed tomography angiography (CCTA) and the Agatston scores (AS) derived from EID-CT and PCD-CT. Material and Methods: In this prospective observational study, 28 patients underwent clinical calcium score and CCTA scans on an EID-CT and a PCD-CT scanner. CCTA images were qualitatively analyzed by five observers using visual grading characteristics. The correlation and agreement of the AS were assessed using Spearman's rank correlation and Bland–Altman plots. Results: This qualitative analyses demonstrated a high fraction of "good" or "excellent" ratings for the image criteria in both CT systems. The sharpness of the distal lumen and image quality regarding motion artifacts were rated significantly higher for EID-CT (P < 0.05). However, the sharpness of coronary calcification was rated significantly higher for PCD-CT (P < 0.05). Spearman's rank correlation and Bland–Altman plots showed good correlation (P = 0.95) and agreement regarding the AS between EID-CT and PCD-CT. Conclusion: Both CT systems exhibited high CCTA image quality. The sharpness of calcifications was rated significantly higher for PCD-CT. A good correlation was observed between the AS derived from the two systems. [ABSTRACT FROM AUTHOR]

Background: Redoable precise and non-invasive diagnostic imaging modality with the least radiation dose is essential for infants with congenital heart disease (CHD). Purpose: To investigate the accuracy and estimate the radiation dose of our cardiac computed tomography (CCT) protocol. Material and Methods: A total of 82 infants with CHD underwent non-ECG-gated CCT without contrast timing scanning techniques and were retrospectively studied. The image quality and radiation dose were estimated. The radiation dose was compared statistically to virtual retrospective ECG-gated and prospective ECG-triggering scanning modes. The diagnostic accuracy was assessed assuming the surgical results as the diagnostic gold standard. Results: Most exams showed a high quality with low radiation doses compared to previous studies. The mean effective dose (ED) was 0.39 ± 1.2, significantly lower than that of the virtual retrospective ECG-gated and prospective ECG-triggering scanning and lower than in previous studies. Our CCT protocol has achieved a diagnostic accuracy of 99.52% with a sensitivity of 94.83% and specificity of 99.91%. Conclusion: Non-ECG-gated CCT without contrast timing techniques can detect the non-coronary cardiovascular defects of CHD in infants with an ultralow radiation dose and a high diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Background: Acute ischemic lesions are challenging to detect by conventional computed tomography (CT). Virtual monoenergetic images may improve detection rates by increased tissue contrast. Purpose: To compare the ability to detect ischemic lesions of virtual monoenergetic with conventional images in patients with acute stroke. Material and Methods: We included consecutive patients at our center that underwent brain CT in a spectral scanner for suspicion of acute stroke, onset <12 h, with or without (negative controls) a confirmed cortical ischemic lesion in the initial scan or a follow-up CT or magnetic resonance imaging. Attenuation was measured in predefined areas in ischemic gray (guided by follow-up exams), normal gray, and white matter in conventional images and retrieved in spectral diagrams for the same locations in monoenergetic series at 40–200 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Visual assessment of diagnostic measures was performed by independent review by two neuroradiologists blinded to reconstruction details. Results: In total, 29 patients were included (January 2018 to July 2019). SNR was higher in virtual monoenergetic compared to conventional images, significantly at 60–150 keV. CNR between ischemic gray and normal white matter was higher in monoenergetic images at 40–70 keV compared to conventional images. Virtual monoenergetic images received higher scores in overall image quality. The sensitivity for diagnosing acute ischemia was 93% and 97%, respectively, for the reviewers, compared to 55% of the original report based on conventional images. Conclusion: Virtual monoenergetic reconstructions of spectral CIs may improve image quality and diagnostic ability in stroke assessment. [ABSTRACT FROM AUTHOR]

Background: Dual-energy X-ray absorptiometry (DXA) is the reference standard for the measurement of bone mineral density (BMD) and subsequent diagnosis of osteoporosis. Since various computed tomography (CT) protocols are scanned for various indications, we can incidentally measure BMD using CT. Previous studies have revealed a correlation between BMD and Hounsfield unit (HU) values obtained with different CT protocols. Purpose: To compare the diagnostic value of CT protocols (lumbar spine CT [LSCT], abdomen-pelvis contrast-enhanced CT [APCT], and low-dose chest CT [LDCT]) for osteoporosis. Material and Methods: We retrospectively included 17 patients (6 men, 11 women; mean age=68 years) who had undergone all four imaging studies within six months, during 2011–2021. HU values were manually measured at the center of the L1 vertebra by a radiology resident. Pearson correlation test was performed between HU values and BMD of L1 vertebra. The diagnostic performance of each CT protocol was assessed with receiver operating characteristic (ROC) analysis. Intra-individual concordance of the four tests to diagnose osteoporosis was analyzed by tabulating. Results: The mean HU values were 104.4 ± 47.2 HU with LSCT, 149.0 ± 56.9 HU with APCT, and 114.3 ± 60.0 HU with LDCT. HU values from each protocol were positively correlated (r = 0.676-0.735; P < 0.005) with BMD. LDCT had the highest diagnostic performance (area under the ROC curve [AUC] = 0.701) and APCT the lowest (AUC = 0.569). APCT was discordant with the other protocols for diagnosing osteoporosis. Conclusion: LDCT had the highest diagnostic performance for osteoporosis with predetermined cutoff value. APCT requires the increase of cutoff value for osteoporosis diagnosis. [ABSTRACT FROM AUTHOR]

Background: The demand for homogeneous and higher vascular contrast enhancement is critical to provide an appropriate interpretation of abnormal vascular findings in coronary computed tomography angiography (CTA). Purpose: To evaluate the effect of various contrast media concentrations (Iohexol-370, Iohexol-300, Iohexol-240) and image reconstructions (filtered back projection [FBP], hybrid iterative reconstruction [IR], and deep learning reconstruction [DLR]) on coronary CTA. Material and Methods: A total of 63 patients referred for coronary CTA between July and October 2021 were enrolled in this prospective study, and they randomly received one of three contrast media. CTA images were reconstructed with FBP, hybrid IR, and DLR. The CT attenuation, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for all three images. The images were subjectively evaluated by two radiologists in terms of overall image quality, artifacts, image noise, and vessel wall delineation on a 5-point Likert scale. Results: The application of DLR resulted in significantly lower image noise; higher CT attenuation, SNR, and CNR; and better subjective analysis among the three different concentrations of contrast media groups (P < 0.001). There was no significant difference in the CT attenuation of the left ventricle (P = 0.089) and coronary arteries (P = 0.072) between hybrid IR at Iohexol-300 and DLR at Iohexol-240. Furthermore, application of DLR to the Iohexol-240 significantly improved SNR and CNR; it achieved higher subjective scores compared with hybrid IR at Iohexol-300 (P < 0.001). Conclusion: We suggest that using DLR with Iohexol-240 contrast media is preferable to hybrid IR with Iohexol-300 contrast media in coronary CTA. [ABSTRACT FROM AUTHOR]

Background: The detection of rib fractures (RFs) on computed tomography (CT) images is time-consuming and susceptible to missed diagnosis. An automated artificial intelligence (AI) detection system may be helpful to improve the diagnostic efficiency for junior radiologists. Purpose: To compare the diagnostic performance of junior radiologists with and without AI software for RF detection on chest CT images. Materials and methods: Six junior radiologists from three institutions interpreted 393 CT images of patients with acute chest trauma, with and without AI software. The CT images were randomly split into two sets at each institution, with each set assigned to a different radiologist First, the detection of all fractures (AFs), including displaced fractures (DFs), non-displaced fractures and buckle fractures, was analyzed. Next, the DFs were selected for analysis. The sensitivity and specificity of the radiologist-only and radiologist-AI groups at the patient level were set as primary endpoints, and secondary endpoints were at the rib and lesion level. Results: Regarding AFs, the sensitivity difference between the radiologist-AI group and the radiologist-only group were significant at different levels (patient-level: 26.20%; rib-level: 22.18%; lesion-level: 23.74%; P < 0.001). Regarding DFs, the sensitivity difference was 16.67%, 14.19%, and 16.16% at the patient, rib, and lesion levels, respectively (P < 0.001). No significant difference was found in the specificity between the two groups for AFs and DFs at the patient and rib levels (P > 0.05). Conclusion: AI software improved the sensitivity of RF detection on CT images for junior radiologists and reduced the reading time by approximately 1 min per patient without decreasing the specificity. [ABSTRACT FROM AUTHOR]

The best settings of deep learning image reconstruction (DLIR) algorithm for abdominal low-kiloelectron volt (keV) virtual monoenergetic imaging (VMI) have not been determined.To determine the optimal settings of the DLIR algorithm for abdominal low-keV VMI.The portal-venous phase computed tomography (CT) scans of 109 participants with 152 lesions were reconstructed into four image series: VMI at 50 keV using adaptive statistical iterative reconstruction (Asir-V) at 50% blending (AV-50); and VMI at 40 keV using AV-50 and DLIR at medium (DLIR-M) and high strength (DLIR-H). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of nine anatomical sites were calculated. Noise power spectrum (NPS) using homogenous region of liver, and edge rise slope (ERS) at five edges were measured. Five radiologists rated image quality and diagnostic acceptability, and evaluated the lesion conspicuity.The SNR and CNR values, and noise and noise peak in NPS measurements, were significantly lower in DLIR images than AV-50 images in all anatomical sites (all P < 0.001). The ERS values were significantly higher in 40-keV images than 50-keV images at all edges (all P < 0.001). The differences of the peak and average spatial frequency among the four reconstruction algorithms were significant but relatively small. The 40-keV images were rated higher with DLIR-M than DLIR-H for diagnostic acceptance (P < 0.001) and lesion conspicuity (P = 0.010).DLIR provides lower noise, higher sharpness, and more natural texture to allow 40 keV to be a new standard for routine VMI reconstruction for the abdomen and DLIR-M gains higher diagnostic acceptance and lesion conspicuity rating than DLIR-H. [ABSTRACT FROM AUTHOR]

Background: The latest International Myeloma Working Group (IMWG) guideline recommends low-dose whole-body (WB) computed tomography (CT) as the first-line imaging technique for the initial diagnosis of plasma cell disorders. Purpose: To evaluate diagnostic performances of CT and diffusion-weighted imaging (DWI) as the first-line imaging modalities and assess misclassification rates obtained following the guideline. Material and Methods: Two independent radiologists analyzed CT (acquired as PET/CT) and DWI (3-T; b-values = 50 and 900 s/mm2) of patients newly diagnosed with plasma cell disorder, categorizing the number of bone lesions. Diagnostic performance of CT and DWI was compared using the McNemar test, and misclassification rates were calculated with a consensus WB-MRI reading as the reference standard. Differences in lesion number categories were assessed using marginal homogeneity and kappa statistics. Results: Of 56 patients (36 men; mean age = 63.5 years), 39 had myeloma lesions. DWI showed slightly higher sensitivity for detecting myeloma lesions (97.4%) than CT (84.6%–92.3%; P > 0.05). CT showed significantly higher specificity (88.2%) than DWI (52.9%–58.8%; P <0.05). CT had a higher additional study requirement rate than DWI (7.7%–15.4% vs. 2.6%), but a lower unnecessary treatment rate (11.8% vs. 41.2%–47.1%). Both readers showed significant differences in categorization of the number of lesions on CT compared with the reference standard (P < 0.001), and one reader showed a significant difference on DWI (P = 0.006 and 0.098). Conclusion: CT interpreted according to the IMWG guideline is a diagnostically effective first-line modality with relatively high sensitivity and specificity. DWI alone may not be an acceptable first-line imaging modality because of low specificity. [ABSTRACT FROM AUTHOR]

Background: The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed. Purpose: To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT). Material and Methods: This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale. Results: The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group (P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images. Conclusion: ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Multidetector computed tomography (MDCT) of the abdomen is currently the imaging examination of choice for the staging and follow-up of ovarian carcinoma (OC). Peritoneal metastases (PMs) represent the most common pathway for the metastatic spread of OC. MDCT scanners, due to several advantages—including increased volume coverage, reduced scanning time, acquisition of thin slices and creation of multiplanar reformations, and three-dimensional reconstructions—provide useful information regarding the early and accurate detection of PMs. Detailed mapping of peritoneal carcinomatosis is feasible, with improved detection of sub-centimeter peritoneal implants and thorough evaluation of curved peritoneal surfaces. [ABSTRACT FROM AUTHOR]

Background: The etiologies of small bowel intussusception (SBI) in adults are varied. Purpose: To investigate multidetector computed tomography (MDCT) characteristics in adults with neoplastic and non-neoplastic SBI. Material and Methods: Clinical data and MDCT images diagnosed with SBI in adults from January 2010 to May 2020 were retrospectively reviewed. Results: The study included a total of 71 patients. Forty-two patients had a combined total of 55 neoplastic intussusceptions, including 29 patients with benign tumors and 13 patients with malignant tumors. Twenty-nine patients had a combined total of 36 non-neoplastic intussusceptions, of which the condition was idiopathic in 23 patients and cased by non-neoplastic benign lesions in six patients. There were no significant differences in patient age or sex ratio in the neoplastic and non-neoplastic groups. In the non-neoplastic group the intussusceptions were shorter in length (3.6 cm vs. 13.2 cm, P <0.05) and smaller in transverse diameter (2.8 cm vs. 4.2 cm, P <0.05), and less likely to be associated with intestinal obstruction (2 vs. 18, P <0.05). The percentage of patients with multiple intussusceptions was greater in the neoplastic group (10/42, 23.8% vs. 4/29, 13.8%). In the non-neoplastic group only one lead point was detected (in a patient with Meckel's diverticulum), whereas lead points were detected in all 55 intussusceptions in the neoplastic group. Conclusion: There are differences in the clinical and MDCT manifestations of adult neoplastic and non-neoplastic SBIs. Whether a lead point is present or not has implications with regard to deciding on the most appropriate treatment and avoiding unnecessary surgery. [ABSTRACT FROM AUTHOR]

Background: The coronary venous system is frequently used as an entry route to the heart and treatment modalities for many cardiac diseases and many procedures. Consequently, evaluation of the coronary venous system and understanding cardiac vein anatomy is crucial.Purpose: To determine the optimal image set in a comparison of noise-optimized linearly blended images (F_0.6) and noise-optimized virtual monoenergetic images (VMI+) evaluated by dual-energy computed tomography (DECT) for cardiac vein assessment.Material and Methods: Thirty-four patients (mean age 58.2 ± 14.2 years) who underwent DECT due to chest pain were enrolled. Images were post-processed with the F_0.6, and VMI+ algorithms at energy levels in the range of 40-100 keV in 10-keV increments. Enhancement (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively measured at two points in the great cardiac vein by consensus of two radiologists. Two blinded observers evaluated the subjective image quality of the great cardiac vein on a 4-point scale.Results: HU, noise, and SNR peaked at 40 keV VMI+ (P < 0.05) among 50-100 keV VMI+. CNR peaked at 100 keV VMI+; however, there were no significant differences compared to CNR images processed at 40-90 keV VMI+. HU and noise were significantly higher in 40 keV VMI+ than F_0.6 images; however, both SNR and CNR were significantly higher in F_0.6 images. An assessment of subjective vein delineation revealed that F_0.6 images had the highest scores.Conclusion: F_0.6 images were superior to VMI+ and provided the optimal image set for cardiac vein assessment. [ABSTRACT FROM AUTHOR]

Background: Difficult cannulation during endoscopic retrograde cholangiopancreatography (ERCP) is associated with increased complications; therefore, its prediction is important. Purpose: To identify radiologic risk factors of difficult cannulation during ERCP based on computed tomography (CT) findings and to develop a predictive model for a difficult cannulation. Material and Methods: A total of 171 patients with native papilla who underwent both enhanced CT and ERCP were recruited. Two radiologists independently measured the distal common bile duct (CBD) diameter and choledochoduodenal (CD) angle and analyzed CT images for presence of CBD stone and papilla bulging, size and type of periampullary diverticulum (PAD), and duodenal segment in which major papilla was located. Multivariate logistic regression analysis and decision-tree analysis were performed to identify risk factors for difficult cannulation. Results: Thirty-nine patients underwent a difficult cannulation. The multivariate logistic regression analysis revealed that a smaller CBD diameter, presence of papilla bulging, location of the major papilla other than the descending duodenum, a smaller CD angle, and a higher worrisome PAD score were statistically relevant factors for difficult cannulation (P < 0.049). In the decision-tree analysis, a higher worrisome PAD score was the strongest predictor of difficult cannulation, followed by the presence of papilla bulging, smaller CD angle, and a smaller CBD diameter. The predictive model had an 82.5% overall predictive accuracy. Conclusion: The CT findings-based decision-tree analysis model showed a high accuracy in predicting cannulation difficulty and may be helpful for making pre-ERCP strategy. [ABSTRACT FROM AUTHOR]

Background: In abdominal imaging, contrast-enhanced computed tomography (CT) examinations are most commonly applied; however, unenhanced examinations are still needed for several clinical questions but require additional scanning and radiation exposure.Purpose: To evaluate accuracy of virtual non-contrast (VNC) from arterial and venous phase spectral-detector CT (SDCT) scans compared to true-unenhanced (TNC) images for the evaluation of liver parenchyma and vessels.Material and Methods: A total of 25 patients undergoing triphasic SDCT examinations were included. VNC was reconstructed from arterial and venous phases and compared to TNC images. Quantitative image analysis was performed by region of interest (ROI)-based assessment of mean and SD of attenuation (HU) in each liver segment, spleen, portal vein, common hepatic artery, and abdominal aorta. Subjectively, iodine subtraction and diagnostic assessment were rated on 5-point Likert scales.Results: Attenuation and image noise measured in the liver from VNC were not significantly different from TNC (TNC: 54.6 ± 10.8 HU, VNC arterial phase: 55.7 ± 10.8 HU; VNC venous phase: 58.3 ± 10.0 HU; P > 0.05). VNC also showed accurate results regarding attenuation and image noise for spleen, portal vein, and abdominal aorta. Only iodine subtraction in the common hepatic artery in the arterial phase was insufficient which was confirmed by the subjective reading. Apart from that, subjective reading showed accurate iodine subtraction and comparable diagnostic assessment.Conclusion: VNC from the arterial and venous phases were very similar to TNC yielding mostly negligible differences in attenuation, image noise, and diagnostic utility. Inadequate iodine subtraction occurred in hepatic arteries in the arterial phase. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) with hepatocyte specific contrast has the highest sensitivity for colorectal liver metastases but comes at high costs and long examination times. Purpose: To evaluate if preoperative detection of colorectal liver metastases with less resource-consuming diffusion-weighted imaging (DWI) alone or in combination with multidetector computed tomography (MDCT) can compete with gadolinium-etoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI. Material and Methods: Forty-four patients with 123 colorectal liver metastases received MDCT and Gd-EOB-DTPA-enhanced MRI including DWI before liver resection for colorectal liver metastases. Five image sets were evaluated by two radiologists. The DWI set consisted of DWI, ADC map, coronal, axial T2-weighted single-shot sequences. The DWI-T2F set contained additionally respiratory-triggered T2-weighted TSE-SPIR sequences. The MDCT set consisted of four-phase MDCT, the MDCT-DWI set also contained DWI. The CE-MRI set contained all MRI sequences including Gd-EOB-DTPA. Reference standards was histopathology and follow-up. Results: CE-MRI set had highest sensitivity (P ≤ 0.013) with 95% compared to 72%, 73%, 73%, and 87% the for DWI set, DWI-T2W-FS set, MDCT set, and MDCT-DWI set, respectively. The CE-MRI set had the highest sensitivity (P ≤0.012) for colorectal liver metastases <10 mm with 87% compared to 55%, 52%, 23%, and 58% for the DWI set, DWI-T2W-FS set, MDCT set, and MDCT-DWI set, respectively. The MDCT-DWI set improved sensitivity overall and in size-dependent subgroup analyses compared to the MDCT set (P ≤ 0.031). The MDCT-DWI set showed the highest specificity of 98% followed by 98%, 98%, 95%, and 88% for the DWI set, DWI-T2W-FS set, MDCT set, and CE-MRI set, respectively. Conclusion: The less resource and time-consuming DWI sets are inferior to Gd-EOB-DTPA-enhanced MRI for the detection of colorectal liver metastases. Gd-EOB-DTPA-enhanced MRI with its excellent sensitivity should be the preferred preoperative modality when meticulous lesion identification is essential. Combination of DWI with MDCT improved significantly sensitivity compared to each modality alone. [ABSTRACT FROM AUTHOR]

Background: The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. Purpose: To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Material and Methods: Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. Results: In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% (P <0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively (P < 0.001). The success rate in group A was 91.2% and 87.9% in group B (P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. Conclusion: We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic. [ABSTRACT FROM AUTHOR]

Background: In order to obtain timely treatment, the early detection of recurrent ovarian cancer is essential. Despite technical advances in multi-detector row computed tomography (MDCT), low sensitivity of CT for recurrence has not been improved much due to its poor soft tissue discrimination. Purpose: The aim of this study is to describe patterns of erroneous postoperative MDCT interpretation of recurred peritoneal lesions in patients with advanced ovarian cancer (AOC). Material and methods: Between 2011 and 2018, we reviewed postoperative follow-up positron emission tomography (PET)/CT images of 240 patients with suspected recurrence based on the images and history of initially diagnosed AOC (International Federation of Gynecology and Obstetrics stage IIIC–IV) who had undergone primary cytoreduction. With awareness of recurred location, we re-evaluated MDCT images taken right before the recurrence was detected on PET/CT and categorized these cases as either the absence of a lesion or the presence of a lesion (missed case). We performed region-based comparisons of these missed cases according to predefined peritoneal locations. Results: Re-evaluation of follow-up MDCT images revealed that 46.9% (105/224) of recurrent lesions were missed. Through region-based analysis, the most commonly missed site was the pelvic cavity (19.0%, 20/105), followed by the porta hepatis (15.2%, 16/105) and the para-aortic/aortocaval lymphadenopathy (13.3%, 14/105). Conclusion: Radiologists should be concerned about these frequently overlooked regions in postoperative follow-up MDCT images when potential risks are identified. Familiarity with these imaging features may aid in the detection of recurrence and facilitate appropriate management. [ABSTRACT FROM AUTHOR]

Background: Recent studies suggest potentially improved inter-patient variability in hepatic enhancement by dosing contrast media (CM) according to lean body weight (LBW); however, studies vary in dosing strategy and most involved solely Japanese patients. Purpose: To compare the magnitude and inter-patient variability in mean hepatic enhancement (MHE) when dosing CM according to total body weight (TBW) versus LBW in a Western population. Material and Methods: With ethics approval, this study comprised two parts: (i) 100 CTs acquired with 1.3 mL Isovue 370/kg TBW were analyzed; (ii) 108 patients were consented for LBW dosing at 1.9 mL/kg (max. 150 mL, both groups). Liver attenuations were obtained from regions of interest. The MHE, MHE per gram of iodine (MHE/I), and adjusted MHE (aMHE = MHE/(I/TBW or LBW)) were calculated. We compared patient populations (Fisher's exact test, t-tests) and inter-patient variability (F-tests of variances in MHE) and performed linear regressions of MHE and aMHE. Results: Cohorts were similar in age, sex, TBW, LBW, and total CM dose. MHE was higher in part 2 (63.1 ± 13 vs. 56.3 ± 12 HU, P = 0.0001) but variances were similar (P > 0.7). In part 2, men received more CM (P = 0.0002) and MHE was higher (P = 0.0002); women received less CM (P = 0.053) but showed a non-significant trend for greater MHE (P = 0.07). MHE/I was higher for women in part 2 (P = 0.01) and stable in men (P = 0.72). Linear regressions showed no lines of best-fit with non-zero slopes, for both sexes and study parts. Conclusion: With CM dose constant, LBW dosing yielded a higher magnitude in MHE but did not reduce inter-patient variability. [ABSTRACT FROM AUTHOR]

Background: Successful cardiac resynchronization therapy (CRT) requires appropriate left ventricular (LV) lead placement on a suitable segment of the free LV wall. Current guidelines suggest targeted lead placement, but the individual anatomy of the cardiac veins is often a limiting factor. Purpose: To map cardiac veins with multidetector computed tomography (MDCT) and plot the veins in cardiac segments to facilitate successful CRT implantation. Material and Methods: Ninety-nine patients were included (mean age = 68 ± 9 years; 26% women; 46% ischemic cardiomyopathy). Contrast-enhanced, ECG-gated, dose-modulated MDCT was used to depict the coronary veins. CT data were reformatted into short-axis view. Veins with diameter ≥1.5 mm and traversing the free LV wall were manually transferred into a 17-segment bulls-eye plot model. Results: In 98 patients, a CT scan with acceptable image quality was obtained. Median radiation dose as dose-length protocol was 231 mGy/cm (interquartile range = 276 mGy/cm). Mean contrast dose, expressed as total iodine load, was 38 ± 8 g. A median of three suitable veins (range = 1–7) covered a mean of 4.4 ± 1.5 relevant LV segments. There was no difference between patients with dilated or ischemic cardiomyopathy in number of veins (2.5 vs. 2.7, P = 0.45) or in number of cardiac segments traversed by suitable veins (4.4 vs. 4.5, P = 0.74). Conclusion: In CRT patients, MDCT can be used for preoperative mapping of the cardiac veins to assess availability of suitable veins in potential target segments for pacemaker-lead placement. Using the 17-segment plot of the left ventricle may improve the clinical usefulness of the data. [ABSTRACT FROM AUTHOR]

Background: Aortic valve calcification quantification using cardiac computed tomography (CCT) is a reliable marker for aortic stenosis (AS) in patients with bicuspid aortic valve (BAV) disease.Purpose: To determine the association of Agatston aortic valve calcium score (AVCS) with morphological and hemodynamic characteristics of BAV and define cut-off AVCS for optimizing the grade of AS in patients with bicuspid AS.Material and Methods: This study included 161 BAV patients with AS regardless of aortic regurgitation who underwent transthoracic echocardiography and CCT. BAVs were classified according to orientation of cusps and presence of raphe. Associations of AVCS with characteristics of BAV morphology and functional variables were determined by linear regression analysis. Area under the receiver operating characteristic curve (AUC) was used to determine the cut-off AVCS greater than which the diagnosis of severe AS was optimized.Results: AVCS was significantly different according to sex ( P < 0.001), AS severity ( P < 0.001), type of valvular dysfunction ( P = 0.011), and orientation of cusps ( P = 0.028). Multiple linear regression showed that AVCS was significantly associated with sex (estimate = -0.583, P < 0.001) and AS severity (estimate = 0.817, P < 0.001). AVCS was a predictor for severe AS with AUC of 0.80 in both women ( P = 0.002) and men ( P < 0.001). Its cut-off value was 1423 Agatston unit (AU) in women and 2573 AU in men.Conclusions: In patients with bicuspid AS, AVCS was significantly higher in men and those with severe AS. However, AVCS was not significantly associated with morphological characteristics of BAV or the type of valvular dysfunction. [ABSTRACT FROM AUTHOR]

Background: X-ray tube voltage (kVp) reduction increases intravenous contrast medium (CM) attenuation at computed tomography (CT), but tube output limits its use in large patients.Purpose: To evaluate the feasibility and image quality of reducing CM dose by low kVp and using dual X-ray source at liver CT.Material and Methods: Patients with estimated glomerular filtration rate (eGFR) < 45 mL/min (n = 43) aged 60-91 years (75 ± 7.7), weighing 42-114 kg (75 ± 15) were prospectively scanned using a reduced CM dose of 0.25 or 0.3 g iodine (I)/kg with 70 or 80 kVp respectively, using either single-source or dual-source CT depending on patient size. Liver contrast-to-noise ratio (CNR), liver noise, and muscle noise were quantitatively compared with those of 43 consecutive patients aged > 65 years with eGFR > 45 mL/min scanned using a standard abdominal protocol at 120 kVp after receiving 0.5 gI/kg.Results: There was no statistically significant difference in CNR, liver noise, or muscle noise at reduced CM protocols compared to the standard protocol: CNR was 4.6 (95% CI = 4.2-5.0) vs. 5.0 (95% CI = 4.5-5.5), liver noise was 11.1 (95% CI = 10.7-11.6) vs. 11.0 (95% CI = 10.5-11.6), muscle noise was 11.7 (95% CI = 11.2-12.1) vs. 10.8 (95% CI = 10.1-11.4). The mean SSDE was 70% higher with the reduced CM protocol.Conclusion: CM dosage can be reduced by 40-50% with maintained measured noise and CNR in patients with BMIs of 15-36 kg/m2 by lowering the tube voltage and dual-source CT scanning of the liver. [ABSTRACT FROM AUTHOR]

Background Non-invasive anatomical and physiological evaluations of coronary artery disease (CAD) may be obtained with static single-scan stress perfusion cardiac computed tomography (SSPCT). Purpose To determine the diagnostic performance of static SSPCT for identifying hemodynamically significant CAD. Material and Methods This prospective study included 29 patients with suspected or known CAD who underwent static SSPCT, cardiovascular magnetic resonance myocardial perfusion imaging (CMR-MPI), and invasive coronary angiography (ICA). CT was performed as follows: (i) coronary calcium scan; (ii) static SSPCT for both coronary artery (coronary CT angiography [CCTA]) and myocardial perfusion (perfusion CT [PCT]) during adenosine infusion; (iii) late-phase scan. The diagnostic performance of CCTA alone, PCT alone, and SSPCT for the detection of a hemodynamically significant CAD (a perfusion defect in a vascular territory subtended by a coronary vessel with ≥ 50% stenosis) was compared with that of combined ICA/CMR-MPI representing the standard of reference. Results Twenty-three (79%) patients and 47 (54%) vascular territories manifested ischemia-causing coronary stenoses by combined ICA/CMR-MPI. The per-vessel sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) of the SSPCT were 92%, 88%, 90%, 90%, and 0.90, respectively, compared to those of the combined ICA/CMR-MPI. These values for the CCTA alone were 96%, 63%, 75%, 93%, and 0.79, respectively; and the values for the PCT alone were 94%, 83%, 86%, 92%, and 0.88, respectively. The AUC of SSPCT was significantly ( P = 0.013) higher than that of the CCTA alone. Conclusion Static SSPCT may facilitate detection of hemodynamically significant CAD. [ABSTRACT FROM AUTHOR]

Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B ( P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups ( P > 0.05). In addition, radiation dose in group A was significantly lower than in group B ( P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP. [ABSTRACT FROM AUTHOR]

Background Patients with acute non-traumatic abdominal pain often undergo abdominal computed tomography (CT). However, abdominal CT is associated with high radiation exposure. Purpose To evaluate diagnostic performance of a reduced-dose 100 kVp CT protocol with advanced modeled iterative reconstruction as compared to a linearly blended 120 kVp protocol for assessment of acute, non-traumatic abdominal pain. Material and Methods Two radiologists assessed 100 kVp and linearly blended 120 kVp series of 112 consecutive patients with acute non-traumatic pain (onset < 48 h) regarding image quality, noise, and artifacts on a five-point Likert scale. Both radiologists assessed both series for abdominal pathologies and for diagnostic confidence. Both 100 kVp and linearly blended 120 kVp series were quantitatively evaluated regarding radiation dose and image noise. Comparative statistics and diagnostic accuracy was calculated using receiver operating curve (ROC) statistics, with final clinical diagnosis/clinical follow-up as reference standard. Results Image quality was high for both series without detectable significant differences ( P = 0.157). Image noise and artifacts were rated low for both series but significantly higher for 100 kVp ( P ≤ 0.021). Diagnostic accuracy was high for both series (120 kVp: area under the curve [AUC] = 0.950, sensitivity = 0.958, specificity = 0.941; 100 kVp: AUC ≥ 0.910, sensitivity ≥ 0.937, specificity = 0.882; P ≥ 0.516) with almost perfect inter-rater agreement (Kappa = 0.939). Diagnostic confidence was high for both dose levels without significant differences (100 kVp 5, range 4-5; 120 kVp 5, range 3-5; P = 0.134). The 100 kVp series yielded 26.1% lower radiation dose compared with the 120 kVp series (5.72 ± 2.23 mSv versus 7.75 ± 3.02 mSv, P < 0.001). Image noise was significantly higher in reduced-dose CT (13.3 ± 2.4 HU versus 10.6 ± 2.1 HU; P < 0.001). Conclusion Reduced-dose abdominal CT using 100 kVp yields excellent image quality and high diagnostic accuracy for the assessment of acute non-traumatic abdominal pain. [ABSTRACT FROM AUTHOR]

Background Triple rule-out computed tomography (TRO CT) is a CT protocol designed to simultaneously evaluate the coronary, aorta, and pulmonary arteries. Purpose To evaluate potential diagnostic performance of TRO CT with restricted volume coverage for detection of pulmonary thromboembolism (PTE) and aortic dissection (AD). Material and Methods This study included 1224 consecutive patients with acute chest pain who visited the emergency department and underwent TRO CT using a 128-slice dual-source CT. Image data were reconstructed according to the display field of view (DFOV) of coronary CT angiography (CCTA) and TRO CT protocols in each patient. The presence of PTE and AD was evaluated by independent observers in each DFOV. The radiation dose was calculated to evaluate the potential benefits by restricting z-axis coverage to cardiac scan range instead of the whole thorax. Results Among all patients, 22 cases with PTE (1.9%) and nine cases with AD (0.8%) were found. Except for one PTE case, all cases were detected on both DFOV of TRO CT and CCTA. Mean effective dose for evaluation of entire thorax and cardiac scan coverage were 5.9 ± 1.1 mSv and 3.5 ± 0.7 mSv, respectively. Conclusion Isolated PTE and AD outside the CCTA DFOV rarely occur. Therefore, modified TRO CT protocol using cardiac scan coverage can be adopted to detect PTE and AD with reduced radiation dose. [ABSTRACT FROM AUTHOR]

Background Understanding the anatomy of the lower extremity veins is essential for successful varicose vein treatment. Computed tomography (CT) venography may be used to obtain a comprehensive overview and detailed information regarding this. Purpose To describe anatomic variations of the lower extremity venous system in patients with varicose veins, using three-dimensional (3D) CT venography. Material and Methods A total of 810 limbs in 405 patients with suspected varicose veins were prospectively referred to undertake CT venography and included in our study population retrospectively. The CT venography images were evaluated by consensus of two cardiovascular radiologists. Anatomical variations of the lower extremity venous system and their incidence were analyzed. Specifically, the number of tributaries at saphenofemoral junction, relative location of the great saphenous vein (GSV) with respect to the common femoral artery bifurcation, pattern of saphenopopliteal junction, and end of thigh extension from the small saphenous vein (SSV) were assessed. Results The most frequent number of tributaries joining the GSV was four (44.4%, 360/810). Only 0.7% (6/810) of the limbs demonstrated unusual location of the GSV between the bifurcated superficial and deep femoral arteries. The most common pattern of veins at the saphenopopliteal junction was a larger caliber of saphenopopliteal junction than thigh extension from SSV (43.8%, 355/810), end of which joining the femoral vein directly (41.0%, 288/703). Conclusion CT venography with 3D reconstruction can be used to understand the anatomy of lower extremity veins and how their variations contribute to varicose veins. [ABSTRACT FROM AUTHOR]

Background Identification of clinical features to determine the aggressive potential of tumors is highly warranted to stratify patients for adequate treatment. Computed tomography (CT) imaging features of clear cell renal cell carcinoma (ccRCC) may contribute to personalized risk assessment. Purpose To assess the correlation between CT imaging features and Fuhrman grade of ccRCC, and to identify the predictors of high Fuhrman grade in conjunction with tumor size. Material and Methods CT scans of 169 patients with 173 pathologically proven ccRCCs were retrospectively reviewed in consensus by two radiologists for the presence of intratumoral necrosis and intratumoral cyst and tumor size. Histologic grade was classified as either low (Fuhrman grade I or II) or high (Fuhrman grade III or IV). Statistical significance was evaluated by using univariate, multivariate regression, receiver operating characteristic (ROC) curve, and Spearman correlation analyses. Results On CT, 20 of the 173 tumors had intratumoral cysts, 60 had intratumoral necrosis, and 93 showed entirely solid tumors. The odds of high grade were higher with intratumoral necrosis and entirely solid tumor than with intratumoral cyst ( P < 0.03). Intratumoral necrosis showed a significantly high odds ratio of 25.73 for high Fuhrman grade. The ROC curve showed a threshold tumor size of 36 mm to predict high Fuhrman grade for overall tumors (area under the ROC curve, 0.70). In ccRCCs with intratumoral necrosis or cyst, tumor size did not significantly correlate with Fuhrman grade. Conclusion Intratumoral necrosis on CT was a strong and independent predictor of biologically aggressive ccRCCs, irrespective of tumor size. [ABSTRACT FROM AUTHOR]

Background Both multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are used for assessment of lumbar foraminal stenosis (LFS). Therefore, it is relevant to assess agreement between these imaging modalities. Purpose To determine intermodality, inter-, and intra-observer agreement for assessment of LFS on MDCT and MRI. Material and Methods A total of 120 foramina in 20 patients who visited our institution in January and February 2014 were evaluated by six radiologists with different levels of experience. Radiologists evaluated presence and severity of LFS on sagittal CT and MR images according to a previously published LFS grading system. Intermodality agreement was analyzed by using weighted kappa statistics, while inter- and intra-observer agreement were analyzed by using intraclass correlation coefficients (ICCs) and kappa statistics. Results Overall intermodality agreement was moderate to good (kappa, 0.478-0.765). In particular, two professors and one fellow tended to overestimate the degree of LFS on CT compared with MRI. For inter-observer agreement of all six observers, ICCs indicated excellent agreement for both CT (0.774) and MRI (0.771), while Fleiss' kappa values showed moderate agreement for CT (0.482) and MRI (0.575). There was better agreement between professors and fellows compared with residents. For intra-observer agreement, ICCs indicated excellent agreement, while kappa values showed good to excellent agreement for both CT and MRI. Conclusion MDCT was comparable to MRI for diagnosis and assessment of LFS, especially for experienced observers. However, there was a tendency to overestimate the degree of LFS on MDCT compared with MRI. [ABSTRACT FROM AUTHOR]

Background: Knowledge of the normal size of the thoracic aorta and pulmonary arteries is important regarding the detection of the abnormal and valuable in the treatment of patients with congenital and acquired cardiovascular diseases. Purpose: To determine the normal diameters of the thoracic vascular structures of pediatric participants on contrast-enhanced multidetector computer tomography (MDCT) scans. Material and Methods: Between July 2010 and July 2014, the MDCT examinations obtained from 520 participants (age range, 0-18 years; mean age, 8.49 years ± 5.54 [standard deviation]; male:female ratio, 1.6:1) with normal cardiovascular examinations were retrospectively evaluated. Patients were divided into six groups according to their age. Diameters of the ascending aorta (AA), descending aorta (DA), main pulmonary artery (MPA), right pulmonary artery (RPA), and left pulmonary artery (LPA) were measured. Results: The diameters of the thoracic vascular structures increased with age and the statistical difference among the age groups and genders were significant. The vascular structures in male patients tended to have higher dimensions than female patients. The LPA demonstrated higher mean values than the RPA in each age group. The mean ratio PA (MPA/AA) is 0.93 ± 0.08 for pediatric participants and it is slightly higher in girls compared to boys (0.93 ± 0.07 and 0.92 ± 0.07, respectively). The level of pulmonary artery bifurcation moves caudally with increasing age with thoracal 6 vertebra being the most common for all age groups (53.3%). Conclusion: We believe that the results of our study can serve as a potential reference in differentiating the normal from the abnormal size of the aorta and pulmonary arteries on chest MDCT studies in the pediatric population. [ABSTRACT FROM AUTHOR]

Background: Multi-detector computed tomography (MDCT) angiography is now used for the diagnosing patients with peripheral arterial disease. The dose of radiation is related to variable factors, such as tube current, tube voltage, and helical pitch. Purpose: To assess the diagnostic performance and radiation dose of lower extremity CT angiography (CTA) using a 128-slice dual source CT at 80 kVp and high pitch in patients with critical limb ischemia (CLI). Material and Methods: Twenty-eight patients (mean, 64.1 years; range, 39-80 years) with CLI were enrolled in this retrospective study and underwent CTA using a 128-slice dual source CT at 80 kVp and high pitch and subsequent intra-arterial digital subtraction angiography (DSA), which was used as a reference standard for assessing diagnostic performance. Results: For arterial segments with significant disease (>50% stenosis), overall sensitivity, specificity, and accuracy of lower extremity CTA were 94.8% (95% CI, 91.7-98.0%), 91.5% (95% CI, 87.7-95.2%), and 93.1% (95% CI, 90.6-95.6%), respectively, and its positive and negative predictive values were 91.0% (95% CI, 87.1-95.0%), and 95.1% (95% CI, 92.1-98.1%), respectively. Mean radiation dose delivered to lower extremities was 266.6 mGy.cm. Conclusion: Lower extremity CTA using a 128-slice dual source CT at 80 kVp and high pitch was found to have good diagnostic performance for the assessment of patients with CLI using an extremely low radiation dose. [ABSTRACT FROM AUTHOR]

Background: The transverse ligament tubercles play an important role in maintaining the stability of upper cervical spine, but the variation of these tubercles with aging has not been studied systematically. Purpose: To evaluate the variation of the height of the transverse ligament tubercles with respect to age and gender, and assess side-to-side differences on multidetector computed tomography (MDCT). Material and Methods: A consecutive series of 291 Chinese patients undergoing a head or neck MDCT were divided into eight age groups. The bony anatomy of the atlas was displayed symmetrically by aligning the axial plane and the mean height of bilateral transverse ligament tubercles was measured. The height was correlated with age and gender and side-to-side differences were analyzed. Finally, the inter-observer performance was assessed. Results: No transverse ligament tubercles were seen in 51 cases (17.5%, 51/291) and unilateral transverse ligament tubercles were seen in two cases (0.7%, 2/291). Bilateral transverse ligament tubercles were observed in 238 cases (81.8%, 238/291). The average height of the left and right tubercles were 2.68 ± 1.58 mm and 2.68 ± 1.54 mm, respectively, with no significant side-to-side differences (t = 0.061, P > 0.05). The height was also similar in both genders (left: t = 0.497, P > 0.05, right: t = 0.730, P > 0.05). The height increased linearly with age (left: r = 0.513, P < 0.05, right: r = 0.516, P < 0.05). The inter-observer reliability was excellent. Conclusion: The height of the transverse ligament tubercles on MDCT linearly increases with increasing age with no significant differences among the genders or the side measured. [ABSTRACT FROM AUTHOR]

Background: Previous studies suggest that oxytocin (OT) negatively modulates adipogenesis while promoting osteogenesis in vitro. Because of its effects on marrow stromal cells, OT might have potential utility in therapy for glucocorticoid-induced osteoporosis (GIO).Purpose: To explore the effects of OT on marrow adipogenesis in a rabbit model of GIO.Material and Methods: Thirty-six-month-old female New Zealand rabbits were randomly assigned to the control, GIO, and GIO + OT groups. Magnetic resonance (MR) spectroscopy and multi-detector computed tomography (MDCT) were performed to detect marrow fat content (MFC) and bone mineral density (BMD) at baseline, and 1, 2, and 3 months. After 3 months of treatment, marrow adipocytes were quantitatively evaluated by histopathology.Results: In the GIO group, MFC substantially increased from 34.1% to 43.2% at month 1, and it was maintained until month 3 (by 59.2%, all P <0.01). MFC values in the GIO group were significantly different from the control and OT-treated groups over time. Early OT treatment reversed marrow adiposity to levels of the controls. BMD values were significantly lower in the GIO group at months 2 and 3 compared to the controls; however, partial recovery of vertebral BMD (87.1% of baseline) and femoral BMD (89.3% of baseline) in the OT-treated group were observed. The mean diameter and density of adipocyte and percentage of adipocyte area increased by 30.0%, 70.1%, and 88.9%, respectively (all P <0.05) in the GIO group, but remained unchanged in the OT-treated group.Conclusion: Early OT treatment was sufficient to eliminate glucocorticoid-induced marrow adiposity. [ABSTRACT FROM AUTHOR]

Background: Multidetector computed tomography angiography (MDCTA) and magnetic resonance angiography (MRA) are accurate techniques for selecting patients with peripheral arterial disease for surgical and endovascular treatment. No studies in the literature have directly compared MDCTA and MRA to establish which one should be employed, in patients suitable for both techniques, before endovascular treatment.Purpose: To compare diagnostic performance of MDCTA vs MRA before endovascular intervention.Material and Methods: We prospectively compared MDCTA (64 slices scanner) and MRA (1.5 T scanner; 3D gadolinium-enhanced bolus-chase acquisition plus time resolved acquisition on calves) to stratify 35 patients according to the TASC II score and a runoff severity score. We also evaluated the accuracy of both techniques in each arterial segment. Selective angiography performed during the treatment was the standard of reference.Results: MDCTA and MRA accurately classify disease in the aorto-iliac (accuracy 0.92 for MDCTA and MRA) and femoro-popliteal (MDCTA 0.94, MRA 0.90) segments. MDCTA was more accurate in stratifying disease in the infrapopliteal segments (0.96 vs. 0.9) and in assessing the impairment of runoff arteries (0.92 vs. 0.85) at per-segment analysis. MDCTA showed a higher confidence and a shorter examination time.Conclusion: Our results suggest that MDCTA can be considered as a first-line investigation in patients being candidates for endovascular procedures when clinical history or duplex sonographic evaluation are indicative of severe impairment of the infrapopliteal segment. [ABSTRACT FROM AUTHOR]

Background: Renal oncocytoma (RO) and chromophobe renal cell carcinoma (ChRCC) share histologic and some imaging features.Purpose: To investigate the multidetector computed tomography (MDCT) characteristics of these two tumor types.Material and Methods: Fifty-six patients with RO and 54 patients with ChRCC were studied retrospectively. MDCT was undertaken to investigate differences in tumor characteristics.Results: Calcifications were visible in 24 (42.8%) patients with RO and in 11 (20.4%) patients with ChRCC (P = 0.011). 26 patients with RO had stellate scars as did 14 patients with ChRCC (P = 0.025). Spoken-wheel-like enhancement was visible in 41 patients with RO and in 11 with ChRCC (P < 0.001). Thirty-nine (69.6%) patients with RO and nine (16.7%) patients with ChRCC showed segmental inversion (P < 0.001). Two patients with RO had retroperitoneal lymph node enlargement as did 13 patients with ChRCC (P = 0.002). Combined evaluation of stellate scar, spoken-wheel-like enhancement, and segmental enhancement inversion features were found to have a sensitivity of 99.1% (106 of 107), a specificity of 100% (3 of 3), a positive predictive value of 100% (106 of 106), and a negative predictive value of 75% (3 of 4). The attenuation of RO tumors was greater than that of ChRCC tumors, normal renal parenchyma on unenhanced CT (P = 0.031). Enhancement was higher with RO than with ChRCC tumors in all phases (P = 0.021, < 0.001, and 0.007, respectively).Conclusion: CT imaging features such as stellate scar, spoken-wheel-like enhancement, and segmental enhancement inversion were more common in RO and they may help in differentiating RO from ChRCC. [ABSTRACT FROM AUTHOR]

Background: Patients with acute myocardial infarct (MI) show additional damage after coronary interventions.Purpose: To longitudinally quantify structural and functional changes in the left ventricle (LV) subjected to microembolized MI using multidisciplinary computed tomography (MDCT) and independent reference methods.Material and Methods: Swine (n = 20) served as controls (group I) or were subjected to a combination of coronary occlusion, microembolization, and reperfusion and imaged at 3 days (group II) or 3 days and 5 weeks (group III). LV volumes, perfusion, and MI mass were quantified on cine, perfusion, and delayed contrast enhancement (DE) MDCT. MRI, cardiac injury biomarkers, histochemical and histopathologic stains were used as independent references.Results: MDCT showed a reduction in ejection fraction and increased end systolic volume (31 ± 2% and 82 ± 3 mL, respectively) of group III compared with I (48 ± 2% and 57 ± 1 mL, respectively). It also demonstrated perfusion deficits in microembolized MI and peri-infarcts. DE-MDCT delineated microvascular obstruction (MVO) zones embedded in acute microembolized MI and microinfarct specks resulting from persistent MVO by deposited microemboli in microvessels of peri-infarct zone. Bland-Altman test showed close agreements between the extents of microembolized MI measured on DE-MDCT, DE-MRI, and histochemical TTC staining, but not between these modalities and microscopy. MI resorption was evident between 3 days and 5 weeks (13.4 ± 0.5 g and 9.8 ± 0.5 g, P < 0.017) and histologic examination revealed incomplete healing. Injury biomarkers were increased after intervention.Conclusion: MDCT can longitudinally quantify regional perfusion deficits, LV dysfunction, and resorption of microembolized MI. MDCT or MRI can be used alternatively after coronary interventions in cases of contraindications for one modality or the other. [ABSTRACT FROM AUTHOR]

Background: Familiarity with the variants of the foramina of the orbit and periorbital region is important in planning anesthesiological blocks and during orbital and maxillofacial surgery to avoid damage to nerves and vessels.Purpose: To assess the visibility and the incidence of variants of the small foramina of the orbit by multidetector computed tomography (MDCT).Material and Methods: The MDCT scans of 400 orbits from 200 patients were evaluated retrospectively. Slice thickness of the reconstructed images were in the range of 0.5-1.0 mm. The visibility and the variants of the foramen supraorbitale, the foramen infraorbitale, the foramen zygomaticofaciale, the foramen ethmoidale anterius et posterius, and the foramen cranio-orbitale were assessed using three-dimensional reconstruction tools.Results: The foramen infraorbitale (100%; n = 400), foramen supraorbitale (99.5%, n = 398), foramen zygomaticofaciale (76.5%; n = 307), and foramen zygomatico-orbitale (74.5%; n = 298) were most reliably detected by MDCT, while the foramen ethmoidale anterius (58.7%; n = 235) et posterius (56.7%; n = 225) were depicted less frequently. The foramen cranio-orbitale could not be identified in any case. Doubling was found for the foramen supraorbitale in 3.25% (n = 13), the foramen infraorbitale in 1.75% (n = 7), the foramen zygomaticofaciale in 16% (n = 64), and the foramen zygomatico-orbitale 14% (n = 56). Three foramina zygomatico-orbitale and foramina infraorbitale were found in 1.5% (n = 6) and in 0.5% (n = 2) of orbits, respectively.Conclusion: The foramina supraorbitale, infraorbitale, zygomatico-orbitale, and zygomaticiofaciale and their variants are well visible on MDCT. Knowledge of the exact number of these small foramina is relevant for preoperative evaluation. [ABSTRACT FROM AUTHOR]

Background: The atlanto-dental interval measurement in the cervical spine in young adults has been reported on multidetector computed tomography (MDCT), but has not been systematically assessed in all ages. Purpose: To evaluate the reference ranges for the atlanto-dental interval (ADI) in a large sample of adult patients on MDCT and to analyze the relationships of these measurements with gender and age of the patients as well as inter-observer performance. Material and Methods: First, a consecutive series of 700 Chinese patients aged over 18 years undergoing an upper cervical MDCT scan were divided equally into seven age groups. Second, the mid-sagittal image of the atlanto-dental joint was chosen for measurement and ADI was defined as the distance intercepted from the segment line linking the center of anterior atlas tubercle with that of posterior tubercle. Third, the correlation of ADI with age and gender was analyzed using linear regression analysis. Finally, the inter-observer performance was assessed using Bland and Altman's limits of agreement. Results: The ADI was 1.77 ± 0.39 mm, 1.61 ± 0.37 mm, 1.58 ± 0.36 mm, 1.41 ± 0.29 mm, 1.31 ± 0.29 mm, 1.34 ± 0.28 mm, and 1.06 ± 0.47 mm in the age groups 18-24 years, 25-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, and older than 70 years, respectively. The range of ADI was 0.85-3.12 mm in the age group 18-39 years, 0.71-2.55 mm in the age group 40-59 years, and 0.00-2.37 mm in the age group older than 60 years. There was no difference between gender and ADI (r = 0.00, P = 1.000). ADI decreased linearly with age (r = -0.511, P = 0.000). The inter-observer performance was reliable. Conclusion: ADI measurements on MDCT linearly decrease with increasing age, and these are not affected by gender in adult patients. Different reference values might be used at different ages when diagnosing atlantoaxial anterior dislocation or subluxation. [ABSTRACT FROM AUTHOR]

Background: Blunt pancreatic trauma is an uncommon injury with high morbidity and mortality. Retrospective analyses of computed tomography (CT) performance report CT to have variable sensitivity in diagnosing pancreatic injury. Both a prospective analysis of multidetector CT (MDCT) performance and diagnostic utility of magnetic resonance imaging (MRI) in acute blunt pancreatic injury remain unexplored. Purpose: To prospectively evaluate the utility of MDCT with MRI correlation in patients with blunt pancreatic trauma using intraoperative findings as the gold standard for analysis. Material and Methods: The contrast-enhanced CT (CECT) scans of patients admitted with blunt abdominal trauma were prospectively evaluated for CT signs of pancreatic injury. Patients detected to have pancreatic injury on CT were assigned a CT grade of injury according to American Association for Surgery of Trauma classification. MRI was performed in patients not undergoing immediate laparotomy and MRI grade independent of CT grade was assigned. Surgical grade was taken as gold standard and accuracy of CT and MRI for grading pancreatic injury and pancreatic ductal injury (PDI) was calculated. A quantitative and qualitative comparison of MRI was also done with CT to determine the performance of MRI in acute pancreatic injury. Results: Thirty out of 1198 patients with blunt trauma abdomen were detected to have pancreatic injury on CT, which was surgically confirmed in 24 patients. Seventeen underwent MRI and surgical correlation was available in 14 patients. CT and MRI correctly identified the grade of pancreatic injury in 91.7% (22/24) and 92.86% (13/14) patients, respectively. Both CT and MRI correctly identified PDI in 18/19 and 11/12 patients, respectively, with good inter-modality agreement of 88.9% (kappa value of 0.78). MRI also qualitatively added to the information provided by CT and increased diagnostic confidence in 58.8% of patients. Conclusion: MDCT performs well in grading pancreatic injury and evaluating pancreatic ductal injury. MRI is useful in evaluation of acute pancreatic trauma as it can increase diagnostic confidence and provide more qualitative information regarding the extent of injury. [ABSTRACT FROM AUTHOR]

Background: Differentiation between angiomyolipoma with minimal fat (AMLmf) and non-clear cell renal cell carcinoma (nccRCC) may be difficult owing to lack of macroscopic fat in AMLmf. However, the differential points between AMLmf and nccRCC has not been well established in the literature. Purpose: To evaluate quantitative triphasic multidetector computed tomography (MDCT) features that differentiate between small AMLmf and nccRCC, and to integrate them to develop a simple and easy diagnostic algorithm. Material and Methods: This study was approved by the Institutional Review Board; informed consent was waived. Triphasic MDCT images of pathologically-proven AMLmfs (n = 24) and nccRCCs (n = 55) of 79 patients were retrospectively evaluated. Age, sex, size, long-to-short axis ratio (LSR), attenuation and enhancement degree in all phases, unenhanced tumor-kidney attenuation difference (UTKAD) in Hounsfield units (HU) were compared with Chi-square analysis, independent-samples t-test, and receiver-operating characteristic (ROC) curves. A criterion was formulated with classification and regression tree analysis (CART). Thereafter, CART-based algorithm was tested with additional interpretations from two radiologists. Intra- and inter-observer variability was analyzed with Bland-Altman analysis. Results: LSR was greater in AMLmf than nccRCC (P < 0.001). AMLmf showed higher attenuation (all phases), CMP enhancement, and wash-out than nccRCC (P ≤ 0.001). UTKAD was greater in AMLmf than nccRCC (P < 0.001). ROC curve analysis yielded area under the curves of 0.936, 0.888, and 0.853 using UTKAD, unenhanced attenuation, and LSR. CART-based algorithm (UTKAD > 7.5 HU, LSR > 1.23) predicted AMLmf with sensitivity, specificity, PPV, and NPV of 87.5%, 96.4%, 91.3%, and 94.6%. Mean intra- and inter-observer difference was -0.1/0.03 HU and -1.0/0.09 HU for UTKAD/LSR, respectively. These interpretations changed the final diagnosis in 1.3% (1/79) and 5.1% (4/79) patients for radiologists 1 and 2. Conclusion: Triphasic MDCT was useful for differentiating AMLmf and nccRCC. CART-based algorithm using UTKAD > 7.5 and LSR > 1.23 was simple and accurate in predicting AMLmf. [ABSTRACT FROM AUTHOR]

Background: Excluding a cerebral venous thrombosis (CVT) through imaging is a frequent request in the emergency setting. This assessment often starts by an unenhanced brain computed tomography (CT). Purpose: Re-evaluate the value of spontaneous hyperdensity of CVT on helical unenhanced brain CT. Methods: Multicentric retrospective study on CVT probability based on visual assessment of spontaneous hyperdensity of cerebral venous system, performed by four blinded radiologists, individually then collectively, on a population including 14 helical unenhanced brain CTs with CVT and 102 unenhanced brain CTs without CVT (all confirmed by CT or magnetic resonance [MR] venography). Exclusion criteria: no DICOM image, symptoms >15 days, CVT indirect signs on unenhanced CT. A fifth radiologist set 768 regions of interest to measure and to compare the density within the normal venous sinuses and the CVTs. Results: After consensus reading, sensitivity of this sign for CVT diagnosis was 100%, specificity 95.1%, and negative predictive value (NPV) 100%, with high individual NPV (99-100%). Area under the receiver-operating characteristic curve was 0.992 after consensus (0.976-0.986 individually). The spontaneous density was significantly different (P <0.05) between normal sinuses and CVTs, with a density >70 HU reported only within the CVTs, except for the horizontal part of the superior sagittal sinus (hSSS). Conclusion: The dense triangle sign on helical unenhanced brain CT has an excellent NPV to exclude a sinus thrombosis during the first 2 weeks. However, we believe that visual assessment of spontaneous hyperdensity is not sufficient for the diagnosis of CVT, with possible false-positive of the hSSS on unenhanced CT. [ABSTRACT FROM AUTHOR]

Background: The imaging features of pleural tuberculosis (PTB) can be similar to those of malignant pleural dissemination (MPD) with several case reports of CT findings in atypical presentations of PTB. Purpose: To describe the computed tomography (CT) features of PTB by comparing these imaging findings with those of MPD and to use the results to differentiate between the two diseases. Material and Methods: The study included 135 patients with PTB and 69 with MPD. The CT images were assessed in terms of the presence, extent, and contour of pleural thickening. Pleural nodules were analyzed in terms of number, size, and location. The CT findings of PTB and MPD were compared. Results: The CT findings of PTB included circumferential pleural thickening (32.6%), mediastinal pleural involvement (31.9%), nodular thickening (8.9%), and pleural thickening >1 cm (2.2%). The CT features of MPD included nodular pleural thickening (56.5%), mediastinal pleural involvement (40.6%), circumferential thickening (23.2%), and pleural thickening >1 cm (7.2%). Comparing PTB and MPD, nodular pleural thickening was observed more frequently with MPD than PTB (P <0.001). Conclusion: Nodular pleural thickening is observed in 8.9% of the patients with PTB on chest CT. Comparing PTB and MPD, nodular pleural thickening was the only finding significantly associated with MPD, particularly with nodules >10 mm. [ABSTRACT FROM AUTHOR]

Background: There are very few reports assessing in-stent restenosis (ISR) after vertebral artery ostium (VAO) stents using multidetector computed tomography (MDCT). Purpose: To compare the diagnostic accuracy of computed tomography angiography (CTA) using 64-slice MDCT with digital subtraction angiography (DSA) for detection of significant ISR after VAO stenting. Material and Methods: The study evaluated 57 VAO stents in 57 patients (39 men, 18 women; mean age 64 years [range, 48-90 years]). All stents were scanned with a 64-slice MDCT scanner. Three sets of images were reconstructed with three different convolution kernels. Two observers who were blinded to the results of DSA assessed the diagnostic accuracy of CTA for detecting significant ISR (≥50% diameter narrowing) of VAO stents in comparison with DSA as the reference standard. The sensitivity, specificity, positive and negative predictive values, and accuracy were calculated. Results: Of the 57 stents, 46 (81%) were assessable using CTA, while 11 (19%) were not. No stents with diameters ≤2.75 mm were assessable. DSA revealed 13 cases of significant ISR in all stents. The respective sensitivity, specificity, positive and negative predictive values, and accuracy were 92%, 82%, 60%, 97%, and 84% for all stents. On excluding the 11 non-assessable stents, the respective values were 88%, 95%, 78%, 97%, and 93%. Of the 46 CTA assessable stents, eight significant ISRs were diagnosed on DSA. Seven of eight patients with significant ISR by DSA were diagnosed correctly with CTA. The area under the receiver-operating characteristic curve (AUC) was 0.87 for all stents and 0.91 for assessable stents, indicating good to excellent agreement between CTA and DSA for detecting significant ISR after VAO stenting. Conclusion: Sixty-four-slice MDCT is a promising non-invasive method of assessing stent patency and can exclude significant ISR with high diagnostic values after VAO stenting. [ABSTRACT FROM AUTHOR]

Background: Beside its value during the initial trauma work-up (focused assessment with sonography for trauma), ultrasound (US) is recommended for early follow-up examinations of the abdomen in multiple injured patients. However, multidetector CT (MDCT) has proven to reliably diagnose traumatic lesions of abdominal organs, to depict their extent, and to assess their clinical relevance. Purpose: To evaluate the diagnostic impact of follow-up US studies after MDCT of the abdomen and to identify possible clinical parameters indicating the need of a follow-up US. Material and Methods: During a 30-month period, patients with suspected multiple trauma were allocated. Patients with admission to the ICU, an initial abdominal MDCT scan, and an US follow-up examination after 6 and 24 h were included. Two patient cohorts were defined: patients with normal abdominal MDCT (group 1), patients with trauma-related pathologic abdominal MDCT (group 2). In all patients, parameters indicating alteration of vital functions or hemorrhage within the first 24 h were obtained by reviewing the medical charts. Results: Forty-four of 193 patients were included: 24 were categorized in group 1 (mean age, 41.1 years; range, 21-90 years), 20 in group 2 (mean age, 36.6 years; range, 16-71 years). In group 1, US did not provide new information compared to emergency MDCT. In group 2, there were no contradictory 6- and 24-h follow-up US findings. In patients with positive MDCT findings and alterations of clinical parameters, US did not detect progression of a previously diagnosed pathology or any late manifestation of such a lesion. In none of the patients with negative abdominal MDCT and pathological clinical parameters US indicated an abdominal injury. Conclusion: Routine US follow-up does not yield additional information after abdominal trauma. In patients with MDCT-proven organ lesions, follow-up MDCT should be considered if indicated by abnormal clinical and/or laboratory findings. [ABSTRACT FROM AUTHOR]

Background: Iterative reconstruction (IR) techniques reduce image noise in multidetector computed tomography (MDCT) imaging. They can therefore be used to reduce radiation dose while maintaining diagnostic image quality nearly constant. However, CT manufacturers offer several strength levels of IR to choose from. Purpose: To determine the optimal strength level of IR in low-dose MDCT of the cervical spine. Material and Methods: Thirty consecutive patients investigated by low-dose cervical spine MDCT were prospectively studied. Raw data were reconstructed using filtered back-projection and sinogram-affirmed IR (SAFIRE, strength levels 1 to 5) techniques. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at C3-C4 and C6-C7 levels. Two radiologists independently and blindly evaluated various anatomical structures (both dense and soft tissues) using a 4-point scale. They also rated the overall diagnostic image quality using a 10-point scale. Results: As IR strength levels increased, image noise decreased linearly, while SNR and CNR both increased linearly at C3-C4 and C6-C7 levels (P < 0.001). For the intervertebral discs, the content of neural foramina and dural sac, and for the ligaments, subjective image quality scores increased linearly with increasing IR strength level (P ≤ 0.03). Conversely, for the soft tissues and trabecular bone, the scores decreased linearly with increasing IR strength level (P < 0.001). Finally, the overall diagnostic image quality scores increased linearly with increasing IR strength level (P < 0.001). Conclusion: The optimal strength level of IR in low-dose cervical spine MDCT depends on the anatomical structure to be analyzed. For the intervertebral discs and the content of neural foramina, high strength levels of IR are recommended. [ABSTRACT FROM AUTHOR]