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To determine the therapeutic efficiency of percutaneous revascularization in renal artery stenosis (RAS), as well as the role of comprehensive factors such as patient selection and degree of artery stenosis, on clinical outcome. 101 patients with hemodynamically relevant RAS underwent percutaneous angioplasty (PTA). 65.7 % were male (mean age: 64 years; range: 18-84). The clinical data was retrospectively analyzed. The serum creatinine (Cr), glomerular filtration rate (GFR), and blood pressure (BP) levels pre- and postprocedural, between 6 months and 1 year, were retrospectively collected and statistically analyzed. Follow-up data was available in 34 (33.7 %) and 28 patients (27.7 %) for Cr and MAP, respectively. A significant drop in mean arterial pressure (MAP) was observed on follow-up (mean -5.27 mmHg). Higher baseline Cr and MAP values showed a more pronounced drop in the follow-up (Cr: p 0.002; difference to baseline -0.25 mg/dL, 95 %CI:-0.36, -0.07 and BP p 0.001; diff. to baseline -0.72 mmHg; 95 %CI: -1.4, -0.40). There was no association between comorbidities, gender, and degree of stenosis with renal and BP outcome. No significant improvement in renal function was observed on follow-up (mean Cr drop: -0.015 mg/dL). The age group 51-60 years showed a significant improvement in BP (p 0.030; diff. to baseline -19.2 mmHg; 95 %CI: -34, -4.3). There was a slight reduction in antihypertensive medication following angioplasty (0.2 fewer). Minor complications were recorded in five procedures (4.9 %). Percutaneous renal artery revascularization in the presence of atherosclerotic RAS is a safe procedure associated with a significant drop in post-procedural BP. No significant improvement in renal function was observed. Further prospective studies focused on patient selection are necessary. · Percutaneous stent angioplasty in renal artery stenosis is associated with a significant improvement in post-procedural blood pressure control.. · There is no improvement in renal function after percutaneous stent angioplasty for renal artery stenosis (RAS).. · Percutaneous stent angioplasty is a safe procedure..· Guerreiro H, Avanesov M, Dinnies S et al. Efficiency of Percutaneous Stent Angioplasty in Renal Artery Stenosis - 15 Years of Experience at a Single Center. Fortschr Röntgenstr 2021; 193: 298 - 304. Bestimmung der therapeutischen Effizienz der perkutanen Revaskularisation bei Nierenarterienstenose (RAS) sowie der Rolle umfassender Faktoren wie Patientenauswahl und Grad der Arterienstenose für das klinische Ergebnis. Bei 101 Patienten mit hämodynamisch relevanter RAS wurde eine perkutane Angioplastie (PTA) durchgeführt. 65,7 % waren männlich, das Durchschnittsalter betrug 64 Jahre (Bereich: 18–84). Die klinischen Daten wurden retrospektiv analysiert. Serumkreatinin (Cr), glomeruläre Filtrationsrate (GFR) und Blutdruckwerte (BP) prä- und postinterventionell sowie zwischen 6 Monaten und einem Jahr wurden retrospektiv erhoben und statistisch analysiert. Follow-up-Daten waren bei 34 (33,7 %) und 28 Patienten (27,7 %) jeweils für Cr und BP verfügbar. Bei der Nachuntersuchung wurde ein signifikanter Abfall des mittleren arteriellen Drucks (MAP) beobachtet (Mittelwert –5,27 mmHg). Höhere Cr- und MAP-Basiswerte zeigten einen ausgeprägteren Abfall im Follow-up (Cr: p = 0,002; Differenz zum Basiswert –0,25 mg/dl, 95 %-KI –0,36 bis-0,07 und BP p 0,001; Differenz zum Basiswert –0,72mmHg; 95 %-KI –1,4 bis –0,40). Es bestand kein Zusammenhang zwischen Komorbiditäten, Geschlecht und Stenosegrad mit dem Nieren- und Blutdruckergebnis. Beim Follow-up wurde keine signifikante Verbesserung der Nierenfunktion beobachtet (mittlerer Cr-Abfall: –0,015 mg/dl). In der Altersgruppe 51–60 Jahre zeigte sich eine signifikante Verbesserung des Blutdrucks (p = 0,030; Differenz zum Ausgangswert –19,2mmHg; 95 %-KI –34 bis –4,3). Die antihypertensive Medikation nach der Angioplastie wurde leicht reduziert (0,2 weniger). Unbedeutende Komplikationen wurden bei 5 Eingriffen festgestellt (4,9 %). Die perkutane Nierenarterienrevaskularisierung bei vorliegender atherosklerotischer RAS ist ein sicheres Verfahren, das mit einem signifikanten Abfall des postprozeduralen Blutdrucks einhergeht. Eine signifikante Verbesserung der Nierenfunktion wurde nicht beobachtet. Weitere prospektive Studien zur Patientenauswahl sind notwendig. · Die perkutane Stentangioplastie bei Nierenarterienstenose ist mit einer signifikanten Verbesserung der postprozeduralen Blutdruckkontrolle verbunden.. · Es gab keine Verbesserung der Nierenfunktion nach der perkutanen Stentangioplastie bei Nierenarterienstenose (RAS).. · Die perkutane Stentangioplastie ist ein sicheres Verfahren..

The purpose of this prospective study was to analyze the relationship between ventricular morphology and parameters of cardiac function in two different athletic groups and controls, using feature tracking cardiac magnetic resonance (FT-CMR). Twenty-three professional soccer players (22 ± 4 years), 19 competitive triathletes (28 ± 6 years) and 16 controls (26 ± 3 years) were included in the study. CMR was performed using a 1.5 T scanner. Cardiac chamber volumes, mass and biventricular global myocardial strain were obtained and compared. In comparison to the control subjects, athletes were characterized by a higher cardiac volume (p p p p p 2, p p p p r = 0.47, p r = − 0.28, p

OBJECTIVE. The purpose of this study is to investigate the feasibility of submillisievert CT of the skeletal pelvis of human cadavers using a standard-dose protocol and four different reduced-dose ...

PurposeFeasibility of a highly reduced-dose lumbar spine CT protocol using iterative reconstruction (IR) in a human cadaver model.Materials and methodsThe lumbar spine of 20 human cadavers was repeatedly examined using three different reduced-dose protocols (RDCT) with decreasing reference tube current-exposure time products (RDCT-1: 50 mAs; RDCT-2: 30 mAs; RDCT-3: 10 mAs) at a constant tube voltage of 140 kV. A clinical standard-dose protocol (SDCT) served as the reference (reference tube current-exposure time product: 70 mAs; tube voltage: 140 kV). Images were reconstructed using filtered back projection (FBP) and two increasing levels of IR: IRL4 and IRL6. A five-point scale was used by two observers to assess the diagnostic quality of anatomical structures (cortical and trabecular bone, intervertebral foramina, pedicles and intervertebral joints, spinous and transverse processes). Objective image noise (OIN) was measured. Results were interpreted using a linear mixed-effects regression model.ResultsRDCT-2 with IRL6 (1.2 ± 0.5mSv) was the lowest reduced-dose protocol which provided diagnostically acceptable and equivalent image quality compared to the SDCT (2.3 ± 1.1mSV) with FBP (p > 0.05). All RDCT protocols achieved a significant reduction of the mean (±SD) effective radiation doses (RDCT-1: 1.7±0.9mSv; RDCT-2: 1.2±0.5mSv; RDCT-3: 0.4±0.2mSv; p < 0.05) compared to SDCT. OIN was lower in all RDCT protocols with the application of IRL4 and IRL6, compared to the SDCT with FBP (p < 0.05).ConclusionHighly reduced-dose lumbar spine CT providing diagnostically acceptable image quality is feasible using IR in this cadaver model and may be transferred into a clinical setting.

Objectives To evaluate benign and malignant pelvine lymph nodes in prostate cancer patients with biexponential intravoxel incoherent motion (IVIM) MRI of the prostate prior to radical prostatectomy. Methods The ethics committee approved this retrospective study with waiver of informed consent. From February 2012 to November 2013 43 patients with histopathologically proven prostatic cancer were included. All patients were examined applying a standardized MRI protocol including IVIM diffusion weighted imaging with multiple b-values ranging from 0 to 950 s/mm². MR imaging was performed one day prior to radical prostatectomy. Thereafter, extended lymph node resection was performed. For each MRI all visible lymph nodes were registered and calculated as individual regions of interest. These findings were correlated with postoperative pathology. The apparent diffusion coefficient ADC, the diffusion coefficient D and the perfusion fraction f were calculated from IVIM DWI using a biexponential fit. Results A total of 120 lymph nodes were detected on MRI. 95 of these were determined as benign and 25 as malignant. The average ADC was significantly lower in malignant compared to benign lymph nodes (0.88 × 10−³ vs 1.67 × 10−³ mm²/s, p Conclusions Applying biexponential IVIM MRI demonstrates significant differences in diffusion parameters ADC and D, as well as in the perfusion fraction f for benign and malignant lymph nodes. Therefore, IVIM might help to further improve the preoperative assessment of lymph nodes in MRI.

The purpose of the study was to assess the impact of iterative model reconstruction (IMR) on reader confidence with respect to stone detection and image quality in comparison to filtered back-projection (FBP) and iDose level 4 (iDose4) in abdominal MDCT with radiation doses below 2 mSv.For 32 consecutive patients with suspected ureteral stone disease, the raw data of unenhanced 256 slice MDCT (120 kV, 40 reference mAs, mean CTDIvol: 2.7 ± 0.8 mGy, mean DLP: 126 ± 38 mGy × cm) were reconstructed using a prototype version of IMR (levels 1 - 3), iDose4 (level 4) and FBP at a 3 mm slice thickness. Image analysis was independently performed by two radiologists in a blinded fashion. The reader confidence level with respect to stone detection was recorded based on a 5-point scale (1 - certain exclusion; 5 - concrement definitely present) as well as for the evaluation of image quality regarding the depiction of anatomical details (1 - poor; 5 - excellent). A clinical reference standard for stone detection was not established. Statistical evaluation included weighted kappa analysis and Wilcoxon test.17 pelvic and ureteral stones were found. 11 further concrements were located within the ostium of the urinary bladder or the bladder itself. Applying IMR, a distinct improvement in image quality was observed at every level (mean value for FBP, 2.0; iDose4, 2.9; IMR L1, 4.2; IMR L2, 4.0; IMR L3, 3.9; all p 0.001). Applying the higher IMR levels L2 and L3, a certain level of so-called "blotchiness" of anatomical contours was observed. Reader confidence was significantly improved and was independent of IMR level (certain stone detection FBP, 69 %; iDose4, 81 %; IMR L1 to L3, 95 %; all p 0.001). With increasing IMR levels, the reduction in streak artifacts was quantified by a decrease in image noise. A loss of anatomical information was not observed. The sensitivity rates for stone detection were equivalent for all MDCTs reconstructed with FBP, iDose4 and IMR. A mean effective dose of 1.9 ± 0.6 mSv was calculated.In comparison to FBP and iDose4, a significant increase in mean image quality, reduction in image noise and improvement in subjective reader confidence can be achieved by applying IMR even at significantly reduced dose settings below 2 mSv. Results indicate that a further dose reduction might be possible with IMR.· Urinary tract. · urolithiasis. · iterative reconstruction.· Schmidt-Holtz J, Laqmani A, Butscheidt S et al. Iterative Model Reconstruction (IMR) in MDCT Below 2mSv for the Detection of Urinary Calculi: Diagnostic Accuracy and Image Quality in Comparison to Filtered Back-Projection and 4th Generation Iterative Reconstruction (iDose4). Fortschr Röntgenstr 2018; 190: 630 - 636.ZIEL: Das Ziel dieser Studie war es, die Auswirkungen der iterativen Modellrekonstruktion (IMR) auf die Sicherheit des Radiologen bei der Steindetektion und auf die Bildqualität im Vergleich zu gefilterten Rückprojektionen (FBP) und iDose Level 4 (iDose4) im Stein-MDCT mit Strahlendosen unter 2 mSv zu beurteilen.Für 32 aufeinanderfolgende Patienten mit Verdacht auf ein Harnleiterkonkrement wurden die Rohdaten der nativen Scans (256 Slice MDCT, 120 kV, 40 Referenz mAs, mittleres CTDIvol: 2,7 ± 0,8 mGy, mittleres DLP: 126 ± 38 mGy × cm) unter Verwendung einer Prototypversion von IMR (Level 1 – 3), iDose4 (Level 4) und FBP mit einer Schichtdicke von 3 mm rekonstruiert. Die Bildanalyse wurde jeweils unabhängig von zwei geblindeten Radiologen durchgeführt. Die diagnostische Sicherheit des Radiologen bei der Steindetektion erfolgte auf der Grundlage einer 5-Punkte-Skala (1 – sicherer Ausschluss, 5 – Konkrement definitiv vorhanden) wie auch für die Auswertung der Bildqualität in Bezug auf die Darstellung von anatomischen Details (1 – mangelhaft; 5 – Ausgezeichnet). Ein klinischer Referenzstandard für die Steindetektion wurde nicht erhoben. Die statistische Auswertung beinhaltet die weighted kappa-analysis und den Wilcoxon-Test.17 Nierenbecken- und Uretersteine wurden gefunden. 11 weitere Konkremente wurden im Harnblasenostium oder der Harnblase selber lokalisiert. Bei der Anwendung von IMR wurde mit jeder Iterationsstufe eine deutliche Verbesserung der Bildqualität beobachtet (Mittelwert für FBP, 2,0, iDose4, 2,9, IMR L1, 4,2, IMR L2, 4,0, IMR L3, 3,9, alle p 0,001). Mit den höheren IMR-Stufen L2 und L3 wurde ein gewisses Maß an sogenannter „blotchiness“ (Unschärfe) anatomischer Konturen beobachtet. Die Sicherheit des Radiologen wurde so unabhängig vom IMR-Level signifikant verbessert (sichere Steindetektion FBP, 69 %; iDose4, 81 %; IMR L1 bis L3, 95 %, alle p 0,001). Mit zunehmenden IMR-Werten wurde die Reduktion von Streifenartefakten durch eine Abnahme des Bildrauschens quantifiziert. Ein Verlust anatomischen Informationen wurde nicht beobachtet. Die Sensitivität der Steindetektion waren äquivalent für alle MDCTs, die mit FBP, iDose4 oder IMR rekonstruiert wurden. Es wurde eine mittlere effektive Dosis von 1,9 ± 0,6 mSv berechnet.Eine Urolithiasis kann zuverlässig durch MDCT bei deutlich reduzierten Dosiseinstellungen unter 2 mSv detektiert werden. Im Vergleich zu FBP und iDose4 kann eine signifikante Erhöhung der durchschnittlichen Bildqualität, eine Verringerung des Bildrauschens und eine Verbesserung der subjektiven diagnostischen Sicherheit des Radiologen bei der Konkrementdetektion mit Hilfe von IMR erreicht werden. Dies deutet darauf hin, dass mit IMR weiterreichende Dosisreduktionen möglich sein könnten.· Urogenitaltrakt. · Urolithiasis. · Iterative Reconstruction.

The purpose of this study is to assess the diagnostic yield of low-dose (LD) CT for alternative diagnoses in patients with suspected urolithiasis.In this retrospective study, we included 776 consecutive patients who underwent unenhanced abdominal CT for evaluation of suspected urolithiasis. All examinations were performed with an LD CT protocol; images were reconstructed using iterative reconstruction. The leading LD CT diagnosis was recorded for each patient and compared with the final clinical diagnosis, which served as the reference standard.The mean (± SD) effective dose of CT was 1.9 ± 0.6 mSv. The frequency of urolithiasis was 82.5% (640/776). LD CT reached a sensitivity of 94.1% (602/640), a specificity of 100.0% (136/136), and an accuracy of 95.1% (738/776) for the detection of urolithiasis. In 93 of 136 patients (68.4%) without urolithiasis, alternative diagnoses were established as the final clinical diagnoses. Alternative diagnoses were most commonly located in the genitourinary (n = 53) and gastrointestinal (n = 18) tracts. LD CT correctly provided alternative diagnoses for 57 patients (61.3%) and was false-negative for five patients (5.4%). The most common clinical alternative diagnoses were urinary tract infections (n = 22). Seven diagnoses missed at LD CT were located outside the FOV. For 43 of all 776 patients (5.5%), neither LD CT nor clinical workup could establish a final diagnosis. The sensitivity, specificity, and accuracy of LD CT for the detection of alternative diagnoses were 91.9% (57/62), 95.6% (43/45), and 93.5% (100/107), respectively.LD CT enables the diagnosis of most alternative diagnoses in the setting of suspected urolithiasis. The most frequent alternative diagnoses missed by LD CT are urinary tract infections or diagnoses located outside the FOV of the abdominopelvic CT scan.

Purpose To determine the value of multidetector computed tomography (MDCT) in patients with acute spondylodiscitis. Methods and Materials For data acquisition, we searched our radiological database for all patients who had undergone magnetic resonance imaging (MRI) for suspected spondylodiscitis between 2007 and 2015 (n = 325). For further analyses, we included all patients (n = 67) who initially underwent MDCT prior to MRI. Overall accuracy, sensitivity, specificity and positive and negative predictive values were calculated for MDCT and, separately, for contrast-enhanced CT (CECT, n = 36) and for non-enhanced CT (NECT, n = 31). MRI together with clinical evaluation served as the standard of reference. Results: In 34 of 43 patients with acute spondylodiscitis on MRI, correct diagnosis was already made by the initial MDCT scan. The specificity and positive predictive value were 100 % for MDCT. The sensitivity was 79 % and the negative predictive value was 72 %. The overall accuracy was 87 %. Accuracy was higher for CECT (89 %) than for NECT (84 %), however without statistical significance (p = 0.55). MDCT detected 90 % of paravertebral abscesses (34/38), but only 6 % of epidural abscesses (2/36). Conclusion MDCT has moderate sensitivity, but high specificity for acute spondylodiscitis. Thus, if MDCT is positive for spondylodiscitis, treatment can be started without further delay. However, MRI should be added to both MDCT negative and positive cases to rule out complications such as epidural abscesses that cannot reliably be detected by MDCT. Key Points: Citation Format

Spinal complaints affect a large proportion of the population and lead to numerous doctor visits.The different techniques of CT-guided infiltration of spinal disorders, taking into account facet infiltration, periradicular infiltration and epidural flooding are demonstrated.Discussion of basic work and expert recommendations as well as presentation of different treatment steps for everyday clinical practice.The CT-guided application of the different types of infiltration allows precise execution of the therapy. Both facet infiltration and periradicular infiltration and epidural flooding have their place depending on the clinical symptoms. The optimal combination of drugs to administer is still the subject of numerous studies and sometimes controversial discussions.An exact clinical and imaging evaluation of the pain symptoms in the back is the basic requirement for a targeted therapy.

Background According to the as low as reasonably achievable (ALARA) principle, radiation exposure in computed tomography (CT) should be minimized while maintaining adequate image quality. Dedicated CT protocols combined with iterative reconstruction (IR) can reduce radiation dose and/or improve image quality. Purpose To investigate the feasibility of extremely reduced-dose (RD) CT of the thoracic spine in human cadavers using a standard-dose (SD) and three different RDCT protocols reconstructed with filtered back projection (FBP) and IR. Material and Methods The thoracic spines of 11 cadavers were examined using different RDCT protocols with decreasing reference tube currents (RDCT-1: 50 mAs; RDCT-2: 30 mAs; RDCT-3: 10 mAs) at 140 kV. A clinical SDCT (70 mAs, 140 kV) served as reference. Raw data were reconstructed using FBP and two increasing levels of IR (IRL4 and IRL6). Images were evaluated for image quality, diagnostic acceptability, and visibility of anatomical structures according to a 5-point-scale. Results Regardless of the reconstruction technique, image quality was rated as diagnostically acceptable for all cadavers in SDCT and RDCT-1. Image quality of reconstructions with FBP were generally rated lower. Application of IR improved image quality ratings in SDCT and RDCT. RDCT-2 with IR was the most reduced-dose CT protocol which enabled diagnostically acceptable image quality in all cadavers. Compared to SDCT, RDCT protocols resulted in significantly reduced effective radiation doses (SDCT: 4.1 ± 1.5 mSv; RDCT-1: 2.9 ± 1.1 mSv; 2:1.7 ± 0.6 mSv; 3:0.6 ± 0.1 mSv; P = 0.001). Conclusion Diagnostically acceptable RDCT of the thoracic spine with 1.7 mSv is feasible using IR.

Recent investigation has underlined the potential of quantitative MR imaging to be used as a complementary tool for the diagnosis of cartilage degeneration at an early state. The presented study analyses T2* relaxation times of articular cartilage of the knee in professional athletes and compares the results to age- and BMI (Body Mass Index)-matched healthy amateur athletes.22 professional football players and 22 age- and BMI-matched individuals were underwent knee Magnetic Resonance Imaging (MRI) at 3T including qualitative and quantitative analysis. Qualitative analysis included e.g. meniscal tears, joint effusion and bone edema. For quantitative analysis T2* (22 ET: 4.6-53.6ms) measurements in 3D data acquisition were performed. Deep and superficial layers of 22 predefined cartilage segments were analysed. All data sets were postprocessed using a dedicated software tool. Statistical analysis included Student t-test, confidence intervals and a random effects model.In both groups, T2* relaxation times were significantly higher in the superficial compared to the deep layers (p0.001). Professional athletes had significantly higher relaxation times in eight superficial and three deep cartilage layers in the predefined cartilage segments (p0.05). Highly significant differences were found in the weight-bearing segments of the lateral superficial femoral condyle (p0.001).Elevated T2* values in cartilage layers of professional football players compared to amateur athletes were noted. The effects seem to predominate in superficial cartilage layers.

Over the last decades, there has been a significant stage migration in renal cell carcinoma and especially older patients are getting diagnosed more frequently with low stage disease, such as small renal masses ≤4 cm of size. Considering the particular risk profile of an older population, often presenting with a nonnegligible comorbidity profile and progressive renal dysfunction, treatment approaches beyond aggressive radical surgical procedures have come to the fore. We sought to give a contemporary overview of the available different treatment strategies for incidental small renal masses in an elderly population with the focus on comparative oncological outcomes of nonsurgical and surgical modalities.

To compare multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) regarding radiation, resolution, image noise, and image quality. CBCT and 256-MDCT were compared based on three scan protocols: Standard-dose (≈24 mGy), reduced-dose (≈9 mGy), and low-dose (≈4 mGy). MDCT images were acquired in standard- and high-resolution mode (HR-MDCT) and reconstructed using filtered back projection (FBP) and iterative reconstruction (IR). Spatial resolution in linepairs (lp) and objective image noise (OIN) were assessed using dedicated phantoms. Image quality was assessed in scans of 25 cadaver heads using a Likert scale. OIN was markedly higher in FBP-MDCT when compared to CBCT. IR lowered the OIN to comparable values in standard-mode MDCT only. CBCT provided a resolution of 13 lp/cm at standard-dose and 11 lp/cm at reduced-dose vs. 11 lp/cm and 10 lp/cm in HR-MDCT. Resolution of 10 lp/cm was observed for both devices using low-dose settings. Quality scores of MDCT and CBCT did not differ at standard-dose (CBCT, 3.4; MDCT, 3.3-3.5; p > 0.05). Using reduced- and low-dose protocols, CBCT was superior (reduced-dose, 3.2 vs. 2.8; low dose, 3.0 vs. 2.3; p

Background Iterative scatter correction (ISC) is a new technique applicable to plain radiography; comparable to iterative reconstruction for computed tomography, it promises dose reduction and image quality improvement. ISC for bedside chest X-rays has been applied and evaluated for some time and has recently been commercially offered for plain skeletal radiography. Purpose To analyze the potential of ISC for plain skeletal radiography with regard to image quality improvement, dose reduction, and replacement for an antiscatter grid. Material and Methods A total of 385 radiographs with different imaging protocols of the pelvis and cervical spine were acquired from 20 body donors. Radiographs were rated by four radiologists. Ratings were analyzed with visual grading characteristics (VGC) analysis. The area under the VGC curve was used as a measure of difference in image quality. Results Without ISC, the grid-less images were rated significantly worse than their grid-based counterparts (0.389, P = 0.005); adding ISC made image quality equal (0.498; P = 0.963). In grid-less imaging, reduction of dose by 50% led to significant image quality impairment (0.415, P = 0.001); this was fully counterbalanced when ISC was added (0.512; P = 0.588). Conclusion ISC for plain skeletal radiography has the ability to replace the antiscatter grid without image quality impairment, to improve image quality in grid-less imaging, and to reduce patient radiation dose by 50% without substantial loss in image quality., publishedVersion

BACKGROUND Rigid image coregistration is an established technique that allows spatial aligning. However, rigid fusion is prone to deformation of the imaged anatomies. In this work, a novel fully automated elastic image registration method is evaluated. METHODS Cervical CT and MRI data of 10 patients were evaluated. The MRI was acquired with the patient in neutral, flexed, and rotated head position. Vertebrawise rigid fusions were performed to transfer bony landmarks for each vertebra from the CT to the MRI space serving as a reference. RESULTS Elastic fusion of 3D MRI data showed the highest image registration accuracy (target registration error of 3.26 mm with 95% confidence). Further, an elastic fusion of 2D axial MRI data (

To quantitatively assess T2 relaxation times of the anterolateral femoral cartilage following anterior cruciate ligament (ACL)-reconstruction with and without a positive deep lateral femoral notch sign (DLNS) at post-traumatic MRI.In 52 patients post-traumatic MRI as well as 12 months after ACL-rupture (ACLR) and surgical treatment were analysed. In 28 patients a positive DLNS was present at post-traumatic MRI. For quantitative analysis, T2 relaxation time measurements (7 TE: 10-70 ms) were performed at time of re-evaluation. Three polygonal ROIs encompassing the full cartilage layer were placed in the anterolateral femoral cartilage. Clinical assessment included Lysholm-Tegner-Activity-Score, Rasmussen's clinical score and modified Cincinnati-Rating-System-Questionnaire. Description and differences were calculated as means and confidence intervals of means, controlled for the cluster effect of person, if appropriate.In patients with a positive DLNS after ACLR, relaxation times in the notch region were significantly prolonged compared to patients without a positive DLNS (Δ 7.4 ms, CI: 5.6-9.2; p-value0.001) as well as to the adjacent anterior (Δ 5.7 ms, CI: 4.7-6.7; p-value0.001) and central femoral cartilage (Δ 6.6 ms, CI: 5.7-7.6; p-value0.001). Solely insignificant differences were noticed in the performed clinical scores comparing the two groups (p 0.05).Significantly prolonged T2 relaxation times of the anterolateral femoral cartilage were found in patients with a positive DLNS following ACL-reconstruction compared to patients without a DLNS. Based on these results, it has to be assumed that a positive DLNS is associated with higher cartilage degradation.

Purpose To compare tibiofibular reduction quality in different types of operatively treated ankle fractures and the impact on clinical and functional outcome at mid-term follow-up. Patients and methods One hundred patients with an acute ankle fracture who had undergone open reduction and internal fixation were included. Eighty-eight patients who suffered from ligamentous ankle injury with neither fracture nor syndesmotic lesions served as a control group. Tibiofibular alignment was measured on MR images in all 188 patients. In case of tibiofibular malreduction tibiotalar positioning was determined as well. Clinical and functional outcome was assessed using the AOFAS hindfoot score as well as the SF-36. Results No tibiofibular malreduction was found in type Weber B fractures, irrespective of syndesmotic instability followed by syndesmotic screw placement, as compared to the control group. A significant tibiofibular malreduction was detected in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic screw, in comparison to the control group. Tibiotalar displacement could not be detected. Clinical and functional outcome analysis revealed no significant differences between the treatment groups. Conclusion Three-dimensional imaging may improve tibiofibular malreduction visualization in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic transfixation. The clinical impact of improving tibiofibular positioning remains highly questionable since there was no correlation between tibiofibular alignment and the clinical outcome at mid-term follow-up.

Background. The influence of increasing lateral plateau widening on the frequency of meniscal and ligamentous lesions in lateral tibial plateau fractures has been examined in very few studies using plain radiographs. Because the amount of this parameter cannot be measured accurately on plain radiographs, the purpose of this survey was to look for a possible correlation between the extent of lateral plateau widening, as measured on multidetector CT (MDCT) scans, and different soft-tissue injuries determined from magnetic resonance imaging (MRI). Materials and Methods. 55 patients with a lateral tibial plateau fracture were included in this retrospective case series. Patient age averaged 52.6 years (SD = 18.0). The degree of lateral plateau widening was measured on CT images. MRIs were screened for meniscal and ligamentous injuries. Results. We found a significant effect of increasing lateral plateau widening on the incidence of lateral meniscus lesions (P = 0.021), lateral collateral ligament tears (P = 0.047), and the overall quantity of meniscal and ligamentous lesions (P = 0.001). Discussion. MRIs are not widely used as a diagnostic tool in lateral plateau fractures of the tibia. Reasons might be the costs and the fact that it is a time-consuming examination. The results of this study may help to estimate the probability of specific soft-tissue lesions in lateral tibial plateau fractures based on measurements of lateral plateau widening on MDCT scans, and they may guide the decision for additional MRI and/or arthroscopically assisted repair.

Objective To quantify standard values of the discus interpubicus in healthy subjects and to determine reliability and repeatability using T2 relaxation time measurements at 3T. Methods 20 asymptomatic participants (10 male, 10 female; mean age: 27.3 years ±4.1, BMI: 22.2 ±1.8) underwent a 3T Magnetic Resonance Imaging (MRI) of the pelvic region in a supine position. We included sagittal and para-axial T2w sequences centred over the pubic symphysis in order to identify the complete discus interpubicus. For quantitative analysis, a multi-echo Turbo Spin Echo (TSE) sequence (including 12 echo times between 6.4 and 76.8 ms) was acquired and analysed by using an in-house developed quantification plugin tool (qMapIt) extending ImageJ. Two readers in consensus defined three central slices of the pubic symphysis with the greatest length. For each slice, both readers separately placed three regions-of-interest (ROI) covering the whole discus interpubicus. Both readers repeated the ROI placements in identical fashion after a four-week interval on the original MRI images. Statistical analysis included intraclass correlation coefficient (ICC), nonparametric Wilcoxon test, Fisher exact test and mean relaxation time in ms and 95% confidence intervals. Results T2 relaxation time analysis was performed for all 20 participants. In total, a mean relaxation time of all analysed segments for both observers was 48.6 (±6.3 ms), with a mean relaxation time for observer 1 of 48.7 (±6.0 ms) and for observer 2 of 48.5 ms (±6.6ms). The calculated ICC comparing inter- and intrarater reproducibility was excellent in all segments (≥0.75). Conclusion T2 mapping of the discus interpubicus demonstrates good inter- and intrarater repeatability as well as reliability. Mean relaxation times were calculated with 48.6ms in healthy volunteers.

Toxoplasmosis and infections by other opportunistic agents such as Pneumocystis jirovecii constitute life-threatening risks for patients after allogeneic hematopoietic stem cell transplantation. Trimethoprim/sulfamethoxazole (TMP-SMX) has been well established for post-transplant toxoplasmosis and pneumocystis prophylaxis, but treatment may be limited due to toxicity. We explored atovaquone as an alternative and compared it with TMP-SMX regarding toxicity and efficacy during the first 100 days after transplantation in 155 consecutive adult stem cell recipients. Eight patients with a prior history of TMP-SMX intolerance received atovaquone as first-line prophylaxis. TMP-SMX was used for 141 patients as first-line strategy, but 13 patients (9.2%) were later switched to atovaquone due to TMP-SMX toxicity or gastrointestinal symptoms. No active toxoplasmosis or active P. jirovecii infection developed under continued prophylaxis with either TMP-SMX or atovaquone. However, for reasons of TMP-SMX and/or atovaquone toxicity, 7 patients were unable to tolerate any efficacious toxoplasmosis prophylaxis and therefore obtained inhalative pentamidine as P. jirovecii prophylaxis but no toxoplasmosis prophylaxis. Importantly, 2 of these patients developed severe toxoplasmosis. In summary, atovaquone appears as a valid alternative for at least some post-transplant patients who cannot tolerate TMP-SMX. This should be further confirmed by multicenter trials.

Renal tumor biopsy is recommended for histological diagnosis of radiologically indeterminate renal masses, to select patients with small-renal masses for surveillance approaches, before ablative treatments and to confirm metastatic spread of renal cell cancer (RCC), according to the EAU guidelines. We aimed to determine outcomes of patients with suspicious renal masses with initial finding of regular renal tissue in renal tumor biopsies. Retrospective database analysis of 101 patients undergoing CT-guided-, percutaneous renal tumor biopsies in local anesthesia. In 23/101 patients, histopathologic evaluation of the biopsies showed regular renal tissue. Of these, two patients underwent simultaneous radiofrequency ablation (RFA), 2/23 underwent radical nephrectomy, despite negative biopsy because of radiological suspicious aspect. Overall, 12 patients underwent a second set of biopsies due to persistent clinical suspicion. Of these, five were diagnosed with RCC: three clear cell renal cell carcinoma (ccRCC) and two papillary renal cell carcinoma (pRCC). Benign tumours were found in two patients. A lymphoma was found in two patients. In 3/12 patients, also the second set of biopsies showed regular renal tissue. An unsuspicious histology in CT-guided renal tumor biopsy does not preclude patients with suspicious renal masses from being diagnosed with malignancies.

Purpose To assess early time-related image findings in postmortem magnetic resonance imaging (MRI) and to evaluate observer agreement in a porcine model. Material and Methods Three pigs were examined by MRI at 15 different time points in the first 36h after death. Two observers independently recorded the postmortem interval (PMI) to the appearance of fluid collection (pleural space, interlobar and interlobular pulmonary fissures and hepatic interlobar fissures), gas accumulation (intrahepatic and intracardial) and blood clotting (aorta and intrahepatic venous vessels). Cohen's Kappa statistics and intraclass correlation coefficient (ICC) were used to evaluate intra- and interobserver agreement. Results Intrahepatic gas was evident after 12, 17 and 30h. Also, intracardiac gas was present in all animals. However, no chronological appearance has been observed. Blood clotting in the hepatic vein was observed within 3min, aortic clotting with a delay of 2–12h after death. Interlobular pulmonary fluid (median PMI: 2h, range 2–2h), pleural effusion (median PMI: 10.5h, range 9-12h) and hepatic interlobar fissure fluid (median PMI: 11.5h, range 11–12h) displayed a chronological appearance pattern. Qualitative and quantitative detection of most postmortem findings showed excellent intra- and interobserver agreement with Kappa values>0.8 or ICC>0.75. Conclusion Pulmonary and hepatic fissural fluid collection as well as intravasal gas accumulation are early time-related image findings in postmortem MRI. The chronological appearance of these findings can be assessed with excellent observer agreement in a porcine model.

Purpose To investigate the feasibility of sub-milliSievert CT of the cervical spine in fresh human cadavers using a standard-dose (SD) and four different reduced-dose (RD) protocols reconstructed with filtered back projection (FBP) and iterative reconstruction (IR). Methods The cervical spine of 29 cadavers was examined using different RDCT protocols with decreasing reference tube currents (RDCT-1:70 mAs; RDCT-2:50 mAs; RDCT-3:30 mAs; RDCT-4:10 mAs) at 140 kV. A clinical SDCT (160 mAs, 120 kV) served as reference. Raw data were reconstructed using FBP and two increasing levels of IR (IRL4&6). Images of the upper (C1–4) and lower (C5–7) cervical spine were evaluated for image quality, diagnostic acceptability and visibility of anatomical structures according to a 5-point-scale. Results Image quality of the upper cervical spine was diagnostically acceptable for all protocols using FBP and IR except for RDCT-4 with FBP. Image quality of the lower cervical spine was rated as non-diagnostic in RDCT-3 with FBP and RDCT-4 with FBP and IR. RDCT-3 with IR was the most reduced dose CT protocol allowing diagnostically acceptable image quality for both upper and lower cervical spine in all cadavers. RDCT protocols achieved significantly reduced effective radiation doses (SDCT: 1.5 ± 0.7 mSv; RDCT-1:1 ± 0.6 mSv; RDCT-2:0.7 ± 0.4 mSv; RDCT-3:0.4 ± 0.2 mSv; RDCT-4:0.2 ± 0.1 mSv; p Conclusion Diagnostically acceptable sub-milliSievert CT of the cervical spine is feasible with a low reference tube current at 140 kV using iterative reconstruction and could be suitable for isolated cervical trauma in cooperative patients.

Objectives To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. Methods 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland–Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. Results HU measurements demonstrated a high interrater reliability (ICC = 0.984). ROC curve analysis (AUC = 0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. Conclusions Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary.

Purpose: To determine the image quality of an iterative reconstruction (IR) technique in low-dose MDCT (LDCT) of the chest of immunocompromised patients in an intraindividual comparison to filtered back projection (FBP) and to evaluate the dose reduction capability. Materials and Methods: 30 chest LDCT scans were performed in immunocompromised patients (Brilliance iCT; 20 – 40 mAs; mean CTDIvol: 1.7 mGy). The raw data were reconstructed using FBP and the IR technique (iDose4™, Philips, Best, The Netherlands) set to seven iteration levels. 30 routine-dose MDCT (RDCT) reconstructed with FBP served as controls (mean exposure: 116 mAs; mean CDTIvol: 7.6 mGy). Three blinded radiologists scored subjective image quality and lesion conspicuity. Quantitative parameters including CT attenuation and objective image noise (OIN) were determined. Results: In LDCT high iDose4™ levels lead to a significant decrease in OIN (FBP vs. iDose7: subscapular muscle 139.4 vs. 40.6 HU). The high iDose4™ levels provided significant improvements in image quality and artifact and noise reduction compared to LDCT FBP images. The conspicuity of subtle lesions was limited in LDCT FBP images. It significantly improved with high iDose4™ levels (> iDose4). LDCT with iDose4™ level 6 was determined to be of equivalent image quality as RDCT with FBP. Conclusion: iDose4™ substantially improves image quality and lesion conspicuity and reduces noise in low-dose chest CT. Compared to RDCT, high iDose4™ levels provide equivalent image quality in LDCT, hence suggesting a potential dose reduction of almost 80 %.

To compare TTwenty-two ankles of professional football players (24.3 ± 3.8 years) and 20 age- and body mass index-matched healthy individuals (25.6 ± 2.4 years) were investigated. The study protocol consisted of multiplanar TTBased on these initial results, T1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:372-379.

To quantitatively assess the immediate effect of long-distance running on T2 and T2* relaxation times of the articular cartilage of the knee at 3.0 T in young healthy adults.30 healthy male adults (18-31 years) who perform sports at an amateur level underwent an initial MRI at 3.0 T with T2 weighted [16 echo times (TEs): 9.7-154.6 ms] and T2* weighted (24 TEs: 4.6-53.6 ms) relaxation measurements. Thereafter, all participants performed a 45-min run. After the run, all individuals were immediately re-examined. Data sets were post-processed using dedicated software (ImageJ; National Institute of Health, Bethesda, MD). 22 regions of interest were manually drawn in segmented areas of the femoral, tibial and patellar cartilage. For statistical evaluation, Pearson product-moment correlation coefficients and confidence intervals were computed.Mean initial values were 35.7 ms for T2 and 25.1 ms for T2*. After the run, a significant decrease in the mean T2 and T2* relaxation times was observed for all segments in all participants. A mean decrease of relaxation time was observed for T2 with 4.6 ms (±3.6 ms) and for T2* with 3.6 ms (±5.1 ms) after running.A significant decrease could be observed in all cartilage segments for both biomarkers. Both quantitative techniques, T2 and T2*, seem to be valuable parameters in the evaluation of immediate changes in the cartilage ultrastructure after running.This is the first direct comparison of immediate changes in T2 and T2* relaxation times after running in healthy adults.

To compare both image quality and visibility of normal and abnormal findings at submillisievert chest CT (smSv-CT) using filtered back projection (FBP) and the two different iterative reconstruction (IR) techniques iterative model reconstruction (IMR) and iDoseThis institutional review board approved study was based on retrospective interpretation of clinically indicated acquired data. The requirement to obtain informed consent was waived. 81 patients with suspected pneumonia underwent smSv-CT (Brilliance iCT, Philips Healthcare; mean effective dose: 0.86±0.2mSv). Data were reconstructed using FBP and two different IR techniques iDoseCompared to FBP and iDoseIMR results for visibility of normal and abnormal lung findings are heterogeneous, indicating that IMR may not represent a priority technique for clinical routine. iDose

PURPOSE:To assess image quality of CT pulmonary angiography (CTPA) at reduced radiation exposure (RD-CTPA) and contrast medium (CM) volume using two different iterative reconstruction (IR) algorithms (iDose4 and iterative model reconstruction (IMR)) in comparison to filtered back projection (FBP). MATERIALS AND METHODS:52 patients (body weight < 100 kg, mean BMI: 23.9) with suspected pulmonary embolism (PE) underwent RD-CTPA (tube voltage: 80 kV; mean CTDIvol: 1.9 mGy) using 40 ml CM. Data were reconstructed using FBP and two different IR algorithms (iDose4 and IMR). Subjective and objective image quality and conspicuity of PE were assessed in central, segmental, and subsegmental arteries. RESULTS:Noise reduction of 55% was achieved with iDose4 and of 85% with IMR compared to FBP. Contrast-to-noise ratio significantly increased with iDose4 and IMR compared to FBP (p

In 2006, a novel method for extracting functional ventilation-weighted lung images using MRI was published. The method exploited the naturally occurring density changes in the lung during breathing and the resulting images showed a clear clinical potential. A decade later, the method has been adapted and further developed by several research groups and has led to many encouraging pre-clinical studies, both in animals and in humans. In this paper we show the development of the method and summarize the current state-of-the-art, aiming to both inform and motivate students and researchers with an interest in this exciting field.

Pulmonary vein (PV) diameter assessment is important for planning and follow-up of PV ablation in atrial fibrillation. Therefore, the aim of our study was to evaluate inter- and intraobserver reliability of PV diameter measurements by contrast-enhanced magnetic resonance angiography (CE-MRA) and ECG-gated 2D multislice unenhanced steady-state-free precession sequences (multislice SSFP). Sixty PV diameters in 17 consecutive patients were measured in transverse and coronal orientation with CE-MRA and multislice SSFP by two observers. Statistics to evaluate inter- and intraobserver reliability included Bland-Altman analysis and F-test. Intraobserver limits of agreement (LAG) ranged between ±0.50 cm (transverse) and ±0.86 cm (coronal) for CE-MRA versus ±0.40 cm (transverse) and ±0.67 cm (coronal) for multislice SSFP. Interobserver agreement showed LAG ranging between ±0.59 cm (transverse) and ±0.83 cm (coronal) for CE-MRA versus ±0.34 cm (transverse) and ±0.75 cm (coronal) for multislice SSFP. Intra- and interobserver variances did not reveal significant differences between CE-MRA and multislice SSFP in any orientation (all p-values >0.05). Multislice SSFP and CE-MRA enable comparable precision of PV diameter measurements. However, both methods reveal a wide range of intra- and interobserver agreement, which has to be thoroughly considered in clinical use. • Unenhanced magnetic resonance imaging can now provide measurement of pulmonary vein diameters • Steady-state-free precession offers a new method of performing unenhanced MR imaging • Both unenhanced and enhanced MRI measurements show wide intra- and interobserver variation • PV diameter measurements assessed by MRI have to be interpreted with care • Nevertheless, unenhanced MRI might replace some CT examinations for pulmonary vein demonstration

Objective To compare diagnostic accuracy and interobserver reliability of Magnetic Resonance Imaging (MRI) and Multidetector Computed Tomography (MDCT) in the detection of acute pelvic fractures. Materials and methods In 38 consecutive patients (mean age 74.7 years) with a positive finding of anterior pelvis fracture in the conventional X-rays, pelvic MRI and MDCT were performed for further evaluation of pelvic ring fractures. Two radiologists independently read all data sets. Sensitivity and specificity were calculated based on mean scores for each method. Sensitivities of CT and MRI were compared using a paired proportion test (McNemar). Diagnostic validity of both methods was assessed by the interobserver variability using kappa statistics. Combined clinical data and findings from all imaging studies served as the reference standard. Results 122 fractures were identified in the reference standard (37 sacral, 58 pubic, 22 acetabular, 1 ischial, 4 ilial). On average, MRI detected 96.3% whereas CT detected 77% of all fractures. With regard to sensitivity, MRI proved to be significantly better compared to MDCT (observer 1, p = 0.0009; observer 2, p = 0.0003 by observer 2). In particular, MRI performed better in the depiction of sacral fractures, reaching a sensitivity of 98.6% compared to 66.1% at CT. The interobserver variability was determined to be very good ( k = 0.955 for MRI and 0.902 for MDCT). Conclusion MRI reaches a significantly higher sensitivity than CT in the detection of acute pelvic fractures, particularly of the sacrum. Especially in elderly patients with suspicion of a sacral fracture and negative results at MDCT, MRI may be considered as the next step in diagnostic workup.

To compare the incidence of pulmonary embolism (PE) and additional pathologic findings (APF) detected by computed tomography pulmonary angiography (CTPA) according to different age-groups.1353 consecutive CTPA cases for suspected PE were retrospectively reviewed. Patients were divided into seven age groups: ≤29, 30-39, 40-49, 50-59, 60-69, 70-79 and ≥80 years. Differences between the groups were tested using Fisher's exact or chi-square test. A p-value0.0024 indicated statistical significance when Bonferroni correction was used.Incidence rates of PE ranged from 11.4% to 25.4% in different age groups. The three main APF were pleural effusion, pneumonia and pulmonary nodules. No significant difference was found between the incidences of PE in different age groups. Furthermore, APF in different age groups revealed no significant differences (all p-values0.0024).The incidences of PE and APF detected by CTPA reveal no significant differences between various age groups.

Computed tomographic (CT) image resolution and quality were evaluated utilizing varying scan protocols with accelerated image acquisition. A resolution phantom with hole diameters from 0.2 to 1.0 mm was scanned in axial, coronal, and sagittal plane using a 64-slice multidetector CT with varying scan parameters. No relevant differences in image resolution and quality were detected between the fastest scan protocol, with the shortest rotation time and highest pitch, and the slowest protocol. Accelerated CT protocols resulted in diagnostic images with adequate resolution and quality.

Rationale and Objectives The aim of this study was to evaluate a new formula for the rapid assessment of pericardial effusion (PE) volume by computed tomography. Materials and Methods Twenty computed tomographic scans positive for PE were reviewed by two observers. Diameters of PE were measured at four locations. Additionally, PE volume was assessed by volumetry. The correlation between PE diameters and volume was evaluated, and a linear equation was derived for each diameter location. To test validity and reliability of the measurements, intraclass correlation and Bland-Altman analysis were performed. Results Good validity was expressed by strong correlations between diameter measurements at all four locations and PE volume (all R values >0.80 and P values 0.75) and Bland-Altman analysis revealed good interobserver and intraobserver reliability of diameter measurements. The best values were observed for apical diameter measurements. The following linear equation was derived for apical diameter measurements: PE volume = 296 (mL/cm) × apical diameter (cm) − 32 mL. Conclusions PE volume can rapidly be assessed by apical PE diameter measurement using the simplified formula PE volume = 0.3 (L/cm) × apical diameter (cm).

Purpose: Evaluation of image quality and resolution of varying sequential axial scan protocols utilizing two resolution phantoms with a 256-MSCT scanner. Materials and Methods: Sequential axial scans were performed on a z-axis and an axial-plane resolution phantom with varying acquisition and reconstruction parameters. Two independent observers evaluated the image quality and resolution, and analyzed quantitative image quality parameters and radiation doses. Results: The best image quality and resolution were achieved with an activated z-flying focal spot (zFFS) and overlapping reconstruction. With an activated zFFS, image degradation was significantly minimized in marginal or overlapping zones of the beam, but the maximum effective detector width was reduced to 82 % and 75 %, respectively depending on the field of view. With a deactivated zFFS, the effective detector width was not restricted, but the image quality decreased and the artifacts increased as the collimation increased. Conclusion: For sequential axial CT data acquisition with multi-planar image reformation, the zFFS technique is crucial to achieve the best image quality and resolution. Major advantages are minimized image degradation and increased spatial resolution along the z-axis, but the zFFS reduces the maximum effective detector width.

Miliary pattern of pulmonary metastases is a rarity in patients with lung cancer. We report five cases of patients with a never-smoking adenocarcinoma of the lung with such a pattern of metastases. In the tumor cells of all five patients, epidermal growth factor receptor (EGFR) mutation gene sequencing identified a deletion in exon 19 of the EGFR gene, and all five patients had a dramatic response to EGFR tyrosine kinase inhibitors. No echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) translocation was detected. We believe that the miliary never-soking adenocarcinoma of the lung is a distinct clinically relevant subgroup of the never-smoking non-small cell lung cancer. Physician should recognize this subgroup of patients with lung cancer when facing a picture of miliary pulmonary metastases in chest x-ray or computed tomography scan in patients with a history of never smoking and consider upfront therapy with EGFR tyrosine kinase inhibitors.

Aim To compare standard (SD-) and reduced-dose computed tomography (RD-CT) in combination with iterative reconstruction (IR) in emergency patients with suspected lumbar spine fracture. Material and methods Forty emergency patients with suspected lumbar spinal disorder who underwent RD-CT and 40 body mass index-matched patients undergoing SD-CT were enrolled in this retrospective study. Raw data for RD-CT were reconstructed using two increasing IR levels (IRL) 4 and 6, while SD-CT was reconstructed with IRL3. Two radiologists assessed image quality, image noise, and reader confidence in interpreting findings of spinal fractures in a blinded manner. Results Effective radiation dose was reduced by 50% using RD-CT. Overall subjective image quality (SIQ) was high for both protocols and slightly superior in the RD-CT protocol for both IRL compared to SD-CT. The detection rate of spinal disorders was high for both protocols with a high interobserver agreement. Conclusion RD-CT with higher levels of IR results in substantial dose reduction of 50% in lumbar spine CT while maintaining an excellent subjective image quality resulting in a high diagnostic confidence.

PURPOSE: To investigate the value of diffusion-weighted echo-planar imaging (DW-EPI) for quantifying functional changes of the parotid gland in Sjogren’s disease and to evaluate whether ADC mapping allows for early diagnosis based on MR sialography grading. MATERIALS AND METHODS: Using a DW-EPI sequence at 1.5T (b-factors: 0, 500 and 1000 sec/mm 2 ), the parotid glands of 52 healthy volunteers and 13 patients with histologically verified affection of Sjogren’s disease were examined. All scans were performed prior to and following gustatory stimulation with 5 ml of lemon juice. ADC maps were evaluated by placing an inordinate region-of-interest (ROI) enclosing the entire parotid gland. Sjogren’s disease was graded based on MR sialography findings using a 4-point grading-scale. Statistics included student t-test and kappa-analysis. RESULTS: In healthy volunteers mean ADCs of 1.14 × 10 -3 mm 2 /sec before and 1.2 × 10 -3 mm 2 /sec after stimulation were observed. Higher ADCs were determined for early-stage Sjogren’s disease, averaging 1.22 × 10 -3 mm 2 /sec before and 1.29 × 10 -3 mm 2 /sec after stimulation. Advanced disease revealed significantly lower ADCs (0.97 × 10 -3 mm 2 /sec (p = 0.002) before and 1.01 × 10 -3 mm 2 /sec (p < 0.001) after stimulation). CONCLUSION: DW-EPI seems to display functional changes of the parotid gland affected by Sjogren’s disease. Combined with MR sialography, it might be a useful tool for discriminating healthy from affected glands and seems to allow differentiation between the early and advanced disease.

Background The incidence of osteochondral lesions (OCLs) in association with displaced ankle fractures has only been examined in two previous studies. In both studies magnetic resonance imaging (MRI) was performed prior to open reduction and internal fixation (ORIF). Because MRI may overdiagnose or overestimate the extent of OCLs in an acute trauma setting the aim of this study was to determine the incidence of OCLs after ORIF of displaced ankle fractures using MRI at medium-term follow-up, and to analyse if the severity of fracture or the clinical outcome correlates with the incidence of OCLs. Patients and methods Following institutional review board approval a total of 100 patients (mean age, 41.3 years; range, 17.9–64.3 years) with a displaced ankle fracture who had undergone ORIF according to the AO principles were included in this study. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to quantify the clinical outcome and MR images were evaluated for OCLs of the talus and distal tibia after a mean of 34.5 months (range, 17.5–54.1 months). Results OCLs were found in 40.4% of the patients. Logistic regression revealed a significant correlation between the severity of fracture and the incidence of OCLs. Patients with a trimalleolar fracture ( p = 0.04) or an ankle fracture dislocation ( p = 0.003) had a significantly higher risk for developing an OCL compared to those with a type B fracture. Logistic regression also demonstrated a significant correlation between the clinical outcome (AOFAS score) and the incidence of OCLs ( p = 0.01). The risk for developing an OCL increases up to 5.6% when the AOFAS score decreases by one point. Conclusion OCLs were frequently found in association with acute ankle fractures at medium-term follow-up, and the severity of fracture was associated with an increased number of OCLs. Considering the disadvantages of MRI including the high cost and limited availability, the results of this study may help to explain why anatomic surgical realignment of displaced ankle fractures may still be associated with poor clinical outcomes.

Introduction and objectives The traditional 4-tiered Fuhrman grading system (FGS) is widely accepted as histopathological classification for clear cell renal cell carcinoma (ccRCC) and has shown prognostic value. As intra- and inter-observer agreement are sub-optimal, simplified 2- or 3-tiered FGSs have been proposed. We aimed to validate these simplified 2- or 3-tiered FGSs for prediction of cancer-specific mortality (CSM) in a large study population from 2 European tertiary care centers. Methods We identified and followed-up 2415 patients with ccRCC who underwent radical or partial nephrectomy in 2 European tertiary care centers. Univariable and multivariable analyses and prognostic accuracy analyses were performed to evaluate the ability of several simplified FGSs (i.e. grades I + II vs., grades III + IV, grades I + II vs. grade III and grade IV) to predict CSM. Results Independent predictor status in multivariate analyses was proved for the simplified 2-tiered FGS (high-grade vs. low-grade), for the simplified 3-tiered FGS (grades I + II vs. grade III and grade IV) as well as for the traditional 4-tiered FGS. The prognostic accuracy of multivariable models of 77% was identical for all tested models. Prognostic accuracy of the model without FG was 75%. Conclusions A simplified 2- or 3-tiered FGS could predict CSM as accurate as the traditional 4-tiered FGS in a large European study population. Application of new simplified 2- or 3-tiered FGS may reduce inter-observer-variability and facilitate clinical practice without compromising the ability to predict CSM in ccRCC patients after radical or partial nephrectomy.

To assess the effect of hybrid iterative reconstruction (HIR) and filtered back projection (FBP) on abdominopelvic CT with reduced-dose (RD-APCT) in the evaluation of acute left-sided colonic diverticulitis (ALCD).Twenty-five consecutive patients with suspected ALCD who underwent RD-APCT (mean CTDIvol 11.2 ± 4.2 mGy) were enrolled in this study. Raw data were reconstructed using FBP and two increasing HIR levels, L4L6. Two radiologists assessed image quality, image noise and reviewer confidence in interpreting findings of ALCD, including wall thickening, pericolic fat inflammation, pericolic abscess, and contained or free extraluminal air. Objective image noise (OIN) was measured.OIN was reduced up to 54 % with HIR compared to FBP. Subjective image quality of HIR images was superior to FBP; subjective image noise was reduced. The detection rate of extraluminal air was higher with HIR L6. Reviewer confidence in interpreting CT findings of ALCD significantly improved with application of HIR.RD-APCT with HIR offers superior image quality and lower image noise compared to FBP, allowing a high level of reviewer confidence in interpreting CT findings in ALCD. HIR facilitates detection of ALCD findings that may be missed with the FBP algorithm.HIR significantly reduces objective image noise in comparison to conventional FBP. HIR offers superior subjective image quality in comparison to conventional FBP. HIR allows reduced-dose abdominopelvic CT with acceptable image quality. Reviewer confidence in interpreting CT findings in ALCD significantly improves with HIR.

To determine the impact of hybrid iterative reconstruction (HIR) on image quality in 80 kV CT pulmonary angiography (CTPA) in comparison to filtered-back-projection (FBP).Fifty patients (body weight80 kg) with suspected pulmonary embolism (PE) underwent CTPA at 80 kV (mean CTDIvol, 2.3 mGy; effective dose, 1.2 mSv). The raw data were reconstructed using FBP and three increasing HIR levels. Two radiologists assessed image quality and image noise. Conspicuity of PE was assessed in central, segmental, and subsegmental arteries. CT attenuation of pulmonary arteries, objective image noise (OIN) and contrast-to-noise ratios (CNR) were assessed.With each HIR level, a significant decrease in subjective and objective image noise was achieved with a reduction of OIN up to 46% in comparison with FBP. CNR significantly increased with the application of HIR compared to FBP. Image quality was rated significantly higher at HIR reconstructions in comparison with FBP. Diagnosis of PE was feasible with each data set; however, conspicuity of central and segmental PE significantly improved with the use of HIR.Eighty kilovoltage CTPA with HIR provides improved image quality and conspicuity of pulmonary embolism enabling low dose CTPA protocols close to 1 mSv in patients weighing less than 80 kg.

Multidetector CT (MDCT) is the established imaging modality in diagnostics of urolithiasis. The aim of iterative reconstruction (IR) is to allow for a radiation dose reduction while maintaining high image quality. This study evaluates its performance in MDCT for assessment of urolithiasis.Fifty-two patients underwent non-contrast abdominal MDCT. Twenty-six patients were referred to MDCT under suspicion of urolithiasis, and examined using a dose-reduced scan protocol (RDCT). Twenty-six patients, who had undergone standard-dose MDCT, served as reference for radiation dose comparison. RDCT images were reconstructed using an IR system (iDose4™, Philips Healthcare, Cleveland, OH, USA). Objective image noise (OIN) was recorded and five radiologists rated the subjective image quality independently. Radiation parameters were derived from the scan protocols.The CTDIvol could be reduced by 50% to 5.8 mGy (P 0.0001). The same reduction was achieved for DLP and effective dose to 253 ± 27 mGy*cm (P 0.0001) and 3.9 ± 0.4 mSv (P 0.0001). IR led to a reduction of the OIN of up to 61% compared with classic filtered back projection (FBP) (P 0.0001). The OIN declined with increasing IR levels. RDCT with FBP showed the lowest scores of subjective image quality (2.32 ± 0.04). Mean scores improved with increasing IR levels. iDose6 was rated with the best mean score (3.66 ± 0.04).The evaluated IR-tool and protocol may be applied to achieve a considerable radiation dose reduction in MDCT for diagnostics of urolithiasis while maintaining a confident image quality. Best image quality, suitable for evaluation of the entire abdomen concerning differential diagnoses, was achieved with iDose6.

Magnetic resonance imaging (MRI) provides sufficient information with regard to specific soft-tissue injuries in the knee, but it is not generally used to evaluate acute tibial plateau fractures. The aim of the present study was to determine whether the amount of tibial plateau fracture depression on multi-detector computed tomography (MDCT) scans correlates with the incidence of associated soft-tissue injuries on MRI.A total of 54 consecutive patients with a mean age of 51.2 years (SD = 18.3) were included in this retrospective study. All patients were admitted to the emergency department of a university clinic with acute tibial plateau fracture. The amount of articular depression was assessed from MDCT scans. Magnetic resonance images were evaluated for crucial and collateral ligament injury, meniscal tears, and patellar retinaculum lesions.Logistic regression revealed a significant impact of increasing tibial plateau fracture depression on the incidence of meniscus lateralis tears (P = 0.025) and anterior cruciate ligament lesions (P = 0.018). Analysis of covariance demonstrated a significant correlation between the amount of articular depression and absolute number of soft-tissue injuries (P = 0.001).Articular depression is a potential predictor of specific meniscal and ligamentous injuries in acute tibial plateau fracture. Magnetic resonance imaging is generally recommended with respect to associated soft-tissue injuries, especially in cases with distinct tibial plateau fracture depression on multi-detector computed tomography scans.Case series, Level IV.

To prove the feasibility of using Hounsfield attenuation values at MDCT to detect bone bruises related to sacral insufficiency fractures.Twenty-two patients with acute sacrum trauma and no fracture findings at MDCT were included in our prospective study. Two observers independently reviewed CTs regarding visual signs of bone bruises in 132 defined regions of the sacral alae. Interobserver agreement was tested by κ statistics. Subsequently, HU values were obtained in the same regions, and attenuation differences between the two sides were calculated. Validity and reliability were assessed by intraclass correlation coefficient and Bland-Altman analysis. HU differences were subjected to ROC curve analysis to determine sensitivity, specificity, PPV and NPV. MRI served as standard reference.MRI revealed 19 regions with bone bruises and associated sacral insufficiency fractures. HU measurements demonstrated good validity and reliability (r = 0.989). ROC curve analysis exhibited an ideal cutoff value of 35.7 HU density difference between affected and non-affected regions. Visual evaluation revealed moderate agreement (κ = 0.48); diagnostic accuracy was inferior to objective evaluation.Assessment of differences in bone marrow density by HU measurements is an objective and reliable tool for detection of bone bruises associated with occult sacral insufficiency fractures.• Bone bruising is associated with occult sacral insufficiency fractures. • Assessment of differences in bone marrow CT attenuation appears valid and reliable. • Comparative HU measurements of bone marrow allow detection of bone bruises. • Comparative HU measurements have high specificity and negative predictive values. • Comparative HU measurements may make further diagnostic workup with MRI unnecessary.

To investigate the feasibility of diffusion-weighted imaging (DWI) MRI for detecting pulmonary nodules at 1.5 Tesla in comparison with standard multidetector computed tomography (MDCT).Twenty patients with disseminated cancer disease in which MDCT had assured the presence of at least one pulmonary nodule were examined using a respiratory-gated DWI MR-sequence. Grey scale inverted source images and coronal maximum intensity projection (MIP) images were consensually analysed by two experienced radiologists. Size and location of any nodule detected were assessed. Additionally, the readers evaluated each hemithorax for the presence of at least one nodule and applied a four-point conspicuity scale (1-hemithorax definitely affected; 4-hemithorax definitely not affected). MDCT data served as reference.At MDCT, a total of 71 pulmonary noduIes was found (size 3-5mm, n=16; 6-9mm, n=22; ≥10mm, n=33). For the DWI MR-sequence, a sensitivity of 86.4% was calculated for nodules ranging 6-9mm and 97% for nodules ≥10mm. In contrast, only 43.8% of lesions ≤5mm was detected. The separate analysis of each hemithorax for the presence of at least one pulmonary nodule revealed a specificity rate, PPV and NPV of DWI-MR of 92.3%, 96% and 80%, respectively.The presented study is the first to confirm the diagnostic potential of DWI-MR in the detection of solid lung nodules. This technique allows for the detection of nodules ≥6mm with reasonably high sensitivity rates (86%). The observation of false positive findings decreases the accuracy of this approach compared with MDCT.

Purpose To evaluate the technical success and therapeutic effect of superselective embolisation of arteriovenous fistulas in renal allografts. Materials and methods Between 2000 and 2009, 20 patients underwent angiography of 24 AV fistulas (AVF) following percutanous biopsy of the transplanted kidney. Indications for angiography were the diagnosis of AVF by ultrasound and in addition persistent or worsening transplant renal function, or haematuria. Superselective catheterisation of the fistula was performed with a coaxial microcatheter and microcoils were used to occlude the fistula. To assess the short-term effect of embolisation, serum creatinine values were evaluated before embolisation, in the first week after embolisation and after a period of minimum 42 days after the procedure. Results Angiography identified a single AVF in 16 patients and two AVFs in 4 patients. In 19 patients, successful embolisation was achieved without complications. In one patient, a second session was needed to embolise the AVF completely. The mean serum creatinine level of all patients with embolisation dropped significantly (p = 0.0014) from 4.4 mg/dl (range: 1.4–11.6 mg/dl, standard deviation: 3.0) before embolisation to 2.7 mg/dl after embolisation (range: 1.0–7.0 mg, standard deviation: 1.8). No patient showed an increase in serum creatinine. Long-term outcomes of the renal allograft revealed a well-functioning allograft in 19/20 patients. One patient returned to haemodialysis due to acute rejection. Conclusion Superselective transcatheter embolisation is a safe and highly effective treatment for AVFs in renal allografts. Renal function was improved in the majority of patients.