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Purpose Obesity has become a major health problem and is associated with endocrine disorders and a disturbed hypothalamic-pituitary axis. The purpose of this study was to correlate pituitary gland volume determined by routine magnetic resonance imaging with patient characteristics, in particular body mass index and obesity. Material and methods A total of 144 ‘healthy’ patients with normal findings in cerebral magnetic resonance imaging were retrospectively included. Pituitary gland volume was measured in postcontrast three-dimensional T1-weighted sequences. A polygonal three-dimensional region of interest covering the whole pituitary gland was assessed manually. Physical characteristics (gender, age, body height and body mass index) were correlated with pituitary gland volume. Multiple subgroup and regression analyses were performed. Results Pituitary gland volumes were significantly larger in females than in males ( p0.05). Regression analysis showed that increased pituitary gland volume is associated with higher body mass index independent from gender, age and body height. Conclusion Pituitary gland volume is increased in obese individuals and a high body mass index can be seen as an independent predictor of increased pituitary gland volume. Therefore, gland enlargement might be an imaging indicator of dysfunction in the hypothalamus-pituitary axis. Besides gender and age, body mass index should be considered by radiologists when diagnosing abnormal changes in pituitary gland volume.

To assess the reproducibility of the renal resistive index (RRI) in a routine clinical setting. 22 patients with a kidney allograft and 19 physicians participated in our prospective study. Within 2 hours each patient was examined by 5 different physicians using 2 out of 3 different, randomly allocated ultrasound machines. Each investigator determined the hilar and parenchymal RRI of the allograft. The reproducibility and reproducibility limit of the RRI were assessed as well as Cronbach's alpha and the intraclass correlation coefficient (ICC). The deviation of the RRI from the mean RRI over the 5 measurements was used as an indicator of reproducibility. The impact of the ultrasound machine, examiner's level of experience, and kidney function impairment (GFR 45 ml/min) was assessed with the Kruskal-Wallis test. The bivariate linear correlation of the minimal transplant distance from the body surface with the variance of the parenchymal RRI was analyzed. A reproducibility of 0.045 with a reproducibility limit of 0.124 was found for the parenchymal RRI. The ICC between RRIs was good with 0.852 for the parenchymal RRI and 0.868 for the hilar RRI. The type of ultrasound machine used was found to have a significant impact on the deviation of the parenchymal RRI (Kruskal-Wallis-Test, p = 0.003). Variance in serial parenchymal RRI measurements correlated significantly with the depth of the kidney transplant (p = 0.001). While the RRI is generally sufficiently reproducible, the type of ultrasound machine used and the depth of the kidney transplant within the recipient's body have a significant impact on reproducibility. · The renal resistive index (RRI) in allografts is reproducible.. · The type of ultrasound machine has an impact on the measured RRI.. · RRI reproducibility decreases with the depth of the renal allograft in the recipient..· Theilig DC, Münzfeld H, Auer TA et al. The Renal Resistive Index in Allografts: Is Sonographic Assessment Sufficiently Reproducible in a Routine Clinical Setting?. Fortschr Röntgenstr 2020; 192: 561 - 566.ZIEL: Die Überprüfung der Reproduzierbarkeit des renalen Widerstandsindex (RRI) in der Alltagssituation. An der prospektiven Studie nahmen 22 Patienten mit Nierentransplantat und 19 Untersucher teil. Jeder Patient wurde innerhalb von 2 Stunden von 5 verschiedenen Untersuchern mit insgesamt 2 von 3 verschiedenen Ultraschallgeräten untersucht, wobei jeweils hilärer und parenchymatöser RRI bestimmt wurden. Die Reproduzierbarkeit, deren Grenzwerte, der Cronbachs Alpha und die Intraklassenkorrelation (ICC) wurden ermittelt. Das Ausmaß der Abweichung vom Mittelwert der 5 Messungen wurde als Indikator für die Reproduzierbarkeit herangezogen. Mittels Kruskal-Wallis-Test wurde der Einfluss von Ultraschallgerät, Erfahrungsgrad des Untersuchers und Nierenfunktionseinschränkung (GFR 45 ml/min) ermittelt. Die bivariate lineare Korrelation der Abhängigkeit der Varianz der RRI-Messungen von der Tiefe des Nierentransplantats im Patienten wurde eruiert. Die statistische Auswertung ergab eine Reproduzierbarkeit des parenchymalen RRI von 0,045 bei einer Grenze von 0,124. Der ICC zwischen den parenchymalen und hilären RRIs lag bei 0,852 bzw. 0,868. Der Kruskal-Wallis-Test zeigte einen signifikanten Unterschied in der Reproduzierbarkeit bei unterschiedlichen Ultraschallgeräten (p = 0,003). Die Korrelation der Varianz der RRIs mit der Tiefe des Nierentransplantats im Patienten war ebenfalls signifikant (p = 0,001). Die Reproduzierbarkeit des RRI ist prinzipiell auch in der Alltagssituation gegeben, nimmt aber mit der Tiefe des Transplantats im Patienten und durch die Benutzung unterschiedlicher Ultraschallgeräte ab. · Der renale Widerstandsindex (RRI) in Nierentransplantaten ist ausreichend reproduzierbar.. · Der gemessene RRI wird vom verwendeten Ultraschallgerät beeinflusst.. · Die Reproduzierbarkeit des RRI nimmt mit der Transplantattiefe im Empfänger ab..

Objectives In recent years, increasing evidence pointed out the clinical importance of adipose tissue (AT) distribution in various patient populations. In particular, visceral adipose tissue (VAT), when compared to subcutaneous adipose tissue (SAT), was found to play a pivotal role in the development of inflammatory reaction. The aim of the present study was to examine whether body fat distribution has an impact on the development of systemic inflammatory response syndrome (SIRS) in patients with polytrauma. Methods In our retrospective study, we filtered our institution records of the German Trauma Registry (Trauma Register DGU) from November 2018 to April 2021 and included 132 adult polytrauma patients with injury severity score (ISS) &gt, 16. Subsequently, we measured the visceral and subcutaneous adipose tissue area based on whole-body CT scan and calculated the ratio of VAT to SAT (VSr). Thereafter, the patient population was evenly divided into three groups, respectively VSr value less than 0.4 for the first group (low ratio), 0.4–0.84 for the second group (intermediate ratio), and greater than 0.84 for the third group (high ratio). Considering the other influencing factors, the groups were further divided into subgroups in the respective analysis according to gender (male/female), BMI (&lt, 25 or ³25), and ISS (&lt, 26 or ³26). Result VSr was an independent factor from body mass index (BMI) (r2 = 0.003, p = 0.553). VSr in male patients was significantly higher (p &lt, 0.001). Patients with low VSr had higher ISS scores (p = 0.028). Polytrauma patients with higher VSr tended to have lower SIRS scores and significant differences of SIRS score were found on multiple days during the whole hospitalization period. In the low VAT/SAT group, male patients, and patients with BMI greater than 25, both exhibited higher SIRS scores during hospital stay (day 16: p = 0.01, day 22: p = 0.048 and p = 0.011, respectively). During hospitalization, patients with higher ISS score (³26) in the low VSr group was found to have higher SIRS score (day 16, p = 0.007). Over the hospital stay, serum markers of CRP, CK, and leukocyte in patients with low VSr were higher than those in patients in the intermediate and high VSr groups, with significant difference discovered on multiple days (day 16: 0.014, day 22: p = 0.048). Conclusion Lower VSr is associated with increased inflammatory response and worse clinical outcome in patients with polytrauma. Furthermore, VSr is an independent factor providing additional information to BMI.

Background Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to clarify testicular findings. CEUS is easy and fast to perform, overcomes the limitations of B-mode US. Objective To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the assessment of unclear testicular pathologies. Methods CEUS examinations of 45 patients with unclear testicular pathologies between 2012 and 2018 were analyzed retrospectively. Examinations were performed using B-mode, colour Doppler (CCDS) and CEUS after injection of contrast agent (SonoVue®, Bracco) and interpreted by an experienced radiologist (EFSUMB level 3). Reference standard was defined as histopathological report and clinical course. Results Overall 19 patients presented with a neoplastic lesion, whereas 14 were malignant. Matched to the histopathological report and clinical follow up, CEUS represented a sensitivity of 93% (95% -CI, 69-99), a specificity of 94% (95% -CI, 80-98), a positive predictive value (PPV) of 87% (95% -CI, 62-96) and a negative predictive value (NPV) of 97% (95% -CI, 83-99). Conclusion CEUS is an accurate additional tool to differentiate between testicular alterations when B-mode US and CCDS are uncertain. CEUS may provide additional information and detect early enhancement in small tumor lesions when CCDS comes to its limit.

Purpose To characterise peritumoral zones in glioblastoma and anaplastic astrocytoma evaluating T2 values using T2 mapping sequences. Materials and methods In this study, 41 patients with histopathologically confirmed World Health Organization high grade gliomas and preoperative magnetic resonance imaging examinations were retrospectively identified and enrolled. High grade gliomas were differentiated: (a) by grade, glioblastoma versus anaplastic astrocytoma; and (b) by isocitrate dehydrogenase mutational state, mutated versus wildtype. T2 map relaxation times were assessed from the tumour centre to peritumoral zones by means of a region of interest and calculated pixelwise by using a fit model. Results Significant differences between T2 values evaluated from the tumour centre to the peritumoral zone were found between glioblastoma and anaplastic astrocytoma, showing a higher decrease in signal intensity (T2 value) from tumour centre to periphery for glioblastoma ( P = 0.0049 – fit-model: glioblastoma –25.02± 19.89 (–54–10); anaplastic astrocytoma –5.57±22.94 (–51–47)). Similar results were found when the cohort was subdivided by their isocitrate dehydrogenase profile, showing an increased drawdown from tumour centre to periphery for wildtype in comparison to mutated isocitrate dehydrogenase ( P = 0.0430 – fit model: isocitrate dehydrogenase wildtype –10.35±16.20 (–51) – 0; isocitrate dehydrogenase mutated 12.14±21.24 (–15–47)). A strong statistical proof for both subgroup analyses ( P = 0.9987 – glioblastoma R2 0.93±0.08; anaplastic astrocytoma R2 0.94±0.15) was found. Conclusion Peritumoral T2 mapping relaxation time tissue behaviour of glioblastoma differs from anaplastic astrocytoma. Significant differences in T2 values, using T2 mapping relaxation time, were found between glioblastoma and anaplastic astrocytoma, capturing the tumour centre to the peritumoral zone. A similar curve progression from tumour centre to peritumoral zone was found for isocitrate dehydrogenase wildtype high grade gliomas in comparison to isocitrate dehydrogenase mutated high grade gliomas. This finding is in accordance with the biologically more aggressive behaviour of isocitrate dehydrogenase wildtype in comparison to isocitrate dehydrogenase mutated high grade gliomas. These results emphasize the potential of mapping techniques to reflect the tissue composition of high grade gliomas.

Background The coronavirus disease 2019 (COVID-19) pandemic led to far-reaching restrictions of social and professional life, affecting societies all over the world. To contain the virus, medical schools had to restructure their curriculum by switching to online learning. However, only few medical schools had implemented such novel learning concepts. We aimed to evaluate students’ attitudes to online learning to provide a broad scientific basis to guide future development of medical education. Methods Overall, 3286 medical students from 12 different countries participated in this cross-sectional, web-based study investigating various aspects of online learning in medical education. On a 7-point Likert scale, participants rated the online learning situation during the pandemic at their medical schools, technical and social aspects, and the current and future role of online learning in medical education. Results The majority of medical schools managed the rapid switch to online learning (78%) and most students were satisfied with the quantity (67%) and quality (62%) of the courses. Online learning provided greater flexibility (84%) and led to unchanged or even higher attendance of courses (70%). Possible downsides included motivational problems (42%), insufficient possibilities for interaction with fellow students (67%) and thus the risk of social isolation (64%). The vast majority felt comfortable using the software solutions (80%). Most were convinced that medical education lags behind current capabilities regarding online learning (78%) and estimated the proportion of online learning before the pandemic at only 14%. In order to improve the current curriculum, they wish for a more balanced ratio with at least 40% of online teaching compared to on-site teaching. Conclusion This study demonstrates the positive attitude of medical students towards online learning. Furthermore, it reveals a considerable discrepancy between what students demand and what the curriculum offers. Thus, the COVID-19 pandemic might be the long-awaited catalyst for a new “online era” in medical education.

To identify predictors of biopsy success and complications in CT-guided pancreas transplant (PTX) core biopsy. We retrospectively identified all CT fluoroscopy-guided PTX biopsies performed at our institution (2000-2017) and included 187 biopsies in 99 patients. Potential predictors related to patient characteristics (age, gender, body mass index (BMI), PTX age, PTX volume) and procedure characteristics (biopsy depth, needle size, access path, number of samples, interventionalist's experience) were correlated with biopsy success (sufficient tissue for histologic diagnosis) and the occurrence of complications. Biopsy success (72.2%) was more likely to be obtained in men [+25.3% (10.9, 39.7)] and when the intervention was performed by an experienced interventionalist [+27.2% (8.1, 46.2)]. Complications (5.9%) occurred more frequently in patients with higher PTX age [OR: 1.014 (1.002, 1.026)] and when many (3-4) tissue samples were obtained [+8.7% (-2.3, 19.7)]. Multivariable regression analysis confirmed male gender [OR: 3.741 (1.736, 8.059)] and high experience [OR: 2.923 (1.255, 6.808)] (biopsy success) as well as older PTX age [OR: 1.019 (1.002, 1.035)] and obtaining many samples [OR: 4.880 (1.240, 19.203)] (complications) as independent predictors. Our results suggest that CT-guided PTX biopsy should be performed by an experienced interventionalist to achieve higher success rates, and not more than two tissue samples should be obtained to reduce complications. Caution is in order in patients with older transplants because of higher complication rates.

Key Points• The management of gliomas has changed dramatically since the presentation of the revised WHO Classification of Tumors of the Central Nervous System in 2016 emphasizing the tumor heterogeneity based on their molecular profile.• The need for a more noninvasive characterization of glioblastomas (GBM) by establishing reliable imaging biomarkers to predict patient outcome and improve therapy monitoring is bigger than ever.• Multiparametric MRI, including promising newer techniques like electrical property tomography and mapping, may have the potential to provide enough information for intelligent imaging postprocessing algorithms to face the challenge by decoding GBM heterogeneity noninvasively.

Purpose Fluid collections due to anastomotic leakage are a common complication after hepatopancreaticobiliary (HPB) surgery and are usually treated with drainage. We conducted a study to evaluate imaging work-up with a postoperative single-sequence (PoSSe) MRI for the detection of collections and indication of drainage. Material and methods Forty-six patients who developed signs of leakage (fever, pain, laboratory findings) after HPB surgery were prospectively enrolled. Each patient was examined by abdominal sonography and our PoSSe MRI protocol (axial T2-weighted HASTE only). PoSSe MRI examination time (from entering to leaving the MR scanner room) was measured. Sonography and MRI were evaluated regarding the detection and localization of fluid collections. Each examination was classified for diagnostic sufficiency and an imaging-based recommendation if CT-guided or endoscopic drainage is reasonable or not was proposed. Imaging work-up was evaluated in terms of feasibility and the possibility of drainage indication. Results Sonography, as first-line modality, detected 21 focal fluid collections and allowed to decide about the need for drainage in 41% of patients. The average time in the scanning room for PoSSe MRI was 9:23 min [7:50–13:32 min]. PoSSe MRI detected 46 focal collections and allowed therapeutic decisions in all patients. Drainage was suggested based on PoSSe MRI in 25 patients (54%) and subsequently indicated and performed in 21 patients (100% sensitivity and 84% specificity). No patient needed further imaging to optimize the treatment. Conclusions The PoSSe MRI approach is feasible in the early and intermediate postoperative setting after HPB surgery and shows a higher detection rate than sonography. Imaging work-up regarding drainage of collections was successful in all patients and our proposed PoSSe MRI algorithm provides an alternative to the standard work-up.

Background Glioblastoma multiforme (GBM) is the commonest malignant primary brain tumor and still has one of the worst prognoses among cancers in general. There is a need for non-invasive methods to predict individual prognosis in patients with GBM. Purpose To evaluate quantitative volumetric tissue assessment of enhancing tumor volume on cranial magnetic resonance imaging (MRI) as an imaging biomarker for predicting overall survival (OS) in patients with GBM. Material and Methods MRI scans of 49 patients with histopathologically confirmed GBM were analyzed retrospectively. Baseline contrast-enhanced (CE) MRI sequences were transferred to a segmentation-based three-dimensional quantification tool, and the enhancing tumor component was analyzed. Based on a cut-off percentage of the enhancing tumor volume (PoETV) of >84.78%, samples were dichotomized, and the OS and intracranial progression-free survival (PFS) were evaluated. Univariable and multivariable analyses, including variables such as sex, Karnofsky Performance Status score, O6-methylguanine-DNA-methyltransferase status, age, and resection status, were performed using the Cox regression model. Results The median OS and PFS were 16.9 and 7 months in the entire cohort, respectively. Patients with a CE tumor volume of >84.78% showed a significantly shortened OS (12.9 months) compared to those with a CE tumor volume of ≤84.78% (17.7 months) (hazard ratio [HR] 2.72; 95% confidence interval [CI] 1.22–6.03; P = 0.01). Multivariable analysis confirmed that PoETV had a significant prognostic role (HR 2.47; 95% CI 1.08–5.65; P = 0.03). Conclusion We observed a correlation between PoETV and OS. This imaging biomarker may help predict the OS of patients with GBM.

BACKGROUND Resection margin status has traditionally been associated with tumor recurrence and oncological outcome following liver resection for colorectal liver metastases. Previous studies, however, did not address the impact of resection margin on the site of tumor recurrence and did not differentiate between true local recurrence at the resection margin and recurrence elsewhere in the liver. This study aimed to determine whether positive resection margins determine local recurrence and whether recurrence at the surgical margin influences long-term survival. METHODS Clinicopathological data and oncological outcomes of patients who underwent curative resection for colorectal liver metastases between 2012 and 2017 at 2 major hepatobiliary centers (Bern, Switzerland, and Berlin, Germany) were assessed. Cross-sectional imaging following hepatectomy was reviewed by radiologists in both centers to distinguish between recurrence at the resection margin, defined as hepatic local recurrence, and intrahepatic recurrence elsewhere. The association between surgical margin status and location of tumor recurrence was evaluated, and the impact on overall survival was determined. RESULTS During the study period, 345 consecutive patients underwent hepatectomy for colorectal liver metastases. Histologic surgical margins were positive for tumor cells (R1) in 63 patients (18%). After a median follow-up time of 34 months, tumor recurrence was identified in 154 patients (45%). Hepatic local recurrence was not detected more frequently after R1 than after R0 resection (P = .555). Hepatic local recurrence was not associated with worse overall survival (P = .436), while R1 status significantly impaired overall survival (P = .025). Additionally, overall survival was equivalent between patients with hepatic local recurrence and patients with any intrahepatic and/or extrahepatic recurrence. In patients with intrahepatic recurrence only, oncological outcomes improved if local hepatic therapy was possible (resection or ablation) in comparison to patients treated only with chemotherapy or best supportive care (3-year overall survival: 85% vs 39%; P < .0001). CONCLUSION The incidence of hepatic local recurrence after hepatectomy for colorectal liver metastases is independent of R1 resection margin status. Additionally, hepatic local recurrence at the resection margin is not associated with worse overall survival compared with any other intra- or extrahepatic recurrence. Therefore, R1 status at hepatectomy seems to be a surrogate factor for advanced disease without influencing location of recurrence and thereby oncological outcome. This finding may support decision-making when extending the indication for surgery in borderline resectable colorectal liver metastases.

Background To date there is no therapy consensus in patients with multifocal hepatocellular carcinoma (mHCC). Purpose To compare outcome of trans-arterial chemoembolization (TACE) with degradable starch microspheres (DSM-TACE) versus selective internal radiation therapy (SIRT) in mHCC. Material and Methods In this single-center study, 36 patients without portal vein invasion, treated between May 2014 and May 2018, were enrolled retrospectively. Eighteen consecutive patients received DSM-TACE and were matched by age, gender, BCLC stage, Child-Pugh status, and tumor volume and 18 patients underwent SIRT. Overall survival (OS), progression-free survival (PFS), and local tumor control (LTC) were evaluated. Toxicity profiles for both therapies were also evaluated and compared. Results In the entire collective, median OS was 9.5, PFS 5.0, and LTC 5.5 months. Subgroup analysis revealed an OS of 9.5 months in both groups ( P = 0.621). PFS was 6 months for the SIRT and 4 months for the DSM-TACE cohort ( P = 0.065). Although not significantly, LTC was lower (4 months) in the SIRT compared to the DSM-TACE cohort (7 months; P = 0.391). When DSM-TACE was performed ≥3 times (n = 11), OS increased, however without statistical difference compared to SIRT, to 11 months, PFS to 7 months, and LTC to 7 months. When DSM-TACE was performed 0.05). Conclusion DSM-TACE might be an alternative to SIRT in multifocal HCC patients as OS, PFS, and LTC did not differ significantly and toxicity profiles seem to be comparable.

Aim To investigate multivariable analyses for noninvasive association of the isocitrate dehydrogenase (IDH) mutational status in grade II and III gliomas including evaluation of T2 mapping-sequences. Methods Magnetic resonance imaging (MRI) examinations with histopathologically proven World Health Organization grade II and III gliomas were retrospectively enrolled. Multivariate receiver operating characteristics (ROC) analyses to associate IDH mutational status were performed containing quantitative T2 mapping analyses and qualitative characteristics (sex, age, localization, heterogeneity, oedema, necrosis and diameter). Relaxation times were calculated pixelwise by means of standardized ROI analyses. Interobserver variability also was tested. Results Out of 32 patients (mean age: 50.7 years; range: 32–83), nine had grade II gliomas and 24 grade III, while 59.5% showed a positive IDH mutated state (IDHm) and 40.5% were wildtype (IDHw). Multivariable ROC analyses were calculated for relaxation time and range, localization and age with a cumulative 0.955 area under the curve (AUC) ( p Conclusions This is the first study evaluating quantitative T2 mapping sequences for association of the IDH mutational status in grade II and III gliomas demonstrating an association between relaxation time and mutational status. Analyses of T2 mapping relaxation times may even be suitable for predicting the correct IDH mutational state. Prognostic accuracy increases significantly in predicting the correct mutational state when combing T2 relaxation time characteristics and the qualitative MRI features age and localization.

Purpose To differentiate subtypes of hepatocellular adenoma (HCA) based on enhancement characteristics in gadoxetic acid (Gd-EOB) magnetic resonance imaging (MRI). Materials and methods Forty-eight patients with 79 histopathologically proven HCAs who underwent Gd-EOB-enhanced MRI were enrolled (standard of reference: surgical resection). Two blinded radiologists performed quantitative measurements (lesion-to-liver enhancement) and evaluated qualitative imaging features. Inter-reader variability was tested. Advanced texture analysis was used to evaluate lesion heterogeneity three-dimensionally. Results Overall, there were 19 (24%) hepatocyte nuclear factor (HNF)-1a-mutated (HHCAs), 37 (47%) inflammatory (IHCAs), 5 (6.5%) b-catenin-activated (bHCA), and 18 (22.5%) unclassified (UHCAs) adenomas. In the hepatobiliary phase (HBP), 49.5% (39/79) of all adenomas were rated as hypointense and 50.5% (40/79) as significantly enhancing (defined as > 25% intralesional GD-EOB uptake). 82.5% (33/40) of significantly enhancing adenomas were IHCAs, while only 4% (1/40) were in the HHCA subgroup (p p = 0.038). Conclusion Gd-EOB MRI is of added value for subtype differentiation of HCAs and reliably identifies the typical heterogeneous HBP uptake of IHCAs. Diagnostic accuracy can be improved significantly by the combined analysis of established morphologic MR appearances and intralesional Gd-EOB uptake. Key Points •Gd-EOB-enhanced MRI is of added value for subtype differentiation of HCA. •IHCA and HHCA can be identified reliably based on their typical Gd-EOB uptake patterns, and accuracy increases significantly when additionally taking established MR appearances into account. •The small numbers of bHCAs and UHCAs remain the source of diagnostic uncertainty.

Background Process optimization in computed tomography (CT) and telemedicine. Purpose To compare image quality and objective diagnostic accuracy of medical-grade and consumer-grade digital displays/computer terminals for detection of intracranial aneurysms. Material and Methods Four radiologists with different levels of experience retrospectively read a total of 60 patients including 30 cases of proven therapy-naïve intracranial aneurysm detectable on a medical-grade grayscale calibrated display. They had 5 min per case reading the first 20 datasets using only axial slices, the next 20 patients using axial slices and multiplanar reconstructions (MPRs), and the last 20 patients using axial slices, MPRs, and maximum intensity projections (MIPs). Three months after the first reading session on a medical-grade display, they read all datasets again under the same standardized conditions but on a consumer-grade display. Diagnostic performance, subjective diagnostic confidence, and reading speed were analyzed and compared. Readers rated image quality on a five-point Likert scale. Results Diagnostic accuracy did not differ significantly with areas under the curve of 0.717–0.809 for all readers on both display devices. Sensitivity and specificity did not increase significantly when adding MPRs and/or MIPs. Reading speed was similar with both devices. There were no significant differences in subjective image quality scores, and overall inter-reader variability of all subjective parameters correlated positively between the two devices ( P Conclusion Diagnostic accuracy and readers’ diagnostic confidence in detecting and ruling out intracranial aneurysm were similar on commercial-grade and medical-grade displays. Additional reconstructions did not increase sensitivity/specificity or reduce the time needed for diagnosis.

To investigate the image quality, diagnostic accuracy, and dose reduction potential of a split-bolus protocol(SBP) compared with a multiphasic protocol(MPP) in the detection of recurrent or progressive pancreatic ductal adenocarcinoma(PDAC) or cholangiocarcinoma(CC) using contrast- enhanced computed tomography(CECT).This prospective study included 56 patients who underwent CECT, 28 with our institutional standard MPP(100 ml contrast bolus) and 28 with a novel SBP(110 ml). Radiation exposure was determined in terms of total dose- length product(DLP) and computed tomography dose index(CTDI). Image quality was measured objectively by analysis of attenuation in Hounsfield units(HU) in regions of interest(ROIs) and subjectively by two blinded readers using a Likert scale. Diagnostic accuracy and interreader variability were tested.The total DLP of the SBP group(498.1 ± 43.7 mGy*cm) was significantly lower than in the MPP group(1,092.5 ± 106.9 mGy*cm; p 0.001). The SBP showed higher contrast enhancement of all critical anatomical structures including portal vein, liver, and pancreas compared with the MPP, except for the aorta(SBP: 326.9 ± 15.7 HU vs. MPP: 246.7 ± 12.2 HU; p 0.001). Subjective analysis revealed poorer image quality ratings for important landmarks with the MPP (resection surface: p = 0.624, portal vein: p = 0.395, liver p = 0.361). The two blinded readers correlated significantly. Sensitivity, specificity, positive and negative predictive values (PPV/NPV), and overall interreader variabilities correlated significantly. Furthermore, significantly fewer slices per exam were required for the SBP(1,823 vs. 3,235; p 0.001).The SBP provides the same image quality and diagnostic accuracy as an MPP while significantly lowering radiation exposure in CT follow-up of PDAC or CC.