Skovbjergadkins0843

PURPOSE To assess the dose-normalized iodine contrast-to-noise-ratio (CNRD) improvement and contrast media reduction potential obtained with photon-counting (PC) CT compared to conventional energy-integrating (EI) CT as a function of patient size and tube voltage. METHOD Images of a semi-anthropomorphic phantom of different sizes (small, medium, large) equipped with vials containing different iodine concentrations were acquired at the SOMATOM CounT prototype CT system using tube voltages of 80 kV-140 kV. CNRD is evaluated in reconstructions obtained using the EI detector, the PC detector using a single bin, and in reconstructions obtained by statistically optimally weighting acquisitions with two bins. Iodine CNRD improvements, potential dose reduction and the potential contrast media volume reduction are reported. RESULTS In general, iodine CNRD improvement increases with increasing tube voltage for all patient sizes. In particular, if only one energy bin is used, the CNRD improvement is up to 30 % (small 10 %, medium 18 %, large 30 %) and up to 37 % if an optimal weighting of two bins is performed (small 13 %, medium 25 %, large 37 %) which is equivalent to the potential contrast media volume reduction. The improved iodine CNRD of PC compared to EI may allow for a potential radiation dose reduction of up to 46 %. CONCLUSIONS All patients' iodine contrast at given x-ray dose, and particularly medium and large sized patients acquired at higher tube voltages, may benefit from photon-counting CT. The iodine contrast improvement can be used to reduce patient dose or to reduce the amount of contrast agent that is administered. V.PURPOSE To evaluate the clinical performance of a newly developed three-dimensional (3D) intra- and extracranial arterial vessel wall joint imaging technique at 3T using T1-weighted 3D variable-flip-angle turbo spin-echo sequence with improved cerebrospinal fluid suppression in patients with cerebrovascular disease. MATERIALS AND METHODS 122 consecutive patients (mean age 45.96 ± 12.16 years) with clinically confirmed cerebrovascular symptoms were imaged using a 3D intra- and extracranial arterial vessel wall joint imaging sequence with and without contrast enhancement on a 3 T MR system. The number of plaques and culprit plaques were evaluated. The image quality score, percent stenosis, remodeling ratio, and plaque burden were measured and compared between intracranial and carotid arterial plaques, and between non-culprit and culprit plaques. RESULTS Except for 23 patients, there were 322 plaques (111 culprit plaques) detected in 96 patients with large artery atherosclerosis. Of the plaques, 278 (96 culprit plaques) and 44 (15 culprit plaques) plaques were identified in intracranial and extracranial arteries, respectively. Image quality did not differ significantly between pre- and post-contrast vessel wall magnetic resonance images. There were also no significant differences in the percent stenosis, remodeling ratio, and plaque burden between intracranial and carotid arteries, and between non-culprit and culprit plaques. The enhancement rate of culprit plaques was significantly higher than that of non-culprit plaques. CONCLUSIONS The described joint imaging is a promising vessel wall magnetic resonance imaging method for comprehensive diagnosis of cerebrovascular symptoms and investigation of etiology. The imaging technique is a potentially valuable means to optimize treatment. V.PURPOSE This cohort aimed to determine the efficacy and safety of abdominal ulrasonography and cine-MRI by a double-blind study in the diagnosis of intraabdominal organs and abdominal wall adhesions in patients with previous abdominal operations. METHODS Between 2017 and 2019, 108 consecutive patients were prospectively included in the study. Visceral slide and induced visceral slide were measured during AU and cine-MRI. An abdominal map consisting of nine segments was created to document the location and extent of the adhesion. The degree and severity of the adhesions detected by the radiologist preoperatively and detected in surgery as the gold standard was recorded in the same abdominal zones. AU, c-MRI and intraoperative findings were correlated. RESULTS The mean age was 53.0 ± 10.3 years, body mass index was 30.4 ± 3.4, male (52.8 %) and female (47.2 %). According to the total nine zones, the sensitivity of AU was 91.4 %, specificity was 100 %, positive predictive value was 90.7 %, negative predictive value was 100 % and diagnostic accuracy was 87.9 %. Considering the total zones, the sensitivity of c-MRI was 90.8 %, specificity was 100 %, PPV was 90.7 %, NPV was 100 % and diagnostic accuracy was 91.7 %. A comparison of AU and c-MRI showed no significant difference in the detection of adhesions to the abdominal wall; however, c-MRI was superior in detecting intraabdominal organs adhesion. CONCLUSION We have demonstrated that AU and c-MRI are accurate for diagnosing adhesions in patients undergoing repeated surgery and may have a place on planning elective laparoscopic or open surgery to avoid bowel injury. PURPOSE to assess if tumor segmentation analysis performed at different post-contrast time points (TPs) on dynamic images could influence the extraction of dynamic contrast enhanced (DCE)-MRI parameters in locally advanced breast cancer (LABC), and potentially represent a source of variability. METHOD forty patients with forty-two LABC lesions were prospectively enrolled and underwent breast DCE-MRI examination at 3 T. On post-processed dynamic images, enhancing tumor lesions were manually segmented at four different TPs at the first post-contrast dynamic image in which the lesion was appreciable (TP 1) and at 1, 5 and 10 min after contrast-agent administration (TPs 2, 3 and 4, respectively) and corresponding DCE-MRI parameters were extracted. Friedman's test followed by Bonferroni-adjusted Wilcoxon signed rank test for post-hoc analysis was used to compare DCE-MRI parameters. Intra- and inter-observer reliability of DCE-MRI parameters measurements was assessed using the Intraclass Correlation Coefficient (ICC) analysis. RESULTS Ktrans, Kep and iAUC were significantly higher when extracted from ROIs placed at TP1 and progressively decreased from TP 2-4. JPH203 ic50 The intra-observer reliability ranged from good to excellent (ICC's 0.894 to 0.990). The inter-observer reliability varied from moderate to excellent (0.770 to 0.942). The inter-observer reliability was significantly higher for Ktrans and Kep extracted at TPs1 and 2 as compared to TPs 3 and 4. CONCLUSIONS A significant variability of DCE-MRI quantitative parameters occurs when tumor segmentation is performed at different TPs. We suggest to performing tumor delineation at an established TP, preferably the earliest, in order to extract reliable and comparable DCE-MRI data.