Performance of an ultra-fast deep-learning accelerated MRI screening protocol for prostate cancer compared to a standard multiparametric protocol.

OBJECTIVES: To establish and evaluate an ultra-fast MRI screening protocol for prostate cancer (PCa) in comparison to the standard multiparametric (mp) protocol, reducing scan time and maintaining adequate diagnostic performance. MATERIALS AND METHODS: This prospective single-center study included consecutive biopsy-naïve patients with suspected PCa between December 2022 and March 2023. A PI-RADSv2.1 conform mpMRI protocol was acquired in a 3 T scanner (scan time: 25 min 45 sec). In addition, two deep-learning (DL) accelerated sequences (T2- and diffusion-weighted) were acquired, serving as a screening protocol (scan time: 3 min 28 sec). Two readers evaluated image quality and the probability of PCa regarding PI-RADSv2.1 scores in two sessions. The diagnostic performance of the screening protocol with mpMRI serving as the reference standard was derived. Inter- and intra-reader agreements were evaluated using weighted kappa statistics. RESULTS: We included 77 patients with 97 lesions (mean age: 66 years; SD: 7.7). Diagnostic performance of the screening protocol was excellent with a sensitivity and specificity of 100%/100% and 89%/98% (cut-off ≥ PI-RADS 4) for reader 1 (R1) and reader 2 (R2), respectively. Mean image quality was 3.96 (R1) and 4.35 (R2) for the standard protocol vs. 4.74 and 4.57 for the screening protocol (p < 0.05). Inter-reader agreement was moderate (κ: 0.55) for the screening protocol and substantial (κ: 0.61) for the multiparametric protocol. CONCLUSION: The ultra-fast screening protocol showed similar diagnostic performance and better imaging quality compared to the mpMRI in under 15% of scan time, improving efficacy and enabling the implementation of screening protocols in clinical routine. CLINICAL RELEVANCE STATEMENT: The ultra-fast protocol enables examinations without contrast administration, drastically reducing scan time to 3.5 min with similar diagnostic performance and better imaging quality. This facilitates patient-friendly, efficient examinations and addresses the conflict of increasing demand for examinations at currently exhausted capacities. KEY POINTS: Time-consuming MRI protocols are in conflict with an expected increase in examinations required for prostate cancer screening. An ultra-fast MRI protocol shows similar performance and better image quality compared to the standard protocol. Deep-learning acceleration facilitates efficient and patient-friendly examinations, thus improving prostate cancer screening capacity.

Feasibility of a radiation dose conserving CT protocol for myocardial function assessment.

OBJECTIVE: Assessment of myocardial function can be performed at higher noise levels than necessary for coronary arterial evaluation. We evaluated image quality and radiation exposure of a dose-conserving function-only acquisition vs retrospectively electrocardiogram(ECG)-gated coronary CTA with automatic tube current modulation. METHODS: Of 26 patients who underwent clinically indicated coronary CTA for coronary and function evaluation, 13 (Group I) underwent prospectively ECG-triggered coronary CTA, followed by low-dose retrospectively ECG-gated scan for function (128-slice dual-source, 80 kVp; reference tube current, 100 mA; 8-mm-thick multiplanar reformatted reconstructions) performed either immediately (n = 6) or after 5- to 10-min delay for infarct assessment (n = 7). 13 corresponding controls (Group II) underwent retrospectively ECG-gated protocols (automatic tube potential selection with CARE kV/CARE Dose 4D; Siemens Healthcare, Forchheim, Germany) with aggressive dose modulation. Image quality assessment was performed on the six Group I subjects who underwent early post-contrast dedicated function scan and corresponding controls. Radiation exposure was based on dose-length product. RESULTS: Contrast-to-noise ratio (CNR) was preserved throughout the cardiac cycle in Group I and varied according to dose modulation in Group II. Visual image quality indices were similar during end systole but were better in Group II at end diastole. Although the total radiation exposure was equivalent in Group I and Group II (284 vs 280 mGy cm), the median radiation exposure associated with only the dedicated function scan was 138 mGy cm (interquartile range, 116-203 mGy cm). CONCLUSION: A low-dose retrospective ECG-gated protocol permits assessment of myocardial function at a median radiation exposure of 138 mGy cm and offers more consistent multiphase CNR vs traditional ECG-modulation protocols. This is useful for pure functional evaluation or as an adjunct to single-phase scan modes. ADVANCES IN KNOWLEDGE: Radiation exposure can be limited with a tailored myocardial function CT protocol while maintaining preserved images.

[Notes on the planned German health fund model]. / Anmerkungen zum geplanten Gesundheitsfondsmodell.

The aim of this paper is to evaluate the planned German health fund model, a special risk adjustment scheme, in terms of competition policy. Starting from the present model of risk adjustment, we have examined the consequences of introducing the fund model on competition in the health insurance market. On the one hand, the risk adjustment fund will, at best, decrease ineffective competition for "good risks". On the other hand, it will increase the pressure of competition inside the health insurance market by providing new incentives to the unemployed to change their sickness fund. Significant economies, however, can only be realised by increasing the competition for contracts between the health insurance companies and the suppliers of medical services. The new risk adjustment fund then will also offer only a limited potential for competition between individual sickness funds. Besides, it remains to be seen to what extent policy-makers are able to achieve an optimally designed risk adjustment fund and whether the sickness funds themselves do not misinterpret the reform as nationalization in disguise and consequently delegate their management responsibilities back to the policy-makers.

Bronchobiliary fistula after hemihepatectomy: cholangiopancreaticography, computed tomography and magnetic resonance cholangiography findings.

A bronchobiliary fistula (BBF), which is defined by an abnormal communication between the biliary system and the bronchial tree, is an uncommon complication after hemihepatectomy, trauma, hydatid disease, choledocholithiasis and other causes of biliary obstruction. We report the case of a 56-year-old man with colon cancer, who developed a BBF 2 months after right hemihepatectomy for liver metastases. The findings at endoscopic retrograde cholangiopancreaticography (ERCP), computed tomography (CT) and magnetic resonance cholangiography (MRC) included a stricture of the common bile duct and biliary leakage from the liver resection plane with biliary infiltration of the right lower lobe of the lung. The patient was treated successfully by endoscopic insertion of a biliary plastic stent which bridged the stricture and lead to closure of the fistula.

Intraoperative endoscopic papillotomy and stone removal.

Endoscopic papillotomy was attempted during cholecystectomy in 33 patients who suffered from both gallbladder and bile duct stones simultaneously (32 conventional, 1 laparoscopic cholecystectomy). Twenty-six of these patients suffered from acute obstruction of the biliary tree which required urgent operation. In addition, 10 of these patients suffered from acute biliary pancreatitis. Because of the unusual intraoperative conditions, cannulation of the papilla was modified ("orthograde papillotomy"); the instruments used were the same as for conventional endoscopic papillotomy. In 28 out of these 33 patients (85%) intraoperative endoscopic papillotomy (IOEP) and duct stone retrieval proved successful, while in the remaining 5 it was inapplicable. Intraoperative endoscopic papillotomy caused one complication which was discovered during the operation and which immediately and easily was corrected. The time for this operative technique was shorter than for the conventional bile duct operation. Over a follow-up of on average of one year, no residual stones or newly formed concrements were found or other delayed complications induced by papillotomy arose. In this series, IOEP proved to be safe and practical, which in comparison to conventional duct exploration reduced inconvenience to the patient. Compared with laparoscopic bile duct operations, IOEP may be preferable because of its modest requirement of time and apparatus as well as its applicability in cases where the common bile duct is difficult to handle.