Staging accuracy of MRI of the prostate with special reference to the influence of the time of last ejaculation on the detection of seminal vesicle invasion.

AIM: To evaluate the Prostate Imaging Reporting and Data System, version 2.1 (PIRADS V2.1) criteria for seminal vesicle invasion (SVI) and examine whether the timing of last ejaculation influences the detection of SVI. MATERIALS AND METHODS: The study population consisted of 68 patients (34 with SVI, 34 without SVI, matching groups by age and prostate volume) who underwent PIRADS V2.1-compliant multiparametric magnetic resonance imaging (MRI; 34 at 1.5 T, 34 at 3 T). Before the examination, the time of last ejaculation (38/68 ≤ 5 days, 30/68 > 5 days) was collected via a questionnaire. The five PIRADS V2.1 criteria for SVI with subsequent overall assessment were evaluated retrospectively by two independent examiners (examiner 1 with >10 years of experience, examiner 2 with 6 months of experience) in a single-blinded fashion for all patients using a questionnaire and a six-point scale (0 = no, 1 = very likely not, 2 = probably not, 3 = possible, 4 = probable, 5 = certain). RESULTS: E1 achieved high specificity (100%) and positive predictive value (PPV; 100%) in the overall assessment, independent of the time of last ejaculation (sensitivity = 76.5%, negative predictive value [NPV] = 81%). The area under the curve (AUC) value was 0.882; for E2, it was 0.765. At ≤5 days, the AUC values of E1 and E2 differed significantly (0.867 versus 0.681, p=0.016), as did the diffusion restriction criterion (0.833 versus 0.681, p=0.028). E1 showed high AUC values independent of time. E2 had better values for all criteria at >5 days than at ≤5 days. There were no significant differences between the examiners in all observations at >5 days. CONCLUSION: The PIRADS V2.1 criteria are well suited for an experienced examiner to detect SVI independent of time point. An inexperienced examiner will benefit from patients being abstinent >5 days prior to MRI.

[Whole-body ferromagnetic detector systems in clinical MRI]. / Ganzkörperferrodetektorsysteme in der klinischen MRT.

CLINICAL/METHODICAL ISSUE: In spite of technical and organizational measures, ferromagnetic objects still find their way into the magnetic resonance imaging (MRI) room and can cause severe injuries. STANDARD RADIOLOGICAL METHODS: A detailed patient education and MRI safety training for personnel are necessary to avoid MRI incidents with ferromagnetic objects. METHODICAL INNOVATIONS: Whole body ferromagnetic detection systems should increase patient safety and minimize risks for personnel and MRI equipment in the clinical routine. PERFORMANCE: In a clinical MRI setting, a screener system used for outpatients and inpatients (n = 400) identified unknown ferrous objects in 2 % of the cases. In two of these cases patients were found to be in possession of unknown foreign ferrous objects. Furthermore, a door guard system only used for outpatients (n = 2500) detected unknown ferromagnetic objects in 0.3 % of the cases. ACHIEVEMENTS: The number of ferrous objects that are unknowingly brought into the scanner room can be reduced with a whole body ferromagnetic detection system. For an optimal benefit of the system a ferrous-free environment and perfectly ferrous-free clothing for the medical personnel are necessary. In the clinical routine, the benefit of the system is limited particularly for immobile patients who have to remain in a horizontal position. PRACTICAL RECOMMENDATIONS: A whole body ferromagnetic detection system can complement but not replace patient education and MRI safety training.

[Turnaround time for reporting results of radiological examinations in intensive care unit patients: an internal quality control]. / Radiologische "report turnaround times" und Untersuchungszeitpunkte bei Patienten auf Intensivstationen : Eine institutsinterne Qualitätskontrolle.

AIMS: The radiological examinations performed in intensive care units (ICUs) were analyzed for the purpose of internal quality control. Data included the type of examination performed, the time of day the examination was performed and the differences in radiologist report turnaround times. MATERIAL AND METHODS: A retrospective analysis of the radiology information system (RIS) database of all radiological examinations performed in the ICU of a large German hospital from 2009 through 2011 was carried out. The search retrieved 75,169 examinations performed in ICU patients which were included in the analysis. The records were analyzed for type of radiological examination performed, i.e. conventional X-ray, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), angiography and nuclear medicine examinations, time of day the examination was performed and the interval between examination and time of reporting and release of the final report. RESULTS: Cross-modality it took on average 52 min until a report was written and approximately 7 h before the final report was released. Turnaround times were shortest for ultrasound, conventional X-ray and CT. Over the 3-year observation period there was an overall tendency toward shorter turnaround times whereby improvement in time until reporting was most marked for conventional X-ray, MRI and ultrasound (reduction of 24, 17, and 15 min, respectively). The time until release of the final report improved most markedly for CT, conventional X-ray and angiography (improvement of approximately 6.67, 5.08 and 0.78 h, respectively). CONCLUSIONS: During the 3-year observation period a reduction in turnaround times for reporting results and release of finalized reports could be observed, despite an increase in the total number of cases.

Magnetic resonance imaging of the active second stage of labour: proof of principle.

OBJECTIVE: To prove that magnetic resonance imaging of foetal anatomy during the active second stage of vaginal delivery is feasible. MATERIALS AND METHODS: Initially, five pregnant volunteers around the 30th week of gestation were examined in an open MRI. Based on the findings, one vaginal delivery was acquired under real-time imaging. To monitor the birth status during image acquisition, an MR-compatible wireless cardiotocography (CTG) system was built. Single-shot sequence parameters were optimised to compensate motion artefacts during labour. RESULTS: Safety requirements to monitor the birth process under real-time MR imaging were met. High-resolution MR images were acquired immediately before and after delivery. In one patient, TSE single-shot cinematic sequences of the active second stage of labour were obtained. All sequences were adapted to tolerate movement of the mother and infant, as well as residual noise from the CTG. Furthermore, the MR imaging during labour showed only minor image artefacts. CONCLUSION: CTG-monitored acquisition of MRI series during the active second stage of delivery is feasible. Image quality should allow various further studies to improve models for birth simulation as well as potential investigation of obstructed labour and obstetric complications.

Satisfaction and quality of life: a survey-based assessment in patients with a totally implantable venous port system.

The purpose was to assess the satisfaction and quality of life in patients with a totally implantable central venous port system using a questionnaire-based survey. A self-designed questionnaire to assess patient satisfaction and the impact of the port on daily life was dispatched 180 days after implantation. The questionnaire was combined with the commonly used short form (SF)-12 Health Survey quality of life questionnaire. Of the 98 patients who received a port system, 75 were contacted, and 42 (56%) returned the questionnaire. Most of the responding patients reported high overall satisfaction. The impact of the system on daily life was widely perceived not to be negative. The physical component summary (PCS) and the mental component summary (MCS) scores from the SF-12 were 35.5 and 45.23 respectively (general German population: PCS = 49.6, MCS = 52.3). The multiple stepwise regression showed that the cosmetic result was a predictor of overall satisfaction; the cosmetic result and a painful port together were predictors of the MCS. Overall, it was found that the cosmetic result of the implantation procedure was a predictor of satisfaction and quality of life and should thus not be underestimated.

CT fluoroscopy-guided percutaneous gastrostomy with loop gastropexy and peel-away sheath trocar technique in 31 amyotrophic lateral sclerosis patients.

BACKGROUND: In amyotrophic lateral sclerosis (ALS) patients with respiratory impairment and/or advanced disease, performing even mild sedation - as is usually necessary for percutaneous endoscopic gastrostomy (PEG) placements - is fraught with risk. These patients are often referred to Interventional Radiology for alternative percutaneous gastrostomy tube placement options. PURPOSE: To report our experience with CT fluoroscopy-guided percutaneous gastrostomy with a novel loop gastropexy and peel-away sheath trocar technique in ALS patients as an alternative to endoscopic techniques. MATERIAL AND METHODS: A consecutive series of 31 amyotrophic lateral sclerosis patients in whom endoscopic gastrostomy was considered too dangerous or impossible to perform underwent CT-guided percutaneous gastropexy and gastrostomy and prospective follow-up. All procedures were performed with a 15 FR Freka® Pexact gastrostomy kit, a 16-row CT scanner (Aquilion 16) and single shot CT fluoroscopy mode. RESULTS: The procedure was performed successfully in 30 of 31 patients (20 men, 11 women; median age 60 years, range 38-80 years). In the remaining case the stomach was punctured under CT fluoroscopy and CO2 insufflation was initiated thereafter, leading to successful gastrostomy without prior gastropexy and without further adverse events during follow-up. Two patients reported unproblematic exchange of a balloon tube due to skin irritations with no further adverse events. One patient reported accidental displacement of an exchanged new balloon tube in domestic environment due to balloon leakage: A new balloon tube was easily re-inserted in a hospital the same day. No serious adverse events such as peritonitis, persistent local bleeding, systemic blood loss, or any local infection requiring surgical intervention were observed. Until August 11, 2011 follow-up resulted in 7473 cumulative gastrostomy-days from the date of first placement. CONCLUSION: Initial results suggest that the described technique under CT guidance is feasible and safe and may especially be advantageous in cases where endoscopic gastrostomy and sedation are contraindicated.

[Computer-assisted diagnostic procedure for multislice computed tomography for assessment of the pulmonary arterial circulation. Clinical relevance]. / Computerassistiertes Diagnoseverfahren für die Mehrschichtcomputertomographie zur Beurteilung der pulmonalarteriellen Strombahn. Klinische Bedeutung.

BACKGROUND: A recently developed CAD software which highlights intravascular thrombotic structures from multislice computed tomography (MSCT) data was tested regarding feasibility, interobserver reliability and effect on radiology reports. MATERIAL AND METHODS: The CAD system ImageChecker® CT-Lung was tested in a randomized double-blinded study on 160 MSCT datasets (standardized technical conditions) performed for suspected pulmonary embolism (PE). The CAD data and images were analyzed by three radiologists in an independent and blinded fashion. RESULTS: The data from all 160 cases could be analyzed and 604 CAD prompts were set. Using the CAD analysis significantly more PEs were found in the peripheral pulmonary arterial circulation than described in the initial report. In 38 cases the 3 radiologists in consensus scored the images with the CAD adjunct as PE positive in peripheral vessels, which were initially reported as negative. Despite differences in the evaluation between two radiologists the amended assessment of the imaging data using the CAD softwear was reliable. There was a significant correlation between D-dimer values and the number of embolic structures detected by the CAD analysis. CONCLUSION: The recently developed CAD system is a useful adjunct as second reader to detect subtle emboli in peripheral vessels of MSCT datasets.

MR-guided discography using an open 1 Tesla MRI system.

OBJECTIVE: To evaluate the feasibility of MR-guided discography using an open 1 Tesla MRI system. METHODS: 48 disc segments of 41 patients scheduled for intradiscal thermal treatment, total disc replacement or spondylodesis were examined. A 1.0-T open MRI was used for instrument guidance and imaging. After primary disc puncture under guidance of interactive PDw TSE imaging, 1-2 ml of gadolinium contrast saline mixture was injected into the disc. The occurrence of memory pain during injection was recorded. Axial and sagittal T1w TSE images with and without fat saturation were obtained. All MRI discograms were analysed by two readers, who were blinded to the clinical findings. RESULTS: Overall, the placement of the puncture needle in the targeted disc was accurate under real-time MR guidance. Injections were technically successful in all cases. No major complications occurred. The mean procedure time was 17 min (range 13-34 min). Image quality of contrast-enhanced MR discograms was excellent when using an optimized gadolinium contrast saline mixture of 1:600. Memory pain was detected in 16 out of 48 affected segments. CONCLUSION: MR-guided discography is accurate and safe. Multiplanar dynamic imaging facilitates the puncture of discs and provides high-quality MR discograms.

Relationship between fetal head station established using an open magnetic resonance imaging scanner and the angle of progression determined by transperineal ultrasound.

OBJECTIVE: We investigated the correlation between the angle of progression measured by transperineal ultrasound and fetal head station measured by open magnetic resonance imaging (MRI), the gold standard, in pregnant women at full term. METHODS: Thirty-one pregnant women at full term with a fetus in the occipitoanterior position were enrolled. First, the distance between the leading part of the skull and the interspinal plane was obtained using an open MRI system with the patient in a supine position. Immediately after MRI, the angle of progression was obtained by transperineal ultrasound without changing the woman's posture. RESULTS: There was a significant correlation between the angle of progression determined by transperineal sonography and the distance between the presenting fetal part and the level of the maternal ischial spines (y = - 0.51x + 60.8, r(2) = 0.38, P < 0.001). None of the fetal heads was engaged at the time of MRI and ultrasound examinations. CONCLUSIONS: The present study demonstrated a predictable relationship between the angle of progression obtained by transperineal ultrasound and the traditional scale used to quantify fetal head descent. Based on our results, station 0 would correspond to a 120° angle of progression. However, this correlation is based on statistical assumptions only and has to be proven in future studies.

RAVE-T2/T1 - Feasibility of a new hybrid MR-sequence for free-breathing abdominal MRI in children and adolescents.

BACKGROUND: The new radial volumetric encoding RAVE-T2/T1 hybrid sequence is a modern three-dimensional sequence with multiparametric approach, which includes T2- and T1-weighted contrasts obtained in identical slice position during one measurement. However, the RAVE-T2/T1 hybrid sequence is not yet being used in clinical routine. PURPOSE: The aim of this study was to evaluate the RAVE-T2/T1 hybrid sequence in a pediatric population with a clinical indication for an abdominal MRI examination to demonstrate that the hybrid imaging may be less challenging to perform on children. MATERIALS AND METHODS: Our retrospective observational study included pediatric patients of all age groups and required for an abdominal MRI examination. Non-contrast standard axial T1 DIXON and non-contrast RAVE-T2/T1 hybrid sequence were obtained at 3 T. MRI studies were analyzed independently by two pediatric radiologists using a 5-point Likert-type scale in five different categories. T1- and T2-weighted sequences were each compared with the RAVE-T2/T1-sequence using a Wilcoxon signed-rank test. RESULTS: The analysis included 15 children (mean age, 11 years and 4 months, 7 girls and 8 boys). The Cohens Kappa of interrater agreement measured 0.62. The T2 weighted part of the RAVE-T2/T1 sequence was significantly better than the standard T2 HASTE sequence in four of five image quality categories: overall image quality (2.2 ± 0.7 vs 1.8 ± 0,7, p = 0.03), respiratory motion artefacts (3.8 ± 0.4 vs 2.0 ± 0.7, p <= 0.01), portal vein clarity (3.3 ± 0.8 vs 2.2 ± 0.7, p <= 0.01), hepatic margin sharpness (2.4 ± 1,0 vs 1.8 ± 0.7, p <= 0.01). The T1 weighted part of the RAVE-T2/T1 sequence was significantly better than the standard T1 DIXON weighted sequence in three of five image quality categories: respiratory motion artefacts (4.0 ± 0.2 vs 3.6 ± 0.8, p = 0.01), portal vein clarity (2.7 ± 0.9 vs 2.1 ± 0.7, p <= 0.01), hepatic margin sharpness (3.2 ± 0.7 vs 2.6 ± 0.9, p <= 0.01). CONCLUSIONS: The RAVE-T2/T1 hybrid sequence is feasible and equal compared to standard T1- and T2-weighted sequences in the assessment of abdominal organs in a pediatric population. Due to non-inferiority to the current standard sequences for abdominal imaging, the RAVE-T2/T1 hybrid sequence is a good alternative for children who cannot be examined in breath-hold technique.

Prostatic Artery Embolization: Influence of Cone-Beam Computed Tomography on Radiation Exposure, Procedure Time, and Contrast Media Use.

PURPOSE: To evaluate the effect of cone-beam computed tomography (CBCT) on radiation exposure, procedure time, and contrast media (CM) use in prostatic artery embolization (PAE). MATERIALS AND METHODS: Seventy-eight patients were enrolled in this retrospective, single-center study. All patients received PAE without (group A; n = 39) or with (group B; n = 39) CBCT. Total dose-area product (DAPtotal; Gycm2), total entrance skin dose (ESDtotal; mGy), and total effective dose (EDtotal; mSv) were primary outcomes. Number of digital subtraction angiography (DSA) series, CM use, fluoroscopy time, and procedure time were secondary outcomes. PAE in group A was performed by a single radiologist with 15 years experience, PAE in group B was conducted by four radiologists with 4 to 6 years experience. RESULTS: For groups A vs. B, respectively, median (IQR): DAPtotal 236.94 (186.7) vs. 281.20 (214.47) Gycm2(p = 0.345); EDtotal 25.82 (20.35) vs. 39.84 (23.75) mSv (p = < 0.001); ESDtotal 2833 (2278) vs. 2563 (3040) mGy(p = 0.818); number of DSA series 25 (15) vs. 23 (10)(p = 0.164); CM use 65 (30) vs. 114 (40) mL(p = < 0.001); fluoroscopy time 23 (20) vs. 28 (25) min(p = 0.265), and procedure time 70 (40) vs.120 (40) min(p = < 0.001). Bilateral PAE was achieved in 33/39 (84.6%) group A and 32/39 (82.05%) group B(p = 0.761), all other patients received unilateral PAE. There were no significant differences between clinical parameters and origins of the prostatic arteries (PA) (p = 0.206-1.00). CONCLUSION: Operators with extensive expertise on PAE may not benefit from addition of CBCT to DSA runs, whereas for operators with less expertise, CBCT when used alongside with DSA runs increased the overall radiation exposure.

Image quality and safety of automated carbon dioxide digital subtraction angiography in femoropopliteal lesions: Results from a randomized single-center study.

PURPOSE: To evaluate the image quality and the safety of automated carbon dioxide (CO2) digital subtraction angiography (DSA). MATERIALS AND METHODS: Fifty patients receiving DSA for femoropopliteal peripheral arterial disease (PAD) were enrolled in this single-center prospective study. All patients received iodinated contrast media (ICM) and CO2 as a contrast agent in the same target lesion. As a primary endpoint, four raters independently evaluated the angiography images based on overall image quality, visibility of collaterals, and assessment of stenoses/occlusions. Inter-rater agreement was assessed using the intraclass correlation coefficient (ICC) and differences between the raters were evaluated using Friedmann's test. Secondary endpoints were procedure safety and patient pain assessment. RESULTS: Inter-rater agreement between CO2-DSA and ICM-DSA images was fair to excellent for overall image quality (ICC: 0.399-0.748), fair to excellent for the visibility of collaterals (ICC: 0.513-0.691), and poor to excellent for the assessment of stenoses/occlusions (ICC: -0.065-0.762). There were no significant differences between the raters. Two patients had a hematoma, one reported pain related to puncture, one became nauseous, and one vomited. No other adverse events were observed. Reported pain scores were significantly higher for CO2-DSA vs. ICM-DSA (1.25 vs. 0625; p < 0.028). CONCLUSION: CO2-DSA using automated injection system in combination with proprietary post-processing software is safe and comparable diagnostic test compared to ICM-DSA.

Image-guided spinal injection procedures in open high-field MRI with vertical field orientation: feasibility and technical features.

OBJECTIVE: We prospectively evaluated the feasibility and technical features of MR-guided lumbosacral injection procedures in open high-field MRI at 1.0 T. METHODS: In a CuSO(4).5H(2)O phantom and five human cadaveric spines, fluoroscopy sequences (proton-density-weighted turbo spin-echo (PDw TSE), T1w TSE, T2w TSE; balanced steady-state free precession (bSSFP), T1w gradient echo (GE), T2w GE) were evaluated using two MRI-compatible 20-G Chiba-type needles. Artefacts were analysed by varying needle orientation to B(0), frequency-encoding direction and slice orientation. Image quality was described using the contrast-to-noise ratio (CNR). Subsequently, a total of 183 MR-guided nerve root (107), facet (53) and sacroiliac joint (23) injections were performed in 53 patients. RESULTS: In vitro, PDw TSE sequence yielded the best needle-tissue contrasts (CNR = 45, 18, 15, 9, and 8 for needle vs. fat, muscle, root, bone and sclerosis, respectively) and optimal artefact sizes (width and tip shift less than 5 mm). In vivo, PDw TSE sequence was sufficient in all cases. The acquisition time of 2 s facilitated near-real-time MRI guidance. Drug delivery was technically successful in 100% (107/107), 87% (46/53) and 87% (20/23) of nerve root, facet and sacroiliac joint injections, respectively. No major complications occurred. The mean procedure time was 29 min (range 19-67 min). CONCLUSION: MR-guided spinal injections in open high-field MRI are feasible and accurate using fast TSE sequence designs.

Magnetic Tracking and Electrocardiography-Guided Tip Confirmation System Versus Fluoroscopy for Placement of Peripherally Inserted Central Catheters: A Randomized, Noninferiority Comparison.

PURPOSE: To determine whether the use of a magnetic tracking and electrocardiography-guided catheter tip confirmation system (TCS) is safe and noninferior to fluoroscopy concerning positioning accuracy of a peripheral inserted central catheter (PICC). METHODS: In this prospective, randomized, single-center study, adult patients scheduled for PICC insertion were assigned 1:1 either to TCS or fluoroscopy. The primary objective was a noninferiority comparison of correct PICC tip position confirmed by X-ray obtained immediately after catheter insertion. Time needed for PICC insertion and insertion-related complications up to 14 days after the procedure were secondary outcomes to be assessed for superiority. RESULTS: A total of 210 patients (62.3 ± 14.4 years, 63.8% male) were included at a single German center between June 2016 and October 2017. Correct PICC tip position was achieved in 84 of 103 TCS (82.4%) and 103 of 104 fluoroscopy patients (99.0%). One-sided 95% lower confidence limit on the difference between proportions was -23.1%. Thus, noninferiority of TCS was not established (p > 0.99). Insertion of PICC took longer with TCS compared to fluoroscopy (8.4 ± 3.7 min vs. 5.0 ± 2.7 min, p < 0.001). Incidence of complications within a mean follow-up of 5.0 ± 2.3 days did not differ significantly between groups. CONCLUSION: Noninferiority of TCS to fluoroscopy in the incidence of correct PICC tip position was not reached. Ancillary benefit of TCS over fluoroscopy including less radiation exposure and lower resource requirements may nonetheless justify the use of TCS. The study is registered with Clinical.Trials.gov (Identifier: NCT02929368).

MR-Guided Percutaneous Intradiscal Thermotherapy (MRgPIT): Evaluation of a New Technique for the Treatment of Degenerative Disc Disease in Cadaveric Lumbar Spine.

PURPOSE: Evaluation of MR feasibility and real-time control of an innovative thermoablative applicator for intradiscal thermotherapy and histological analysis of laser annuloplasty in human ex vivo intervertebral discs. MATERIALS AND METHODS: We evaluated a new MR-compatible applicator system for MR-guided percutaneous intradiscal thermotherapy (MRgPIT) in an open 1.0-T MRI-system. Needle artefacts and contrast-to-noise ratios (CNR) of six interactive sequences (PD-, T1-, T2w TSE, T1-, T2w GRE, bSSFP) with varying echo-times (TE) and needle orientations to the main magnetic field (B0) were analysed. Additionally, five laser protocols (Nd: YAG Laser, 2-6 W) were assessed in 50 ex vivo human intervertebral discs with subsequent histological evaluation. RESULTS: In vitro, we found optimal needle artefacts of 1.5-5 mm for the PDw TSE sequence in all angles of the applicator system to B0. A TE of 20 ms yielded the best CNR. Ex vivo, ablating with 5 W induced histological denaturation of collagen at the dorsal annulus, correlating with a rise in temperature to at least 60 °C. The MRgPIT procedure was feasible with an average intervention time of 17.1 ± 5.7 min. CONCLUSION: Real-time MR-guided positioning of the MRgPIT-applicator in cadaveric intervertebral disc is feasible and precise using fast TSE sequence designs. Laser-induced denaturation of collagen in the dorsal annulus fibrosus proved to be accurate.

Forensic postmortem computed tomography in suspected unnatural adult deaths.

PURPOSE: Our study sought to evaluate validity of forensic postmortem CT in establishing cause of death (COD) in suspected unnatural adult death based on the reference standard of autopsy. METHODS: In our prospective, single-center study, 64 of 94 consecutive corpses (70.7 % male, mean age: 47.4 years) who underwent CT and autopsy between November 2013 and April 2019 were included in the analysis. Primary objective was agreement between CT and autopsy on primary COD using kappa statistics. Secondary objectives were competing COD and specific pathological findings. RESULTS: Agreement on primary COD between forensic CT and autopsy without or in consideration of toxicological and histological findings was strong (85.9 % [55 of 64 corpses]; κ = 0.83 [95 %CI: 0.74 to 0.93] and 95.3 % [61 of 64 corpses]; κ = 0.94 [95 %CI: 0.84-1.04], respectively, McNemar p = 0.03). Sensitivity and specificity of CT in identification of acute heart failure, intracranial bleeding, burns and heat shocks, gunshot wounds, polytrauma, cranio-cerebral trauma, and strangulation or hanging was 100 %, each. Acute respiratory failure was detected with a sensitivity and specificity of 100 % and 96.8 %, cuts and stab wounds with 95.2 % and 100 %, and intoxication, pneumonia, or gastrointestinal bleeding with 60.0 % and 100 %, respectively. Agreement on competing COD was moderate (51.6 %, [33 of 64 corpses]; κ = 0.47 [95 %CI: 0.40 to 0.53], p < 0.001). CONCLUSIONS: Forensic postmortem CT, complemented by external, toxicological, and histological examination was sufficiently valid to assess primary COD in the majority of suspected unnatural deaths with few restrictions.

Imaging sequences for intraoperative MR-guided laparoscopic liver resection in 1.0-T high field open MRI.

The aim of this study was to identify suitable interactive (dynamic) magnetic resonance (MR) sequences for real-time MR-guided liver dissection in a 1.0-T high field open MRI system. Four dynamic sequences encompassing balanced steady state free precession (bSSFP), T1W gradient echo (GRE), T2W GRE and T2W fast spin echo (FSE) were analysed regarding the image quality, artefact susceptibility and the performance of SNR and CNR. The T2W FSE sequence (1.5 s/image) was considered superior because of an intraoperative SNR of 6.9 (+/-0.7) and CNR (vessel to parenchyma) of 5.6 (+/-1.7) in the interventional setting. As a proof of concept, MR-guided laparoscopic liver resection was performed in two healthy domestic pigs by using the T2W FSE sequence. The additional MR images offered simultaneous multiplanar real-time visualisation of the liver vessels during the intervention and thereby increased the anatomical orientation of the surgeon.

T1 and T2* mapping of the human quadriceps and patellar tendons using ultra-short echo-time (UTE) imaging and bivariate relaxation parameter-based volumetric visualization.

Quantification of magnetic resonance (MR)-based relaxation parameters of tendons and ligaments is challenging due to their very short transverse relaxation times, requiring application of ultra-short echo-time (UTE) imaging sequences. We quantify both T1 and T2* in the quadriceps and patellar tendons of healthy volunteers at a field strength of 3 T and visualize the results based on 3D segmentation by using bivariate histogram analysis. We applied a 3D ultra-short echo-time imaging sequence with either variable repetition times (VTR) or variable flip angles (VFA) for T1 quantification in combination with multi-echo acquisition for extracting T2*. The values of both relaxation parameters were subsequently binned for bivariate histogram analysis and corresponding cluster identification, which were subsequently visualized. Based on manually-drawn regions of interest in the tendons on the relaxation parameter maps, T1 and T2* boundaries were selected in the bivariate histogram to segment the quadriceps and patellar tendons and visualize the relaxation times by 3D volumetric rendering. Segmentation of bone marrow, fat, muscle and tendons was successfully performed based on the bivariate histogram analysis. Based on the segmentation results mean T2* relaxation times, over the entire tendon volumes averaged over all subjects, were 1.8 ms ±â€¯0.1 ms and 1.4 ms ±â€¯0.2 ms for the patellar and quadriceps tendons, respectively. The mean T1 value of the patellar tendon, averaged over all subjects, was 527 ms ±â€¯42 ms and 476 ms ±â€¯40 ms for the VFA and VTR acquisitions, respectively. The quadriceps tendon had higher mean T1 values of 662 ms ±â€¯97 ms (VFA method) and 637 ms ±â€¯40 ms (VTR method) compared to the patellar tendon. 3D volumetric visualization of the relaxation times revealed that T1 values are not constant over the volume of both tendons, but vary locally. This work provided additional data to build upon the scarce literature available on relaxation times in the quadriceps and patellar tendons. We were able to segment both tendons and to visualize the relaxation parameter distributions over the entire tendon volumes.

[Small animal MRI: clinical MRI as an interface to basic biomedical research]. / Experimentelle Kleintier-MRT: Klinische MRT-Systeme als Schnittstelle zur biomedizinischen Grundlagenforschung.

The demand for highly resolved small animal MRI for the purpose of biomedical research has increased constantly. Dedicated small animal MRI scanners working at ultra high field strengths from 4.7 to 7.0 T and even above are MRI at its best. However, using high resolution RF coils in clinical scanners up to 3.0 T, small animal MRI can achieve highly resolved images showing excellent tissue contrast. In fact, in abundant experimental studies, clinical MRI is used for small animal imaging. Mostly clinical RF coils in the single-loop design are applied. In addition, custom-built RF coils and even gradient inserts are used in a clinical scanner. For the reduction of moving artifacts, special MRI-compatible animal ECG und respiration devices are available. In conclusion, clinical devices offer broad availability, are less expense in combination with good imaging performance and provide a translational nature of imaging results.

[Transjugular intrahepatic portosystemic shunt in patients with portal vein thrombosis]. / Transjugulärer intrahepatischer portosystemischer Shunt bei Patienten mit Pfortaderthrombose.

PURPOSE: To evaluate the feasibility of TIPS for portal vein thrombosis (PVT) with/without portal vein occlusion/cavernomatous transformation and with/without underlying cirrhosis. MATERIALS AND METHODS: 13 patients with PVT and refractory ascites (n=7) and variceal bleeding (n = 6) received TIPS placement. The function of the TIPS was controlled with Doppler US at 1 day, 1 week, 4 weeks and 4 months after TIPS placement and subsequently every 3 months. The rates of technical success, revision and mortality after TIPS were evaluated. RESULTS: The TIPS was successfully placed in 85% (11/13) of the cases. TIPS placement was successful in 87.5% (7/8) of patients with occlusion of the right portal vein and in 100% (5/5) of patients with non-occlusive right portal vein (p > 0.05), in 80% (8/10) of cirrhotic (x/10) and in 100% (3/3) of non-cirrhotic patients (p > 0,05), as well as in one patient with a fresh PVT and in 1 of 2 patients with cavernous transformation. 30 and 14.3% of patients needed a TIPS revision in the first and second year, respectively. No patient with occlusion of the right portal vein required a revision. 54.5% (6/11) of patients died within 6 months. Under exclusion of 4 patients with advanced malignant diseases, the mortality rate was 28.6%. CONCLUSION: TIPS should be considered for selected patients with symptomatic occlusive PVT with/without cavernous transformation and with/without underlying cirrhosis. The frequency of TIPS revision is not greater, and the mortality rate 6 months after PVT recanalization seems to be comparable with that of patients without PVT.