European Radiology

The purpose of this study was to evaluate the feasibility of a dry bowel preparation, i.e. without laxative fluids, for virtual CT colonography (VCTC), and its impact on patient acceptance compared with conventional colonoscopy (CC). A randomly chosen patient population scheduled for CC (n=11) was first submitted to VCTC after a dry preparation, consisting of low-residue meals combined with a small amount of a iodinated water-soluble contrast medium during each meal 3 days before VCTC. In different colon segments and between different persons, the degree of tagging in VCTC was evaluated and graded. Patient acceptance and future preference were assessed for both preparations as well as for both investigations. The mixing of the contrast with the intestinal content results in contrast impregnated stool, the tagged feces. The degree of fecal tagging was good in the majority of the patients and the colonic segments, especially in the descending colon and sigmoid. Furthermore, patient acceptance and preference were clearly in favour of VCTC compared with CC merely because of the non-invasiveness of the dry preparation. Dry bowel preparation and VCTC is a promising approach towards a patient-friendly colon cancer-screening setup.

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-08017-2

Previous attempts at meta-analysis and systematic review have not provided clear recommendations for the clinical application of thermal ablation in metastatic colorectal cancer. Many authors believe that the probability of gathering randomised controlled trial (RCT) data is low. Our aim is to provide a consensus document making recommendations on the appropriate application of thermal ablation in patients with colorectal liver metastases. This consensus paper was discussed by an expert panel at The Interventional Oncology Sans Frontières 2013. A literature review was presented. Tumour characteristics, ablation technique and different clinical applications were considered and the level of consensus was documented. Specific recommendations are made with regard to metastasis size, number, and location and ablation technique. Mean 31 % 5-year survival post-ablation in selected patients has resulted in acceptance of this therapy for those with technically inoperable but limited liver disease and those with limited liver reserve or co-morbidities that render them inoperable. In the absence of RCT data, it is our aim that this consensus document will facilitate judicious selection of the patients most likely to benefit from thermal ablation and provide a unified interventional oncological perspective for the use of this technology. • Best results require due consideration of tumour size, number, volume and location. • Ablation technology, imaging guidance and intra-procedural imaging assessment must be optimised. • Accepted applications include inoperable disease due to tumour distribution or inadequate liver reserve. • Other current indications include concurrent co-morbidity, patient choice and the test-of-time approach. • Future applications may include resectable disease, e.g. for small solitary tumours.

To investigate the feasibility of subtractionless first-pass single contrast medium dose (0.1 mmol/kg) peripheral magnetic resonance angiography (MRA) at 1.5 T using two-point Dixon fat suppression and compare it with conventional subtraction MRA in terms of image quality. Twenty-eight patients (13 male, 15 female; mean age ± standard deviation, 66 ± 16 years) with known or suspected peripheral arterial disease underwent subtractionless and subtraction first-pass MRA at 1.5 T using two-point Dixon fat suppression. Results were compared with regard to vessel-to-background contrast. A phantom study was performed to assess the signal-to-noise ratio (SNR) of both MRA techniques. Two experienced observers scored subjective image quality. Agreement regarding subjective image quality was expressed in quadratic weighted κ values. Vessel-to-background contrast improved in all anatomical locations with the subtractionless method versus the subtraction method (all P < 0.001). Subjective image quality was uniformly higher with the subtractionless method (all P < 0.03, except for the aorto-iliac arteries for observer 1, P = 0.052). SNR was 15 % higher with the subtractionless method (31.9 vs 27.6). This study demonstrates the feasibility of subtractionless first-pass single contrast medium dose lower extremity MRA. Moreover, both objective and subjective image quality are better than with subtraction MRA. • MRA is increasingly used for vascular applications. • Dixon imaging offers an alternative to image subtraction for fat suppression. • Subtractionless first-pass peripheral MRA is possible using two-point Dixon fat suppression. • Subtractionless peripheral MRA is possible at 1.5 T a single contrast medium dose. • Subtractionless first-pass peripheral MRA provides good image quality with few non-diagnostic studies.

To determine ancillary features that help distinguish between scirrhous hepatocellular carcinoma (S-HCC) and intrahepatic cholangiocarcinoma (ICC) and investigate added value of ancillary features to enhancement pattern-based diagnosis on gadoxetic acid-enhanced MRI. This retrospective study included 96 patients with S-HCCs and 120 patients with ICCs who underwent gadoxetic acid MRI before surgical resection. Two observers reviewed MRIs of the tumours. After determining ancillary features for differentiating tumour types, we measured the diagnostic performance of adding ancillary features to enhancement pattern-based diagnosis. T2 central darkness, capsule and septum were significant and independent features differentiating S-HCC from ICC (p ≤ .06). Adding ancillary features to enhancement pattern led to increased accuracy (observer 1, 78.9 vs. 93.8 %; observer 2, 80.3 vs. 92.8 %; p < .001), sensitivity (observer 1, 74.5 vs. 96.4 %; observer 2, 77.1 vs. 93.2 %; p < .001 and .001), and specificity (observer 1, 82.5 vs. 91.7 %; observer 2, 82.9 vs. 92.5 %; p = .006 and .005) for diagnosis of S-HCC by differentiation from ICC. Adding ancillary features capsule, septum and T2 central darkness to conventional enhancement patterns on gadoxetic acid-enhanced MRI improved accuracy, sensitivity and specificity for S-HCC diagnosis with differentiation from ICC. • Capsule, septum, and T2 central darkness were ancillary features for S-HCC. • A typical HCC enhancement was seen in 31.3% of S-HCCs. • Ancillary MRI features were useful in differentiation between S-HCC and ICC.

Since improvement in the material, true aneurysms and pseudoaneurysm formations have become relatively rare complications after femoro-popliteal reconstruction with polytetrafluoroethylene (PTFE) grafts. We report a case of late graft rupture and pseudoaneurysm formation within the straight femoral part of a femoro-popliteal bypass with reinforced (PTFE-wrapped) Gore-Tex graft. The rupture occurred 7 years after implantation without history of direct traumatization. Intraoperatively the whole bypass showed macro- and microscopically visible deterioration of the wall with almost complete disruption at the site of the aneurysm. The graft had to be replaced completely. In conclusion, we recommend continuous long-term follow-up of these patients preferably with duplex ultrasonography.

Recently, an MRI quantification sequence has been developed which can be used to acquire T1- and T2-relaxation times as well as proton density (PD) values. Those three quantitative values can be used to describe soft tissue in an objective manner. The purpose of this study was to investigate the applicability of quantitative cardiac MRI for characterization and differentiation of ischaemic myocardial lesions of different age. Fifty post-mortem short axis cardiac 3 T MR examinations have been quantified using a quantification sequence. Myocardial lesions were identified according to histology and appearance in MRI images. Ischaemic lesions were assessed for mean T1-, T2- and proton density values. Quantitative values were plotted in a 3D-coordinate system to investigate the clustering of ischaemic myocardial lesions. A total of 16 myocardial lesions detected in MRI images were histologically characterized as acute lesions (n = 8) with perifocal oedema (n = 8), subacute lesions (n = 6) and chronic lesions (n = 2). In a 3D plot comprising the combined quantitative values of T1, T2 and PD, the clusters of all investigated lesions could be well differentiated from each other. Post-mortem quantitative cardiac MRI is feasible for characterization and discrimination of different age stages of myocardial infarction. • MR quantification is feasible for characterization of different stages of myocardial infarction. • The results provide the base for computer-aided MRI cardiac infarction diagnosis. • Diagnostic criteria may also be applied for living patients.

To compare the diagnostic value of high frame rate contrast-enhanced ultrasound (H-CEUS) in distinguishing gallbladder adenomas from cholesterol polyp lesions with that of CEUS. This study enrolled 94 patients with gallbladder polyp lesions (GPLs) who underwent laparoscopic cholecystectomy. CEUS and H-CEUS were performed before surgery. The perfusion features of GPLs and the final diagnosis as determined by both technologies were compared. There were differences in vascular types between gallbladder adenomas and cholesterol polyp lesions observed on H-CEUS (p < 0.05), while there were no differences in vascular types between gallbladder adenomas and cholesterol polyp lesions observed on CEUS (p > 0.05). In the cholesterol polyp lesion group, there were no differences in vascular types between CEUS and H-CEUS (p > 0.05), while the vascular types were different between CEUS and H-CEUS in the gallbladder adenoma group (p < 0.05). The diagnostic value of H-CEUS in distinguishing gallbladder adenomas from cholesterol polyp lesions was better than that of CEUS. H-CEUS improved the time resolution by increasing the frame rate, which helped to accurately reflect the difference in the microcirculation of GPLs and improved the ability of a differential diagnosis between cholesterol polyp lesions and adenomas. H-CUES may provide an effective means of imaging for patients with GPLs regarding the choice of treatment options. • High frame rate CEUS improves the time resolution of CEUS by increasing the frame rate. • High frame rate CEUS is helpful to accurately evaluate the microvascular morphology of a gallbladder polyp lesion in the arterial phase. • High frame rate CEUS helps patients with gallbladder polyp lesions to choose the appropriate treatment means.