Feature-Tracking Strain Parameters Differ Between Highly Accelerated and Conventional Acquisitions: A Multisoftware Assessment.

BACKGROUND: Cardiac magnetic resonance imaging protocols have been adapted to fit the needs for faster, more efficient acquisitions, resulting in the development of highly accelerated, compressed sensing-based (CS) sequences. The aim of this study was to evaluate intersoftware and interacquisition differences for postprocessing software applied to both CS and conventional cine sequences. MATERIALS AND METHODS: A total of 106 individuals (66 healthy volunteers, 40 patients with dilated cardiomyopathy, 51% female, 38±17 y) underwent cardiac magnetic resonance at 3T with retrospectively gated conventional cine and CS sequences. Postprocessing was performed using 2 commercially available software solutions and 1 research prototype from 3 different developers. The agreement of clinical and feature-tracking strain parameters between software solutions and acquisition types was assessed by Bland-Altmann analyses and intraclass correlation coefficients. Differences between softwares and acquisitions were assessed using Kruskal-Wallis analysis of variances. In addition, receiver operating characteristic curve-derived cutoffs were used to evaluate whether sequence-specific cutoffs influence disease classification. RESULTS: There were significant intersoftware ( P <0.002 for all except LV end-diastolic volume per body surface area) and interacquisition differences ( P <0.02 for all except end-diastolic volume per body surface area from Neosoft, left ventricular mass per body surface area from cvi42 and TrufiStrain and global circumferential strain from Neosoft). However, the intraclass correlation coefficients between acquisitions were strong-to-excellent for all parameters (all ≥0.81). In comparing individual softwares to a pooled mean, Bland-Altmann analyses revealed smaller magnitudes of bias for cine acquisition than for CS acquisition. In addition, the application of conventional cutoffs to CS measurements did not result in the false reclassification of patients. CONCLUSION: Significantly lower magnitudes of strain and volumetric parameters were observed in retrospectively gated CS acquisitions, despite strong-to-excellent agreement amongst software solutions and acquisition types. It remains important to be aware of the acquisition type in the context of follow-up examinations, where different cutoffs might lead to misclassifications.

Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease.

OBJECTIVES: Cardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD. METHODS: Patients (n = 58, age 40 (29-51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26-56] years, 31 female). RESULTS: A total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82). CONCLUSIONS: LA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications. KEY POINTS: • Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease. • Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain. • Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.

Biventricular strain assessment indicates progressive impairment of myocardial contractility in phenotypically negative patients with Fabry's disease.

PURPOSE: The accumulation of sphingolipids in Fabry's disease (FD) leads to left ventricular (LV) hypertrophy and shortened T1 in cardiac magnetic resonance (CMR). Early detection of myocardial involvement is essential for the timely initiation and efficacy of enzyme replacement therapy. However, there is a diagnostic gap between the onset of accumulation and detectable myocardial changes. This study aimed to evaluate the diagnostic value of biventricular strain assessment in early FD. METHODS: Genetically proven FD patients (n = 58) and healthy volunteers (HV, n = 62) who had undergone 3 T CMR were retrospectively identified and stratified into 3 groups according to disease severity. Biventricular volumetry, global longitudinal strains (GLS), indexed biventricular masses (RVMi/LVMi), and T1 were evaluated. Group comparisons were performed by ANOVA and diagnostic accuracy was evaluated by ROC-analysis. RESULTS: The study population included 19 group I, 20 group II and 19 group III patients. LV volumetry and T1 showed no significant difference between early FD patients and HV (all p > 0.760). However, RVMi was increased, while RV-GLS and LV-GLS were significantly impaired (p = 0.024 and < 0.001, respectively). Biventricular strains accurately discriminated early FD patients and HV with RV-GLS being non-inferior to LV-GLS (AUC for both 0.83, p > 0.05). Adding strains to the established approach using T1 and LVMi further increased diagnostic accuracy (AUC 0.99, p < 0.05). CONCLUSIONS: Biventricular strains may help detect altered myocardial deformation patterns in phenotypically negative FD patients. These findings may lead to an earlier initiation of therapy, which in turn may slow hypertrophy and the associated long-term risks.

Integrative Analysis of Intrahepatic Cholangiocarcinoma Subtypes for Improved Patient Stratification: Clinical, Pathological, and Radiological Considerations.

Intrahepatic cholangiocarcinomas (iCCAs) may be subdivided into large and small duct types that differ in etiology, molecular alterations, therapy, and prognosis. Therefore, the optimal iCCA subtyping is crucial for the best possible patient outcome. In our study, we analyzed 148 small and 84 large duct iCCAs regarding their clinical, radiological, histological, and immunohistochemical features. Only 8% of small duct iCCAs, but 27% of large duct iCCAs, presented with initial jaundice. Ductal tumor growth pattern and biliary obstruction were significant radiological findings in 33% and 48% of large duct iCCAs, respectively. Biliary epithelial neoplasia and intraductal papillary neoplasms of the bile duct were detected exclusively in large duct type iCCAs. Other distinctive histological features were mucin formation and periductal-infiltrating growth pattern. Immunohistochemical staining against CK20, CA19-9, EMA, CD56, N-cadherin, and CRP could help distinguish between the subtypes. To summarize, correct subtyping of iCCA requires an interplay of several factors. While the diagnosis of a precursor lesion, evidence of mucin, or a periductal-infiltrating growth pattern indicates the diagnosis of a large duct type, in their absence, several other criteria of diagnosis need to be combined.

Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium.

OBJECTIVES: To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)-based cine sequences in comparison to conventional (Conv) cine imaging. METHODS: CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis. RESULTS: CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7-32.7), CS 25.7 ml (19.2-35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7-58.4), CS 49.0% (42.0-54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76-0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin - 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF. CONCLUSION: Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging. KEY POINTS: • Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible. • Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging. • No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

Endovascular simulation training: a tool to increase enthusiasm for interventional radiology among medical students.

OBJECTIVES: Interventional radiology (IR) is a growing field but is underrepresented in most medical school curricula. We tested whether endovascular simulator training improves medical students' attitudes towards IR. MATERIALS AND METHODS: We conducted this prospective study at two university medical centers; overall, 305 fourth-year medical students completed a 90-min IR course. The class consisted of theoretical and practical parts involving endovascular simulators. Students completed questionnaires before the course, after the theoretical and after the practical part. On a 7-point Likert scale, they rated their interest in IR, knowledge of IR, attractiveness of IR, and the likelihood to choose IR as subspecialty. We used a crossover design to prevent position-effect bias. RESULTS: The seminar/simulator parts led to the improvement for all items compared with baseline: interest in IR (pre-course 5.2 vs. post-seminar/post-simulator 5.5/5.7), knowledge of IR (pre-course 2.7 vs. post-seminar/post-simulator 5.1/5.4), attractiveness of IR (pre-course 4.6 vs. post-seminar/post-simulator 4.8/5.0), and the likelihood of choosing IR as a subspecialty (pre-course 3.3 vs. post-seminar/post-simulator 3.8/4.1). Effect was significantly stronger for simulator training compared with that for seminar for all items (p < 0.05). For simulator training, subgroup analysis of students with pre-existing positive attitude showed considerable improvement regarding "interest in IR" (× 1.4), "knowledge of IR" (× 23), "attractiveness of IR" (× 2), and "likelihood to choose IR" (× 3.2) compared with pretest. CONCLUSION: Endovascular simulator training significantly improves students' attitude towards IR regarding all items. Implementing such courses at a very early stage in the curriculum should be the first step to expose medical students to IR and push for IR. KEY POINTS: • Dedicated IR-courses have a significant positive effect on students' attitudes towards IR. • Simulator training is superior to a theoretical seminar in positively influencing students' attitudes towards IR. • Implementing dedicated IR courses in medical school might ease recruitment problems in the field.

Validation of the SNACOR clinical scoring system after transarterial chemoembolisation in patients with hepatocellular carcinoma.

BACKGROUND: Transarterial chemoembolisation is the standard of care for intermediate stage (BCLC B) hepatocellular carcinoma, but it is challenging to decide when to repeat or stop treatment. Here we performed the first external validation of the SNACOR (tumour Size and Number, baseline Alpha-fetoprotein, Child-Pugh and Objective radiological Response) risk prediction model. METHODS: A total of 1030 patients with hepatocellular carcinoma underwent transarterial chemoembolisation at our tertiary referral centre from January 2000 to December 2016. We determined the following variables that were needed to calculate the SNACOR at baseline: tumour size and number, alpha-fetoprotein level, Child-Pugh class, and objective radiological response after the first transarterial chemoembolisation. Overall survival, time-dependent area under receiver-operating characteristic curves, Harrell's C-index, and the integrated Brier score were calculated to assess predictive ability. Finally, multivariate analysis was performed to identify independent predictors of survival. RESULTS: The study included 268 patients. Low, intermediate, and high SNACOR scores predicted a median survival of 31.5, 19.9, and 9.2 months, respectively. The areas under the receiver-operating characteristic curve for overall survival were 0.641, 0.633, and 0.609 at 1, 3, and 6 years, respectively. Harrell's C-index was 0.59, and the integrated Brier Score was 0.175. Independent predictors of survival included tumour size (P < 0.001), baseline alpha-fetoprotein level (P < 0.001) and Child-Pugh class (P < 0.004). Objective radiological response (P = 0.821) and tumour number (P = 0.127) were not additional independent predictors of survival. CONCLUSIONS: The SNACOR risk prediction model can be used to identify patients with a dismal prognosis after the first transarterial chemoembolisation who are unlikely to benefit from further transarterial chemoembolisation. However, Harrell's C-index showed only moderate performance. Accordingly, this risk prediction model can only serve as one of several components used to make the decision about whether to repeat treatment.

Validation of Clinical Scoring Systems ART and ABCR after Transarterial Chemoembolization of Hepatocellular Carcinoma.

PURPOSE: To perform an external validation of the Assessment for Retreatment with Transarterial Chemoembolization (ART) and α-fetoprotein (AFP), Barcelona Clinic Liver Cancer (BCLC), Child-Pugh, and response (ABCR) scores and to compare them in terms of prognostic power. MATERIALS AND METHODS: From 2000 to 2015, 871 patients with hepatocellular carcinoma underwent transarterial chemoembolization at a tertiary referral hospital, and 176 met all inclusion and exclusion criteria for both scores and were analyzed. Nineteen percent (n = 34) had BCLC stage A disease and 81% had stage B disease. Thirty-nine patients (22%) presented with elevated AFP levels. Overall survival was calculated. Scores were validated and compared with a Harrell C-index, integrated Brier score (IBS), and prediction error curves. RESULTS: Before the second chemoembolization procedure, 22 patients (12%) showed an increase of 1 point in Child-Pugh score and 51 patients (22%) had an increase of ≥ 2 points. Thirty-one patients (23%) showed a > 25% increase in aspartate aminotransferase level, and 114 (65%) showed a response to treatment. Consequently, 127 patients (72%) had a low ART score and 49 (28%) had a high ART score. One hundred fifty-eight patients (90%) had a low ABCR score, whereas 18 (10%) had a high ABCR score. Low and high ART score groups had median survival durations of 20.8 and 15.3 mo, respectively. Harrell C-indexes were 0.572 and 0.608, and IBSs were 0.135 and 0.128, for ART and ABCR, respectively. For both scores, an increase in Child-Pugh score ≥ 2 points and a radiologic response were significantly associated with survival. CONCLUSIONS: Both scores were of limited predictive value, and neither was sufficient to support clear-cut clinical decisions. Further effort is necessary to determine criteria for making valid clinical predictions.

Differences of airway dimensions between patients with and without bronchiolitis obliterans syndrome after lung transplantation-Computer-assisted quantification of computed tomography.

BACKGROUND: The aim of our retrospective study was to determine whether a dedicated software for assessment of airway morphology can detect differences in airway dimensions between patients with and without bronchiolitis obliterans syndrome (BOS), regarded as the clinical correlate of chronic lung allograft rejection. METHODS: 12 patients with and 14 patients without diagnosis of BOS were enrolled in the study. Evaluation of bronchial wall area percentage (WA%) and bronchial wall thickness (WT) in all follow-up CT scans was performed using a semiautomatic airway assessment tool. We assessed temporal changes (ΔWA%, ΔWT) and compared these morphological parameters with forced expiratory volume in one second (ΔFEV1). RESULTS: In patients with and without BOS, the temporal changes over the entire follow-up were 26.6% versus 16.2% for ΔFEV1 (p=0.034), 14.2% versus 5.4% for ΔWA% (p=0.003) and 0.212mm versus 0.064mm for ΔWT (p=0.011). CONCLUSIONS: We detected significant differences of the temporal changes of airway dimensions (ΔWA%, ΔWT) between lung transplant recipients with and without BOS. We conclude that computer-assisted bronchial wall measurements in CT scans might complement the information from pulmonary function tests and establish as a non-invasive method to confirm BOS in lung transplant recipients in the future.

Conventional transarterial chemoembolization versus drug-eluting bead transarterial chemoembolization for the treatment of hepatocellular carcinoma.

BACKGROUND: To compare the overall survival of patients with hepatocellular carcinoma (HCC) who were treated with lipiodol-based conventional transarterial chemoembolization (cTACE) with that of patients treated with drug-eluting bead transarterial chemoembolization (DEB-TACE). METHODS: By an electronic search of our radiology information system, we identified 674 patients that received TACE between November 2002 and July 2013. A total of 520 patients received cTACE, and 154 received DEB-TACE. In total, 424 patients were excluded for the following reasons: tumor type other than HCC (n=91), liver transplantation after TACE (n=119), lack of histological grading (n=58), incomplete laboratory values (n=15), other reasons (e.g., previous systemic chemotherapy) (n=114), or were lost to follow-up (n=27). Therefore, 250 patients were finally included for comparative analysis (n=174 cTACE; n=76 DEB-TACE). RESULTS: There were no significant differences between the two groups regarding sex, overall status (Barcelona Clinic Liver Cancer classification), liver function (Child-Pugh), portal invasion, tumor load, or tumor grading (all p>0.05). The mean number of treatment sessions was 4±3.1 in the cTACE group versus 2.9±1.8 in the DEB-TACE group (p=0.01). Median survival was 409 days (95% CI: 321-488 days) in the cTACE group, compared with 369 days (95% CI: 310-589 days) in the DEB-TACE group (p=0.76). In the subgroup of Child A patients, the survival was 602 days (484-792 days) for cTACE versus 627 days (364-788 days) for DEB-TACE (p=0.39). In Child B/C patients, the survival was considerably lower: 223 days (165-315 days) for cTACE versus 226 days (114-335 days) for DEB-TACE (p=0.53). CONCLUSION: The present study showed no significant difference in overall survival between cTACE and DEB-TACE in patients with HCC. However, the significantly lower number of treatments needed in the DEB-TACE group makes it a more appealing treatment option than cTACE for appropriately selected patients with unresectable HCC.

Visceral artery aneurysms: Incidence, management, and outcome analysis in a tertiary care center over one decade.

OBJECTIVES: To evaluate the incidence, management, and outcome of visceral artery aneurysms (VAA) over one decade. METHODS: 233 patients with 253 VAA were analyzed according to location, diameter, aneurysm type, aetiology, rupture, management, and outcome. RESULTS: VAA were localized at the splenic artery, coeliac trunk, renal artery, hepatic artery, superior mesenteric artery, and other locations. The aetiology was degenerative, iatrogenic after medical procedures, connective tissue disease, and others. The rate of rupture was much higher in pseudoaneurysms than true aneurysms (76.3% vs.3.1%). Fifty-nine VAA were treated by intervention (n = 45) or surgery (n = 14). Interventions included embolization with coils or glue, covered stents, or combinations of these. Thirty-five cases with ruptured VAA were treated on an emergency basis. There was no difference in size between ruptured and non-ruptured VAA. After interventional treatment, the 30-day mortality was 6.7% in ruptured VAA compared to no mortality in non-ruptured cases. Follow-up included CT and/or MRI after a mean period of 18.0 ± 26.8 months. The current status of the patient was obtained by a structured telephone survey. CONCLUSIONS: Pseudoaneurysms of visceral arteries have a high risk for rupture. Aneurysm size seems to be no reliable predictor for rupture. Interventional treatment is safe and effective for management of VAA. KEY POINTS: • Diagnosis of visceral artery aneurysms is increasing due to CT and MRI. • Diameter of visceral arterial aneurysms is no reliable predictor for rupture. • False aneurysms/pseudoaneurysms and symptomatic cases need emergency treatment. • Interventional treatment is safe and effective.

Randomized comparison of selective internal radiotherapy (SIRT) versus drug-eluting bead transarterial chemoembolization (DEB-TACE) for the treatment of hepatocellular carcinoma.

PURPOSE: To prospectively compare SIRT and DEB-TACE for treating hepatocellular carcinoma (HCC). METHODS: From 04/2010-07/2012, 24 patients with histologically proven unresectable N0, M0 HCCs were randomized 1:1 to receive SIRT or DEB-TACE. SIRT could be repeated once in case of recurrence; while, TACE was repeated every 6 weeks until no viable tumor tissue was detected by MRI or contraindications prohibited further treatment. Patients were followed-up by MRI every 3 months; the final evaluation was 05/2013. RESULTS: Both groups were comparable in demographics (SIRT: 8males/4females, mean age 72 ± 7 years; TACE: 10males/2females, mean age 71 ± 9 years), initial tumor load (1 patient ≥25 % in each group), and BCLC (Barcelona Clinic Liver Cancer) stage (SIRT: 12×B; TACE 1×A, 11×B). Median progression-free survival (PFS) was 180 days for SIRT versus 216 days for TACE patients (p = 0.6193) with a median TTP of 371 days versus 336 days, respectively (p = 0.5764). Median OS was 592 days for SIRT versus 788 days for TACE patients (p = 0.9271). Seven patients died in each group. Causes of death were liver failure (n = 4 SIRT group), tumor progression (n = 4 TACE group), cardiovascular events, and inconclusive (n = 1 in each group). CONCLUSIONS: No significant differences were found in median PFS, OS, and TTP. The lower rate of tumor progression in the SIRT group was nullified by a greater incidence of liver failure. This pilot study is the first prospective randomized trial comparing SIRT and TACE for treating HCC, and results can be used for sample size calculations of future studies.

Selective internal radiotherapy (SIRT) versus transarterial chemoembolization (TACE) for the treatment of intrahepatic cholangiocellular carcinoma (CCC): study protocol for a randomized controlled trial.

BACKGROUND: Cholangiocellular carcinoma is the second most common primary liver cancer after hepatocellular carcinoma. Over the last 30 years, the incidence of intrahepatic cholangiocellular carcinoma has risen continuously worldwide. Meanwhile, the intrahepatic cholangiocellular carcinoma has become more common than the extrahepatic growth type and currently accounts for 10-15% of all primary hepatic malignancies. Intrahepatic cholangiocellular carcinoma is typically diagnosed in advanced stages due to late clinical symptoms and an absence of classic risk factors. A late diagnosis precludes curative surgical resection. There is evidence that transarterial chemoembolization leads to better local tumor control and prolongs survival compared to systemic chemotherapy. New data indicates that selective internal radiotherapy, also referred to as radioembolization, provides promising results for treating intrahepatic cholangiocellular carcinoma. METHODS/DESIGN: This pilot study is a randomized, controlled, single center, phase II trial. Twenty-four patients with intrahepatic cholangiocellular carcinoma will be randomized in a 1:1 ratio to receive either chemoembolization or radioembolization. Randomization will be stratified according to tumor load. Progression-free survival is the primary endpoint; overall survival and time to progression are secondary endpoints. To evaluate treatment success, patients will receive contrast enhanced magnetic resonance imaging every 3 months. DISCUSSION: Currently, chemoembolization is routinely performed in many centers instead of systemic chemotherapy for treating intrahepatic cholangiocellular carcinoma confined to the liver. Recently, radioembolization has been increasingly applied to cholangiocellular carcinoma as second line therapy after TACE failure or even as an alternative first line therapy. Nonetheless, no randomized studies have compared radioembolization and chemoembolization. Considering all this background information, we recognized a strong need for a randomized controlled trial (RCT) to compare the two treatments. Therefore, the present protocol describes the design of a RCT that compares SIRT and TACE as the first line therapy for inoperable CCC confined to the liver. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT01798147, registered 16th of February 2013.

Radiation exposure in CT-guided interventions.

PURPOSE: To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction. MATERIALS AND METHODS: We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series. RESULTS: Eighty-five percent of the total radiation dose was applied during the pre- and post-interventional CT series, leaving only 15% applied by the CT-guided intervention itself. Single slice acquisition was associated with lower doses than continuous CT-fluoroscopy (37 mGy cm vs. 153 mGy cm, p<0.001). The third quartile of radiation doses varied considerably for different interventions. The highest doses were observed in complex interventions like RFA/MWA of the liver, followed by vertebroplasty and RFA/MWA of the lung. CONCLUSIONS: This paper suggests preliminary reference levels for various intervention types and discusses strategies for dose reduction. A multicenter registry of radiation exposure including a broader spectrum of scanners and intervention types is needed to develop definitive reference levels.

Noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI: correlation with simultaneous invasive pressure recordings.

BACKGROUND: Right heart catheterization is the gold standard for assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension. To date, MRI has not been able to produce precise measurements of mean pulmonary arterial pressure (mPAP). The purpose of the study was to create a model for estimating mPAP and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension by high temporal resolution phase-contrast MRI (PC-MRI) and to correlate the results with simultaneously acquired, invasive catheter-based measurements (simultaneously measured mPAP) and with right heart catheterization measurements. METHODS AND RESULTS: A total of 19 patients with chronic thromboembolic pulmonary hypertension underwent right heart catheterization and-after digital subtraction angiography of the pulmonary arteries-subsequent PC-MRI at 1.5 T with simultaneous recording of mPAP. Velocity- and flow-time curves of PC-MRI were used to calculate absolute acceleration time (Ata), maximum of mean velocities (MV), volume of acceleration (AV), and maximum flow acceleration (dQ/dt). On the basis of these parameters, multiple linear regression analysis revealed maximum achievable model fit (B=0.902) for the following linear combination equation to calculate mPAP (mPAP_cal): mPAP_cal=69.446-(0.521 × Ata)-(0.570 × MV)+(1.507 × AV)+(0.002 × dQ/dt). There was a statistically significant equivalence of mPAP_cal and simultaneously measured mPAP with a goodness of fit of 0.892. Pulmonary vascular resistance was overestimated by calculated pulmonary vascular resistance on the basis of PC-MRI in comparison with right heart catheterization-based measurements by a median of -112 dyn·s·cm(-5), the pairwise regression formula revealed a goodness of fit of 0.792. CONCLUSIONS: PC-MRI-derived parameters enable noninvasive assessment of pulmonary hemodynamics in patients with chronic thromboembolic pulmonary hypertension.

Strategies for endovascular aortic repair in aortobronchial and aortoesophageal fistulas.

OBJECTIVE: To report our experience of thoracic endovascular aortic repair (TEVAR) for acute bleeding originating from the thoracic aorta in patients with aortobronchial fistula (ABF) or aortoesophageal fistula (AEF). PATIENTS AND METHODS: A total of nine patients (three woman) were treated from September 1995 to March 2012 by TEVAR for ABF (n = 5) and AEF (n = 4). The implants (N = 14) were introduced with fluoroscopic guidance via the aorta (n = 1), the iliac (n = 2), or femoral (n = 11) artery, respectively. RESULTS: All aortic lesions could be sealed successfully. Perioperative morbidity was 0% in the ABF group and 50% (2 of 4) in the AEF group and no procedure-related morbidity was noted except one patient who received aortofemoral reconstruction because of iliac occlusive disease. After an overall mean follow-up of 56 months, three patients of the ABF group are alive and well and two patients died of nonrelated cause. Of the AEF group, one patient is alive after 22 months, and one died from metastasized esophageal cancer after 7 months. CONCLUSION: TEVAR is a safe and reliable procedure in the management of ABF. For AEF, TEVAR provides a successful first-line treatment to seal the fistula and control bleeding. However, prognosis is limited by the esophageal lesion and by ongoing mediastinitis/sepsis.

Midterm follow-up after DC-BEAD™-TACE of hepatocellular carcinoma (HCC).

AIM: To determine local response, its predictors and survival and complication rates after DC-Bead™-TACE in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: DC-Beads™ are non-resorbable, polyvinyl-alcoholic hydrophilic microspheres. They release high amounts of chemotherapeutics directly into the tumour. Delivery is sustained over time, tumour feeders are embolised. We used beads from 100-300 to 500-700 µm loaded with Doxorubicin (max. 150 mg/4ml). Fifty patients (mean age: 68.5 ± 8.8 years) with HCC were analysed. DC-Bead™-TACE was performed once or repeated in two-month intervals. Imaging scans (CT or MRI) were done one-month following each procedure. To evaluate tumour response EASL and RECIST criteria was applied. If eligible, every patient received a non-selective TACE. RESULTS: 128 DC-Bead™ sessions were performed: 127 showed technical success, 120 successful stasis. Complications occurred in 7% (9/128): active bleeding into the tumour (n=1), liver failure (n=1), liver abscess (n=1) ascites (n=3), pleural effusion (n=1), false aneurysm (n=1) and hypoglycaemia (n=1). At imaging after the 1st, 2nd, 3rd and 4th-8th session, objective response (complete+partial) was 49%, 67%, 67% and 31%, progressive disease was seen in n=11/50. Baseline diameter and differentiation significantly impacted response. Median overall survival was 25.1 months (95% [CI]: 18.3-31.9) with an estimated cumulative survival rate at one and two-to-four years of 66.7% and 45.7%, respectively. CONCLUSION: DC-Beads™ can be safely and effectively control HCC. Survival and response rates are encouraging, complications are low. Many factors are involved in response to treatment like liver function or child state.

MDCT versus MRI assessment of tumor response after transarterial chemoembolization for the treatment of hepatocellular carcinoma.

The purpose of this study was to compare the ability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) to evaluate treatment results after transarterial chemoembolization (TACE), with a special focus on the influence of Lipiodol on calculation of tumor necrosis according to EASL criteria. A total of 115 nodules in 20 patients (17 males, 3 females; 69.5 +/- 9.35 years) with biopsy-proven hepatocellular carcinoma were treated with TACE. Embolization was performed using a doxorubicin-Lipiodol emulsion (group I) or DC Beads loaded with doxorubicin (group II). Follow-up included triphasic contrast-enhanced 64-row MDCT (collimation, 0.625 mm; slice, 3 mm; contrast bolus, 120 ml iomeprol; delay by bolus trigger) and contrast-enhanced MRI (T1 native, T2 native; five dynamic contrast-enhanced phases; 0.1 mmol/kg body weight gadolinium-DTPA; slice thickness, 4 mm). Residual tumor and the extent of tumor necrosis were evaluated according to EASL. Contrast enhancement within tumor lesions was suspected to represent vital tumor. In the Lipiodol-based TACE protocol, MDCT underestimated residual viable tumor compared to MRI, due to Lipiodol artifacts (23.2% vs 47.7% after first, 11.9% vs 31.2% after second, and 11.4% vs 23.7% after third TACE; p = 0.0014, p < 0.001, and p < 0.001, respectively). In contrast to MDCT, MRI was completely free of any artifacts caused by Lipiodol. In the DC Bead-based Lipiodol-free TACE protocol, MRI and CT showed similar residual tumor and rating of treatment results (46.4% vs 41.2%, 31.9 vs 26.8%, and 26.0% vs 25.6%; n.s.). In conclusion, MRI is superior to MDCT for detection of viable tumor residuals after Lipiodol-based TACE. Since viable tumor tissue is superimposed by Lipiodol artifacts in MDCT, MRI is mandatory for reliable decision-making during follow-up after Lipiodol-based TACE protocols.

MRI versus 64-row MDCT for diagnosis of hepatocellular carcinoma.

AIM: To compare the diagnostic capability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection of hepatocellular carcinoma (HCC) tumour nodules and their effect on patient management. METHODS: A total of 28 patients (25 male, 3 female, mean age 67 +/- 10.8 years) with biopsy-proven HCC were investigated with 64-row MDCT (slice 3 mm native, arterial and portal-venous phase, 120 mL Iomeprol, 4 mL/s, delay by bolus trigger) and MRI (T1fs fl2d TE/TR 2.72/129 ms, T2tse TE/TR 102/4000 ms, 5-phase dynamic contrast-enhanced T1fs fl3d TE/TR 1.56/4.6, Gadolinium-DTPA, slice 4 mm). Consensus reading of both modalities was used as reference. Tumour nodules were analyzed with respect to number, size, and location. RESULTS: In total, 162 tumour nodules were detected by consensus reading. MRI detected significantly more tumour nodules (159 vs 123, P < 0.001) compared to MDCT, with the best sensitivity for early arterial phase MRI. False-negative CT findings included nodules < or = 5 mm ( n = 5), < or = 10 mm ( n = 17), < or = 15 mm ( n = 12 ), < or = 20 mm ( n = 4 ), and 1 nodule > 20 mm. MRI missed 2 nodules < or = 10 mm and 1 nodule < or = 15 mm. On MRI, nodule diameters were greater than on CT (29.2 +/- 25.1 mm, range 5-140 mm vs 24.1 +/- 22.7 mm, range 4-129 mm, P < 0.005). In 2 patients, MDCT showed only unilobar tumour spread, whereas MRI revealed additional nodules in the contralateral lobe. Detection of these nodules could have changed the therapeutic strategy. CONCLUSION: Contrast-enhanced MRI is superior to 64-row MDCT for the detection of HCC nodules. Patients should be allocated to interventional or operative treatment according to a dedicated MRI-protocol.