Jochen Herrmann

18F-FDG PET/CT for detection and localization of residual or recurrent disease in patients with multiple myeloma after stem cell transplantation

PurposeThe aim of the study was to determine the diagnostic performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for the detection and localization of residual or recurrent disease in patients with multiple myeloma (MM) after stem cell transplantation.MethodsA total of 197 whole-body 18F-FDG PET/CT scans were performed in 99 patients with MM at different time points in the course of disease after autologous or allogeneic stem cell transplantation. Post-transplant PET/CT scans and clinical remission status as determined by the clinical gold standard (Uniform Response Criteria) were analysed and compared.ResultsA total of 576 focal osseous and extramedullary lesions were detected in 79 scans. Additional diffuse bone marrow involvement was detected in 17 patients. 18F-FDG PET/CT had a sensitivity of 54.6%, a specificity of 82.1%, a positive predictive value of 82.3%, a negative predictive value of 54.2% and an overall accuracy of 65.5%. The sensitivity of 18F-FDG PET/CT was shown to depend on the disease category according to the Uniform Response Criteria for myeloma.ConclusionIn patients with MM in the post-transplant setting, 18F-FDG PET/CT may (1) contribute to the detection and localization of disease, (2) provide information about the extent of distinct myeloma manifestations and the total disease burden and (3) add information about the metabolic activity of disease, but (4) has substantially lower sensitivity for this purpose compared to the pretreatment setting.

Diffusion-weighted imaging of the healthy pancreas: apparent diffusion coefficient values of the normal head, body, and tail calculated from different sets of b-values.

To evaluate differences in apparent diffusion coefficient (ADC) values between head, body, and tail regions and the impact of sets of b‐values used in diffusion weighted imaging (DWI) of the normal pancreas.

Follow-up of radiologically totally implanted central venous access ports of the upper arm: long-term complications in 127,750 catheter-days.

OBJECTIVE The purpose of this article is to retrospectively evaluate radiologically totally implanted central venous access ports (VAPs) of the upper arm in terms of safety, technical feasibility, and device-related complications. MATERIALS AND METHODS Five hundred seven consecutive patients (mean [± SD] age, 59.2 ± 11.4 years) who received a totally implanted central VAP between January 2005 and July 2010 were included. The insertion procedure was performed in an interventional radiology suite using the Seldinger technique. Neither antibiotic prophylaxis nor long-term anticoagulation was administered. RESULTS In 507 patients, a total of 523 devices were implanted. Of these 523 procedures, 512 complete datasets were available during follow-up. The primary technical success rate was 99.04%. All procedures were completed without major complications. During follow-up and with a total number of 127,750 days of totally implanted central VAP implantation (248 ± 279 days/patient; range, 1-1687 days/patient), 50 devices had to be revised because of complications (9.8%). Complications occurred at a mean of 114 ± 183 days (range, 1-1113 days) after placement. Early complications were noted in 21 of 512 cases (4.1%), and late complications were noted in 29 of 512 cases (5.7%). Complications were as follows: local infections, 4.9% (25/512); systemic infections, 0.4% (2/512); venous thrombosis, 1.6% (8/512); paralysis of the median nerve, 0.6% (3/512); skin dehiscence at the port site, 0.2% (1/512); and mechanical problems including catheter line displacement, port hub rotation, and catheter fracture, 2.1% (11/512). CONCLUSION Radiologic placement of a totally implanted central VAP is a safe procedure with a low rate of both early and late device-related complications. The method is effective for delivery of chemotherapy, parenteral nutrition, and frequent IV medication.

Age-related distribution of vertebral bone-marrow diffusivity

PURPOSE To determine age-related diffusivity changes of the lumbar bone marrow by measurement of apparent diffusion coefficient (ADC) values. MATERIALS AND METHODS The local ethics committee approved this study and written informed consent was obtained. The study group comprised 88 individuals including 75 healthy volunteers and 13 patients (48 female, 40 male; mean age 36 years, range 0-84 years). The pediatric cases were recruited from patients. Echo-planar diffusion weighted imaging (DWI) was performed with b-values of 50, 400 and 800 s/mm(2). ADC-values were calculated and measured in the 1st and 2nd vertebral body of the lumbar spine. Correlation between age and ADC-values was analyzed with Spearmans rho test. RESULTS The ADC values of the vertebral bone marrow of the lumbar spine showed a significant negative correlation with age (rho=-0.398, p=0.001). The mean ADC values (×10(-3)mm(2)/s) in the age groups 0-29 years (mean age 18.0 years, n=42) and 30-88 years (mean age 51.6 years, n=46) were 0.54 ± 0.07 and 0.47 ± 0.08, respectively (p<0.001, T-test). No significant differences were found between children and young adults. CONCLUSION Bone marrow ADC values of the lumbar spine show a linear decrease with growing age and thereby reflect the gradual changes of cell composition occurring during marrow conversion.

Diffusion-weighted imaging of the healthy pancreas: ADC values are age and gender dependent

To investigate the healthy pancreas with diffusion‐weighted imaging (DWI) for characterization of age and gender‐related differences in apparent diffusion coefficient (ADC) values.

Follow-up of abdominal aortic aneurysm after endovascular aortic repair: Comparison of volumetric and diametric measurement

PURPOSE To determine the correlation of maximal diameter measurements with volumetric evaluation of size after endovascular aortic repair (EVAR) of abdominal aortic aneurysms (AAA) using computed tomography angiography (CTA) and to survey its applicability for clinical follow-up. MATERIALS AND METHODS 73 consecutive patients (2 females, 71 males; age 38-84 years; mean age, 69.1 ± 8 years) with AAA were treated with percutaneous EVAR in a single institution. For follow-up, CTA was performed periodically after EVAR. Images were evaluated for maximal diameter in consensus by two experienced radiologists. Using OsirixTM, volumetric measurements were done by one radiologist, including the entire infrarenal abdominal aorta. RESULTS In 73 patients 220 CTA examinations were performed after EVAR with a mean follow-up of 17.3 months (range, 1.8-42.7 months). The mean postinterventional volume of aneurysm was 165.63 ml ± 93.29 ml (range, 47.94-565.67 ml). The mean maximal postinterventional diameter was 5.91 ± 1.52 cm (range, 3.72-13.82 cm). At large over the entire observation period a slight, non-significant decrease of 1.6% (2.58ml ± 69.05 ml, range 82.82-201.92 ml) in volumes and a 9.3% (mean 0.55 cm ± 1.22 cm, range 2.85-1.93cm) in diameters were observed. For all examinations a high correlation of volume and diameter was calculated (r = 0.813-0.905; α<0.01). CONCLUSION For follow-up of abdominal EVAR using CTA there is a high correlation between volumetric and diametric measurements of aneurysm. Based on a daily clinical routine setting, measurements of maximal diameters in cross sectional imaging of AAA after EVAR seems to be sufficient to exclude post interventional enlargement.

Material Failure of Silicone Catheter Lines: A Retrospective Review of Partial and Complete Ruptures in 553 Patients

OBJECTIVE This present study reports the frequency and outcome of material failure of the silicone catheter lines of a port device implanted in the upper arm during a 5-year period. MATERIALS AND METHODS From 2006 to 2011, a total of 553 patients had a port device implanted percutaneously in the upper arm. In the spring of 2013, several instances of material failure led to device withdrawal. At that time, 39 patients (7.1%) with the specific device in situ were still alive, and 36 of these patients agreed to removal. Linear mixed-effects models were used to analyze the log-transformed device dwell time. Random effects were modeled using group variables. The mean estimated values and their corresponding 95% CIs were reported. Nominal p values were reported, and two-sided p < 0.05 was considered to denote statistical significance. RESULTS Among the 553 patients, material failure was noticed in 19 patients (3.4%), with a mean estimated dwell time of 243 days (95% CI, 104-570 days). Specifically, complete rupture occurred in 10 patients (1.8%) after a mean of 322 days (95% CI, 95-1089 days), partial rupture occurred in eight patients (1.4%) after a mean of 190 days (95% CI, 61-596 days), and disconnection occurred in one patient (0.2%) 8 days after device placement. CONCLUSION The frequency of catheter line rupture was 3.4%. The mean estimated interval to rupture was less than a year, with an increasing probability of rupture noted in association with a longer dwell time. The exact cause of material failure remains unexplained, and further investigation of the mechanical properties contributing to rupture is required. Insight into the safety profile of these devices is needed to avoid potentially severe injury and improve the management of affected patients.

Transcapsular Arterial Neovascularization after Liver Transplantation in Pediatric Patients Indicates Transplant Failure

PURPOSE To identify transcapsular arterial neovascularization with Doppler ultrasonography (US) in pediatric patients after liver transplantation and to assess the frequency of the finding, its underlying causes, and its relevance in terms of clinical outcome. MATERIALS AND METHODS The study was approved by the local ethics committee, with waived informed consent. All pediatric patients who underwent liver transplantation between January 2000 and December 2003 were retrospectively evaluated. Patients were followed up until June 2008, by using a predefined US protocol with prospective documentation. Of 182 consecutive liver transplantations performed in 162 patients (mean age, 4.5 years; range, 0.1-18.4 years) in this period, 25 patients with a total of 27 liver transplantations underwent US examinations conducted by multiple investigators and were primarily excluded. Student t tests and χ(2) tests were performed where appropriate. The Tarone-Ware test was used to compare transplant survival times. RESULTS Transcapsular arterial neovascularization was noticed in 13 of 137 patients (9.5%) and in 13 of 155 liver transplants (8.4%). The mean time until arterial neovessels appeared was 157 days after liver transplantation (median, 97 days; range, 19-477 days). Arterial neovascularization was associated with pronounced transplant malperfusion and inflammatory changes (P < .001). Patients with transcapsular arterial neovascularization had a significantly shorter mean transplant survival time (1426.4 days ± 244.5 [standard error], with 95% confidence interval: 947.23, 1905.23, vs 2526.4 days ± 92.1, with 95% confidence interval: 2345.84, 2706.97; P = .008) and a higher retransplantation rate (53.8% vs 19.7%, P = .009). CONCLUSION Transcapsular arterial neovascularization, detected with color Doppler US, occurred in 9.5% (13 of 137) of pediatric patients and 8.4% (13 of 155) of liver transplants and was associated with underlying malperfusion and inflammation. The diagnosis of transcapsular arterial neovascularization was associated with reduced graft survival times and a high retransplantation rate. The negative prognostic value of the sign may assist in a strategy of organ allocation.

Hepatic shear wave elastography in children under free-breathing and breath-hold conditions

ObjectivesTo compare hepatic 2D shear wave elastography (2D SWE) in children between free-breathing and breath-hold conditions, in terms of measurement agreement and time expenditure.MethodsA cohort of 57 children (12.7±4.3 years) who underwent standardized 2D SWE between May and October 2015 were retrospectively evaluated. Liver elastograms were obtained under free-breathing and breath-hold conditions and time expenditure was measured. Median stiffness, interquartile range (IQR), and IQR/median ratio were calculated based on 12, six, and three elastograms. Results were compared using Pearson correlation coefficient, intraclass correlation coefficient (ICC), Bland-Altman analysis, and Student’s t.ResultsMedian liver stiffness under free-breathing and breath-hold conditions correlated strongly (7.22±4.5kPa vs. 7.21±4.11kPa; r=0.97, P<0.001). Time to acquire 12 elastograms with free-breathing was lower than that with breath-holding (79.3±32.5sec vs. 143.7±51.8sec, P<0.001). Results for median liver stiffness based of 12, six, and three elastograms demonstrated very high agreement for free-breathing (ICC 0.993) and for breath-hold conditions (ICC 0.994).ConclusionsHepatic 2D SWE performed with free-breathing yields results similar to the breath-hold condition. With a substantially lower time requirement, which can be further reduced by lowering the number of elastograms, the free-breathing technique may be suitable for infants and less cooperative children not capable of breath-holding.Key Points• Hepatic 2D SWE performed with free-breathing yields results similar to breath-hold condition.• Benefit of the free-breathing approach is the substantially lower time requirement.• Lowering the number of elastograms can further reduce time expenditure.• Free-breathing 2D SWE is suitable in children with suspected liver disease.

Radiologically inserted gastrostomy: differences of maintenance of balloon- vs. loop-retained devices

Abstract Purpose: To compare outcome and associated complications of ballon- vs. loop-retained devices for radiologically inserted gastrostomy (RIG). Methods: From 2007 to 2011 233 patients (age 63.7 ± 10.6 years) were referred for a RIG because of pharyngeal stricture Intervention was performed with four different devices: balloon-retained – Freka® GastroTube, Fresenius Kabi (n = 121); MIC® Gastrostomy Feeding Tube, Kimberly–Clark (n = 34); Russell® Gastrostomy Tray, Cook Medical Inc. (n = 17); and loop-retained – Tilma® Gastrostomy Set, Cook Medical Inc. (n = 50). Follow-up was performed with regard to RIG-related complications, cause of removal and fatalities. Revision-free survival times after RIG were evaluated using Kaplan–Meier analysis and group differences by log-rank tests. For analysis of demographic and methodical variables multivariate Cox regression models were used. Results: With a primary technical success rate of 95.3% (222/233) a total of 92 instances of revisions were necessary in 66 patients (66/233, 28.3%) during follow-up (mean 182.8 ± 86.6 days). The most common complication was tube dislodgement (14.3%). There were no significant differences between the distinct devices (p = 0.098), but analyzing the data in subgroups of balloon-compared to loop-retained gastrostomy tubes we observed a significantly higher probability of minor complications for the latter (p = 0.023). Conclusion: As it is significantly less prone to minor complications we recommend the use of balloon-retained gastrostomy tubes to improve the practicability and maintenance of RIG.