Dynamic 18F-FET PET is a powerful imaging biomarker in gadolinium-negative gliomas.

BACKGROUND: We aimed to elucidate the place of dynamic O-(2-[18F]-fluoroethyl)-L-tyrosine (18F-FET) PET in prognostic models of gadolinium (Gd)-negative gliomas. METHODS: In 98 patients with Gd-negative gliomas undergoing 18F-FET PET guided biopsy, time activity curves (TACs) of each tumor were qualitatively categorized as either increasing or decreasing. Additionally, post-hoc quantitative analyses were done using minimal time-to-peak (TTPmin) measurements. Prognostic factors were obtained from multivariate hazards models. The fit of the biospecimen- and imaging-derived models was compared. RESULTS: A homogeneous increasing, mixed, and homogeneous decreasing TAC pattern was seen in 51, 19, and 28 tumors, respectively. Mixed TAC tumors exhibited both increasing and decreasing TACs. Corresponding adjusted 5-year survival was 85%, 47%, and 19%, respectively (P < 0.001). Qualitative and quantitative TAC measurements were highly intercorrelated (P < 0.0001). TTPmin was longest (shortest) in the homogeneous increasing (decreasing) TAC group and in between in the mixed TAC group. TTPmin was longer in isocitrate dehydrogenase (IDH)-mutant tumors (P < 0.001). Outcome was similarly precisely predicted by biospecimen- and imaging-derived models. In the biospecimen model, World Health Organization (WHO) grade (P < 0.0001) and IDH status (P < 0.001) were predictors for survival. Outcome of homogeneous increasing (homogeneous decreasing) TAC tumors was nearly identical, with both TTPmin > 25 min (TTPmin ≤ 12.5 min) tumors and IDH-mutant grade II (IDH-wildtype) gliomas. Outcome of mixed TAC tumors matched that of both intermediate TTPmin (>12.5 min and ≤25 min) and IDH-mutant, grade III gliomas. Each of the 3 prognostic clusters differed significantly from the other ones of the respective models (P < 0.001). CONCLUSION: TAC measurements constitute a powerful biomarker independent from tumor grade and IDH status.

Acute basilar thrombosis: Recanalization following intravenous thrombolysis is dependent on thrombus length.

INTRODUCTION: We investigated whether thrombus length measured in Computed Tomography Angiography (CTA) is predictive of the success rate of intravenous thrombolysis (IVT) in acute basilar occlusion and whether recanalization can be achieved by additional mechanical endovascular thrombectomy. METHODS: In 51 patients with acute basilar thrombosis thrombus length was measured on CTA images before intravenous thrombolysis (IVT) with rt-PA was started. After 114 minutes on average success of IVT was evaluated either by CTA or DSA. Patients with persistent basilar occlusion and no major brainstem infarction on CT underwent endovascular recanalization. RESULTS: 87% of patients had no recanalization of basilar artery after IVT alone. The average thrombus length was 15 mm in patients with persistent basilar occlusion after IVT and 7 mm in patients with recanalization after IVT. Thrombi longer than 13 mm did not resolve after IVT alone and 80% of thrombi shorter than 13 mm did not resolve either. 41 patients were transferred to endovascular recanalization; endovascular therapy was performed successfully in 90% (37 / 41). CONCLUSIONS: Recanalization rates in acute basilar occlusion after IVT alone are low and dependent on thrombus length. Additional mechanical endovascular thrombectomy showed to be a very successful recanalization therapy.

Successful mechanical thrombectomy in a three-year-old boy with cardioembolic occlusion of both the basilar artery and the left middle cerebral artery.

BACKGROUND: Paediatric stroke is a potentially life-threatening emergency and requires immediate treatment to improve clinical outcome. In contrast to adult treatment recommendations, little is known about safety and efficacy of thrombolysis and mechanical thrombectomy in children. CASE DESCRIPTION AND CONCLUSION: We report on a three-year-old boy with a cardioembolic intracranial two-vessel occlusion and successful therapy with thrombolysis and mechanical thrombectomy. Furthermore, this case emphasizes the need of standardized protocols for acute management of paediatric stroke.

Efficacy of two antiseptic regimens on skin colonization of insertion sites for two different catheter types: a randomized, clinical trial.

PURPOSE: Catheter-related bloodstream infections affect patients in surgical and intensive care settings worldwide, causing complications, aggravation of existing symptoms and increased length of stay. The trial aimed at comparing two registered skin antiseptics with respect to their residual and therefore infection-preventing effects. METHODS: In a parallel, monocentric, prospective, triple-blind, randomized trial the difference in bacterial recolonization of catheter skin sites in central venous (CVC) and epidural catheters (EC) was investigated by comparing two alcoholic-based skin disinfectants. Patients receiving planned surgeries or intensive care were eligible for the trial. Those in the trial group received skin disinfection with the additive octenidine dihydrochloride (OCT) (n = 51), those in the control group were treated with benzalkonium chloride as additive (BAC) (n = 59) prior to catheter insertion. Randomization was carried out by assigning patients to groups week-wise. Endpoints of the investigation were skin colonization of the catheter site counted in colony forming units per swab at three time points: (1) prior to catheter insertion, on untreated skin; (2) directly after catheter insertion, prior to sterile coverage; (3) 48 h after catheter insertion. The hypothesis was tested by a Wilcoxon test with a two-sided alpha = 5 %. RESULTS: From second to third swab, recolonization of the catheter-surrounding skin was significantly lower in the trial group for both sorts of catheters: delta 2-3 OCT group: 0.72 (95 % CI: 0.42; 1.02); delta 2-3 BAC group: 1.97 (95 % CI: 1.45; 2.50); p < 0.001. None of the patients enrolled developed a catheter-related blood stream infection (CRBSI) during follow-up. CONCLUSIONS: Previous studies have shown that skin colonization is strongly associated with the occurrence of CRBSI. This randomized controlled trial supports the observations made in previous trials that octenidine dihydrochloride in disinfectants is more effective than agents containing other additives with regard to skin recolonization surrounding CVC and EC insertion sites. Therefore, it is likely to also reduce the risk of CRBSI in these patient groups. The trial was approved by the North Rhine Medical Association in July 2014 (application-no.: 2014222).

Microstructural alterations in trigeminal neuralgia determined by diffusion tensor imaging are independent of symptom duration, severity, and type of neurovascular conflict.

OBJECTIVE: In this prospective study diffusion tensor imaging (DTI) was used to evaluate the influence of clinical and anatomical parameters on structural alterations within the fifth cranial nerve in patients with trigeminal neuralgia (TN) due to neurovascular compression. METHODS: Overall, 81 patients (40 men and 41 women; mean age 60 ± 5 years) with typical TN were included who underwent microsurgical decompression. Preoperative 3.0-T high-resolution MRI and DTI were analyzed in a blinded fashion. The respective fractional anisotropy (FA) and apparent diffusion coefficient values were compared with the clinical, imaging, and intraoperative data. This study was approved by the institutional review board, and written informed consent was obtained from all patients. RESULTS: DTI analyses revealed significantly lower FA values within the vulnerable zone of the affected trigeminal nerve compared with the contralateral side (p = 0.05). The DTI analyses also included 3 patients without clear evidence of neurovascular conflict on preoperative MRI. No differences were seen between arterial and venous compression. Lower FA values were found 5 months after symptom onset; however, no correlation was found with the duration of symptoms or severity of compression. CONCLUSIONS: DTI analysis allows the quantification of structural alterations, even in those patients without any discernible neurovascular contact on MRI. Moreover, our findings support the hypothesis that both the arteries and veins can cause structural alterations that lead to TN. These aspects can be useful for making treatment decisions.

[18F]fluoroethyltyrosine-positron emission tomography-based therapy monitoring after stereotactic iodine-125 brachytherapy in patients with recurrent high-grade glioma.

Therapy monitoring of glioma after stereotactic iodine-125 brachytherapy (SBT) remains challenging because posttherapeutic changes in magnetic resonance imaging can mimic tumor progression. We evaluated the prognostic value of serial [18F]fluoroethyltyrosine (FET)-positron emission tomographic (PET) scans for therapy monitoring of high-grade glioma (HGG) after SBT. Thirty-three patients with recurrent HGG were included. Serial FET-PET scans were performed prior to therapeutic intervention and at 3-month intervals during the first year after SBT. FET-PET evaluation was performed by both conventional data analysis and kinetic analysis. Prognostic factors were obtained from proportional hazard models. Median local progression-free survival (LPFS) was 11.1 months. Maximal standardized background uptake value (SUVmax/BG) and biologic tumor volume (BTV) differentiated accurately between therapeutic effects and local tumor progression at the 6-month and subsequent examinations. Increasing uptake kinetics at baseline (p < .05) and during follow-up (p < .01) were stringently associated with a longer LPFS. Early increase in FET uptake after SBT is not unequivocally associated with tumor progression; it might be induced by reactive changes and could easily lead to a misclassification of the tumor status (pseudoprogression). Six months after SBT (or later), however, increased SUVmax/BG and BTV values are associated with a worse prognosis. Multivariate analysis stresses the prognostic importance of dynamic studies.

Evaluation of the supraaortic arteries using non-contrast-enhanced Velocity MR angiography "Inhance".

INTRODUCTION: The aim of this study was to compare the recently developed phase contrast-based Inhance 3D Velocity magnetic resonance angiography technique (Inhance) to the contrast-enhanced standard method (CE-MRA) in the evaluation of the supraaortic arteries. METHODS: Inhance and CE-MRA were performed in ten consecutive patients with a suspected pathology of the supraaortic arteries on a 3-T MR scanner. Two neuroradiologists evaluated in consensus both sequences regarding the visualisation of the supraaortic arteries and their segments on a five-point score. Diagnostic certainty regarding the overall presence of a vascular pathology was rated on the same five-point score. RESULTS: On CE-MRA as well as on Inhance, a vascular pathology of the supraaortic arteries was detected in seven patients. There was no statistically significant difference in the overall diagnostic certainty regarding the presence or absence of pathologic findings for CE-MRA compared to Inhance. Furthermore, no statistically significant difference was found with regard to visualisation of the distal cervical and intracranial arterial segments, while CE-MRA was superior to Inhance in the visualisation of the origins of the cervical vessels from the aortic arch. CONCLUSION: Non-contrast Inhance proved useful in the evaluation of the supraaortic arteries with limited assessment of the proximal supraaortic branches. Hence, this technique features a valuable alternative to CE-MRA in the visualisation of the supraaortic arteries, particularly in patients with renal insufficiency.

MRI-suspected low-grade glioma: is there a need to perform dynamic FET PET?

PURPOSE: Since differentiation between low-grade glioma (LGG) and high-grade glioma (HGG) remains challenging according to MRI criteria alone, we investigated the discriminative value of additional dynamic FET PET in patients with MRI-suspected LGG. METHODS: Included in this retrospective study were 127 patients with newly diagnosed MRI-suspected LGG and dynamic FET PET prior to histopathological assessment. FET PET lesions were visually classified as having reduced, normal, or increased tracer uptake. Maximal tumour uptake scaled to the mean background uptake (SUV(max)/BG), mean tumour uptake (SUV(mean)/BG), biological tumour volume and kinetics were evaluated and correlated with individual histopathological findings. RESULTS: Histopathological analysis revealed 71 patients with LGG, 47 patients with HGG (including 5 glioblastoma multiforme), 2 patients with low-grade ganglioglioma and 7 patients with non-neoplastic lesions. Of the 127 patients, 97 had lesions with increased FET uptake, of which 93 were neoplastic. Increased uptake was found in 49/71 LGG (69 %) and 42/47 HGG (89 %). None of the conventional uptake parameters differed significantly between the HGG and LGG groups. Kinetic analysis reliably identified HGG (sensitivity 95 %, specificity 72 %, PPV 74 %, NPV 95 %). Normal tracer uptake was observed in 19 patients (15 with LGG, 1 with HGG and 3 with non-neoplastic lesions) and reduced uptake in 11 patients (7 with LGG and 4 with HGG). CONCLUSION: Among the MRI-suspected LGG, kinetic but not conventional analysis of FET uptake enabled remarkably high sensitivity for detection of HGG. This held true even for lesions with low or diffuse tracer uptake. Lesions with reduced tracer uptake must be interpreted with caution, as they can also harbour HGG tissue.

IDH1 mutations in grade II astrocytomas are associated with unfavorable progression-free survival and prolonged postrecurrence survival.

BACKGROUND: The favorable prognostic impact of mutations in the IDH1 gene is well documented for malignant gliomas; its influence on World Health Organization (WHO) grade II astrocytomas, however, is still under debate. METHODS: A previously published database of 127 predominantly surgically treated patients harboring WHO grade II astrocytomas was revisited. Patients were screened for TP53 mutations (sequencing analysis), IDH1 mutations (pyrosequencing), and MGMT promoter methylation (methylation-specific polymerase chain reaction and bisulfite sequencing). Endpoints were overall survival, progression-free survival (PFS), time to malignant transformation, and postrecurrence survival. Radiotherapy was usually withheld until tumor progression/malignant transformation occurred. RESULTS: IDH1 mutations, TP53 mutations, and methylated MGMT promoters were seen in 78.1%, 51.2%, and 80.0% of the analyzed tumors, respectively. IDH1 mutations, which were significantly associated with TP53 mutations and/or MGMT promoter methylation (P < .001), resulted in shortened PFS (median, 47 vs 84 months; P = .004); postrecurrence survival, however, was significantly increased in those patients undergoing malignant transformation (median, 49 vs 13.5 months; P = .006). Overall survival was not affected by IDH1. A similar pattern of influence was seen for MGMT promoter methylation. Methylated tumors did significantly worse (better) in terms of PFS (postrecurrence survival); a low number of unmethylated tumors, however, limited the power of this analysis. Conversely, TP53 mutations were stringently associated with a worse prognosis throughout the course of the disease. CONCLUSIONS: IDH1 mutations are associated with a Janus headlike phenomenon; unfavorable prognostic influence on PFS turns into favorable impact on postrecurrence survival. A similar pattern of influence might exist for MGMT methylation.

O-methylguanine-DNA methyltransferase (MGMT) mRNA expression predicts outcome in malignant glioma independent of MGMT promoter methylation.

BACKGROUND: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression. METHODOLOGY/PRINCIPAL FINDINGS: ADULT PATIENTS WITH A HISTOLOGICALLY PROVEN MALIGNANT ASTROCYTOMA (GLIOBLASTOMA: N = 53, anaplastic astrocytoma: N = 10) were included. MGMT promoter methylation was determined by methylation-specific PCR (MSP) and sequencing analysis. Expression of MGMT and DNMTs mRNA were analysed by real-time qPCR. Prognostic factors were obtained from proportional hazards models. Correlation between MGMT mRNA expression and MGMT methylation status was validated using data from the Cancer Genome Atlas (TCGA) database (N = 229 glioblastomas). Low MGMT mRNA expression was strongly predictive for prolonged time to progression, treatment response, and length of survival in univariate and multivariate models (p<0.0001); the degree of MGMT mRNA expression was highly correlated with the MGMT promoter methylation status (p<0.0001); however, discordant findings were seen in 12 glioblastoma patients: Patients with methylated tumors with high MGMT mRNA expression (N = 6) did significantly worse than those with low transcriptional activity (p<0.01). Conversely, unmethylated tumors with low MGMT mRNA expression (N = 6) did better than their counterparts. A nearly identical frequency of concordant and discordant findings was obtained by analyzing the TCGA database (p<0.0001). Expression of DNMT1 and DNMT3b was strongly upregulated in tumor tissue, but not correlated with MGMT promoter methylation and MGMT mRNA expression. CONCLUSIONS/SIGNIFICANCE: MGMT mRNA expression plays a direct role for mediating tumor sensitivity to alkylating agents. Discordant findings indicate methylation-independent pathways of MGMT expression regulation. DNMT1 and DNMT3b are likely to be involved in CGI methylation. However, their exact role yet has to be defined.

Predominant influence of MGMT methylation in non-resectable glioblastoma after radiotherapy plus temozolomide.

BACKGROUND: Patients with non-resectable glioblastoma generally exhibit a poor prognosis, even after radiotherapy plus concomitant and adjuvant temozolomide (XRT/TMZ→TMZ). Unfortunately, no data are available concerning the predictive value of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation for this important subpopulation. For clarification, a prospective study was conducted. METHODS: Adult patients with a non-resectable glioblastoma were included. A molecular stereotactic biopsy technique was used for tumour characterisation combining histopathological diagnosis with small sample size adjusted methylation-specific PCR (MSP) and sodium bisulfite sequencing. Treatment included XRT (60 Gy in 30 fractions)/TMZ (daily dose of 75 mg/m(2))→TMZ (150-200 mg/m(2) per day for 5 days of every 28-day cycle). The primary end point was progression-free survival (PFS). Secondary endpoints were overall survival (OS) and treatment response (TR). Patients were categorised in the Radiation Therapy Oncology Group (RTOG)-recursive partitioning analysis (RPA) Classes III (N=4), IV (N=12), V (N=28) and VI (N=12). RESULTS AND DISCUSSION: The success rates of MSP and sequence analyses were 100%. The MGMT promoter was methylated in 30/56 tumours, which was associated with an increased PFS (median 56 versus 20 weeks; hazard ratio 0.15; range 0.07 to 0.33; p<0.0001), higher frequency of TR (93.3% vs 46.2%; p=0.0008) and increased OS (median 104 vs 28 weeks; hazard ratio 0.18; range 0.08 to 0.38; p<0.0001). The transient perioperative morbidity was 1.8%. CONCLUSION: MGMT promoter methylation has a predominant favourable influence even for the important subpopulation with non-resectable glioblastoma. The molecular stereotactic biopsy technique is safe and effective for predictive evaluation and helps to avoid both over- and undertreatment.

Trigeminal neuralgia due to neurovascular compression: high-spatial-resolution diffusion-tensor imaging reveals microstructural neural changes.

PURPOSE: To preoperatively detect, by using diffusion-tensor imaging coregistered with anatomic magnetic resonance (MR) imaging, suspected microstructural tissue changes of the trigeminal nerves in patients with trigeminal neuralgia (TN) resulting from neurovascular compression. MATERIALS AND METHODS: The study was approved by the institutional review board, and written informed consent was obtained from all patients. Twenty patients (mean age, 51.3 years) with TN and evidence of neurovascular contact were examined with use of a 3.0-T MR unit combined with an eight-channel head coil before undergoing surgical decompression. A single-shot diffusion-tensor echo-planar sequence was used along 15 different diffusion directions, with a b value of 1000 sec/mm(2) and a section thickness of 2 mm. For anatomic correlation, 0.6-mm isotropic three-dimensional fast imaging employing steady-state images were acquired for coregistration with the functional diffusion-tensor maps. After region of interest placement, mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for each nerve by using the paired-sample two-tailed t test (with P < .005 indicating significance) and compared with surgical findings. RESULTS: FA was significantly lower (P = .004) on the trigeminal neuralgia-affected side (mean FA, 0.203) than on the contralateral side (mean FA, 0.239). ADCs were nearly identical between the normal and TN-affected nerve tissues. CONCLUSION: These findings suggest that diffusion-tensor imaging enables the identification and quantification of anisotropic changes between normal nerve tissue and TN-affected trigeminal nerves. Coregistration of anatomic three-dimensional fast imaging employing steady-state imaging and diffusion-tensor imaging facilitates excellent delineation of the cisternal segments of the trigeminal nerves.

Prediction of the fracture load of whole proximal femur specimens by topological analysis of the mineral distribution in DXA-scan images.

OBJECTIVE: To evaluate scanner-generated images of hip specimens obtained from dual energy X-ray absorptiometry (DXA) by quantitative image analysis of bone mineral distribution in the standard regions of interest (ROI), to predict the ultimate mechanical strength, and to compare the predictive potential with standard densitometry. MATERIALS AND METHODS: Femoral bone mineral density (BMD) of 100 hip specimens was obtained by DXA in the total hip, shaft, trochanteric, and neck ROI. Maximum compressive strength (MCS) of the specimens was measured in a mechanical loading device simulating a fall on the greater trochanter. The topology of bone mineral distribution in the scan images was evaluated by image processing methods based on the Minkowski functionals (MF) using the optimized topological parameter MF2D. Correlation and multivariate analysis were employed to assess the statistical potential of BMD and MF2D with respect to predict the mechanical strength of the femur specimens. RESULTS: R2 for the correlation between load-to-failure and BMD varied between 0.73 and 0.79 (exponential curve fit, p<0.001), being highest in the trochanteric ROI. Correlation between load-to-failure of the specimens with the topological parameter MF2D ranged from R2 =0.8 to 0.91 (p<0.001). In a multivariate model combining the topological information from all ROIs, correlation with MCS rose to R2 =0.94. CONCLUSION: The topological parameter MF2D can be employed to predict the mechanical strength of proximal femur specimens from DXA-generated images. Performance is superior to standard evaluation of DXA. In the future, the proposed image processing method may serve to improve the assessment of an individual's fracture risk.

CT cholangiography in potential liver donors: effect of premedication with intravenous morphine on biliary caliber and visualization.

PURPOSE: To retrospectively determine whether premedication with intravenously administered morphine improves bile duct caliber and visualization in potential liver donors undergoing computed tomographic (CT) cholangiography. MATERIALS AND METHODS: This was a retrospective single institution study approved by the institutional review board and compliant with requirements of the HIPAA. Multidetector CT cholangiography was performed after slow infusion of 20 mL of iodipamide meglumine 52% diluted in 80 mL of normal saline in 143 consecutive potential liver donors (81 men and 62 women; mean age, 37 years); 43 received premedication with intravenous morphine sulfate (0.04 mg per kilogram of body weight) and 100 did not. Two independent readers recorded common bile duct diameter and area on axial CT images. Readers also scored bile duct visualization, including all second-order biliary branches, on a four-point scale (0, not seen; 3, excellent visualization). RESULTS: For scans obtained without and those obtained with morphine, there was no significant difference in the mean common bile duct diameter (4.1 vs 4.3 mm for reader 1 and 4.4 vs 4.6 mm for reader 2, respectively; P > .39 for both readers), in common bile duct area (20.7 vs 21.5 mm(2), for reader 1 and 21.3 vs 20.2 mm(2) for reader 2, respectively, P > .60 for both), or in second-order bile duct visualization score (2.34 vs 2.36 for reader 1 and 2.58 vs 2.50 for reader 2, respectively; P > .5 for both). CONCLUSION: The results suggest that premedication with intravenous morphine prior to CT cholangiography in potential liver donors does not increase bile duct caliber or improve biliary visualization.

Evidence of subcortical and cortical aging of the acoustic pathway: a diffusion tensor imaging (DTI) study.

RATIONALE AND OBJECTIVES: During aging, there is evidence of microstructural changes in certain cortical and subcortical brain regions. Diffusion tensor imaging (DTI) is used to study age related microstructural changes in the acoustic pathway. MATERIALS AND METHODS: Twenty healthy volunteers (mean age 28.5 years) and 15 healthy volunteers (mean age 61.3 years) were examined using a 1.5-T MR system with a high-resolution T1-weighted sequence and an integrated parallel imaging technique DTI Echo-planar-imaging (EPI) sequence. For reliability, 10 subjects underwent a second examination 2 days later. The fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were measured in six brain regions of the auditory pathway. RESULTS: We found no left/right asymmetry in the selected brain structures. There were no significant differences (P < .05) in the ADC and FA in the lateral lemniscus and medial geniculate body of young and elderly subjects. However, FA was significantly increased (P < .05) in the inferior colliculus and decreased in the auditory radiation, the superficial temporal gyrus, and the transverse temporal gyrus in the elder subjects than in the younger ones. There were no significant differences in anisotropy in subsequent examinations in the younger individuals. CONCLUSIONS: These findings suggest evidence of age-related changes in the acoustic pathway. These changes are associated with a decrease in anisotropy mainly in the cortical grey and white matter rather than in the subcortical regions. Our DTI measurements were reproducible.

Experience after the evaluation of 700 potential donors for living donor liver transplantation in a single center.

Adequate selection of donors is a major prerequisite for living donor liver transplantation (LDLT). Few centers report on the entire number of potential donors considered or rejected for living donation. From April 1998 to July 2003, a total of 111 living donor liver transplantations were performed at our institution, with 622 potential donors for 297 adult recipients and 78 potential donors for 52 pediatric recipients evaluated. In the adult group, only 89 (14%) potential donors were considered suitable, with a total of 533 (86%) potential donors rejected. Of these, 67% were excluded either at initial screening or during the first and second steps of the evaluation procedure. In 31% of all cases, the evaluation of donors was canceled because of recipient issues. In the pediatric group, 22 (28%) donors were selected, with the other 56 (72%) rejected. Costs of the complete evaluation process accounted for 4,589 Euro (Euro) per donor. The evaluation of a potential living donor is a complex and expensive process. We present the results on the evaluation of the largest group of potential donors for adults reported in the literature. Only 14% of potential donors in our series were considered suitable candidates. It has not yet been established who should cover the expenses of the evaluation of all rejected donors. In conclusion, all efforts should be made in order to develop an effective screening protocol for the evaluation of donors with the aim of saving time and resources for a liver transplantation program.

Postoperative evaluation of complex aortovisceral and aortorenal reconstructions by magnetic resonance angiography.

RATIONALE AND OBJECTIVES: To assess the ability of magnetic resonance angiography (MRA) to evaluate complex vascular bypass reconstructions of the abdominal aorta and its major branches in the postoperative period. MATERIALS AND METHODS: Thirteen patients with bypass grafts connecting the aorta to visceral, renal, and lower limb inflow vessels were evaluated with MRA. Three of these patients were also studied with digital subtraction angiography soon after MRA was completed. MRA was evaluated for its ability to detect the grafts and to determine the degree of stenosis in the graft conduit or at the anastomoses to native vessels. RESULTS: Detection of graft conduits and anastomotic sites by MRA was 100% and 99%, respectively. Comparison with digital subtraction angiography in a subset of the patients showed a 100% agreement between the two modalities in their description of stenotic disease in graft conduits and 95% agreement in stenosis characterization at graft anastomotic sites. CONCLUSION: MRA of complex aortic reconstructions with bypass grafts to its major abdominal branches arteries accurately describes the resulting complicated vascular anatomy and likely has a high degree of correlation to digital subtraction angiography in describing the disease within the bypass grafts.

Intrahepatic portal-to-portal venous shunts in cirrhosis: a potential mimic of hepatocellular carcinoma.

Two intrahepatic portal-to-portal venous shunts demonstrated at computed tomography (CT) and ultrasound in a 40-year-old woman with cirrhosis are described. The shunts appeared as hypervascular hepatic foci on CT, simulating multifocal hepatocellular carcinoma. Follow-up multiphase CT with multiplanar reformation and Doppler ultrasound confirmed the correct diagnosis. Recognition of intrahepatic portal-to-portal venous shunts as a rare mimic of hepatocellular carcinoma in cirrhosis should prevent misinterpretation or inappropriate management.