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Objectives: To investigate the prevalence of cerebrovascular stenosis and white matter lesions on preoperative magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) in liver transplantation candidates.Methods: This retrospective study included 1,460 consecutive patients with liver cirrhosis (LC) who underwent MRA with/without brain MRI for pretransplantation evaluation. These patients were matched with 5,331 controls using propensity scores, and the prevalences of significant cerebrovascular stenosis and white matter lesions were compared.Results: A matched analysis of 1,264 pairs demonstrated that the prevalence of significant stenosis was comparable between LC patients and controls (2.2% vs. 1.4%, P = 0.143). LC and most of LC-related parameters were not associated with stenosis. Significant white matter lesions were more common in LC patients (2.8% vs. 1.3%, P = 0.036). A high Model for End-Stage Liver Disease (MELD) score (OR 1.11, CI 1.03-1.20, P = 0.008, for infarction; OR 1.1, CI 1.04-1.16, P = 0.001, for haemorrhage) and stroke history (OR 179.06, CI 45.19-709.45, P < 0.001) were predictors of perioperative stroke.Conclusions: LC patients and control subjects demonstrated similar cerebrovascular stenosis prevalences, whereas white matter lesions were more common in LC patients. A high MELD score and stroke history contribute as predictors of perioperative stroke.Key Points: • Routine preoperative MR imaging in liver transplantation candidates may not be necessary. • Liver cirrhosis patients and control subjects had similar prevalences of significant cerebrovascular stenosis. • Liver cirrhosis and cirrhosis-related parameters were not correlated with significant cerebrovascular stenosis. • Significant white matter lesions were more frequent in liver cirrhosis patients. [ABSTRACT FROM AUTHOR]

Objectives: To determine if gemistocytic grade II astrocytoma (GemA) and its MR imaging characteristics are associated with a shorter time-to-progression (TTP) compared with non-gemistocytic grade II astrocytoma (non-GemA).Materials and Methods: We enrolled 78 patients who were followed up more than 5 years (29 pathologically proven GemA and 49 non-GemA) during a 10-year period. Contrast-enhanced T1-weighted, diffusion-weighted imaging (DWI), dynamic susceptibility contrast (DSC), and MR spectroscopy (MRS) and clinical data were retrospectively reviewed. Clinical and MR imaging features were analyzed as possible prognostic factors of high-grade transformation, and multivariate analysis of TTP was performed using Cox proportional modeling.Results: GemA showed more frequent high-grade features than non-GemA, including diffusion restriction (P < .001), increased choline/creatine (P = .02), and increased choline/NAA ratio (P = .015). Patients with GemA had a significantly shorter median TTP (53.1 vs 68 months; P < .001). A gemistocytic histopathology (hazard ratio = 3.42; P = .015) and low ADC (hazard ratio = 3.61; P = .001) were independently associated with a shorter TTP.Conclusions: GemA can present with MR imaging findings mimicking high-grade glioma at initial diagnosis and transforms to high-grade disease earlier than non-GemA. Low ADC on DWI might be useful in stratifying the risk of progression in patients with grade II astrocytoma.Key Points: • Gemistocytic grade II astrocytoma (GemA) showed more frequent high-grade features than non-GemA. • Patients with GemA had a significantly shorter median TTP than non-GemA. • Gemistocytic histopathology and low ADC were independently associated with shorter TTP. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to determine whether diffusion and perfusion imaging parameters demonstrate different diagnostic values for predicting pseudoprogression between glioblastoma subgroups stratified by O6-mythylguanine-DNA methyltransferase (MGMT) promoter methylation status.Methods: We enrolled seventy-five glioblastoma patients that had presented with enlarged contrast-enhanced lesions on magnetic resonance imaging (MRI) one month after completing concurrent chemoradiotherapy and undergoing MGMT promoter methylation testing. The imaging parameters included 10 or 90 % histogram cutoffs of apparent diffusion coefficient (ADC10), normalized cerebral blood volume (nCBV90), and initial area under the time signal-intensity curve (IAUC90). The results of the areas under the receiver operating characteristic curve (AUCs) with cross-validation were compared between MGMT methylation and unmethylation groups.Results: MR imaging parameters demonstrated a trend toward higher accuracy in the MGMT promoter methylation group than in the unmethylation group (cross-validated AUCs = 0.70-0.95 and 0.56-0.87, respectively). The combination of MGMT methylation status with imaging parameters improved the AUCs from 0.70 to 0.75-0.90 for both readers in comparison with MGMT methylation status alone. The probability of pseudoprogression was highest (95.7 %) when nCBV90 was below 4.02 in the MGMT promoter methylation group.Conclusions: MR imaging parameters could be stronger predictors of pseudoprogression in glioblastoma patients with the methylated MGMT promoter than in patients with the unmethylated MGMT promoter.Key Points: • The glioblastoma subgroup was stratified according to MGMT promoter methylation status. • Diagnostic values of diffusion and perfusion parameters for predicting pseudoprogression were compared. • Imaging parameters showed higher diagnostic accuracy in the MGMT promoter methylation group. • Imaging parameters were independent to MGMT promoter methylation status for predicting pseudoprogression. • Imaging biomarkers might demonstrate different diagnostic values according to MGMT promoter methylation. [ABSTRACT FROM AUTHOR]

Objectives: To determine the diagnostic superiority of parametric response mapping of apparent diffusion coefficient (ADCPR) for predicting glioblastoma treatment response, compared to single time point measurement.Methods: Fifty post-treatment glioblastoma patients were enrolled. ADCPR was calculated from serial apparent diffusion coefficient (ADC) maps acquired before and at the time of first detection of an enlarged contrast-enhancing lesion on voxel-by-voxel basis. The percentage-decrease in ADCPR and tenth percentile histogram cutoff value of ADC (ADC10) were compared at subsequent 3-month and 1-year follow-ups.Results: The percentage-decrease in ADCPR was significantly higher in the progression group (mean = 33.2-38.3 %) than in the stable-response group (mean = 9.7 %) at 3 months follow-up (corrected p < 0.001 for both readers). ADCPR significantly improved area under the receiver operating characteristic curve from 0.67 to 0.88 (corrected p = 0.037) and from 0.70 to 0.92 (corrected p = 0.020) for both readers, respectively, compared to ADC10 at 3-month follow-up, but did not significantly improve at 1-year follow-up. The inter-reader agreement was higher for ADCPR than ADC10 (intraclass correlation coefficient, 0.93 versus 0.86).Conclusion: Voxel-based ADCPR appears to be a superior imaging biomarker than ADC, particularly for predicting early tumour progression in patients with glioblastoma.Key Points: • Treatment response pattern of glioblastoma was evaluated using voxel-based ADCPR and ADC10. • Voxel-based ADCPR was more accurate in predicting treatment response pattern than ADC10. • Inter-reader agreement was higher in ADCPR calculation than in ADC10 calculation. • Voxel-based ADCPR can be a predictor of early treatment response pattern for glioblastoma. [ABSTRACT FROM AUTHOR]

The outcomes of expanded criteria donor ( ECD) kidneys have been reported to be inferior compared with standard criteria donor ( SCD) kidneys. However, the graft survival rate of ECD is not so inferior to SCD in Korea. The purposes of this study were to compare the outcomes of ECD kidneys with SCD kidneys and identify the influencing factors. We retrospectively studied 143 deceased donor transplants from August 2006 to June 2010. The patients were divided into SCD (n = 117) and ECD (n = 26) by UNOS criteria. The one- and three-yr graft survival rates of SCD and ECD (99.1% and 94.4% vs. 100% and 92.9%, respectively, p = 0.15) were not significantly different between groups. The mean cold ischemic time ( CIT) was 3.8 ± 2.2 h. When compared the outcome of ECD kidneys with data reported by Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients ( OPTN/ SRTR) (one- and three-yr graft survival rate: 86.7% and 73.2%), the graft survival rate of our center was superior. In OPTN/ SRTR data, transplant with CIT shorter than 11 h was only 20%. The outcomes of ECD grafts are outstanding and comparable with SCD grafts in our center, and the only distinguishing factor is markedly short CIT. Finishing the allocation before organ recovery and immediate operations after recovery could shorten the CIT. [ABSTRACT FROM AUTHOR]

Objectives: There are few long-term follow-up studies about the result of revascularization surgery for the treatment of popliteal artery entrapment syndrome (PAES). We performed this retrospective study to analyze the long-term result of revascularization surgery in patients with advanced PAES during the last 16 years. Methods: Twenty-two limbs in 18 consecutive patients with PAES were treated surgically at Seoul National University Hospital between January 1994 and December 2009. The preoperative diagnosis of PAES was made by duplex ultrasonography, three-dimensional computed tomography angiography, magnetic resonance imaging, or conventional angiography. The method of surgical approach was determined by the extent of arterial occlusion in preoperative images. Results: The mean age was 31 years old and the majority of patients were men (94%). The chief complaints were claudication in 18 limbs, ischemic rest pain in three limbs, and toe necrosis in one limb. All 22 limbs underwent revascularization for advanced PAES with segmental arterial occlusion. Fourteen limbs underwent musculotendinous section and popliteo-popliteal interposition graft (13 posterior approaches, one medial approach), five femoropopliteal (below-knee) bypasses, one femoro-posterior tibial bypass, and two popliteo-posterior tibial bypasses. All revascularization surgeries were performed with reversed saphenous veins. The overall primary graft patency rates at 1, 3, and 5 years were 80.9%, 74.6%, and 74.6%, respectively. Comparing 5-year graft patency according to the extent of arterial occlusion, patients with occlusion confined to the popliteal artery (n = 14) showed a better patency rate than patients with occlusion extended beyond the popliteal artery (n = 8) with no statistical significance (83.6% vs 53.6%; P = .053). Comparing 5-year graft patency according to the inflow artery, superficial femoral artery inflow (n = 6) showed a worse patency rate than popliteal artery inflow (n = 16) (30.0% vs 85.9%; P = .015). Conclusion: In advanced popliteal entrapment syndrome, longer bypass with superficial femoral artery inflow showed poor long-term graft patency rate. The graft patency rate was excellent in patients whose arterial occlusion was confined to the popliteal artery and treated by popliteal interposition graft with reversed saphenous vein. With these data, we suggest that longer bypass extending beyond the popliteal artery might only be indicated in patients with critical limb ischemia when the extent of disease does not allow short interposition graft. [ABSTRACT FROM AUTHOR]

Objective: Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) is extremely rare. Various treatment options are currently available, including conservative management, anticoagulation, endovascular stenting, and surgical repair. Herein, we present our experience in the treatment of symptomatic SIDSMA. Methods: A retrospective study was conducted on 14 consecutive patients with symptomatic SIDSMA between January 2000 and January 2010. All patients had acute onset abdominal pain. The decision to intervene was based on patient symptoms and signs, as well as the morphologic characteristics of superior mesenteric artery (SMA) dissection on computed tomography (CT) angiography. Endovascular stenting (ES) was indicated in patients with severe compression of the true lumen or dissecting aneurysm likely to rupture. Self-expandable stents were placed via a right common femoral approach. None of the patients underwent anticoagulation, and patients who underwent ES were maintained on antiplatelet therapy for 3 months postoperatively. Results: The median age of the study subjects was 59 years (range, 50-75 years). The median follow-up time was 27.5 months (range, 2-64 months). Treatment included conservative management without the use of anticoagulation in seven patients, ES in six, and necrotic bowel resection in one. Four patients with severe compression of the true lumen or large dissecting aneurysm underwent ES as a primary treatment. ES was additionally performed in two patients in whom initial conservative treatment failed (increasing dissecting aneurysm at 7-day follow-up CT scan in one and a reappearance of abdominal pain after resuming diet in the other). The median fasting time was significantly shorter in patients with primary ES (2.5 days) than in those managed conservatively (8.0 days). No complications associated with the SIDSMA or ES were developed. The patency of stents was demonstrated on follow-up CT scans up to 60 months (range, 1-60 months). Conclusions: Conservative management without anticoagulation can be applied successfully to the patients with symptomatic SIDSMA. Primary endovascular stenting is indicated if patients have suspected bowel ischemia, compression of the true lumen of the SMA >80%, or SMA aneurysm of >2.0 cm in diameter on initial CT scan. Endovascular stenting can also be provided to the patients in whom initial conservative treatment failed, as a rescue therapy. [Copyright &y& Elsevier]

Purpose: Computed tomography venography (CTV) with three-dimensional reconstruction can provide complementary road maps for varicose vein (VV) surgery. The purpose of this study is to verify the role of CTV in the treatment of VV in terms of advantages and complications. Methods: Ninety-four consecutive patients with VV underwent conventional high ligation, stripping, and varicosectomy by a single vascular surgeon in 2007. All patients were evaluated with duplex ultrasound and CTV. Patients with renal dysfunction, allergy to radiocontrast, telangiectasia only, or treated by endovenous laser therapy (EVLT) were excluded from the study. Computed tomography (CT) examination was performed with a 16-Multidetector CT scanner (Siemens, Erlangen, Germany) and 3D images were reconstructed by personal computer-based software (Rapidia, Infinitt, Seoul, Korea). Medical records and the CT images were reviewed retrospectively. Results: VV surgeries were done in 127 limbs of 94 patients (both in 33, right in 29, and left in 32). There were 56 females and 38 males with the mean age of 57 years (range, 28-79 years). The CEAP classification was C2-3 EpAsPr. Perforators larger than 1 mm near the varicose veins were detected and marked on the CT volume-rendering images. The average numbers of perforators marked by CTV were 12.07 ± 4.27 in each limb. The perforators were evaluated by duplex for the presence of reflux (≥0.5 sec). Mean number of perforators with reflux in each limb was 1.41 ± 1.67, which were ligated during the surgery. Incidental detections of other disease were done in six patients, including uterine myomas, an ovarian cyst, a gallstone, a scrotoal varicocele, and a pes anserine bursitis. Operation was performed with the CTV images on screen. CTV was helpful in designing the operation in most patients. Three-D CTV images of saphenopopliteal junction especially provided thorough understanding of the complex variable anatomy of the lesion. There were no CT-related complications, such as renal dysfunction or allergic reaction. Conclusions: CT venography can provide excellent road map for VV surgery without significant complications. It cannot replace duplex ultrasound, but can provide powerful 3D images for designing operation as well as education and research. [Copyright &y& Elsevier]

Purpose: Since the publication of Dialysis Outcomes Quality Initiative (DOQI) guidelines, the use of native veins for the construction of arteriovenous fistulas (AVF) for hemodialysis has been highly recommended rather than prosthetic arteriovenous grafts (AVG). Upper arm basilic vein transposition (BVT) has been accepted widely, with superior patency compared with AVG, but only a few studies have reported outcomes of forearm BVT (FBVT). This study evaluated the efficacy of FBVT compared with direct AVF (DAVF) and AVG in a tertiary referral center. Methods: From January 2005 to December 2007, 461 patients underwent AV access for hemodialysis in Seoul National University Hospital. We retrospectively reviewed the medical records and dialysis sheets and evaluated the current AVF function in the outpatient clinic or by telephone interviews. Patients were grouped by the operation type: DAVF, FBVT, and AVG. The outcomes compared were primary, assisted-primary and secondary patency rates, maturation failure, and complications. Result: The mean age was 59 years (range, 14-92 years), and 280 patients (60.7%) were male. By operation type, the 461 accesses were 389 DAVF (84.4%), 34 FBVT (7.4%), and 38 AVG (8.2%). Mean follow-up duration was 21 months (range, 1-51 months). The primary patency rates for DAVF, FBVT, and AVG were 67.6%, 41.5%, 35% at 12 months and 53.9%, 30.2%, 10.3% at 24 months, respectively. The secondary patency rates were 89.2%, 79.1%, 78.3% at 12 months and 83.8%, 74.4%, 64.9% at 24 months, respectively. Maturation failure occurred in five DAVF patients and in one FBVT patient. The infection rate was 0.3% in DAVF and 12.5% in AVG, but no infection occurred in patients with FBVT. Multivariate analysis revealed that age and history of previous access were associated with lower primary patency. Conclusion: Forearm BVT showed an acceptable, high 2-year patency rate and fewer thromboses and infectious complications than AVG. Forearm BVT could be considered before forming an upper arm AVF or forearm AVG, if the basilic vein is available. [Copyright &y& Elsevier]

Abstract: Background: Ischemic lesion growth may be a surrogate marker of clinical outcome, but no such interrelationship after thrombolysis has yet been determined. We evaluated the association between early infarct growth on diffusion-weighted imaging (DWI) and long-term clinical outcome after thrombolysis. Methods: We retrospectively reviewed outcomes in patients with acute middle cerebral artery territory stroke who had been treated with intravenous tissue plasminogen activator or intra-arterial urokinase. DWI lesion volumes were measured at baseline and within 7days, and the difference was calculated. Clinical outcome was evaluated using the modified Rankin Scale (mRS) at 3months. Good and poor clinical outcomes were defined as: a) mRS 0–1 vs. mRS 2–6, b) mRS 0–2 vs. mRS 3–6, and c) responder analysis which was influenced by the baseline National Institutes of Health Stroke Scale (NIHSS) scores: good and poor outcomes were defined as mRS 0 vs. mRS 1–6 if the baseline NIHSS score was <8, mRS 0–1 vs. mRS 2–6 if the NIHSS score was 8–14, and mRS 0–2 vs. mRS 3–6 if the NIHSS score was >14. The relationship between the ischemic lesion volume change and clinical outcome was explored. The cut-off value of infarct growth predicting long-term outcome was estimated using receiver operating characteristic analysis. Results: Of the 81 patients included, 67 (82.7%) showed lesion growth, and absolute growth was significantly related to poor outcomes (P<0.001 all for mRS 2–6, mRS 3–6, and responder analysis). Multivariate analysis showed that absolute lesion growth was an independent predictor of poor outcome, defined as mRS 2–6 (P=0.002; odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02–1.10), mRS 3–6 (P=0.001; OR, 1.06; 95% CI, 1.02–1.10), and poor outcome by responder analysis (P=0.001; OR, 1.06; 95% CI, 1.03–1.10). The cut-off values of lesion growth that discriminated between good and poor outcomes were 14.11cm3 for mRS 2–6; 15.87cm3 for mRS 3–6; and 14.11cm3 in responder analysis. Conclusions: Early DWI lesion growth is an independent predictor of poor outcome after thrombolysis and may serve a potential surrogate marker of clinical outcome in acute stroke trials. [Copyright &y& Elsevier]

Abstract: The purpose of our study was to evaluate the ultrasound features of suture granulomas at the thyroid bed after thyroidectomy for papillary thyroid carcinoma with an emphasis on their differentiation from locally recurrent thyroid carcinomas. We enrolled 14 suture granulomas in 10 patients and 20 locally recurrent carcinomas in 18 patients after thyroidectomy, confirmed by surgery (15 out of 20 recurrent carcinomas), or ultrasound-guided fine needle aspiration cytology (14 suture granulomas and 5 recurrent carcinomas). The ultrasound findings, including presence of internal echogenic foci suggesting calcification or suture material, were compared between the two groups. In the cases with internal echogenic foci, the size, number, distribution pattern, and the presence of a paired appearance were also evaluated. In result, most of the suture granulomas were irregular (n=13) and heterogeneous (n=9) (p <0.05). The incidence of internal echogenic foci was higher in suture granulomas (n=12) than in recurrent carcinomas (n=7) (p <0.05). The internal echogenic foci in all suture granulomas were clustered centrally or paracentrally, unlike those in recurrent carcinomas (p <0.05). Most of the echogenic foci in suture granulomas were larger than 1 mm in diameter (p <0.05) and had a paired appearance (p <0.05). Shape, heterogeneity, and the presence of central or paracentral internal echogenic foci are helpful criteria for differentiating suture granulomas from locally recurrent tumors in the thyroid bed. (E-mail: jeonghlee@hanmir.com) [Copyright &y& Elsevier]