In the field of diagnostic test accuracy (DTA), the use of systematic review and meta-analyses is steadily increasing. By means of objective evaluation of all available primary studies, these two processes generate an evidence-based systematic summary regarding a specific research topic. The methodology for systematic review and meta-analysis in DTA studies differs from that in therapeutic/interventional studies, and its content is still evolving. Here we review the overall process from a practical standpoint, which may serve as a reference for those who implement these methods.

Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies.

Liposuction is one of the most frequently performed cosmetic surgeries worldwide for reshaping the body contour. Although liposuction is minimally invasive and relatively safe, it is a surgical procedure, and it carries the risk of major and minor complications. These complications vary from postoperative nausea to life-threatening events. Common complications include infection, abdominal wall injury, bowel herniation, bleeding, haematoma, seroma, and lymphoedema. Life-threatening complications such as necrotizing fasciitis, deep vein thrombosis, and pulmonary embolism have also been reported. In this paper, we provide a brief introduction to liposuction with the related anatomy and present computed tomography and ultrasonography findings of a wide spectrum of postoperative complications associated with liposuction.

Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field.

Objective: To investigate the image quality (IQ) and apparent diffusion coefficient (ADC) of reduced field-of-view (FOV) di-ffusion-weighted imaging (DWI) of pancreas in comparison with full FOV DWI. Materials and Methods: In this retrospective study, 2 readers independently performed qualitative analysis of full FOV DWI (FOV, $38{\times}38cm$; b-value, 0 and $500m^2/sec$) and reduced FOV DWI (FOV, $28{\times}8.5cm$; b-value, 0 and $400mm^2/sec$2). Both procedures were conducted with a two-dimensional spatially selective radiofrequency excitation pulse, in 102 patients with benign or malignant pancreatic diseases (mean size, $27.5{\pm}14.4mm$). The study parameters included 1) anatomic structure visualization, 2) lesion conspicuity, 3) artifacts, 4) IQ score, and 5) subjective clinical utility for confirming or excluding initially considered differential diagnosis on conventional imaging. Another reader performed quantitative ADC measurements of focal pancreatic lesions and parenchyma. Wilcoxon signed-rank test was used to compare qualitative scores and ADCs between DWI sequences. Mann Whitney U-test was used to compare ADCs between the lesions and parenchyma. Results: On qualitative analysis, reduced FOV DWI showed better anatomic structure visualization ($2.76{\pm}0.79$ at $b=0s/mm^2$ and $2.81{\pm}0.64$ at $b=400s/mm^2$), lesion conspicuity ($3.11{\pm}0.99$ at $b=0s/mm^2$ and $3.15{\pm}0.79$ at $b=400s/mm^2$), IQ score ($8.51{\pm}2.05$ at $b=0s/mm^2$ and $8.79{\pm}1.60$ at $b=400s/mm^2$), and higher clinical utility ($3.41{\pm}0.64$), as compared to full FOV DWI (anatomic structure, $2.18{\pm}0.59$ at $b=0s/mm^2$ and $2.56{\pm}0.47$ at $b=500s/mm^2$; lesion conspicuity, $2.55{\pm}1.07$ at $b=0s/mm^2$ and $2.89{\pm}0.86$ at $b=500s/mm^2$; IQ score, $7.13{\pm}1.83$ at $b=0s/mm^2$ and $8.17{\pm}1.31$ at $b=500s/mm^2$; clinical utility, $3.14{\pm}0.70$) (p < 0.05). Artifacts were significantly improved on reduced FOV DWI ($2.65{\pm}0.68$) at $b=0s/mm^2$ (full FOV DWI, $2.41{\pm}0.63$) (p < 0.001). On quantitative analysis, there were no significant differences between the 2 DWI sequences in ADCs of various pancreatic lesions and parenchyma (p > 0.05). ADCs of adenocarcinomas ($1.061{\times}10^{-3}mm^2/s{\pm}0.133$ at reduced FOV and $1.079{\times}10^{-3}mm^2/s{\pm}0.135$ at full FOV) and neuroendocrine tumors ($0.983{\times}10^{-3}mm^2/s{\pm}0.152$ at reduced FOV and $1.004{\times}10^{-3}mm^2/s{\pm}0.153$ at full FOV) were significantly lower than those of parenchyma ($1.191{\times}10^{-3}mm^2/s{\pm}0.125$ at reduced FOV and $1.218{\times}10^{-3}mm^2/s{\pm}0.103$ at full FOV) (p < 0.05). Conclusion: Reduced FOV DWI of the pancreas provides better overall IQ including better anatomic detail, lesion conspicuity and subjective clinical utility.

Ultrasound-guided percutaneous radiofrequency (RF) ablation has become one of the most promising local cancer therapies for both resectable and nonresectable hepatic tumors. Although RF ablation is a safe and effective technique for the treatment of liver tumors, the outcome of treatment can be closely related to the location and shape of the tumors. There may be difficulties with RF ablation of tumors that are adjacent to large vessels or extrahepatic heat-vulnerable organs and tumors in the caudate lobe, possibly resulting in major complications or treatment failure. Thus, a number of strategies have been developed to overcome these challenges, which include artificial ascites, needle track ablation, fusion imaging guidance, parallel targeting, bypass targeting, etc. Operators need to use the right strategy in the right situation to avoid the possibility of complications and incomplete thermal tissue destruction; with the right strategy, RF ablation can be performed successfully, even for hepatic tumors in high-risk locations. This article offers technical strategies that can be used to effectively perform RF ablation as well as to minimize possible complications related to the procedure with representative cases and schematic illustrations.

This pictorial review aims to illustrate the magnetic resonance imaging (MRI) findings and presentation patterns of anatomical variations and various benign and malignant pathologies of the duodenum, including sphincter contraction, major papilla variation, prominent papilla, diverticulum, annular pancreas, duplication cysts, choledochocele, duodenal wall thickening secondary to acute pancreatitis, postbulbar stenosis, celiac disease, fistula, choledochoduodenostomy, external compression, polyps, Peutz-Jeghers syndrome, ampullary carcinoma and adenocarcinoma. MRI is a useful imaging tool for demonstrating duodenal pathology and its anatomic relationships with adjacent organs, which is critical for establishing correct diagnosis and planning appropriate treatment, especially for surgery.

Candida is a commensal organism that is frequently found in the human gastrointestinal tract. It is the most common organism that causes pancreatic fungal infections. However, magnetic resonance imaging findings of Candida infection in the pancreas have not been described. We report imaging findings of pancreatic candidiasis in a patient in immunocompetent condition. It presented as a multi-septated cystic mass with a peripheral solid component in the background of pancreatitis and restricted diffusion on diffusion-weighted image that mimicked a malignant pancreatic cystic tumor.

A large number of major cardiovascular events occur in patients due to minimal or some lumen narrowing of the coronary artery. Recent biological studies have shown that the biological composition or vulnerability of the plaque is more critical for plaque rupture compared to the degree of stenosis. To overcome the limitations of anatomical images, molecular imaging techniques have been suggested as promising imaging tools in various fields. F-18 fluorodeoxyglucose (FDG), which is widely used in the field of oncology, is an example of molecular probes used in atherosclerotic plaque evaluation. FDG is a marker of plaque macrophage glucose utilization and inflammation, which is a prominent characteristic of vulnerable plaque. Recently, F-18 fluoride has been used to visualize vulnerable plaque in clinical studies. F-18 fluoride accumulates in regions of active microcalcification, which is normally observed during the early stages of plaque formation. More studies are warranted on the accumulation of F-18 fluoride and plaque formation/vulnerability; however, due to high specific accumulation, low background activity, and easy accessibility, F-18 fluoride is emerging as a promising non-invasive imaging probe to detect vulnerable plaque.

Here we report a case of 41-year-old man with a soft tissue density mass at right upper lung and palpable abscesses at right upper backside and right wrist. $^{18}F$-fluorodeoxyglucose positron emission tomography/computed tomography demonstrated a $7.8{\times}5.0cm$ mass with soft-tissue density in the upper lobe of the right lung with high metabolic activity. The infiltrative mass extended to adjacent chest wall soft tissue. Final diagnosis of pulmonary actinomycosis with multiple abscesses was made. The patient responded well to antibiotics treatment.

Irregular hypoechoic masses in the breast do not always indicate malignancies. Many benign breast diseases present with irregular hypoechoic masses that can mimic carcinoma on ultrasonography. Some of these diseases such as inflammation and trauma-related breast lesions could be suspected from a patient's symptoms and personal history. Careful ultrasonographic examination and biopsy could help to differentiate these from malignancies.

Objective: We intended to calculate approximate fetal doses in pregnant women who underwent diagnostic radiology procedures and to evaluate the safety of their pregnancies. Materials and Methods: We contacted hospitals in different cities in Turkey where requests for fetal dose calculation are usually sent. Fetal radiation exposure was calculated for 304 cases in 218 pregnant women with gestational ages ranging from 5 days to 19 weeks, 2 days. FetDose software (ver. 4.0) was used in fetal dose calculations for radiographic and computed tomography (CT) procedures. The body was divided into three zones according to distance from the fetus. The first zone consisted of the head area, the lower extremities below the knee, and the upper extremities; the second consisted of the cervicothoracic region and upper thighs; and the third consisted of the abdominopelvic area. Fetal doses from radiologic procedures between zones were compared using the Kruskal-Wallis test and a Bonferroni-corrected Mann-Whitney U-test. Results: The average fetal doses from radiography and CT in the first zone were $0.05{\pm}0.01mGy$ and $0.81{\pm}0.04mGy$, respectively; $0.21{\pm}0.05mGy$ and $1.77{\pm}0.22mGy$, respectively, in the second zone; and $6.42{\pm}0.82mGy$ and $22.94{\pm}1.28mGy$, respectively, in the third zone (p < 0.001). Our results showed that fetal radiation exposures in our group of pregnant women did not reach the level (50 mGy) that is known to increase risk for congenital anomalies. Conclusion: Fetal radiation exposure in the diagnostic radiology procedures in our study did not reach risk levels that might have indicated abortion.

Objective: To evaluate the safety and clinical outcomes of chemoembolization in Child-Pugh class C patients with hepatocellular carcinomas (HCC). Materials and Methods: The study comprised 55 patients with HCC who were classified as Child-Pugh class C and who underwent initial chemoembolization between January 2003 and December 2012. Selective chemoembolization was performed in all technically feasible cases to minimize procedure-related complications. All adverse events within 30 days were recorded using the Common Terminology Criteria for Adverse Events (CTCAE). The tumor response to chemoembolization was evaluated using the modified Response Evaluation Criteria In Solid Tumors. Results: Thirty (54.5%) patients were within the Milan criteria, and 25 (45.5%) were beyond. The mortality of study subjects at 30 days was 5.5%. Major complications were observed in five (9.1%) patients who were all beyond the Milan criteria: two hepatic failures, one hepatic encephalopathy, and two CTCAE grade 3 increases in aspartate aminotransferase/alanine aminotransferase abnormality. The mean length of hospitalization was $6.3{\pm}8.3days$ (standard deviation), and 18 (32.7%) patients were discharged on the next day after chemoembolization. The tumor responses of the patients who met the Milan criteria were significantly higher (p = 0.014) than those of the patients who did not. The overall median survival was 7.1 months (95% confidence interval: 4.4-9.8 months). Conclusion: Even in patients with Child-Pugh class C, chemoembolization can be performed safely with a selective technique in selected cases with a small tumor burden.

Objective: The purpose of this study was to evaluate the reliability of a new magnetic resonance imaging (MRI) grading system for cervical neural foraminal stenosis (NFS). Materials and Methods: Cervical NFS at bilateral C4/5, C5/6, and C6/7 was classified into the following three grades based on the T2-weighted axial images: Grade 0 = absence of NFS, with the narrowest width of the neural foramen greater than the width of the extraforaminal nerve root (EFNR); Grade 1 = the narrowest width of the neural foramen the same or less than (but more than 50% of) the width of the EFNR; Grade 2 = the width of the neural foramen the same or less than 50% of the width of the EFNR. The MRIs of 96 patients who were over 60 years old (M:F = 50:46; mean age 68.4 years; range 61-86 years) were independently analyzed by seven radiologists. Interobserver and intraobserver agreements were analyzed using the percentage agreement, kappa statistics, and intraclass correlation coefficient (ICC). Results: For the distinction among the three individual grades at all six neural foramina, the ICC ranged from 0.68 to 0.73, indicating fair to good reproducibility. The percentage agreement ranged from 60.2% to 70.6%, and the kappa values (${\kappa}$ = 0.50-0.58) indicated fair to moderate agreement. The percentages of intraobserver agreement ranged from 85.4% to 93.8% (${\kappa}$ = 0.80-0.92), indicating near perfect agreement. Conclusion: The new MRI grading system shows sufficient interobserver and intraobserver agreement to reliably assess cervical NFS.

Objective: To assess the performance of diffusion tensor imaging (DTI) for the diagnosis of cervical spondylotic myelopathy (CSM) in patients with deformed spinal cord but otherwise unremarkable conventional magnetic resonance imaging (MRI) findings. Materials and Methods: A total of 33 patients who underwent MRI of the cervical spine including DTI using two-dimensional single-shot interleaved multi-section inner volume diffusion-weighted echo-planar imaging and whose spinal cords were deformed but showed no signal changes on conventional MRI were the subjects of this study. Mean diffusivity (MD), longitudinal diffusivity (LD), radial diffusivity (RD), and fractional anisotropy (FA) were measured at the most stenotic level. The calculated performance of MD, FA, MD${\cap}$FA (considered positive when both the MD and FA results were positive), LD${\cap}$FA (considered positive when both the LD and FA results were positive), and RD${\cap}$FA (considered positive when both the RD and FA results were positive) in diagnosing CSM were compared with each other based on the estimated cut-off values of MD, LD, RD, and FA from receiver operating characteristic curve analysis with the clinical diagnosis of CSM from medical records as the reference standard. Results: The MD, LD, and RD cut-off values were $1.079{\times}10^{-3}$, $1.719{\times}10^{-3}$, and $0.749{\times}10^{-3}mm^2/sec$, respectively, and that of FA was 0.475. Sensitivity, specificity, positive predictive value and negative predictive value were: 100 (4/4), 44.8 (13/29), 20 (4/20), and 100 (13/13) for MD; 100 (4/4), 27.6 (8/29), 16 (4/25), and 100 (8/8) for FA; 100 (4/4), 58.6 (17/29), 25 (4/16), and 100 (17/17) for MD${\cap}$FA; 100 (4/4), 68.9 (20/29), 30.8 (4/13), and 100 (20/20) for LD${\cap}$FA; and 75 (3/4), 68.9 (20/29), 25 (3/12), and 95.2 (20/21) for RD${\cap}$FA in percentage value. Diagnostic performance comparisons revealed significant differences only in specificity between FA and MD${\cap}$FA (p = 0.003), FA and LD${\cap}$FA (p < 0.001), FA and RD${\cap}$FA (p < 0.001), MD and LD${\cap}$FA (p = 0.024) and MD and RD${\cap}$FA (p = 0.024). Conclusion: Fractional anisotropy combined with MD, RD, or LD is expected to be more useful than FA and MD for diagnosing CSM in patients who show deformed spinal cords without signal changes on MRI.

Objective: To evaluate the correlation between bone tunnel diameter after anterior cruciate ligament (ACL) reconstruction measured by computed tomography (CT) using multiplanar reconstruction (MPR) and stability or clinical scores. Materials and Methods: Forty-seven patients (41 men and 6 women, mean age: 34 years) who had undergone ACL reconstruction with the double bundle technique using auto-hamstring graft and had subsequently received CT scans immediately after the surgery (T1: range, 1-4 days, mean, 2.5 days) and at a later time (T2: range, 297-644 days, mean, 410.4 days) were enrolled in this study. The diameter of each tunnel (two femoral and two tibial) at both T1 and T2 were independently measured using MPR technique by two radiologists. Stability and clinical scores were evaluated with a KT-2000 arthrometer, International Knee Documentation Committee objective scores, and the Lysholm score. Statistical analysis of the correlation between the diameter at T2 or the interval diameter change ratio ([T2 - T1] / T1) and clinical scores or stability was investigated. Results: The tibial bone tunnels for the anteromedial bundles were significantly widened at T2 compared with T1 (observer 1, 0.578mm to 0.698mm, p value of < 0.001; observer 2, 0.581mm to 0.707mm, p value of < 0.001). There was no significant correlation between the diameter at T2 and stability or clinical scores and between the interval change ratio ([T2 - T1] / T1) and stability or clinical scores (corrected p values for all were 1.0). Intraobserver agreement for measurements was excellent (> 0.8) for both observers. Interobserver agreement for measurement was excellent (> 0.8) except for the most distal portion of the femoral bone tunnel for anterior medial bundle in immediate postoperative CT, which showed moderate agreement (concordance correlation coefficient = 0.6311). Conclusion: Neither the diameter nor its change ratio during interval follow-up is correlated with stability or clinical scores.

Objective: To evaluate the association between alpha angle and herniation pit on MRI in asymptomatic hip joints and their associations with demographic variables. Materials and Methods: Hip MRI of 185 asymptomatic hip joints of 105 adults (age 18 to 80 years) from September 2011 through December 2012 were retrospectively studied. Alpha angles were measured on oblique axial MR images by 2 observers. Herniation pit was determined by 1 observer. Size measures, prevalence, and statistical analyses were conducted regarding its association with age, gender, laterality (right or left hip). Intra- and inter-observer agreements were determined by intra-class correlation coefficient. Results: The prevalence of herniation pit in asymptomatic hips was 21.6%. The range of alpha angle was 27.6-65.0 degrees. Seventeen and 16 out of 185 (9.1% and 8.6%) hip joints showed alpha angle of ${\geq}55$ degrees in first and second measurement sessions, respectively. There was no association between alpha angle ${\geq}55$ and presence of herniation pit. There was no association between alpha angle ${\geq}55$ and the size of herniation pit. Inter-observer agreement of alpha angle was 0.485 between first measurements of first vs. second observer, respectively. Intra-observer agreement of alpha angle was 0.654, respectively. Forty (21.6%) of 185 hip joints (35 of 105 patients, 33.3%) had herniation pit, with no difference according to age, gender, or laterality of hip joint. Conclusion: There is no association between alpha angle ${\geq}55$ degrees and presence of herniation pit or demographic variables.

Objective: We described the technique of ultrasound (US)-guided percutaneous removal of the foreign bodies (FB) with hydro-dissection in the radiologic department and presented video files of several cases. Materials and Methods: Four patients referred to the radiology department for US evaluation and US-guided percutaneous removal of the FBs in the upper and lower extremities between November, 2006 and November, 2013 were included in this study. The procedures started with US evaluation for the exact location and shape of the FB. A 5mm-sized skin incision was made at the site of the nearest point from the FB where no passing arteries or tendons were present. We adopted a hydrodissection technique to separate the FB from adjacent tissue using a 2% lidocaine solution. Injected anesthetics detached the FBs from surrounding tissue and thereby facilitated removal. After the tip of the mosquito forceps reached the FB, the wooden FBs were removed. Results: The mean time required for the entire procedure was approximately 20 minutes. There were no significant complications during the US-guided removal or long-term complications after the procedure. All 4 FBs were successfully removed from the soft tissue under US guidance. Conclusion: Ultrasound-guided percutaneous removal of the FBs with hydro-dissection in the radiology department is a less invasive and safe method over surgical removal in the operating room. Additionally, the use of a guide wire and serial dilator may help minimize soft tissue injury and facilitate the introduction of forceps.

Objective: To compare single-session radiofrequency ablation (RFA) and ethanol ablation (EA) for treating predominantly cystic thyroid nodules (PCTNs). Materials and Methods: This single-blind, randomized trial was approved by the Institutional Review Board of two centers and informed consent was obtained from all patients before enrollment. Fifty patients with a single PCTN (cystic portion less than 90% and greater than 50%) were randomly assigned to be treated by either RFA (25 patients) or EA (25 patients) at two hospitals. The primary outcome was the tumor volume reduction ratio (%) at the six-month follow-up and the superiority margin was set at 13% (RFA minus EA). Analysis was performed primarily in an intention-to-treat manner. The secondary outcomes were the therapeutic success rate, improvement of symptomatic and cosmetic problems, and the number of major complications. Results: The mean volume reduction was $87.5{\pm}11.5%$ for RFA (n = 22) and $82.4{\pm}28.6%$ for EA (n = 24) (p = 0.710; mean difference [95% confidence interval], 5.1% [-8.0 to 18.2]), indicating no significant difference. Regarding the secondary outcomes, therapeutic success (p = 0.490), mean symptom (p = 0.205) and cosmetic scores (p = 0.710) showed no difference. There were no major complications in either group (p > 0.99). Conclusion: The therapeutic efficacy of RFA is not superior to that of EA; therefore, EA might be preferable as the first-line treatment for PCTNs.

Objective: To determine whether histogram values of the normalized apparent diffusion coefficient (nADC) and normalized cerebral blood volume (nCBV) maps obtained in contrast-enhancing lesions detected on immediate post-operative MR imaging can be used to predict the patient response to concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ). Materials and Methods: Twenty-four patients with GBM who had shown measurable contrast enhancement on immediate post-operative MR imaging and had subsequently undergone CCRT with TMZ were retrospectively analyzed. The corresponding histogram parameters of nCBV and nADC maps for measurable contrast-enhancing lesions were calculated. Patient groups with progression (n = 11) and non-progression (n = 13) at one year after the operation were identified, and the histogram parameters were compared between the two groups. Receiver operating characteristic (ROC) analysis was used to determine the best cutoff value for predicting progression. Progression-free survival (PFS) was determined with the Kaplan-Meier method and the log-rank test. Results: The 99th percentile of the cumulative nCBV histogram (nCBV C99) on immediate post-operative MR imaging was a significant predictor of one-year progression (p = 0.033). ROC analysis showed that the best cutoff value for predicting progression after CCRT was 5.537 (sensitivity and specificity were 72.7% and 76.9%, respectively). The patients with an nCBV C99 of < 5.537 had a significantly longer PFS than those with an nCBV C99 of ${\geq}5.537$ (p = 0.026). Conclusion: The nCBV C99 from the cumulative histogram analysis of the nCBV from immediate post-operative MR imaging may be feasible for predicting glioblastoma response to CCRT with TMZ.

Thyroid cancer may have small adipose structures detected by microscopy. However, there are no reports of thyroid cancer with gross fat evaluated by radiological methods. We reported a case of a 58-year-old woman with a fat containing thyroid mass. The mass was hyperechoic and ovoid in shape with a smooth margin on ultrasonography. On computed tomography, the mass had markedly low attenuation suggestive of fat, and fine reticular and thick septa-like structures. The patient underwent a right lobectomy. The mass was finally diagnosed as a follicular variant of papillary thyroid cancer with massive stromal fat.

Objective: To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV). Materials and Methods: Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared. Results: Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ${\geq}0.951$ ). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2). Conclusion: Subtraction magnetic resonance venography is a promising MRV method, with acceptable image quality and good arterial suppression.

Objective: To assess the diagnostic value of various ultrasound (US) findings and to make a decision-tree model for US diagnosis of biliary atresia (BA). Materials and Methods: From March 2008 to January 2014, the following US findings were retrospectively evaluated in 100 infants with cholestatic jaundice (BA, n = 46; non-BA, n = 54): length and morphology of the gallbladder, triangular cord thickness, hepatic artery and portal vein diameters, and visualization of the common bile duct. Logistic regression analyses were performed to determine the features that would be useful in predicting BA. Conditional inference tree analysis was used to generate a decision-making tree for classifying patients into the BA or non-BA groups. Results: Multivariate logistic regression analysis showed that abnormal gallbladder morphology and greater triangular cord thickness were significant predictors of BA (p = 0.003 and 0.001; adjusted odds ratio: 345.6 and 65.6, respectively). In the decision-making tree using conditional inference tree analysis, gallbladder morphology and triangular cord thickness (optimal cutoff value of triangular cord thickness, 3.4mm) were also selected as significant discriminators for differential diagnosis of BA, and gallbladder morphology was the first discriminator. The diagnostic performance of the decision-making tree was excellent, with sensitivity of 100% (46/46), specificity of 94.4% (51/54), and overall accuracy of 97% (97/100). Conclusion: Abnormal gallbladder morphology and greater triangular cord thickness (> 3.4mm) were the most useful predictors of BA on US. We suggest that the gallbladder morphology should be evaluated first and that triangular cord thickness should be evaluated subsequently in cases with normal gallbladder morphology.