Yun Hwan Kim

High-resolution ct appearance of miliary tuberculosis

Objective The purpose of this study was to define the range of abnormalities and to assess the contribution of high-resolution CT (HRCT) in the evaluation of miliary tuberculosis involving the lung parenchyma. Materials and Methods The authors retrospectively reviewed HRCT scans of 11 patients with microbiologically or clinically proved miliary tuberculosis. Results In 10 patients, the most characteristic HRCT finding of miliary tuberculosis was the presence of small nodules uniformly distributed throughout both lungs. The profusion of nodules was numerous in all 10 patients. High-resolution CT scans showed both sharply and poorly defined, small nodules varying in sizes from 1 to 2 mm (n = 6), 1 to 3 mm (n = 2), and 1 to 4 mm (n = 2) in diameter. These nodules had a diffuse random distribution in the secondary lobule in all 10 patients. In 1 of the 10 patients with small nodules on HRCT, chest radiography had shown no evidence of miliary nodules in the lung. In addition to nodules, HRCT showed diffuse or localized reticular opacities superimposed on nodules in five patients, especially in the lower lung zones. In 1 of all 11 patients, ground-glass attenuation was the predominant abnormality seen on HRCT. Conclusion We believe that in the appropriate clinical situation, miliary tuberculosis may be suggested on HRCT. Moreover, in cases with no evidence of miliary nodules on the chest radiograph, HRCT scan may depict miliary nodules in the lung parenchyma.

Can magnetic resonance imaging accurately predict concordant pain provocation during provocative disc injection

ObjectiveTo correlate magnetic resonance (MR) image findings with pain response by provocation discography in patients with discogenic low back pain, with an emphasis on the combination analysis of a high intensity zone (HIZ) and disc contour abnormalities.Materials and methodsSixty-two patients (aged 17–68xa0years) with axial low back pain that was likely to be disc related underwent lumbar discography (178 discs tested). The MR images were evaluated for disc degeneration, disc contour abnormalities, HIZ, and endplate abnormalities. Based on the combination of an HIZ and disc contour abnormalities, four classes were determined: (1) normal or bulging disc without HIZ; (2) normal or bulging disc with HIZ; (3) disc protrusion without HIZ; (4) disc protrusion with HIZ. These MR image findings and a new combined MR classification were analyzed in the base of concordant pain determined by discography.ResultsDisc protrusion with HIZ [sensitivity 45.5%; specificity 97.8%; positive predictive value (PPV), 87.0%] correlated significantly with concordant pain provocation (Pu2009<u20090.01). A normal or bulging disc with HIZ was not associated with reproduction of pain. Disc degeneration (sensitivity 95.4%; specificity 38.8%; PPV 33.9%), disc protrusion (sensitivity 68.2%; specificity 80.6%; PPV 53.6%), and HIZ (sensitivity 56.8%; specificity 83.6%; PPV 53.2%) were not helpful in the identification of a disc with concordant pain.ConclusionThe proposed MR classification is useful to predict a disc with concordant pain. Disc protrusion with HIZ on MR imaging predicted positive discography in patients with discogenic low back pain.

The Incidence and Anatomy of Accessory Pudendal Arteries as Depicted on Multidetector-Row CT Angiography: Clinical Implications of Preoperative Evaluation for Laparoscopic and Robot-Assisted Radical Prostatectomy

Objective To help preserve accessory pudendal arteries (APAs) and to ensure optimal postoperative sexual function after a laparoscopic or robot-assisted radical prostatectomy, we have evaluated the incidence of APAs as detected on multidetector-row CT (MDCT) angiography and have provided a detailed anatomical description. Materials and Methods The distribution of APAs was evaluated in 121 consecutive male patients between February 2006 and July 2007 who underwent 64-channel MDCT angiography of the lower extremities. We defined an APA as any artery located within the periprostatic region running parallel to the dorsal vascular complex. We also subclassified APAs into lateral and apical APAs. Two radiologists retrospectively evaluated the origin, course and number of APAs; the final APA subclassification based on MDCT angiography source data was determined by consensus. Results We identified 44 APAs in 36 of 121 patients (30%). Two distinct varieties of APAs were identified. Thirty-three APAs (75%) coursed near the anterolateral region of the prostatic apex, termed apical APAs. The remaining 11 APAs (25%) coursed along the lateral aspect of the prostate, termed lateral APAs. All APAs originated from the internal obturator artery and iliac artery or a branch of the iliac artery such as the inferior vesical artery. The majority of apical APAs arose from the internal obturator artery (84%). Seven patients (19%) had multiple APAs. Conclusion APAs are more frequently detected by the use of MDCT angiography than as suggested by previous surgical studies. The identification of APAs on MDCT angiography may provide useful information for the surgical preservation of APAs during a laparoscopic or robot-assisted radical prostatectomy.

Radioembolization Is a Safe and Effective Treatment for Hepatocellular Carcinoma with Portal Vein Thrombosis: A Propensity Score Analysis.

Background/Aims Limited treatment options are available for patients with hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT). Transarterial radioembolization using Yttrium-90 microspheres is a new treatment modality for HCC with PVT. For this analysis, we compared responses to treatment with radioembolization and with sorafenib. Methods We evaluated 32 patients who were part of a multicenter retrospective cohort. All patients had PVT without extrahepatic metastasis and were treated with radioembolization in one of six tertiary referral hospitals in Korea. We retrospectively enrolled another 31 consecutive PVT patients without extrahepatic metastasis from a single center who received sorafenib treatment to serve as the control group. We used inverse probability weighting (IPW) using propensity scores to adjust for the between-group differences in baseline characteristics. Results At 3 months, the response rate and disease control rate were 32.1% (9/32) and 57.1% (16/32), respectively, in the radioembolization group and 3.2% (1/31) and 41.9% (13/31) in the sorafenib group. Median overall survival (OS) and time to progression (TTP) were not significantly different between the radioembolization group and the sorafenib group (13.8 months and 10.0 months, P = 0.22; and 6.0 months and 6.0 months, P = 0.08; respectively). No differences in OS (P = 0.97) or TTP (P = 0.34) were observed after IPW was applied to balance the population characteristics. The sorafenib group showed significantly more grade 3/4 adverse effects than the radioembolization group (P < 0.01). Conclusion HCC patients with PVT who underwent radioembolization achieved comparable survival to patients who received sorafenib, even after application of IPW. The radioembolization group also experienced fewer severe adverse effects. Radioembolization can be considered a new treatment option for patients with HCC with PVT.

Non-Calcified Ductal Carcinoma in Situ: Ultrasound and Mammographic Findings Correlated with Histological Findings

Purpose To evaluate radiological findings of non-calcified ductal carcinoma in situ (DCIS) and to correlate those with histological features. Materials and Methods From July 2002 to March 2006, 22 patients with histologically-proven non-calcified DCIS were included. Mammography was obtained in 19 patients, ultrasound in 18 patients, and both examinations in 15 patients. Radiological findings were evaluated according to the Breast Imaging Reporting and Data System by American College of Radiology. Histological tumor subtype and Van Nuys classification of DCIS were assessed. Results Histological subtypes consisted of mixed type in 11 patients (50%), comedo in 4 (18%), cribriform in 4 (18%), papillary type in 2 (9%), and solid in one (5%). According to Van Nuys classification, group 3 DCIS was observed in 13 (59%) patients. In the 19 patients who underwent mammography, 13 patients presented with abnormal findings: focal asymmetry in 7 patients (37%), masses in 4 (21%), skin thickening in one (5%), and architectural distortion in one (5%). In the 18 patients who had received breast ultrasound, a mass was present in 15 (83%) patients and ductal changes in 3 patients (17%). Sixty percent of patients with masses on ultrasound had group 3 DCIS and 100% of patients with ductal change had group 1 DCIS (p = 0.017). Conclusion Diagnosis of non-calcified DCIS by mammography is not an easy task due to the lack of typical malignant calcifications or masses. High resolution ultrasound can be useful for detecting non-calcified DCIS, and ultrasound findings are correlated with histological features.

Radioembolization with Yttrium-90 resin microspheres in hepatocellular carcinoma: A multicenter prospective study

Objectives:The aim of this prospective study was to reveal the efficacy and safety of Yttrium-90 (90Y) radioembolization in Korean patients with hepatocellular carcinoma (HCC). Methods:A total of 40 HCC patients were prospectively recruited from 7 centers. The response to treatment was assessed on the basis of the modified Response Evaluation Criteria in Solid Tumors criteria. The time to progression and overall survival were also evaluated, and the assessment of safety was done according to National Cancer Institute Common Terminology Criteria, Version 3.0. Results:Forty-two treatments of 90Y radioembolization were carried out. Median follow-up was 29 months. At 3 months, the complete response, partial response (PR), and stable disease were seen in 4 (10.0%), 19 (47.5%), and 15 (37.5%) patients, respectively. The response rate was 57.5% (23/40), and disease control rate was 95% (38/40) at 3 months. The response rate at 6 months was 63.9% (23/36), and disease control rate was 83.3% (30/36). The median time to progression was 18 months. During follow-up, 10 HCC-related deaths occurred and the 3-year survival rate was 75%. In 19 patients with Barcelona Clinic Liver Cancer-B stage, the 3-year survival rate was 50%. The tumor number (>5) was the only significant predictor associated with survival. The most common adverse event was abdominal pain of mild to moderate degree, and all the complications were manageable. Twenty-six (65%) patients underwent other treatments such as transarterial chemoembolization because of local progression or remnant viable lesion. Conclusions:90Y radioembolization might be a safe and effective treatment modality in intermediate-stage to advanced-stage HCC.

Supraspinatus tendon tears: comparison of 3D US and MR arthrography with surgical correlation

ObjectiveThe objective of the study was to compare the diagnostic reliability of 3D US with MR arthrography in diagnosing supraspinatus tendon tears, with arthroscopic findings used as the standard.Materials and methodsIn a prospective study 50 patients who later underwent arthroscopic surgery of the rotator cuff were examined pre-operatively by 3D US with MR arthrography. The presence or absence of a full- or partial-thickness supraspinatus tendon tear and the tear size as demonstrated by each imaging and arthroscopy was recorded. The tear size was divided into three grades: small (<1xa0cm), medium (1-3xa0cm), and large (>3xa0cm).ResultsThe arthroscopic diagnosis was a full-thickness tear in 40 patients, partial-thickness tears in 5, and intact supraspinatus tendon in 5. 3D US correctly diagnosed 35 out of 40 full-thickness tears and MR arthrography 39 out of 40 full-thickness tears. Regarding partial-thickness tears, 3D US underestimated 2 cases as no tear and overestimated 1 case as a full-thickness tear. MR arthrography underestimated 1 case as a partial-thickness tear and overestimated 2 cases as full-thickness and partial-thickness tears respectively. 3D US and MR arthrography yield a sensitivity for full-thickness tears of 87.5% and 97.5% with specificity of 90.0% and 90.0%. Based on the grading system, 3D US measurements correctly predicted the tear size of 23 (65.7%) of the 35 full-thickness tears and MR arthrography 30 (75.0%) of the 39 full-thickness tears.ConclusionThree-dimensional ultrasound seems to be a promising imaging modality comparable to MR arthrography for the assessment of the supraspinatus tendon tears.

Yttrium-90 Radioembolization for Hepatocellular Carcinoma: What We Know and What We Need to Know

In spite of substantial progress in the management of hepatocellular carcinoma (HCC), suboptimal treatment results are frequently seen in the intermediate and advanced stages of HCC. The current staging system indicates that multinodular HCC without vascular invasion needs to be treated by transarterial chemoembolization (TACE) and HCC with vascular nvasion or distant metastasis is linked to sorafenib, an an-tiangiogenic therapy. Radioembolization with yttrium-90 (90Y) is a recently introduced liver-directed therapy employing a catheter-based approach. Growing data suggest that 90Y radioembolization has a potent anticancer effect with negligible adverse events if appropriate pretreatment evaluations including dosimetry, calculation of lung shunt fraction and assessment of vascular anatomy are performed. Retrospective and small prospective studies have shown response rates and survival after 90Y therapy which are comparable to TACE and sorafenib in the intermediate and advanced stages, respectively. Although a large sample size is necessary to compare the outcome between TACE and radioembolization in intermediate-stage HCC, selected populations, for whom TACE would not be effective, are candidates for testing the role of 90Y radioembolization. A multidisciplinary, combined approach in advanced HCC using loco-regional therapy such as radioembolization and systemic therapy including sorafenib also has to be investigated.

Preoperative Detection and Localization of Accessory Pudendal Artery with Contrast-enhanced MR Angiography

PURPOSEnTo evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) angiography for preoperative detection and localization of accessory pudendal arteries (APAs) in patients with prostate cancer.nnnMATERIALS AND METHODSnThis prospective study was approved by the institutional review board, and informed consent was obtained. Between July 2007 and December 2010, 127 patients underwent contrast-enhanced MR angiography following prostate MR imaging at 3.0 T before robot-assisted laparoscopic radical prostatectomy (RALP). APAs were defined as any arteries located in the periprostatic region and anastomosed with the common penile artery or its branches; they were then subclassified into lateral and apical APAs. For detecting and localizing APAs, MR angiograms were evaluated prospectively by one reader and retrospectively by two independent blinded readers. Diagnostic performance was determined on a per-patient basis by using surgical findings as the reference standard. In addition, the origin of APAs identified at both surgery and contrast-enhanced MR angiography was determined by consensus of two retrospective readers. Interreader agreements were assessed by using k statistics.nnnRESULTSnAt surgery, 19 APAs (seven right apical, three left apical, four right lateral, and five left lateral) were detected in 16 patients, and 16 of these APAs were localized in 13 patients at preoperative contrast-enhanced MR angiography. Prospectively, sensitivity, specificity, and accuracy of contrast-enhanced MR angiography for the localization of APAs were 81.3%, 93.7%, and 92.1%, while retrospectively they were 87.5%, 91.9%, and 91.3% for reader 2 and 75.0%, 90.1%, and 88.2% for reader 3, respectively. Overall interreader agreement was substantial (k = 0.795). Nine and seven APAs originated from the obturator artery and the inferior vesical artery, respectively.nnnCONCLUSIONnContrast-enhanced MR angiography can be used for the preoperative detection of APAs in patients with prostate cancer.

Imaging of the various continent urinary diversions after cystectomy.

Continent urinary diversions have recently become the preferred procedures rather than performing an ileal conduit. Intravenous urography, pouchography, and computed tomography scans are frequently used for postoperative evaluation of patients with bladder carcinoma. During postoperative follow-up imaging studies, the radiologist must keep these 4 facets in mind as his primary focus: 1) the detection of newly developed urothelial tumors, 2) the detection of metastasis, 3) the detection of postoperative complications, and 4) the monitoring of upper urinary tract distention. Various surgical techniques that are used in continent diversions alter the normal anatomy and make the imaging interpretation difficult. An accurate interpretation can be made only if radiologists become familiar with the various surgical procedures and the appearances of various postoperative anatomic changes.