Young Ha Park

N-butyl-2-cyanoacrylate pulmonary embolism after endoscopic injection sclerotherapy for gastric variceal bleeding.

Purpose The purpose of this work was to describe the radiologic and clinical manifestations of n-butyl-2-cyanoacrylate pulmonary embolism (PE) after endoscopic injection sclerotherapy (EIS) for gastric variceal bleeding. Method From 1992 to 1999, the medical records of 140 patients who had undergone EIS using n-butyl-2-cyanoacrylate were reviewed for identification of respiratory symptoms and amount of injection, and their pre-and postprocedure chest radiographs were reviewed to identify PE. In patients with PE, pre-and postprocedure chest radiographs (6/6), chest CT scans (3/6), lung perfusion scans (3/6), and follow-up chest radiographs (6/6) were analyzed retrospectively. Results Radiographically evident PE was observed in 6 (4.3%) of 140 patients. In comparison with patients without emboli, these patients received a higher mean volume of injection (4.2 vs. 1.8 ml) (p = 0.0011). Four of the six patients with pulmonary emboli had respiratory symptoms. Chest radiographs and CT scans showed unusual tubular or nodular, radiopaque pulmonary emboli along the pulmonary vessels. Multiple peripheral, wedge-shaped, subsegmental perfusion defects were seen on perfusion lung scans. In five of six patients, the radiographic abnormalities showed complete or partial resolution. There were no fatalities directly associated with PE. Conclusion Radiographically evident PEs are uncommonly observed following EIS and appear to be more common in patients receiving a higher volume of liquid acrylate. Affected patients were either mildly symptomatic or asymptomatic, and there were no direct fatalities of this complication.

MRI of Tuberculous pyomyositis

PURPOSEnThe purpose of this article is to describe the findings of MRI in tuberculous pyomyositis (PM).nnnMETHODnThe MR images of four proven cases of tuberculous PM were retrospectively reviewed and analyzed with clinical and laboratory findings. The location, signal intensity on T1- and T2-weighted spin echo images, presence of abscess, signal intensity of peripheral rim, patterns of contrast enhancement, and associated findings were evaluated.nnnRESULTSnOn MR images, all cases demonstrated low signal intensity on T1-weighted images and high signal intensity on T2-weighted images in a single muscle. Abscess was seen in all cases. Peripheral rim showed subtle hyperintensity on T1-weighted images and hypointensity on T2-weighted images. After gadolinium infusion, peripheral rim enhancement was observed in all cases. Cellulitis was associated in one case. The patients clinically presented with a palpable mass of long duration.nnnCONCLUSIONnTuberculous PM shows characteristic findings of a well demarcated abscess with rim enhancement at MRI and can be distinguished from other soft tissue masses.

Incidental thyroid uptake on F-18 FDG PET/CT: correlation with ultrasonography and pathology

PurposeTo evaluate the usefulness of maximum standard uptake value (max SUV) calculated from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) examination and findings from ultrasonographic (US) examination on incidentally detected thyroid FDG uptake on FDG PET/CT.Materials and methodsWe collected and reviewed FDG PET/CT images performed at our institution from March 2005 to March 2008. This study included 190 subjects with increased FDG uptake of thyroid gland who later underwent thyroid US and histological examinations. Of these subjects, the uptake pattern on FDG PET/CT was classified as either diffuse or focal. The FDG uptake pattern, max SUV, and US findings were evaluated and correlated with the histological results.ResultsIn the focal FDG uptake pattern cases (nxa0=xa0148), the mean max SUV of malignant cases was higher than that of benign cases (5.93xa0±xa05.35 vs. 3.47xa0±xa02.89). Of the diffuse FDG uptake cases (nxa0=xa042), nodules were detected in 25 subjects (59.5%) by US examination. Thyroid nodules were well characterized on US studies, and combined findings of suspicious US features or high max SUV of focal FDG uptake lesion increased sensitivity, PPV, NPV, and accuracy.ConclusionsFocal uptake pattern and high max SUV may be helpful in differentiating benign and malignant nodules on FDG PET/CT. However, US examination provides further information, and for lesions with increased FDG uptake of thyroid, US examination should be recommended.

Poland's syndrome with lung cancer. A case report.

Polands syndrome, a rare congenital anomaly characterized by pectoralis muscle defect, has been reported in association with lymphoreticular malignancies and some solid tumors. Lung cancer associated with Polands syndrome has not been previously described. We present the first report of a case of Polands syndrome associated with lung cancer and demonstrate the CT findings.

Atypical benign lipomatous tumors in the soft tissue: radiographic and pathologic correlation.

This article describes the characteristic imaging findings and correlates them with the pathology in the nonfatty regions of benign atypical lipomatous tumors, which have different findings compared with typical lipomas and well-differentiated liposarcomas. For differentiating these tumors from typical lipomas and well-differentiated liposarcomas, it may be helpful to analyze nonfatty regions in benign atypical lipomatous tumors.

Spontaneous rupture of hydronephrotic kidney during pregnancy: Value of serial sonography

Hydronephrosis during pregnancy is common but rarely results in renal rupture. We report an unusual case of spontaneous rupture of a hydronephrotic kidney during pregnancy. Although we could not predict the renal rupture on the basis of sonographic findings, serial sonography was useful in the early detection and management of the rup‐ture.

High-resolution CT findings of re-expansion pulmonary edema.

Objective To describe the high-resolution CT (HRCT) findings of re-expansion pulmonary edema (REPE) following a thoracentesis for a spontaneous pneumothorax. Materials and Methods HRCT scans from 43 patients who developed REPE immediately after a thoracentesis for treatment of pneumothorax were retrospectively analyzed. The study group consisted of 41 men and two women with a mean age of 34 years. The average time interval between insertion of the drainage tube and HRCT was 8.5 hours (range, 1-24 hours). The patterns and distribution of the lung lesions were analyzed and were assigned one of the following classifications: consolidation, ground-glass opacity (GGO), intralobular interstitial thickening, interlobular septal thickening, thickening of bronchovascular bundles, and nodules. The presence of pleural effusion and contralateral lung involvement was also assessed. Results Patchy areas of GGO were observed in all 43 patients examined. Consolidation was noted in 22 patients (51%). The geographic distribution of GGO and consolidation was noted in 25 patients (58%). Interlobular septal thickening and intralobular interstitial thickening was noted in 28 patients (65%), respectively. Bronchovascular bundle thickening was seen in 13 patients (30%), whereas ill-defined centrilobular GGO nodules were observed in five patients (12%). The lesions were predominantly peripheral in 38 patients (88%). Of these lesions, gravity-dependent distribution was noted in 23 cases (53%). Bilateral lung involvement was noted in four patients (9%), and a small amount of pleural effusion was seen in seven patients (16%). Conclusion The HRCT findings of REPE were peripheral patchy areas of GGO that were frequently combined with consolidation as well as interlobular septal and intralobular interstitial thickening.

Depiction of Nidi and Fibrovascular Zones of Osteoid Osteomas Using Gamma-Correction Tc-99m HDP Pinhole Bone Scan and Conventional Radiograph, and Correlation with CT, MRI, and PVC Phantom Imaging

PurposeFor the precise imaging diagnosis of osteoid osteoma (OO), the identification of the nidus and fibrovascular zone (FVZ) is essential. However, the latter sign has received little attention because it is difficult to demonstrate. We applied the recently introduced gamma correction (GC) to depict the FVZ on pinhole bone scan (PBS), conventional radiography (CR), and computed tomography (CT). Non-gamma correction MRI was also analyzed for reference.MethodsTen patients with histologically proven diagnoses of OO were enrolled in this retrospective study. PBS, CR, and CT were processed by GC to demonstrate the nidi and FVZ as distinct yet integrating components of OO. PBS was performed using a 4-mm pinhole collimator 3 h after iv injection of 925 to 1,110xa0MBq (25 to 30xa0mCi) of Tc-99m HDP, and anteroposterior and mediolateral CR and transverse CT were taken according to the standard technique. MRI sequences included T1- and T2-weighted images. For gamma correction, we utilized the Photo Correction Wizard program of ACD Photo Editor v3.1. A team of three qualified nuclear physician-radiologists, two nuclear physicians, and one MRI specialist read bone scans, radiographs, and MRIs of OO according to each specialty, and orthopaedic aspects and histology were reviewed by one qualified orthopedic surgeon and two qualified pathologists, respectively. Each observer first read the images separately with basic information about the aim of the study given and then in concert. Interpretive disagreement was settled by discussion and consensus.ResultsOn pinhole scan, nidi were presented as areas of intense tracer uptake in all cases, and, importantly after GC, a thin ring-like zone with lower tracer uptake became visible in seven out of ten cases. GCCR also revealed a thin lucent zone that circumscribed the nidi in six out of ten cases and GCCT in two of four cases. MRI, without GC, presented nidi with high signal in the center and a thin ring-like zone with low signal in the periphery in five out of six cases. Ring-like zones were 1–2xa0mm in thickness and circumscribed the nidus as an integrated part and, hence, were morphologically interpreted as FVZ. Histologically, the presence of a variously mineralized FVZ was confirmed in four cases, but individual locus-by-locus image-histology correlation could not be accompolished because specimens were fragmentary. In the FVZ, tracer uptake was lower than in nidi, presumably reflecting that bone metabolism in the two parts differs as in their histology. Statistically, no significant correlation existed between the duration of symptoms and imaging demonstrability of the FVZ (Spearman’s test ru2009=u2009−0.057, pu2009=u20090.877), but parallelism existed in the demonstrability of the FVZ among GC PBS, CR, and CT, and non-correction MRI.ConclusionsGC was useful to enhance the resolution of PBS, CR, and CT in OO so that both the nidi and FVZ were separately imaged. The use of CG PBS and CR in combination is recommended for the specific diagnosis of OO with information about bone metabolism and anatomical characteristics. PBS and CR are economical and widely available.

Influence of thyroid-stimulating hormone on 18F-fluorodeoxyglucose and 99mTc-methoxyisobutylisonitrile uptake in human poorly differentiated thyroid cancer cells in vitro

ObjectiveIn poorly differentiated thyroid cancer originating from thyroid follicular cells, the ability to concentrate iodine is lost. This makes recurrence undetectable by 131I whole-body scan. In this situation, other radiopharmaceuticals, such as 18F-fluorodeoxyglucose (18F-FDG) and technetium-99m-methoxyisobutylisonitrile (99mTc-MIBI), are used to evaluate recurrence or metastasis. Some reports suggest that 18F-FDG uptake is increased by thyroid-stimulating hormone (TSH) stimulation. This study aimed to determine the influence of TSH on 18F-FDG and 99mTc-MIBI uptake in human poorly differentiated thyroid cancer cells in vitro.Materials and methodsThe cells were stimulated with 1000 μU/ml of recombinant human thyroid-stimulating hormone (rhTSH) for 1 day, 3 days, and 5 days. Each cell was incubated with 0.5 MBq/ml-1 MBq/ml of 18F-FDG or 0.5 MBq/ml-1 MBq/ml of 99mTc-MIBI for 1 h at 37°C. The uptake of each radiopharmaceutical in the cells was quantified as a percent of whole radioactivity per total viable cell number. The quantification of glucose transporter 1, 2, 3 and 4 mRNA expression was measured using RT-PCR.ResultsTSH stimulation increased 18F-FDG uptake in a time-dependent manner. Following 5 days of rhTSH stimulation, 18F-FDG uptake was approximately 2.2 times that of the control. The increase in 18F-FDG uptake following rhTSH stimulation was correlated to the increase in GLUT4 mRNA level. The GLUT1 mRNA level was unchanged. An increased uptake of 99mTc-MIBI was observed with a pattern similar to that of 18F-FDG. The 99mTc-MIBI uptake was approximately 1.5 times that of the control 5 days later.ConclusionsThese results suggest that TSH stimulates 18F-FDG and 99mTc-MIBI uptake in poorly differentiated papillary thyroid cancer, and therefore 18F-FDG-PET or 99mTc-MIBI scans under TSH stimulation may be more accurate than under suppression.

Influence of hydration status in normal subjects: fractional analysis of parameters of Tc-99m DTPA and Tc-99m MAG3 renography

Rationale and Objectives: The purpose of this study was to evaluate the influence of hydration status upon renogram patterns and renal physiological parameters and clarify the differences between DTPA and MAG3 studies in normal volunteers.Material and Methods: The study populations were 22 kidneys of 11 volunteers with no history of hypertension or renal disease with normal serum creatinine levels. They were 6 men and 5 women aged from 24 to 48 yrs (mean age: 33.4 yrs). Renal scintigraphies with both 185 MBq (5 mCi) of Tc-99m DTPA and Tc-99m MAG3 were performed after dehydration (urine specific gravity > 1.025) and adequate hydration (urine specific gravity < 1.010) in each subject at least with a 5–7-day interval. Renograms were generated from the whole kidney and cortical ROIs. We analyzed the clearance, renogram pattern, mean transit time, time to maximum activity, time from maximum activity to half activity, and residual cortical activity. Paired t-test and Wilcoxon signed rank test were used as statistical analysis methods. Statistical analysis was considered significant at p < 0.05.Results: In the dehydrated state, with Tc-99m DTPA and whole kidney ROI, parameters such as time to maximum activity, time from maximum activity to half activity, residual cortical activity, and mean transit time were delayed as compared to parameters in the adequately hydrated state, but the clearance was not changed. With the cortical ROI, the changes of parameters due to dehydration were partially offset. There were insignificant differences between most parameters of Tc-99m DTPA and Tc-99m MAG3 with the whole kidney and cortical ROIs.Conclusions: Dehydration may bring about a false positive curve pattern on renograms which can be prevented or minimized by using the cortical ROI. There were insignificant differences between most parameters of Tc-99m DTPA and Tc-99m MAG3.