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Purpose: The purpose of this study was to establish a quality standard for mammographic equipment in Korea and to eventually improve mammographic quality in clinics and hospitals throughout Korea by educating technicians and clinic personnel. Materials and Methods: For the phantom test and on site assessment, we visited 37 sites and examined 43 sets of mammographic equipment. Items that were examined include phantom test, radiation dose measurement, developer assessment, etc. The phantom images were assessed visually and by optical density measurements. For the clinical image assessment, clinical images from 371 sites were examined following the new Korean standard for clinical image evaluation. The items examined include labeling, positioning, contrast, exposure, artifacts, collimation among others. Results: Quality standard of mammographic equipment was satisfied in all equipment during on site visits. Average mean glandular dose was 114.9 mRad. All phantom image test scores were over 10 points (average, 10.8 points). However, optical density measurements were below 1.2 in 9 sets of equipment (20.9%). Clinical image evaluation revealed appropriate image quality in 83.5%, while images from non-radiologist clinics were adequate in 74.6% (91/122), which was the lowest score of any group. Images were satisfactory in 59.0% (219/371) based on evaluation by specialists following the new Korean standard for clinical image evaluation. Satisfactory images had a mean score of 81.7 (1 S.D.=8.9) and unsatisfactory images had a mean score of 61.9 (1 S.D=11). The correlation coefficient between the two observers was 0.93 (p

Purpose: The goal of this study was to survey the overall quality of mammographic images in Korea. Materials and Methods: A total of 598 mammographic images collected from 257 hospitals nationwide were reviewed in terms of eight image quality categories, namely positioning, compression, contrast, exposure, sharpness, noise, artifacts, and examination identification, and rated on a five-point scale: (1=severe deficiency, 2=major deficiency, 3=minor deficiency, 4=good, 5=best). Failure was defined as the occurrence of more than four major deficiencies or one severe deficiency (score of 1 or 2). The results were compared among hospitals of varying kinds, and common problems in clinical image quality were identified. Results: Two hundred and seventeen mammographic images (36.3%) failed the evaluation. Poor images were found in descending order of frequency, at The Society for Medical Examination (33/69, 47.8%), non-radiology clinics (42/88, 47.7%), general hospitals (92/216, 42.6%), radiology clinics (39/102, 38.2%), and university hospitals (11/123, 8.9%) (p

Purpose: To compare the usefulness of real-time compound US (RCUS) with that of conventional US (CUS) and pulse inversion harmonic (PIH) imaging in the diagnosis of malignant breast tumors. Materials and Methods: In 22 female patients whose mean age was 49 years, we evaluated the RCUS findings of pathologically proven [core biopsy (n=9), mammotome tissue bigpsy (n=10), excisional bispsy (n=3)] malignant breast tumors, comparing them with the findings of CUS and PIH imaging. Evaluation of these masses was in terms of their marginal distinction, internal echogenicity, boundary and posterior echo pattern, relationship with the adjacent lactiferous ductal system, and the presence of necrosis (12/22) and calcification (6/22). Results: In terms of marginal distinction, internal echogenicity, boundary echo patterns, and the relationship with adjacent ductal system, RCUS was superior to both conventional US and PIH Imaging (p

Purpose: To evaluate the radiologic findings of direct invasion of the spleen by malignant tumors of adjacent organs. Materials and Methods: We retrospectively reviewed the CT(n=6) and MR(n=3) images of six patients with direct invasion of the spleen by malignant tumor of left lower lung, stomach, colon, pancreas, left kidney, and left adrenal gland. We evaluated the tumor margin, attenuation or intensity, perisplenic fat infiltration, regional lymphnode enlargement, and invaded site of the spleen. Results: Ill-defined masses were found in the spleen with central necrosis and infiltration into perisplenic fatty tissue in all six patients; left adrenal mass was present also in three patients. Regional lymphnode enlargement was found in four patients. The masses showed heterogenous low attenuation on CT. The invaded site was variable and corresponding to their anatomical connections to the spleen. Conclusion: Direct invasion of the spleen by malignant tumors of adjacent organs showed ill-defined masses with central necrosis and were commonly associated with infiltration to perisplenic fatty tissue and adrenal invasion. The pattern and invaded site can be helpful to assess the primary cancer.

Purpose : To compare the radiologic findings of pyogenic abscess(PA) and inflammatory cancer(IC) of the breast, as seen on mammograms, US, and MR images and to evaluate the usefulness of the differential diagnostic findings of MRI for differentiation of PA and IC of the breast. Materials and Methods : We retrospectively analyzed the mammographic, US and MR findings of nine histopathologically proven cases of PA and four cases of IC of the breast. Parenchymal density, mass density, skin thickening and calcification were evaluated by mammography, and the extent of lesion and its morphologic characteristics and changes of dermal lymphatics by US and MRI. The latter was also used to analyse signal intensity and enhancement pattern. Results : Mammographic findings for both lesions were non-specific. US showed that the pyogenic abscess was a hypoechoic and anechoic complex lesion with posterior acoustic enhancement, while inflammatory cancer was a spiculated lesion with a heterogeneous hypoechoic echotexture. On 3D-GRE dynamic enhanced MRI, PA was shown in six cases(66.7 %) to be a lesion with superficial periareolar involvement, in contrast to the deep parenchymal spread seen in all cases of IC. A central non- enhanced portion with an irregular thick peripheral enhanced rim was seen in eight cases of PA(88.9 %) , and in all cases of IC an inhomogeneously enhanced spiculated lesion in parenchyma and a diffusely enhanced dermal and subcutaneous layer was apparent. An MRI time-intensity curve showed that the enhancement pattern was slow in five cases of PA(55.6 % ) and irregular in four(44.4 %), while for IC it was rapid in three cases(33.3 %) and irregular in one(11.1 % ). Conclusion : As compared with mammography and US, 3D-GRE dynamic MRI was a useful method for the differential diagnosis of PA and IC of the breast. The characteristic MR findings of PA were a central non-enhanced portion with an irregularly thick peripheral enhanced rim, located mainly in the superficial periareloar area and spreading into the parenchymal layer. An inhomogeneously enhanced spiculated solid mass in the parenchyma associated with diffuse dermal thickening and lymphatic dilatation was more suggestive of IC.

Purpose : To evaluate the usefulness of MR imaging in the differential diagnosis of the underlying causes of early-stage acute renal failure (ARF) by comparing the MRI findings of experimentally-induced crescentic glomerulonephritis (CGN) and acute tubular necrosis (ATN) in rabbits. Materials and Methods : Experimental CGN was induced by injecting anti-glomerular basement membrane antibody into six rabbits, and ATN by injecting glycerol solution into six rabbits. A normal control group of three rabbits was also used. Renal MR imaging (T1-and T2-weighted coronal images and dynamic MRI : DMRI) was performed the day before, and one, four, and seven days after the induction of CGN; and immediately before, and four, and eight hours, and one, four, and seven days after the induction of ATN. Sequential renal gun-biopsies and blood sampling (serum creatinine, sCr) were performed. Renal area, corticomedullary differentiation(CMD), and the passage of Gd-DTPA (pattern of dark band), as seen on MRI, were analyzed and correlated with serial change of sCr. Results : In normal kidneys, CMD was clearly apparent on both T1- and T2-weighted images. DMRI demonstrated a progressively inwardly migrating dark band in the kidneys. CMD was relatively clearly demonstrated in the ATN group but less clearly identified in the CGN group. Renal size (area) and sCr gradually increased in both the CGN and ATN groups, and dark bands were moderately to poorly defined in both. Conclusion : We conclude that DMRI could be used to differentiate and evaluate disease processing and compromised renal function in cases of CGN and ATN. On T1- and T2-weighted images, CMD was relatively well preserved in the ATN group, but was less clear in the CGN group. These MRI findings may be helpful for differentiation of the underlying causes of early-stage ARF, particularly between CGN and ATN.

Purpose : To clarify the distribution of joint effusion, and the relationship between type of injury andamount of joint effusion seen in traumatic knee joint magnetic resonance imaging (MRI). Materials and Methods : Weretrospectively reviewed the MR images of 400 patients with traumatic knee joint effusion. The knee joint spacewas divided into four compartments: central portion (para-ACL, para-PCL), suprapatellar pouch, posterior femoralrecess, and subpopliteal recess, and we then compared the amount and distribution of effusion. For statisticalanalysis, the chi-square test was used. Results : Among 400 MRI examinations of joint effusion, 383 knees (96%)showed homogeneous low intensity on T1-weighted images, and - except for ten cases of fluid-fluid levels-homogeneous high intensity on T2-weighted images. Knee joint effusion was clearly shown to be distributed mainlyin the suprapatellar pouch (345, 86%), followed by the central posterior femoral recess, and the subpoplitealrecess (P

Localized fibrous tumor of the scrotum is a very rare disease, and few radiologic features have been report-ed. We report the sonographic and CT findings of a case of localized fibrous tumor, which developed in the scrotum of a thirty-years-old man.

Pituitary abscess is a rare condition of the pituitary gland. We report MR imaging findings in two cases of surgically-confirmed pituitary abscess occuring in women aged 39 and 28. In both a peripheral rim enhancing lesion, similar to abscesses in other areas of brain, was seen in the pituitary fossa.

Purpose : To evaluate MR imaging findings of degenerating parenchymal neurocysticercosis and to determine the characteristics which distinguish it from other brain diseases. Methods : MR imagings of 19 patients (56 lesions) of degenerating parenchymal neurocysticercosis were retrospectively evaluated, focusing on the size and location of lesions, signal intensity patterns of cyst fluid and wall, the extent of the surrounding edema and features of contrast enhancement. Results: Degenerating parenchymal neurocysticercosis was located in gray or subcortical white matter in 89.3% of 56 lesions(50/56) ; most of these (98.2%) were smaller than 2cm in diameter. Cyst fluid signal was hyperintense relative to CSF on T1 and proton density weighted images (92.9%). A hypointense signal rim of the cyst wall was noted in the lesions on proton density (92.9%) and T2 weighted (98.2%) images. Surrounding edema was mostly mild. Peripheral rim enhancement was noted in all lesions, and this was frequently irregular and lobulated (67.9%) with a focal defect in the enhancing rim (41.1%). Conclusion : Findings which could be helpful in distinguishing degenerating parencymal neurocysticerosis from other brain diseases are as follows : small, superficial lesions ; hyperintense signal of the cyst fluid on T1 and proton density weighted images ; hypointense signal of the cyst wall on proton density and T2 weighted images ; relatively mild extent of surrounding edema, and peripheral rim enhancement which is frequently irregular and lobulated with a focal defect in the enhancing rim.