Misregistration Artifact due to Respiratory Motion on Spiral CT of the Liver

PURPOSE: To determine the frequency and patterns of respiratory-induced misregistration artifact seen on spiral CT of the liver. MATERIALS AND METHODS: Two hundred patients with hepatic mass underwent spiral CT, and arterial phase images were compared with those of the portal phase in all cases and or of the delayed phase in 138. The patterns of misregistration artifact were divided into two groups: skipping, where at least two slices in the craniocaudal length of the mass were missed, and the partial volume veraging artifact thus excluded; and overlapping, where the same or reversed images were seen in succeeding sequences. We reviewed the location and size of the masses, and the presence or absence, and patterns of the misregistration artifact. RESULTS: Fourteen (7%) of 200 spiral CT scans demonstrated the misregistration artifact; in five of these there was skipping (involving a hepatic mass larger than 2 cm in two cases, and one smaller than 2 cm in three cases), and in nine there was overlapping (six masses larger than 2 cm, and three smaller than this). A lipiodol-laden mass measuring 5 mm was completely missed during the arterial phase. and in one case the spleen sequence was reversed. Thirteen (93%) of fourteen masses were located in the right lobe. CONCLUSION: Two patterns of misregistration artifact, skipping and overlapping, were observed, and their combined frequency was 7%. So as not to miss small hepatic masses or overestimate their size, careful respiratory control is therefore needed.

MR Findings of the Spinal Paraganglioma : Report of Three Cases

Extraadrenal paragangliomas involving the spine is less common and usually takes the form of intradural compression of the cauda equina. The authors report three cases of spinal paragangliomas resulting in extradural spinal cord compression and their MR findings. The MR imaging revealed a well-demarcated extradural mass with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-weighted images compared to paravertebral muscles. After Gd-DTPA administration, heterogeneous and intense enhancement was found. Multiple punctate and serpiginous structures of signal void due to high-velocity flow were noted around and within the tumors on all sequences. In one case, the signal void structures were well corresponded with feeding arteries on angiography. These may be the characteristic findings of the extraadrenal paraganglioma involving the spine.

Usefulness of Enteral Contrast Media in MR Evaluation of Pelvic Mass

PURPOSE: To assess the value of enteral contrast media for the evaluation of pelvic masses by MR imaging. MATERIALS AND METHODS: Between April and July 1998, 16 women with pelvic masses were examined by MRI. The origin of the lesion was the ovary in twelve cases, the uterus in three, and the sigmoid in one. Using a 1.5T scanner(Magnetom Vision, Siemens), T1-weighted axial spin echo(SE), T2-weighted turbo spin echo(TSE), two-dimensional fast low-angle shot(FLASH 2D), and half-Fourier TSE(HASTE) images were obtained in all patients after the administration of Magnevist Enteral (Shering, Berlin, Germany). In each MR imaging sequence, distinction between the lesion and adjacent bowel (1, not distinguished; 2, partly distinguished; 3, clearly distinguished), artifact (0, absent; 1, mild; 2, severe), image quality (1, poor; 2, fair; 3, good), were compared before and after the use of enteral contrast media. Changes in MRI impression after the use of enteral contrast media were also evaluated. Two radiologists reached a consensus after reviewing the images. Statistical significance was determined by Wilcoxon's signed ranked test. RESULTS: For distinguishing lesions, SE T1WI and FLASH 2D with enteral contrast media were significantly superior to SE T1WI without enteral contrast media (p<0.05). With regard to image quality, FLASH 2D and HASTE, both with enteral contrast media, were significantly superior to SE T1WI and TSE T2WI, respectively, both without enteral contrast media (p<0.05). Artefacts were more frequently found after the application of enteral contrast media in conventional sequences but were not present in breathhold sequences. In two patients, MRI impression changed after the appilication of enteral contrast media. CONCLUSION: In a limited number of cases, enteral contrast media improved lesion detection, image quality and diagnostic accuracy when breathhold fast MR imaging was applied.

Differential Riagnosis of the Brain Tumor and Brain Abscess: the Usefulness of Dynamic MR Imaging

PURPOSE: To evaluate the usefulness of dynamic MR imaging in the differential diagnosis of intracranial tumorand abscess. MATERIALS AND METHODS: Dynamic MR images of 36 patients with surgically or clinically provenintracranial enhancing lesions were retrospectively reviewed. These lesions comprised 15 metastases, 14 gliomas,and seven abscesses. Images were sequentially obtained every 30 seconds for 3-5 minutes using the spin-echotechnique(TR/TE : 200 msec/15 msec) after bolus injection of gadolinium dimeglumine(2-3cc/sec). The dynamics ofcontrast enhancement of the lesions was analyzed visually and by calculating the sequential contrast-enhancementratio(CER). RESULTS: CER during the 30-second early dynamic phase was 93.16 in metastases, 67.78 in gliomas, and48.3 in abscesses(ANOVA, p<0.005). The contrast enhancement pattern of metastases showed rapidly increased signalintensity(SI) up to 30 seconds, followed by a relatively rapid decrease; less time was then required to reach theCER peak. In gliomas, SI increased gradually up to 180 seconds and then took a longer time to reach the CER peak.The SI of abscesses was similar to that of gliomas, with a more gradual increase for 30-60 seconds and a longertime for the CER peak to be reached. CONCLUSION: The contrast enhancement pattern and CER parameters seen ondynamic MRI can help differentiate intracranial tumor and abscess.

MR Imaging Findings of Ovarian Epithelial Tumor: Emphasis on Borderline Malignancy

PURPOSE: To evaluate the role of MR in the diagnosis of borderline epithelial tumors of the ovary comparedwith that of benign and malignant tumors. MATERIALS AND METHODS: MR images of 42 ovarian epithelial tumors in 39patients were retrospectively analyzed, focusing on the morphologic characters distinguishing borderlineepithelial tumors from benign and malignant tumors. All images were obtained using a 1.5T imager 3-27 (mean, 12)days before surgery. The size, shape, internal signal intensity, wall and septal thickness, papillary nodule,solid component, and contrast enhancement of the tumor were evaluated. RESULTS: Histopathologic diagnoses were 16serous epithelial tumors [benign (SB) 3, borderline malignancy (SBM) 5, malignancy (SM) 8]; 24 mucinous epithelialtumors [benign (MB) 11, borderline malignancy (MBM) 9, malignant (MM) 4]; one endometrial carcinoma (EC), and oneclear cell carcinoma (CC). Mucinous epithelial tumors were multilocular in 23 of 24 tumors, while signal intensityof the locules varied in 22 of 24. Six of 16 serous epithelial tumors were unilocular, and 15 of 16 were ofhomogeneous signal intensity. Papillary projection was seen in 14 tumors (SB 1/3, SBM 5/5, SM 3/8, MB 2/11, MBM2/9, CC 1/1), but multiple (>10) projections were seen in SBM (5/5) and CC (1/1). Multiple irregular thick septawere found in 18 tumors (SM 3/8, MB 2/11, MBM 9/9, MM 4/4), while solid components were seen in ten (SM 6/8, MB1/11, MM 2/4, EC 1/1). CONCLUSION: Multiple (>10) papillary projections and multiple irregular thick septa withoutremarkable solid components are suggestive MR findings of ovarian SBM and MBM, respectively.

CT Differentiation of Invasive thymoma and Thymic carcinoma

PURPOSE: In order to determine the differential points between them, we analyzed the CT findings of invasivethymoma and thymic carcinoma. MATERIALS AND METHODS: We retrospectively reviewed the CT scans of 14 patients withinvasive thymoma and 15 with thymic carcinoma, confirmed by surgery(n=19) or percutaneous needle aspiration (n=10)between 1988 and 1996. CT findings were evaluated in each group for intrathoracic spread (posterior, directposterior, and anterolateral), obliteration of the fat plane between the mass and vascular structures, vesselencasement, invasion of adjacent mediastinal structures, pleural implants, mediastinal nodes and distantmetastasis. RESULTS: Direct posterior spread was more common in thymic carcinoma than invasive thymoma ; it wasseen in one case (7%) of invasive thymoma and 12(80%) of thymic carcinoma(p=0.00). Posterior spread was seen insix cases (43%) of invasive thymoma and nine (60%) of thymic carcinoma. Anterolateral spread was seen only in twocases (13%) of thymic carcinoma. Obliteration of the fat plane was seen in nine cases (64%) of invasive thymomaand 14 (93%) of thymic carcinoma, while vessel encasement was seen in two cases (14%) of invasive thymoma and13(87%) of thymic carcinoma(p=0.00). Invasion of adjacent structures was seen in two cases (14%) of invasivethymoma and eight (53%) of thymic carcinoma. Pleural implants were more common in invasive thymoma than thymiccarcinoma, being seen in six cases (43%) of the former and one (7%) of the latter(p=0.04). Mediastinallymphadenopathy was seen in three cases (21%) of invasive thymoma and ten (67%) of thymic carcinoma. Distantmetastases were observed only in six cases (40%) of thymic carcinoma(p=0.02). CONCLUSION: Althoughdifferentiation between invasive thymoma and thymic carcinoma is difficult on the basis of CT findings, there arecertain differential points. Thymic carcinomas showed a higher rate of direct posterior intrathoracic spread,vessel encasement, mediastinal nodes and distant metastases than invasive thymomas. These, however, were morecommonly associated with pleural implants than were thymic carcinoma.

Verrucous Carcinoma of the Bladder Unassociated with Bilharzial Cystitis: A Case Report

Verrucous carcinoma that occurs only in the bladder is a very rare, well-differentiated squamous cell carcinoma. The tumor is a histologically and clinically distinctive variant of squamous cell carcinoma, and is almost exclusively associated with bilharzial infection. We report the radiologic findings of a case of verrucous carcinoma of the bladder unassociated with bilharzial infection.

Effect of Pelvic Irradiation on the Bone Mineral Content of Lumbar Spine in Cervical Cancer / 대한치료방사선과학회지

PURPOSE: To evaluate the loss of bone mineral contents(BMC) in lumbar spine within the radiation field for cervical cancer treatment, BMC in the irradiated patient group was compared with that of a normal control group. METHOD AND MATERIALS: Measurements of BMC in the trabecular bone in lumbar spines(L3-L5) were performed in the both patient and normal control groups. Investigators used dual-energy quantitative computerized tomography(DEQCT) using photon energy of 120 and 80kVp. The numbers of patient and control groups were 43 in each with age distribution of fifth to seventh decade of women. The numbers of control group were 22 in fifth, 10 in sixth, and 11 in seventh decade, those of patient group were 14 in fifth, 14 in sixth, and 15 in seventh decade of women. The radiation field was extended to L5 spine for pelvic irrdiation with 45-54Gy of external radiation dose and 30Gy of high dose rate brachytherapy in cervical cancer. RESULTS: The BMC is decreased as increasing age in both control and patient groups. BMC in lumbar spine of patient group was decreased by about 13% to 40% maximally. The BMC of L3 and L4 a region that is out of a radiation field for the patient group demonstrated 119.5+/-30.6, 117.0+/-31.7 for fifth, 83.3+/-37.8, 88.3+/-46.8 for sixth and 61.5+/-18.3, 56.2+/-26.6mg/cc for seventh. Contrasted by the normal control group has shown 148.0 +/-19.9, 153.2+/-23.2 for fifth, 96.1+/-30.2, 105.6+/-26.5 for sixth and 73.9+/-27.9, 77.2+/-27.2mg/cc for seventh decade, respectively. The BMC of patient group was decreased as near the radiation field, while the lower lumbar spine has shown more large amounts of BMC in the normal control group. In particular, the BMC of L5 within the radiation field was significantly decresed to 33%, 31%, 40% compared with the control group of the fifth, sixth and seventh decades, respectively. CONCLUSION: The pelvic irradiation in cervical cancer has much effected on the loss of bone mineral content of lumbar spine within the radiation field, as the lower lumbar spine has shown a smaller BMC in patient group with pelvic irradiation in contrast to that of the normal control groups.

Comparative Analysis of Bone Mineral Contents withDual-Energy Quantitative Computed Tomography / 대한치료방사선과학회지

PURPOSE: The Dual-Energy Quantitative Computed Tomography(DEQCT) was compared with bone equivalent K2HPO4 standard solution and ash weight of animal cadaveric trabecular bone in the measurement of bone mineral contents(BMC). METHOD AND MATERIALS: The attenuation coefficient of tissues highly depends on the radiation energy, density and effective atomic number of composition.The bone mineral content of DEQCT in this experiments was determined from empirical constants and mass attenuation coefficients of bone,fat and soft tissue equivalent solution in two photon spectra.In this experiments, the BMC of DEQCT with 80 and 120kVp X rays was compared to ash weight of animal trabecular bone. RESULTS: We obtained the mass attenuation coefficient of 0.2409, 0.5608 and 0.2206 in 80kVp, and 0.2046, 0.3273 and 0.1971cm2/g in 120kVp X-ray spectra for water, bone and fat equivalent materials, respectively.The BMC with DEQCT was acomplished with empirical constants K1=0.3232, K2=0.2450 and mass attenuation coefficients has very closed to ash weight of animal trabecular bone. The BMC of empirical DEQCT and that of manufacturing DEQCT were correlated with ash weight as a correlation r=0.998 and r=0.996, respectively. CONCLUSION: The BMC of empirical DEQCT using the experimental mass attenuation coefficients and that of manufacture have showed very close to ash weight of animal trabecular bone.

The Value of CT in detecting Pathologic Bowel Perforation

PURPOSE: To evaluate the usefulness of CT for assessing the location and cause of pathologic gastrointestinal perforation. MATERIALS AND METHODS: A retrospective analysis of abdominal CT was performed in 27 perforations of 26 patients with underlying gastrointestinal pathology. Fifteen benign and 12 malignant perforations consisted of five gastric cancers, one gastric ulcer, ten duodenal bulb ulcers, two bowel adhesions, one jejunal metastasis from lung cancer, one ileocolic Crohn's disease, one radiation colitis and six colon cancers. CT scans were evaluated for 1) diagnosis of bowel perforation, 2) assessment of the cause and site of perforation, and, in particular, differentiation between benignancy and malignancy, and 3) complications and their extent. RESULTS: CT easily detected varying amounts of free air or fluid collection, and infiltration or abscess formation adjacent to the main lesion, and the diagnosis of gastrointestinal perforation was therefore easy. In 11 of the 12 malignancies (92%), primary tumor was diagnosed, but detection of the site of perforation was possible in only seven cases (7/12, 58%). The 15 benign lesions revealed nonspecific CT findings, and the perforation site could be presumed in six (6/15, 40%). In one case of Crohn's disease, the primary cause was visualized. Among six colonic cancers, four pericolic abscesses and two fistulas to adjacent organs were found, but there was no evidence of diffuse peritonitis. CONCLUSION: CT was helpful to lead to optimal treatment of pathologic gastrointestinal On CT, the detectability of perforation, primary benign or malignant lesion, perforation site and extent of complication was high, and this modality was therefore a useful indicator of the optimal treatment for pathologic gastrointestinal perforations.

Immature Teratoma of the Ovary: CT and US Findings

PURPOSE: To compare CT and US features of immature and mature teratomas of the ovary. MATERIALS AND METHODS: We retrospectively reviewed CT and US findings of 11 patients with immature teratoma and 18 patients(20 cases) with mature teratoma. The tumors were classified into three groups on the basis of image findings : predominantlycystic(type I), predominantly solid(type II), and mixed cystic and solid(type III). RESULT: All eleven cases of immature teratoma were of the mixed type(type III), showing multiple small(less than 2 cm) nodular and linear calcifications and fatty nodules within the solid component and adjacent to the septa of the cystic component of the masses. In contrast, mature teratomas were predominantly cystic in six cases, predominantly solid in eight,and mixed in six cases. In five of six mixed type mature teratomes, calcified fatty nodules were fewer and largerthan in immature teratomas. CONCLUSION: Immature teratoma may be diagnosed by the demonstration on CT or US ofmultiple small(less than 2cm) nodular and linear calcifications and fatty nodules in the solid and cystic components of the tumor.

Experimental Study on the Rim-Enhancing Lesion of Rabbit Brain Abscess: MR Imaging and Histopathologic Correlation

PURPOSE: To evaluate on the basis of histopathologic carrelation the MR findings of mature brain abscess inthe rabbit, with particular attention to rim-enhancing lesions. MATERIALS AND METHODS: The evolution of abscess formation was obtained by the direct inoculation of Staphylococcus aureus into the gray-white matter junctions ofthe brains of 16 rabbits. The stages of brain abscesses were divided into four : early cerebritis (days 1 to 5after inoculation of the organism) ; late cerebritis (days 6 to 14) ; early capsular (days 16 to 21) ; and latecapsular (days 22 to 28). The available MR images showed 14 cases at the stage of early cerebritis, seven at thelate cerebritis stage, three at the early capsular, and one at the late capsular stage. According to the known pathology of brain abscesses and on the basis of both MR imaging and histopathologic findings, the lesions weregrouped according to whether they were found in the central necrotic, border, or peripheral zone. We analyzed the patterns of rim-enhancement (completeness of the rim, thickness, and margin) and the signal intensities of theabscess walls on MR images at each stage. Histopathologic correlation was performed in one case of each stage. We evaluated the presence or absence and degree of infiltration by inflammatory granulation tissue, microhemorrhage, reticulin, collagen, and hemosiderin of the abscess walls. RESULTS: Rim-enhancing lesions were present in threeof 14 cases at the late cerebritis stage, in all three cases at the early capsular, in one at the late capsular, but in none at the early cerebritis stage. The enhancing pattern of the late cerebritis stage was irregular-margined incomplete rim-enhancement, with irregular thickness of the abscess walls (3/3). The enhancing pattern of the capsular stages was well-defined, complete rim-enhancement with uniform thickness of the abscess walls (3/4). The signal intensities of the abscess walls at the late cerebritis and early capsular stages were variable. The late capsular stage was characterized by hypointensity of the abscess wall on both T1- and T2-weighted images. Histopathologically, the capsular stages were distinguished from the late cerebritis stage bythe marked infiltration of reticulin and the presence of collagen in the abscess walls. The most conspicuous pathologic finding distinguishing the late from the early capsular stage was abundant infiltration of the abscess wall by collagen and hemosiderin. CONCLUSION: The enhancing pattern of a brain abscess with mature capsule formation was characterized by a well-defined, complete rim-enhancing abscess wall of uniform thickness. The mature abscess wall was hypointense on both T1- and T2-weighted images, may be explained by marked infiltration bymature collagen and hemosiderin.

Pelvic Actinomycosis

PURPOSE: To demonstrate the radiologic characteristics of the pelvic actinomycosis. MATERIALS AND METHODS: We retrospectively reviewed the radiologic findings of seven patients with pathologically proven pelvic actinomycosis and analyzed the anatomical location, characteristics of the lesion and alteration of surrounding structures. RESULTS: The location of the lesions were the ovary and adnexa(n=4), rectum(n=1), cecum and terminalileum(n=1), and bladder(n=1). Three of the seven patients had a past history of intrauterine devices.Post-contrast enhanced CT showed an ill-defined mass with inhomogeneous enhancement and a tendency to invade th esurrounding normal tissue plane. CONCLUSION: Pelvic actinomycosis should be included in differential diagnosis when an unusually aggressive infiltrative mass is located in the pelvic cavity, especially in a patient with long-term use of intrauterine contraceptive devices.

Segmental Dilatation of the Sigmoid Colon: A Rare Cause of Chronic Constipation

Segmental dilatation of the colon is a very rare disease entity of unknown etiology and may mimic Hirschsprung's disease. It is characterized by dilatation of a segment of the colon of variable length with obstruction due to lack of peristalsis in a normally innervated intestine. Recently authors experienced a case of segmental dilatation of the sigmoid colon in a 6 month-old male, who presented with severe constipation, abdominal distention, and abdominal mass since 2 months of age. Down's syndrome and congenital nystagmus were associated. Barium enema demonstrated focal dilatation of the sigmoid colon, but the rectum and descending colon proximal to the affected colon were of normal caliber. Rectal suction biopsy with acetylcholinesterase staining was normal and anorectal manometry showed normal rectosphincteric reflex. At operation, there was a massively dilated and hypertrophied sigmoid colon with increased tortuous serosal vessels, measuring 15 cm in length and 10 cm in width. Teniae coli were identifiable in the affected segment. Frozen section biopsies at the proximal, affected, and distal colon showed ganglion cells. Descending loop colostomy was constructed initially and segmental resection and end to end colocolostomy were carried out 3 months later. Final histologic examination showed 1) normal colonic mucosa with ganglion cells, 2) prominent submucosal fibrosis and marked muscular hypertrophy, 3) unremarkable acetylcholinesterase activity and immunohistochemical findings against S-100 protein. On 8 months follow-up, he has been doing well and moves bowels 1-2 times daily.

MR Imaging of Proximal Femur: Age-related Changes

PURPOSE: The purpose of this study is to illustrate MR patterns of signal intensity of proximal femur in normal subjects according to the age distribution. METHOD AND MATERIAL: Tl-weighted MR images of the proximal femur in 125 subjects, aged 13 days to 25 years, were retrospectively analyzed. Age distribution was classified to 4 groups;below 4 months, 5 months to 4 years, 5 years to 14 years, and 15 years to 25 years. RESULTS: By the age of 4 months, the non-ossified femoral epiphysis was seen as intermediate-signal-intensity cartilage. At 5 months-4 years, the ossified fernoral capital epiphysis was seen within intermediate-signal-intensity cartilage and appeared as decreased or increased signal-intensity red or yellow marrow surrounded by a rim of low-signal-intensity cortical bone. At 5-14 years, the ossified femoral capital and greater trochanteric epiphysis were seen within the intermediate-signal-intensity cartilage and appeared as decreased or increased signal-intensity red or yellow marrow. At 15-25 years, the proximal metaphyseal marrow showed increased signal intensity. Four patterns of the metaphyseal marrow were recognized by Ricci et al. The frequency of pattern la progressively decreased with age. Pattern 2 and 3 were visible in the 15-25 years age group. CONCLUSION: An understanding of the spectrum of normal age-related change of the proximal femoral cartilage and marrow patterns serves as the foundation for interpretation of proximal femur pathologies.

Usefulness of Automated Biopsy Guns in Image-guided Biopsy

PURPOSE: To evaluate the usefulness of automated biopsy guns in image-guided biopsy of lung, liver. pancreas and other organs. MATERIALS AND METHODS: Using automated biopsy devices, 160 biopsies of variable anatomic sites were performed:Biopsies were performed under ultrasonographic(US) guidance in 95 and computed tomographic (CT) guidance in 65. We retrospectively analyzed histologic results and complications. RESULTS: Specimens were adequate for histopathologic diagnosis in 143 of the 160 patients(89.4%)-Diagnostic tissue was obtained in 130 (81.3%), suggestive tissue obtained in 13(8.1%), and non-diagnostic tissue was obtained in 14(8.7%). Inadequate tissue was obtained in only 3(1.9%). There was no statistically significant difference between US-guided and CT-guided percutaneous biopsy. There was no occurrence of significant complication. We have experienced mild complications in only 5 patients-2 hematuria & 2 hematochezia in transrectal prostatic biopsy, and 1 minimal pneumothorax in CT-guided percutaneous lung biopsy. All of them were resolved spontaneously. CONCLUSION: The image-guided biopsy using the automated biopsy gun was a simple, safe and accurate method of obtaining adequate specimen for the histopathologic diagnosis.

MR Findings of Intravertebral Vacuum Cleft: Report of Two Cases

Intravertebral vacuum cleft in collapsed vertebra was considered as a typical finding of avascular necrosis. However, several authors reported some cases of intravertebral vacuum cleft in primary or secondary neoplasm, or in spondylitis emphasiging the differenhal diagnosis. MRI is known to be a useful diagnostic modality for diferentiation between benign and malignanct conditions causing vertebral collapse. We report MRI findings of two cases with intravertebral vacuum cleft diagnosed as posttraumatic collapse with avascular necrosis on radiological and clinical bases.

MR Imaging in the Evaluation of Mullerian Duct Anomalies

PURPOSE: To assess the role of MRI in the diagnosis of uterine anomaly. MATERIAL AND METHODS: MRI(n:15), hysterosalpingography(n:7) and ultrasonography(n:7) were performed in 15 patients with suspected MullerJan duct anomaly. Nine cases were proved by operation and six cases were diagnoed with imaging and clinical findings. According to Buttram and Gibbons modified classification, the anomalies were 4 cases of class I, 2 cases of class III, one case of class IV, and 8 cases of class V. RESULTS: MRI enabled accurate diagnoses of anomalies in all cases, but HSG and USG showed wrong diagnoses in 3 of 7 cases and in 1 of 7 cases. CONCLUSION: MRI, especially T2-weighted images parallel to long axis of uterine corpus, was very useful in diagnosis of the Mullerian duct anomaly, because it could depict exactly the external fundal contour, intercornual distance, septum, transverse vaginal septum, and associated abnormalities such as hematocolpos and hematometra.

Usefulness of Dynamic Magnetic Resonance Imaging in Brain Tumors

PURPOSE: To investigate the usefulness of dynamic MR imaging in the differential diagnosis of brain tumors. MATERIALS AND METHODS: Dynamic MR imaging was performed in 43 patients with histopathologically proved brain tumrs. Serial images were sequentially obtained every 30 seconds for 3--5 minutes with use of spin-echo technique(TR 200msec/TE 15msec) after rapid injection of Gd-DTPA in a dose of 0.1mmol/kg body weight. Dynamics of contrast enhancement of the brain tumors were analyzed visually and by the sequential contrast enhancement ratio(CER). RESULTS: On the dynamic MR imaging, contrast enhancement pattern of the gliomas showed gradual increase in signal intensity(SI) till 180 seconds and usually had a longer time to peak of the CER. The SI of metastatic brain tumors increased steeply till 30 seconds and then rapidly or gradually decreased and the tumors had a shorter time to peak of the CER. Meningiomas showed a rapid ascent in SI till 30 to 60 seconds and then made a plateau or slight descent of the CER. Lymphomas and germinomas showed relatively rapid increase of Sl till 30 seconds and usually had a longer time peak of the CER. CONCLUSION: Dynamic MR imaging with Gd-DTPA may lead to further information about the brain tumors as the sequential contrast enhancement pattern and CER parameters seem to be helpful in discriminating among the brain tumors.

Transfusional Hemosiderosis; Correlation of MR Findings with Clinical Findings

PURPOSE: Parenchymal iron deposition occurs in hemochromatosis, while iron is deposited in reticuloendothelial cells after blood transfusions(Hemosiderosis). We stuided correlation between MR finding and clinical findings(serum ferritin, TSI, LFT, disease duration) of hemosiderosis. MATERIALS AND METHODS: 12 patients with chronic renal failure and one patient with aplastic anemia, who have received multiple transfusion, were performed MRI with a 2.0 Tesla unit. RESULTS: In All of 13 patients(17 cases), the liver revealed low signal intensity equal to background noise. In 4 of 17 cases whose serum ferritin level was below 1000 ng/ml, pancreas, gastric wall, adrenal gland were involved in 1 case. In 4 cases with serum ferritin level between 1000 and 1500, pancreas was involved in 2 cases, and other organ was involved in 1 case. In 9 cases with serum ferritin level above 1500ng/ml, pancreas involved in 9 cases, and other organ in 4 cases. CONCLUSIONS: The MR findings are well correlated with serum ferritin level whereas the TSI, LFT, disease duration are not correlated with involved organ on MR.