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.
Artifacts* ; Humans ; Liver* ; Spleen ; Tomography, Spiral Computed*

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.
Adult ; Aged ; Female ; Human ; Magnetic Resonance Imaging ; Male ; Middle Age ; Paraganglioma, Extra-Adrenal/*diagnosis/pathology ; Spinal Neoplasms/*diagnosis/pathology

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.
Artifacts ; Berlin ; Colon, Sigmoid ; Consensus ; Contrast Media* ; Female ; Gadolinium DTPA ; Humans ; Magnetic Resonance Imaging ; Ovary ; Uterus

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.
Diagnosis ; Endometrial Neoplasms ; Female ; Magnetic Resonance Imaging* ; Mucins ; Ovary ; Retrospective Studies

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.
Humans ; Needles ; Neoplasm Metastasis ; Retrospective Studies ; Thymoma* ; Tomography, X-Ray Computed

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.
Abscess ; Brain Abscess* ; Brain Neoplasms* ; Brain* ; Diagnosis, Differential ; Gadolinium ; Glioma ; Humans ; Magnetic Resonance Imaging* ; Neoplasm Metastasis ; Retrospective Studies

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.
Animals ; Bone Density* ; Cadaver ; Water

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.
Age Distribution ; Bone Density* ; Brachytherapy ; Female ; Humans ; Research Personnel ; Spine* ; Uterine Cervical Neoplasms*

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.
Carcinoma, Squamous Cell ; Carcinoma, Verrucous* ; Cystitis* ; Urinary Bladder*

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.
Abscess ; Colitis ; Colonic Neoplasms ; Crohn Disease ; Diagnosis ; Fistula ; Humans ; Lung Neoplasms ; Neoplasm Metastasis ; Pathology ; Peritonitis ; Pneumoperitoneum ; Retrospective Studies ; Stomach Neoplasms ; Stomach Ulcer ; Tomography, X-Ray Computed ; Ulcer