MRI Findings of Lipiodol Uptake in Hepatocellular Carcinomas: A Focus on Signal Intensity / 이화의대지

OBJECTIVES: To evaluate MRI findings of non-recurrent hepatocellular carcinomas with lipiodol uptake (LHCCs) treated with transarterial chemoembolization. METHODS: 28 LHCCs were divided into two groups according to amount of lipiodol uptake and tumor size, retrospectively. According to amount of lipiodol uptake, HCCs were classified into group A with dense lipiodol uptake (more than 90%) and group B with partial lipiodol uptake (between 50% and 90%). For HCC size analysis, group I was defined by a longest diameter of less than 2 cm, and group II was defined by a longest diameter of greater than or equal to 2 cm. RESULTS: In group A (n=16), eight LHCCs showed high signal intensity (SI) on T2-weighted images (T2WI), ten LHCCs showed low SI on T1-weighted imaged (T1WI), six LHCCs showed decreased SI at higher b value of diffusion-weighted images (DWI). In group B (n=12), six LHCCs revealed high SI on T2WI, six LHCCs revealed low SI on T1WI, ten LHCCs decreased SI at higher b value of DWI. As compared with tumor size and SI, six of 12 LHCCs in group I and eight of 16 LHCCs in group II showed high SI on T2WI. Six LHCCs in group I and ten LHCCs in group II showed low SI on T1WI. All LHCCs were not enhanced. CONCLUSION: Signal intensities of LHCCs were variable, but more than half of LHCCs showed high SI on T2WI, low SI on T1WI, decreased SI at higher b value of DWI, regardless of lipiodol uptake or tumor size.

Dual-Energy CT in the Assessment of Mediastinal Lymph Nodes: Comparative Study of Virtual Non-Contrast and True Non-Contrast Images

OBJECTIVE: To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes. MATERIALS AND METHODS: A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed. RESULTS: CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 +/- 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (kappa value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245). CONCLUSION: VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.

Computer-Aided Evaluation of Breast MRI for the Residual Tumor Extent and Response Monitoring in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

OBJECTIVE: To evaluate the accuracy of a computer-aided evaluation program (CAE) of breast MRI for the assessment of residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy. MATERIALS AND METHODS: Fifty-seven patients with breast cancers who underwent neoadjuvant chemotherapy before surgery and dynamic contrast enhanced MRI before and after chemotherapy were included as part of this study. For the assessment of residual tumor extent after completion of chemotherapy, the mean tumor diameters measured by radiologists and CAE were compared to those on histopathology using a paired student t-test. Moreover, the agreement between unidimensional (1D) measurement by radiologist and histopathological size or 1D measurement by CAE and histopathological size was assessed using the Bland-Altman method. For chemotherapy monitoring, we evaluated tumor response through the change in the 1D diameter by a radiologist and CAE and three-dimensional (3D) volumetric change by CAE based on Response Evaluation Criteria in Solid Tumors (RECIST). Agreement between the 1D response by the radiologist versus the 1D response by CAE as well as by the 3D response by CAE were evaluated using weighted kappa (k) statistics. RESULTS: For the assessment of residual tumor extent after chemotherapy, the mean tumor diameter measured by radiologists (2.0 +/- 1.7 cm) was significantly smaller than the mean histological diameter (2.6 +/- 2.3 cm) (p = 0.01), whereas, no significant difference was found between the CAE measurements (mean = 2.2 +/- 2.0 cm) and histological diameter (p = 0.19). The mean difference between the 1D measurement by the radiologist and histopathology was 0.6 cm (95% confidence interval: -3.0, 4.3), whereas the difference between CAE and histopathology was 0.4 cm (95% confidence interval: -3.9, 4.7). For the monitoring of response to chemotherapy, the 1D measurement by the radiologist and CAE showed a fair agreement (k = 0.358), while the 1D measurement by the radiologist and 3D measurement by CAE showed poor agreement (k = 0.106). CONCLUSION: CAE for breast MRI is sufficiently accurate for the assessment of residual tumor extent in breast cancer patients receiving neoadjuvant chemotherapy. However, for the assessment of response to chemotherapy, the assessment by the radiologist and CAE showed a fair to poor agreement.

Efficacy of the Focused Ultrasound as an Additional Study to Characterize Small Hepatic Lesions on CT in Patients with Cancer

PURPOSE: The purpose of this study was to evaluate the efficacy of focused ultrasound (US) to characterize small indeterminate hepatic lesions on contrast-enhanced CT in cancer patients. MATERIALS AND METHODS: Forty-three consecutive patients with proven cancers developed 70 indeterminate hepatic lesions that were less than 1.5 cm in size, as detected on contrast-enhanced CT. Two radiologists performed ultrasound focusing on the targeted area after referencing the location of the hepatic lesions on a previous CT image. When the hepatic lesions were visualized by focused US, the lesions were characterized as cysts, hemangiomas, or solid/metastases. Verification of the hepatic lesions was assessed by a histopathological examination or by follow-up imaging. RESULTS: Focused US detected 51 (73%) of 70 indeterminate hepatic nodules on CT and all of the nodules visualized on focused US could be characterized as cysts (n = 40), hemangiomas (n = 7), or solid/metastases (n = 4). All of the cysts and six hemangiomas were verified as benign lesions. One hemangioma was subsequently identified as a metastasis. Nineteen (27%) indeterminate hepatic nodules were not visible on focused US and 18 nodules were verified as benign lesions. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of focused US for differentiating metastases among indeterminate hepatic nodules less than 1.5 cm in size on CT were 66.7%, 100%, 97.1%, 100%, and 97%, respectively. CONCLUSION: Focused US may be the next appropriate examination to perform for cancer patients with indeterminate hepatic nodules detected on CT, Focused US may be a pivotal modality for defining prognosis and treatment.

Efficacy of Preoperative US Vascular Mapping for Arteriovenous Fistula in Patients with Hemodialysis

PURPOSE: The purpose of this study is to assess the efficacy of preoperative US vascular mapping to predict postoperative patency of the arteriovenous fistula for hemodialysis. MATERIALS AND METHODS: Sixty-six patients who underwent hemodialysis for end-stage renal failure (M: F=34:32, mean age, 58.8 years) were observed prospectively from January 2001 to April 2003. The patients were divided into two groups: the vascular mapping group and the control group. A comparative analysis of the re-operation rate between the two groups was determined by use of the chi-square rest, efficacy of preoperative US vascular mapping according to the type of surgery. A comparative analysis of the secondary patency after percutaneous transluminal angioplasty was determined by the use of Fischer exact test, and a comparative analysis of the diminution of patency during the follow-up periods was determined by the use of the Log-rank test. In the mapping group, the diameters of intraoperatively selected vessels were investigated and compared with the recommended diameter on preoperative US vascular mapping determined statistically by the use of Fisher's exact test. RESULTS: The preoperative US vascular mapping group had relatively lower re-operation rates (11.8%) than the control group (28.1%) (p=0.09). The preventive role of US vascular mapping is more effective in decreasing the re-operation rate for a native arteriorvenous fistula (7.4%) than for a synthetic arteriovenous graft (25.9%) (p=0.06). For patients that had an interventional procedure, the failure rate to obtain a secondary patency was smaller than in the mapping group (33.3%), compared with the control group (46.3%) (p=0.37). Patients in the mapping group had a higher patency than the control group patients for a native arteriovenous fistula (92.0%) and a synthetic arteriovenous graft (71.4%) at one year following surgery (p=0.10, p=0.79). The arteriovenous fistulas in the mapping group had a higher patency for both a native arteriovenous fistula (16.6%) and a synthetic arteriovenous graft (22.2%), which was statistically significant (p=0.01, p=0.03). CONCLUSION: Preoperative US vascular mapping is considered to be a useful technique for the preoperative evaluation of an arteriovenous fistula and to contribute to maintaining its postoperative patency and reducing the rate of repeated surgery.

Synchronous Papillary Tumor of the Fallopian Tube and Endometrium: A Case Report

Synchronous tumor of the fallopian tube and endometrium is an unusual co-occurrence of gynecologic malignancies. To the best of our knowledge, there have been no reports on synchronous papillary tumor of the fallopian tube and endometrium. In this report, we present the case of a patient who synchronously suffered with papillary serous adenocarcinoma of the fallopian tube and endometrium and the tumor showed characteristic frondlike projections on magnetic resonance imaging.

Efficacy of CT Colonography in the Detection of Colorectal Polypoid Lesions

PURPOSE: We wished to compare CT colonography with conventional colonoscopy for the detection of colorectal polypoid lesions, and we wanted to evaluate the role of IV contrast-enhanced CT colonography for the differentiation between benign polypoid lesions and malignant polypoid lesions. MATERIALS AND METHODS: Thirty-four consecutive patients underwent CT colonography prior to conventional colonoscopy. Precontrast prone-position CT images and postcontrast supine position CT images were obtained and the virtual colonoscopic images were reconstructed. Axial, sagittal and coronal images with virtual colonoscopic images were prospectively interpreted for the presence, size and morphologic features of colorectal polypoid lesions, and then these findings were compared with the colonoscopic findings. The degree of enhancement of colorectal polypoid lesions was measured by subtracting the attenuation values obtained with precontrast and postcontrast CT images for the differentiation of benignity and malignancy of the colorectal polypoid lesions. RESULTS: Among 75 colorectal polypoid lesions identified on conventional colonoscopy, 49 neoplasms were found on CT colonography, and the overall detection rate was 65.3%. Detection rate of lesions smaller than 10 mm was 52.1% (24/46), and the detection rate for lesions equal to or larger than 10 mm was 86.2% (25/29). Morphologic features of the sessile type lesions on CT colonography were well correlated with those noted on colonoscopy, but the stalks were not identified in 6 of 13 polyps on CT colonography. There was no statistical correlation between benignity and malignancy and the degree of contrast enhancement on CT colonography. CONCLUSION: CT colonography is a useful modality for the detection of colorectal polypoid lesions equal to or larger than 10mm, and it well demonstrates the morphologic features, except for the stalk of pedunculated polyps. However, CT colonography cannot differentiate benignity from malignancy.

The Value of Ultrasonographic Detection for Metastatic Axillary Lymph Nodes in Breast Cancer

PURPOSE: We evaluated the significance and accuracy of sonographic detection of metastatic axillary lymph nodes (LNs) in breast cancer. MATERIALS AND METHODS: We retrospectively reviewed the sonographic findings and postoperative results of axillary LNs in 47 patients with breast cancer. The sonographic criteria for metastatic LNs were defined as the loss of the echogenic hilum and any uneven cortical thickness of over 3 mm. We analyzed the correlation between the preoperative sonographic findings and the postoperative results of the LNs. RESULTS: Out of 47 patients, 22 patients showed 43 sonographic metastatic LNs. Among these 22 patients, 18 patients had 183 histopathologically proven metastatic LNs. The pathological examination of the remaining 25 patients revealed metastatic LNs in 6 patients. The overall sensitivity, specificity and accuracy of ultrasonography for detecting metastatic axillary LNs in breast cancer were 75%, 82.6% and 78.7%, respectively. As the number of metastatic LNs detected on sonography increased, the number of histologically proven metastatic LNs increased. CONCLUSION: Ultrasonographic evaluation of axillary LNs in breast cancer can provide relatively accurate information about the presence or absence of metastasis. Therefore, it is useful to decide the initial staging and treatment planning of patients with breast cancer.

A Case of Abdominal Actinomycosis Mimicking Colon Carcinoma / 대한소화기내시경학회지

Actinomycosis is a chronic suppurative and granulomatous-disease caused by Actinomycosis israelli. Clinical presentation of the abdominal form of actinomycosis is nonspecific-pain, fever, leukocytosis, increased erythrocyte sedimentation rate, a sensation of abdominal mass and a formation of fistula. In addition, abdominal actinomycosis may mimic a carcinoma, diverticular abscess, inflammatory bowel disease, and tuberculosis. Most of abdominal actinomycosis develops after trauma, appendicitis, diverticulitis or gastrointestinal perforation. We report a case of abdominal actinomycosis preoperatively mimicking as colon carcinoma, which had no predisposing factors.

US and CT Imaging of Undifferentiated Carcinoma of the Pancreas

We report the case of a 64-year-old female patient with an undifferentiated carcinoma involving the pancreatic head in whom hepatic metastasis and encasement of the portal and superior mesenteric veins had occurred. Ultrasound demonstrated a round well-defined hypoechoic mass with increased color Doppler flow signals at the periphery, while CT revealed a heterogeneously enhanced mass with a less attenuated central portion and rim enhancement of the pancreatic head.

Solitary Fibrous Tumor of the Adrenal Gland: A Case Report

Solitary fibrous tumor is a rare mesenchymal tumor, usually involving the pleura. Its occurrence in various organs of the body has recently been described; in particular, two cases of solitary fibrous tumor of the adrenal gland have been reported worldwide, but no case has been reported in Korea. We describe a case of solitary fibrous tumor occurring in the left adrenal gland and discovered incidentally at CT.

Ultrasonographic Evaluation of Focal Hepatic Lesions : Comparison of Fundamental, Tissue Harmonic, Fundamental Compound and Harmonic Compound Imaging Techniques

PURPOSE: To compare the ultrasonographic image quality of fundamental imaging (FI), tissue harmonic imaging (THI), fundamental compound imaging (FCI), and harmonic compound imaging (HCI) in the evaluation of focal hepatic lesions. MATERIALS AND METHODS: Ninety-four focal hepatic lesions (27 hemangiomas, 15 hepatocellular carcinomas, 14 metastases, and 38 cysts) in 74 patients [30 males and 44 females aged 33-82 (mean, 55) years] were included in our study. All patients underwent FI, THI, FCI, and HCI using an HDI 5000 Sono CT scanner (Advanced Technology Laboratories, Bothell, CA., U.S.A.) with a 2-5MHz convex transducer. Images were analysed by two abdominal radiologists who used a 4-point scale and reached a consensus. In the case of solid lesions, four parameters, as follows, were evaluated: lesion conspicuity, internal morphology, overall image quality, and peripheral halo. For cysts, three parameters (internal artifact, sharpness of margin, and posterior enhancement) were assessed. For statistical analysis, the Scheffe method (ANOVA test) was used. RESULTS: For solid lesions (hemangioma, hepatocellular carcinoma, and metastasis), THI, FCI and HCI were superior to FI in terms of lesion conspicuity, internal morphology and overall image quality (p<0.05), though for peripheral halo, the four imaging techniques were not statistically different. For cysts, THI, FCI and HCI revealed clearer internal artifact and better margin sharpness than FI (p<0.05), while in terms of posterior enhancement, THI was superior to both FI and FCI, and HCI was superior to FCI (p<0.05). CONCLUSION: For the evaluation of focal hepatic lesions, harmonic imaging techniques (i.e. THI and HCI) appear to provide better image quality than fundamental imaging techniques (i.e. FI and FCI). There is, however no significant difference in image quality between the two harmonic techniques.

The Pitfalls of the Magnetic Resonance Cholangio-Pancreatography the Diagnosis of Biliary Stones

PURPOSE: To determine the incidence of flow artifact and vascular compression, phenomena that mimic biliary stone disease at magnetic resonance cholangio pancreatography (MRCP). MATERIALS AND METHODS: In 160 patients who underwent MRCP, the prescence and location of flow artifact were determined. The signal intensity of flow artifacts was chassifieded as either higher than renal cortical density (group I), the same as renal cortical density (group II), the same as hepatic density (group III), or the same as vascular density (group IV). Correlation between flow artifact and the largest diameter of the extrahepatic duct (EHD) was statistically evaluated, and the location of vascular compression in the biliary system and causative vessels was also determined. RESULTS: At MRCP, flow artifacts were observed in 81 patients (76.4%). Forty-five (42.5%) were classified as group I, 15 (14.2%) as group II, 18 (17.0%) as group III, and three (2.8%) as group IV. They were located in the common bile duct (78.3%), common hepatic duct (70.0%), or intrahepatic duct (29.2%) or at the cystic duct insertion site (7.5%). In patients in whom a flow artifact was not apparent, the diameter of the EHD was 7.1mm; in those with an artifact, this diameter was 11.3 mm. The mean diameter of the EHD was greater in groups II, III and IV (11.4 mm) than in group I (9.8 mm). Vascular compression was demonstrated in 21 patients (19.8%), occurring in the common hepatic duct in 8.5%, the left intrahepatic duct in 8.5%, the common bile duct in 1.9%, and the right intrahepatic duct in 0.9%. Causative vessels were the right hepatic artery (12.5%), left hepatic artery (5.7%), and branches of the gastroduodenal artery (1.9%). CONCLUSION: As the extrahepatic duct is wide, a flow artifact appears and signal intensity decreases. In particular, flow artifacts with a signal intensity of grade III or IV, occuring in 19.8% of patients, mimicked biliary stones at MRCP. The presence of a flow artifact and vascular compression, which mimic biliary stone, therefore be carefully interpreted.

Diagnostic Accuracy of Mammography and Ultrasonography in Detection of Early Breast Cancer

PURPOSE: To determine the value of mammography and ultrasonography in the detection of early breast cancer, and the usefulness of combining the two modalities for the diagnostic study of this condition. MATERIALS AND METHODS: The mammographic and ultrasonographic features of 47 female patients aged 23-68 (average, 46) years with pathologically proven early breast cancer were analyzed retrospectively. Mammography was performed in 46 patients and ultrasonography in 38, and 37 underwent both mammography and ultrasonography. Analysis of the mammographic and/or ultrasonographic features focused on mass, microcalcification, mass with microcalcification, multiple nodules, duct dilatation, and architectural distortion. RESULTS: Mammography revealed microcalcification in 29 (63%) patients, mass in 13 (28%) patients, mass with microcalcification in 8 (17%) patients, multiple nodules in 2 (4%) patients, architectural distortions in 1 (2%) patient, and negative finding in 9 (20%) patients. Ultrasonography revealed mass in 25 (66%) patients, microcalcifcation in 9 (24%) patients, mass with microcalcification in 8 (21%) patients, multiple nodules in 2 (5%) patients, duct dilatation in 3 (8%) patients, and negative finding in 7 (18%) patients. On combined study of mammography and ultrasonography of the 37 patients, mammography or ultrasonography revealed mass in 25 (68%) patients, microcalcification in 20 (54%) patients, multiple nodules in 2 (5%) patients, duct dilatation in 3 (8%) patients, and architectural distortion in 1 (3%) patient. In one (3%) patient among them, both mammography and ultrasonography revealed negative findings. The false negative rate of mammography, ultrasonography or both was 20%, 18%, and 3%, respectively, which was statistically significant difference (p < 0.05). CONCLUSION: Combined study of mammography and ultrasonography is the most useful as a diagnostic study for early breast cancer. So, ultrasonography seems to be the important additional method for detection of early breast cancer.

Evaluation of Accuracy and Interobserver Agreement of MR Cholangiography for Diagnosis of Cholelithiasis

PURPOSE: To assess the accuracy of MR cholangiography(MRC) in the diagnosis of cholelithiasis, and to determine interobserver agreement. MATERIALS AND METHODS: Between March and September 1999, 43 consecutive patients with biliary obstruction [24 men and 19 women aged 25 -85 (mean, 58) years] underwent MRC using the single-shot fast spin-echo technique. Heavily T2-weighted source images(axial and coronal) 3 -5 mm thick and 12 projection images with 15- degree rotation and 5-cm thickness were obtained. All images were reviewed blindly and indepen-dently by two radiologists specialized in the interpretation of abdominal imaging information. Choledocholithiasis was evaluated in eight segments of the intrahepatic duct(IHD), extrahepatic duct(EHD) and gall bladder lumen. Final diagnosis was established on the basis of operative (n=31) and other radiological (n=12) findings. The sensitivity, specificity and accuracy of the MRC findings were assessed, and using kappa measurement (cross-table analysis,SPSS Windows for 8.0), interobserver agreement was determined. RESULTS: Thirty of the 43 patients, had choledocholithiasis (IHD stones in 7 cases, EHD stones in 15, and GB stones in 18). For radiologist 1, sensitivity, specificity and accuracy were 86%, 100% and 98%, respectively, in the diagnosis of IHD stones; 100%, 89% and 93%, respectively, in the diagnosis of EHD stones; and 81%, 96% and 91%, respectively, in the diagnosis of GB stones. For radiologist 2, the corresponding figures were 86%, 94% and 93% (1HD stones); 87%, 89% and 88% (EHD stones); and 81%, 86% and 84% (GB stones). Interobserver agreement for the diagnosis of choledocholithiasis was excellent in all cases. The kappa mesurement was 0.91 for 1HD stones, 0.77 for EHD stones, and 0.70 for GB stones. CONCLUSION: MRC is an excellent imaging modality for the diagnosis of choledocholithiasis, and interobserver agreement was also excellent.

The Diagnostic Role of US in Patients with Right Lower Quadrant Abdominal Pain

PURPOSE: To determine the frequency with which ultrasonography (US) provides a correct diagnosis and suggests appropriate guidance for the treatment of patients with right lower quadrant abdominal pain. MATERIALS AND METHODS: During an 11-month period, US was consecutively performed in 84 patients who were presented with right lower quadrant abdominal pain. In the 76 [M ; F=16 ; 60, age range 14 -87 (mean, 41) years] who formed the study population, final diagnoses were made surgically or clinically. For US, a 5 -7-MHz convex-array, 4-MHz vector-array, and/or 7-MHz linear-array transducer was used, according to the patient 's body habitus. To determine how often our US reports had provided a correct diagnosis and suggested appropriate guidance for surgical or medical treatment, and to calculate their diagnostic value, the reports were retrospectively compared with final diagnoses. RESULTS: US diagnoses were acute appendicitis in 40 patients (53%), diseases other than this in 25 patients (33%), and no abnormality in 11 (14%). In 38 of the 40 patients (95%), the diagnosis of acute appendicitis was surgically confirmed as correct, and for other diseases, diagnoses based on the findings of US proved to be correct in 21 of 25 patients (84%). Overall, diagnosis was correct in 67 (88%). As regards appropriate guidance for treatment, 46 (61%) and 30 (39%) patients were diagnosed by US to have surgical and medical diseases, respectively. In 44 of the 46 (96%), it was confirmed guidance was appropriate, and for the 30 with medical disease, this was so in all but one case (97%). Overall, the treatment plan was appropriate in 72 patients (95%). CONCLUSION: Our study revealed that US was able to provide a correct diagnosis in 88% of patients with right lower quadrant abdominal pain, and in 95% of these, the treatment plan suggested was appropriate. US is, therefore, a valuable screening tool in the diagnosis and therapeutic guidance of such patients.

Differential Diagnosis of Bicornuate and Septate Uterus : Is Comparison of Septal Signal Intensity on MR Image Useful?

PURPOSE: To evaluate the usefulness of comparison of the signal intensity of uterine septum in the differential diagnosis of bicornuate and septate uterus on magnetic resonance (MR) imaging. MATERIALS AND METHODS: Preoperative MR imaging findings of surgically proven 5 bicornuate and 6 septate uteri were retrospectively analyzed. Because preoperative differential diagnosis of both was possible in all cases in terms of the intercornual distance, external contour of uterine fundus, and divergent angle of two uterine cavities, these criteria were excluded in this study. The signal intensity of uterine septum in patients with bicornuate and septate uterus was analyzed on T1-weighted and fast spin echo T2-weighted images obtained in the axial and coronal planes, using a 1.5-T MR scanner. The signal intensity of uterine septum especially on T2-weighted images was compared with that of myometrium or junctional zone. RESULTS: The signal intensity of uterine septum in patients with bicornuate uterus (n=5) and septate uterus (n=6) was similar to that of myometrium in all cases on T1-weighted images. The septum of bicornuate uterus (n=5) on fast spin echo T2-weighted images was isointense with myometrium in three and hypointense in two cases. The uterine septum of septate uterus (n=6) on T2-weighted images was isointense with myometrium in two, hypointense in two, and isointense with or more hypointense than junctional zone in two cases. No patient showed different signal intensity between upper and lower uterine septum. CONCLUSION: Because the MR signal intensity of the uterine septum in bicornuate or septate uterus is variable, it should not be used alone in the differential diagnosis of them. In these clinically important differentiation, therefore, comprehensive analysis of MR findings in terms of the external contour of uterine fundus, intercornual distance, divergent angle of two uterine cavities, in addition to the signal intensity of the uterine septum, should be considered.

MR Findings of a Primary Ovarian Lymphoma

The imaging findings of primary ovarian lymphoma have not been reported, and, we therefore describe the MRI(magnetic resonance imaging) findings of a case of this disease, which manifested as bilateral lobulated solid masses with heterogenous signal intensity and central feeding vessels.

Lenticulostriate Vasculopathy of Brain Ultrasonography

PURPOSE: To describe the associated conditions and clinical significance of lenticulostriate uasculopathy (LSV) as demonstrated by cranial sonography. MATERIALS AND METHODS: We retrospectively studied 77 LSV cases who between January 1994 and January 1996 had undergone cranial sonography for neonatal asphyxia, seizure, or bulging of anterior fontanel. Cranial sonography was performed with 7 MHz real-time linear and sector transducers using an Acuson computed sonography unit ; examinations were performed in sagittal and coronal planes. Twenty-six LSV patients underwent color Doppler studies, and in 24 of these, color signal and arterial pulse spectral wave were detected. LSV was grouped as one of three types, according to echogenicity : type I (less echogenic than sylvian fissure), type II (similar to sylvian fissure), and type III (more echogenic than sylvian fissures). We retrospectively evaluated associated sonographic abnormalities of the brain, and reviewed medical records for associated conditions and neurologic sequelae. Follow-up sonographic examinations were performed in 23 patients. RESULTS: There were 56 type I cases (73 %), 17 of type II (22 %) and 4 of type III (5 %). Cranial sonographic results were normal in 36 cases (47 %) and abnormal in 41(53 %). Forty-eight cases of nonspecific causes and 29 cases of perinatal and acquired causes accounted for associated conditions. The echogenicity of LSV had not changed in 21 of 23 follow-up cases. Neurologic examinations were performed in 18 cases and in 14 of these (78 %) there was no neurologic sequela. CONCLUSION: LSV in basal ganglia may be associated with nonspecific neonatal conditions, in addition to well known perinatal causes.

CT after Gastrectomy for Gastric Carcinoma: Significance of Soft Tissue Surrounding the Celiac Axis

PURPOSE: To evaluate whether soft tissue surrounding the celiac axis, as seen on abdominal CT imaging after gastrectomy for gastric carcinoma, should be considered as the recurrence of carcinoma or postoperative change. MATERIALS AND METHODS: One hundred and forty-one abdominal CT examinations of 71 patients who had undergone subtotal or total gastrectomy for gastric carcinoma were included in our study. Conventional CT scans were obtained with 1 cm thickness and interval from the diaphragm to the kidneys after contrast enhancement. It was considered that carcinoma had not recurred if findings were negative on UGI series, endoscopy with biopsy and a normal level of carcinoembryonic antigen except for soft tissue surrounding the celiac axis on abdominal CT. We then divided subjects into a recurrence group (N = 20) and normal group (N = 51) and on initial follow-up CT (FU-CT), analyzed the incidence, margin, shape, extent, degree and pattern of attenuation of the soft tissue surrounding the celiac axis in both groups. Since the second FU-CT examination, we observed changes in the soft tissue surrounding the celiac axis. RESULTS: On initial follow-up CT, at mean 308 days after surgery, fifty-five percent(39/71) of total patients (70% (14/20) of the recurrence group and 49% (25/51) of the normal group) showed soft tissue surrounding the celiac axis. The margin was distinct in 12 (86%) of the recurrence group and indistinct in 21 (84%) of the normal group (P < 0.001). Twelve (86%) of the recurrence group showed a nodular or confluent nodular shape and 21 (84%) of the normal group showed a permeative shape (P < 0.001). Extent was unilateral in eight (57%) of the recurrence group and bilateral in 16 (64%) of the normal group. Attenuation was similar to that of the spleen and muscle in seven (50%) of the recurrence group and was similar to that of muscle in 18 (72%) of the normal group. The pattern of attenuation was homogeneous in 13 (93%) of the recurrence group and 21 (84%) of the normal group. There was no significant difference in extent, degree and pattern of attenuation between the two groups. Since the second FU-CT examination, soft tissue surrounding the celiac axis was seen to have changed. In one patient in the recurrence group it had a distinct margin, was nodular in shape, unilateral in extent and showed attenuation similar to that of the spleen. In one patient in the normal group, it had changed and had an indistinct margin, three patients showed a decrease in the amount of soft tissue and eight showed decreased attenuation. CONCLUSION: Follow-up abdominal CT is useful in the differentiation of cancer recurrence and postoperative change, and for observing changes in soft tissue surrounding the celiac axis.