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.

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.

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.

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.

Evaluation of Renal Resistive Index in Cirrhotic Patients for Predicting the Hepatorenal Syndrome

PURPOSE: To evaluate the usefulness of renal resistive index(RI) in patients with liver cirrhosis as an indicator for predicting hepatorenal syndrome. MATERIALS AND METHODS: Renal RIs of thirty cirrhotic patients were analyzed using the gray-scale and Doppler ultrasonograms. As a control group, eight normal subjects were alsoincluded. Renal RIs were measured at three sites of interlobar or arcuate arteries of both kidneys. The patients were divided into three groups (A, B, or C) according to the Child-Turcotte-Pugh classification and their serum BUN and creatinine levels were compared. We determined whether RIs of normal controls differed from those of cirrhotic patients or whether RIs of cirrhotic patients correlated with the Child-Turcotte-Pugh classification or BUN and creatinine levels. RESULTS: Mean RIs(0.63 +/-0.03) of normal subjects were statistically different from those(0.67 +/-0.05) of cirrhotic patients(P=0.009). RIs of group A(n=6), B(n=9) and C(n=15) were 0.65 +/-0.03,0.65 +/-0.04 and 0.70 +/-0.04, respectively. The ANOVA test revealed statistically significant differences between the three groups(F ratio=4.472, P=0.021). RIs did not correlate with BUN or creatinine levels. CONCLUSION: RI could be used as an index for predicting hepatorenal syndrome before the renal function becomes impaired.

Lesser Omental Internal Hernia with Strangulation: A Case Report

Internal hernia is an unusual cause of the intestinal obstruction. The advances of CT make the diagnosis more easier than in the past. We report one case of internal hernia with herniation of the ileum into the lesser omenturn. The diagnosis could be made when abdominal radiographs showed fixed clustering of the small bowel loops in upper abdomen medial to the stomach. CT and ultrasound showed characteristic interposition of the ileum between the left hepatic lobe and the stomach.

Small Cell Carcinoma of the Prostate: A Case Report

Primary small cell carcinoma of the prostate is a rare malignancy of unknown origin and with poor prognosis. We report a case occurring in a 74-year-old man. Radiologic findings showed that the prostate was markedly enlarged, with a lobulated contour and unclearly defined internal architecture. It was therefore impossible to distinguish it from prostatic adenocarcinoma, but the huge mass and normal range of serum tumor markers (prostate-specific antigen and prostate acid phosphatase) suggested small cell carcinoma of the prostate.

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.

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.

Evaluation of computer tomography in cerebro-vascular disease (strokes)

Most of cerbrovascular disease are composed of vascular occlusive changes & hemorrhage. Now a day, the computed tomograhy is the best way for evaluation of cerebrovascular disease including detection of nature,location ,& associated changes. This study includes evaluation of CT of 70 patients with cerebrovascular disease during the period of 10 months from April. 1983 to Feb. 1984 in Department of Radiology, Ewha Womans University Hospital. The results were as follows; 1. Age distribution of the total 70 patients was broad ranging from 25years to 79 years. 78.6% of patients were over the age of 50. The male and female sex ratio was 1.4:1. 2. 4 out of70 patients were normal and 66 patients revealed abnormal on C.T, findings; those were intracranial hemorrhage(28patients), cerebral infarction,(34 patients) and brain atrophy(4 patients). 3. In cases of cerebral infarction,the cerebral hemisphere was most common sit of lesion(28 cases), and next was basal ganglia (2 cases). Most of the infarcts in cerebral hemisphere were located in the parietal and temporal lobes. 4. In cases of intracranial hemorrhage, the basal ganglia was most common site of lesion(15 cases). The next common site was cerebral hemisphere (9 cases). 6 patients of all intracranial hemorrhage were combined with intraventricular hemorrhage.Ratio of right and left was 2:3. 5. In patients with motor weakness of hemiparesis, more common findings on CT scan were cerebral infarction. In case with hemiplegia, more common CT findings were intracerbral hemorrhage. 6.Of the 40 cases thought to be cerebral infarction intitially by clinical findings and spinal tap. 8 cases (20.0%)were proved to be cerebral hemorrhage by the CT scan. However, of the 22 cases thought to be cerbral hemorrhage,initially, only two cases (9.0%) were cerebral infarction.

Computed tomography (CT) in acute head trauma

The retrospective evaluation of 50 cases of head trauma that were subjected to CT leads to the following conclusion; 1. CT survey, should be the first neuroradiological procedures to performe. 2. There is generally adirect relationship between the severity of clinical presentation and the CT findings of the abnormality; responsible for the clinical status, the number and intensity of tissue abnormalities on CT scans increase proportionately with the severity of the clinical signs and symptoms. 3. An accuracy is 100% in diagnosis of intra and extracerebral collections of blood. 4. The causes of acute head tauma were automobile, 64% and falling down,32%.

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.

Mammographic findings of breast cancer: Emphasis on the tumor and microcalcifications

Most of the breast cancer revealed mass and/or microcalcifications on mammography. We analyzed morphologic characteristics of the masses and microcalcifications on mammography which confirmed as breast cancer pathologically. Of all 54 cases, 4 patients (7%) showed microcalcification only, 27 patients (50%), mass only, and the other 23 patients (43%), both microcalcification and mass on the mammography. The margin of the breast mass were ill-defined in 37 cases, well-defined in 8 cases, and well-defined with surrounding infiltration in 5 cases. The morphologic characteristics of the microcalcification were punctate-linear-V shape in 11 patients, punctate-linear shape in 9 patients, and punctate shape in 7 patients.

Non-breath-hold MR Cholangiography for the Evaluation of Obstructive Biliary Diseases

PURPOSE: MR cholangiography(MRC) in patients with obstructive biliary diseases was evaluated in order to compare its role with that of ERCP or PTC. MATERIALS AND METHODS: Twenty consecutive patients with obstructive biliary and peribiliary diseases (Eleven biliary and peribiliary carcinomas, seven intrahepatic stone diseases and seven extrahepatic stone diseases) were included and ERCP(16 ccases) or PTC(four cases) was performed in all twenty cases. Non-breasth-hold, heavily T2-weighted, fast spin echo MRC was carried out and 2-D axial, coronal images and 3-D images with maximum intensity projection protocol were obtained. We regarded ERCP or PTC as thegold standard and then comparedn MRC with ERCP of PTC retrospectively. RESULTS: In 11 patients with biliary and peribiliary carcinomas, the level of obstruction was depicted in nine cases(83%) on MRC and in six of seven cases(86%) on ERCP. The causes of obstruction were demonstrated in eight cases(73%) on MRC and in six of seven cases(86%) on ERCP. On MRC, Seven cases(64%) revealed similar findings to ERCP or PTC. Of seven cases of EHD and seven of IHD stone diseases, EHD stones were detected in six cases(86%) on MRC and in seven cases (100%) on ERCP,IHD stones were detected in four cases(57%) on MRC and in five cases(71%) on ERCP. 2D-MRC was superior to 3D-MRCin the detection of stones. The extent and grade of ductal dilatiation was accurately revealed in six cases(86%)on MRC and in seven cases(100%) on ERCP of EHD stones, in six cases(86%) on MRC and in three cases(43%) on ERCP of IHD stones. Six cases(86%) of EHD stones and two cases(29%) of IHD stones revealed similar findings between MRCand ERCP. CONCLUSION: MRC findings were similar to those of ERCP or PTC in the evaluation of malignant biliary diseases or extrahepatic stone diseases and was valuable in their diagnoses. In the evaluation of intrahepaticstone diseases, MRC demonstrated dilated peripheral IHDs with stones more difinitely than ERCP but in the detection its accuracy was low. Further studies may therefore be needed.

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.