Purpose To analyze the sources of errors and discuss the techniques to eliminate pitfalls in detecting deep vein thrombosis (DVT) of the proximal lower extremities with color duplex ultrasonography (CDUS). Methods Sixty-eight cases with initial and repeat venous CDUS of the proximal lower extremities were retrospectively reviewed. The repeat was done within 24 hours after initial CDUS scanning. Comparing repeated images to initial ones, the pitfalls and sources of error in CDUS of the proximal lower extremities were discussed. Results In total 68 repeat studies, there were 62 results as same as initials and 4 cases of false negative DVT and 2 cases of false positive DVT. Conclusion Venous CDUS in detecting DVT is observer dependent. Some pitfalls and errors can be eliminated and corrected with proper scan techniques. CDUS is the most valuable imaging modality for assessing suspected DVT in the proximal lower extremities.

OBJECTIVE: To evaluate the usefulness of MR imaging for diseases of the small intestine, emphasizing a comparison with CT. MATERIALS AND METHODS: Thirty-four patients who underwent both CT and MR imaging using FLASH 2D and HASTE sequences were analyzed. All patients had various small bowel diseases with variable association of peritoneal lesions. We compared the detectabilities of CT and MR imaging using different MR pulse sequences. The capability for analyzing the characteristics of small intestinal disease was also compared. RESULTS: MR imaging was nearly equal to CT for detecting intraluminal or peritoneal masses, lesions in the bowel and mesentery, and small bowel obstruction, but was definitely inferior for detecting omental lesions. The most successful MR imaging sequence was HASTE for demonstrating bowel wall thickening, coronal FLASH 2D for mesenteric lesions, and axial FLASH 2D for omental lesions. MR imaging yielded greater information than CT in six of 12 inflammatory bowel diseases, while it was equal to CT in six of seven neoplasms and inferior in five of seven mesenteric ischemia. In determining the primary causes of 15 intestinal obstructions, MR imaging was correct in 11 (73%) and CT in nine (60%) patients. CONCLUSION: MR imaging can serve as an alternative diagnostic tool for patients with suspected inflammatory bowel disease, small intestinal neoplasm or obstruction. is a high-speed, heavily T2-weighted sequence with a great sensitivity for fluid (11). This advance may make it possible to use breath-hold turbo spin-echo MR.
Comparative Study ; Female ; Human ; Inflammatory Bowel Diseases/*diagnosis ; Intestinal Neoplasms/*diagnosis ; Intestinal Obstruction/*diagnosis ; Intestine, Small/*pathology ; *Magnetic Resonance Imaging ; Male ; Middle Age ; *Tomography, X-Ray Computed

Cavernous hemangioma is the most common benign hepatic tumor. Typically, the most common features revealed by ultrasound(US) include its small size(4cm or less in diameter), uniform hyperechogenicity, welldefined margins, position in the subcapsular region of the right lobe of the liver, and some posterior echo enhancement. In addition, follow-up scanning may reveal changes in size, though this is rare. The US findings of hepatic hemangiomas may vary, however, especially when lesions are large and/or multiple. For that reason, differential diagnosis between this condition and hepatocellular carcinomas, metastatic lesions, lymphomas and other tumors is difficult. An understanding of the various sonographic findings of hepatic hemangioma can facilitate the early detection of the condition.
Carcinoma, Hepatocellular ; Classification* ; Diagnosis, Differential ; Follow-Up Studies ; Hemangioma* ; Hemangioma, Cavernous ; Liver ; Lymphoma ; Ultrasonography

Vascular complications after liver transplantation may involve the hepatic artery, and hepatic and portal veins. Arterial complications are common and significant vascular complications include thrombosis or stenosis, as well as pseudoaneurysms. Venous complications include thrombisis or stenosis of the inferior vena cana, or hepatic or portal vein. Since recent evidence has shown that emergent revascularization leads to improved graft salvage and patient survival with a relatively low rate of late biliary complications, accurate and pronpt di-agnosis of hepatic arterial complications is important. Doppler US is a relatively inexpensive, accurate, and non-invasive method of diagnosing the vascular complications which may arise from liver transplantation.
Aneurysm, False ; Constriction, Pathologic ; Hepatic Artery ; Humans ; Liver Transplantation* ; Liver* ; Portal Vein ; Thrombosis ; Transplants

PURPOSE: The purpose of this study was to evaluate the findings and significance of postoperative imaging after living related liver transplantation (LRLT) in pediatric patients. MATERIALS AND METHODS: We retrospectively reviewed all imaging findings, including those of post-LRLT ultra-sonography (US) and computed tomography (CT), in 20 children who had undergone LRLT at our institute. RESULTS: Postoperative findings on US and CT were perihepatic or subcapsular fluid collection (60%), periportal edema (35%), anastomotic narrowing of the IVC (10%), biliary stricture (5%), and focal hepatic infarction (5%). Liver biopsy was performed in nine patients in whom rejection was clinically suspected, and pathologic examination revealed acute rejection in five. US and CT revealed perihepatic fluid collection in one of these, periportal edema and fluid collection in two, and normal findings in two. CONCLUSION: An understanding of the various postoperative findings after LRLT is helpful for accurate diagnosis and appropriate decisions regarding the preservation of normal graft function.
Biopsy ; Child ; Constriction, Pathologic ; Diagnosis ; Edema ; Humans ; Infarction ; Liver Transplantation* ; Liver* ; Retrospective Studies ; Transplants

PURPOSE: The purpose of this study was to evaluate the findings and significance of postoperative imaging after living related liver transplantation (LRLT) in pediatric patients. MATERIALS AND METHODS: We retrospectively reviewed all imaging findings, including those of post-LRLT ultra-sonography (US) and computed tomography (CT), in 20 children who had undergone LRLT at our institute. RESULTS: Postoperative findings on US and CT were perihepatic or subcapsular fluid collection (60%), periportal edema (35%), anastomotic narrowing of the IVC (10%), biliary stricture (5%), and focal hepatic infarction (5%). Liver biopsy was performed in nine patients in whom rejection was clinically suspected, and pathologic examination revealed acute rejection in five. US and CT revealed perihepatic fluid collection in one of these, periportal edema and fluid collection in two, and normal findings in two. CONCLUSION: An understanding of the various postoperative findings after LRLT is helpful for accurate diagnosis and appropriate decisions regarding the preservation of normal graft function.
Biopsy ; Child ; Constriction, Pathologic ; Diagnosis ; Edema ; Humans ; Infarction ; Liver Transplantation* ; Liver* ; Retrospective Studies ; Transplants

PURPOSE: To assess the value of the bolus-tagging method for improving the image quality of contrast-enhanced MR abdominal angiography, and to evaluate the relationship between peak arterial enhancement time and patients' age, weight and heart rate. MATERIALS AND METHODS: Contrast-enhanced 3D FISP abdominal MR angiography was performed in 81 patients during a four-month period. The bolus-tagging method was used in a study group comprising 33 patients, and to this end, 1 ml of Gd-DTPA (gadolinium-diethylenetriamine penta-acetic acid) was administered. thirty sequential images (1 image/sec) were then obtained using turbo-FLASH sequencing. After determining peak arterial enhancement time from the time-to-signal intensity curve, optimal scan delay time can be calculated according to the formula used in our patient series. The 48 patients in whom the bolus-tagging method was not used comprised the control group ; in the study group scanning commenced at the optimal scan delay time (and at 10 seconds in the control group) after the administration of 0.2 mM/kg Gd-DTPA using an automatic power injector. Using a three-point scale we evaluated and compared between the two groups the success with which arterial images were obtained. In addition, vascular visibility -an indication of the quality of arteries and veins-was determined using a four-point scale. In the study group, the relationship between peak arterial enhancement time and patients' age, weight heart rate was also assessed. RESULTS: Pure arterial images were successfully obtained in 32 patients (97%) in the study group and in 40 (83%) in the control group. This difference was not statistically significant (p>.05). With regard to vascular visibility, diagnostic arterial images were seen in 30 patients (91%) in the study group and in 33 patients (69%) in the control group; arterial visibility was significantly better in the study group (p=.0197). On the other hand, the diagnostic venous images were seen in 31 patients (94%) in the study group and in 36 (75%) in the control group; there was no significant difference between the two groups (p=.2367). Peak arterial enhancement time increased significantly with age (r=.443, p=.0098); no correlation,however was seen between peak arterial enhancement time and weight (p>.05) or heart rate (p>.05). CONCLUSION: Used with contrast-enhanced 3-D FISP MR abdominal angiography, the bolus-tagging method provides better arterial visibility. Peak arterial enhancement time increased significantly with age.
Angiography* ; Arteries ; Gadolinium ; Gadolinium DTPA ; Hand ; Heart Rate ; Humans

PURPOSE: To assess the value of the bolus-tagging method for improving the image quality of contrast-enhanced MR abdominal angiography, and to evaluate the relationship between peak arterial enhancement time and patients' age, weight and heart rate. MATERIALS AND METHODS: Contrast-enhanced 3D FISP abdominal MR angiography was performed in 81 patients during a four-month period. The bolus-tagging method was used in a study group comprising 33 patients, and to this end, 1 ml of Gd-DTPA (gadolinium-diethylenetriamine penta-acetic acid) was administered. thirty sequential images (1 image/sec) were then obtained using turbo-FLASH sequencing. After determining peak arterial enhancement time from the time-to-signal intensity curve, optimal scan delay time can be calculated according to the formula used in our patient series. The 48 patients in whom the bolus-tagging method was not used comprised the control group ; in the study group scanning commenced at the optimal scan delay time (and at 10 seconds in the control group) after the administration of 0.2 mM/kg Gd-DTPA using an automatic power injector. Using a three-point scale we evaluated and compared between the two groups the success with which arterial images were obtained. In addition, vascular visibility -an indication of the quality of arteries and veins-was determined using a four-point scale. In the study group, the relationship between peak arterial enhancement time and patients' age, weight heart rate was also assessed. RESULTS: Pure arterial images were successfully obtained in 32 patients (97%) in the study group and in 40 (83%) in the control group. This difference was not statistically significant (p>.05). With regard to vascular visibility, diagnostic arterial images were seen in 30 patients (91%) in the study group and in 33 patients (69%) in the control group; arterial visibility was significantly better in the study group (p=.0197). On the other hand, the diagnostic venous images were seen in 31 patients (94%) in the study group and in 36 (75%) in the control group; there was no significant difference between the two groups (p=.2367). Peak arterial enhancement time increased significantly with age (r=.443, p=.0098); no correlation,however was seen between peak arterial enhancement time and weight (p>.05) or heart rate (p>.05). CONCLUSION: Used with contrast-enhanced 3-D FISP MR abdominal angiography, the bolus-tagging method provides better arterial visibility. Peak arterial enhancement time increased significantly with age.
Angiography* ; Arteries ; Gadolinium ; Gadolinium DTPA ; Hand ; Heart Rate ; Humans

PURPOSE: To determine the effects of blood vessels on the size and shape of microwave coagulation. MATERIALS AND METHODS: Microwave coagulation was performed with 60 W output and 60 second duration. In the first experiment five exvivo porcine livers were used to determine the size of the coagulation area and its reproducibility. The second experiment involved the used of two in-vivo porcine livers to determine how adjacent vessels affect the size and shape of coagulation. RESULTS: The result of the first experiment was that the maximum mean diameter of lesions was 1.4 cm +/- 0.1 , reproducible in the range of 1.3 c m -1 .5 cm. In the second experiment, maximum mean diameter was found to be 1.5cm +/- 0.1, reproducible in the range of 1.3 cm - 1.7cm, and the size and shape of the lesion was affected by nearby blood vessels. The shape factor of the lesion, defined as roundness of sphere, was 0.8, but the r a n g e ( 0 . 5 8 -0.92) was wide due to the effect of vascular cooling. This was more prominent in the portal vein than in the hepatic vein, and the minimum diameter of the portal vein which deformed the lesion by more than 1 mm was 0.1 mm. CONCLUSION: Microwave coagulation gives a well-defined lesion, the size of which can be reproduced, but size variation and nonuniformity can be caused by nearby blood vessels.
Animals ; Blood Vessels* ; Hepatic Veins ; Liver ; Microwaves* ; Portal Vein

PURPOSE: To determine the effects of blood vessels on the size and shape of microwave coagulation. MATERIALS AND METHODS: Microwave coagulation was performed with 60 W output and 60 second duration. In the first experiment five exvivo porcine livers were used to determine the size of the coagulation area and its reproducibility. The second experiment involved the used of two in-vivo porcine livers to determine how adjacent vessels affect the size and shape of coagulation. RESULTS: The result of the first experiment was that the maximum mean diameter of lesions was 1.4 cm +/- 0.1 , reproducible in the range of 1.3 c m -1 .5 cm. In the second experiment, maximum mean diameter was found to be 1.5cm +/- 0.1, reproducible in the range of 1.3 cm - 1.7cm, and the size and shape of the lesion was affected by nearby blood vessels. The shape factor of the lesion, defined as roundness of sphere, was 0.8, but the r a n g e ( 0 . 5 8 -0.92) was wide due to the effect of vascular cooling. This was more prominent in the portal vein than in the hepatic vein, and the minimum diameter of the portal vein which deformed the lesion by more than 1 mm was 0.1 mm. CONCLUSION: Microwave coagulation gives a well-defined lesion, the size of which can be reproduced, but size variation and nonuniformity can be caused by nearby blood vessels.
Animals ; Blood Vessels* ; Hepatic Veins ; Liver ; Microwaves* ; Portal Vein