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Biomedical subjects

M C Han

Publications and source records attributed to M C Han.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Colitis in Behçet's disease: characteristics on double-contrast barium enema examination in 20 patients.

We performed a retrospective review of double-contrast barium enema examinations of 20 patients with clinically proven Behçet's colitis. Main lesion was ovoid or geographic ulcers with a mean diameter of 2.7 cm. The number of ulcers was single in 15 cases and multiple in five. On six resected specimens, ulcers involved submucosa in three, muscle layer in one, and serosa in two cases with an undermining tendency and transmural inflammation. Aphthous ulcers were present in three cases. Neither perforation nor fistula was demonstrated. In all 20 patients, the ulcer was localized in the ileocecal area, with extension to the ascending colon in seven. Skip lesions were observed in the transverse colon and descending colon in three cases. Destruction of surrounding mucosa resulted in cecal contraction in 19 cases, widening of the ileocecal valve in 19, and fold thickening in the terminal ileum in 12. Six cases (30%) manifested as ileocecal mass accompanied by ulcer, fold thickening, and adjacent mucosal deformity. The appendix was visualized in only three (20%) of the 15 patients with no history of appendectomy. On follow-up study of 15 cases, the ulcers disappeared or decreased in size in 13 cases (86%) and the mucosal deformity was not improved in all cases. On the basis of our results, we believe that the characteristic findings of colitis in Behçet's disease in barium enema examination are ovoid or geographic, relatively large, and deep ulcerations with persistent surrounding deformity which tend to localize in the ileocecal area.

Adolescent↗
PubMedDate not supplied

Transcatheter arterial embolization of unresectable renal cell carcinoma with a mixture of ethanol and iodized oil.

PURPOSE: The effectiveness of renal transcatheter arterial embolization (TAE) with a mixture of ethanol and iodized oil (Lipiodol) was analyzed retrospectively in 27 patients with unresectable renal cell carcinoma. METHODS: Symptomatic or permanent palliation by TAE was performed with the intent to achieve total or partial ablation of the kidney with 10-28 ml of embolic material in a 3:1 mixture of ethanol and iodized oil. Clinical, angiographic, and computed tomographic (CT) follow-up were analyzed. Cumulative survival was estimated with the Kaplan-Meier method. RESULTS: Partial (5) or complete (22) ablation of the embolized kidneys was achieved in all cases. Follow-up CT after 1 month revealed Lipiodol uptake in the tumor area (14/14), decreased size of the tumor (6/14), and gas formation (7/14). Pulmonary metastasis improved significantly in one patient after transcatheter arterial embolization and adjunctive chemotherapy. Overall median survival of the 27 patients was 8.5 months. The median survival was 23 months in 10 patients with stage III, three of whom are still alive, and was 7 months in 15 patients with stage IV tumors. CONCLUSION: The mixture of ethanol and Lipiodol is not only a convenient embolic material to use, but is also effective for selective or nonselective devascularization for unresectable renal cell carcinoma.

Adult↗
PubMedDate not supplied

Combined hepatocellular and cholangiocarcinoma of the liver: sonography, CT, angiography, and iodized-oil CT with pathologic correlation.

To evaluate the characteristics of combined hepatocellular and cholangiocarcinoma of the liver by imaging techniques, six patients (five male and one female), aged 46-60 years, with proved combined tumors were selected for this study from the review of 500 resected specimens of liver tumors. Images obtained from sonography, computed tomography (CT), angiography, and CT after intraarterial injection of iodized oil (iodized-oil CT) were retrospectively reviewed and correlated with the appearance of pathologic specimens. Sonographic findings were round or ovoid hypoechoic masses with central hyperechoic area (target appearance) in all patients. On CT scans, tumors were relatively well-defined low-and/or iso-attenuation masses in all patients. Angiography showed hypovascular masses in five patients. In one patient, the tumor appeared as a hypovascular mass with a central hypervascular area. On iodized-oil CT scans, all patients showed partial retention of iodized oil in tumors. Echogenicity in tumors at sonography or attenuation in tumors at CT could not be correlated with histologic difference in tumors at pathologic specimens. However, the hypervascular area at angiography and the compact retention areas of iodized oil at iodized-oil CT corresponded to portions of hepatocellular carcinoma within the combined tumor. On the basis of our results, imaging features, including target appearance at sonography, hypovascular mass with central hypervascular portions at angiography, and partial retention of iodized oil in tumors at iodized-oil CT, might be helpful in making accurate diagnosis of these rare tumors.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Magnetic resonance evaluation of mitral stenosis.

In order to study magnetic resonance (MR) abnormalities in mitral stenosis, electrocardiogram (ECG)-gated MR imaging was performed with a 2.0 T MR system in 41 patients with mitral stenosis before catheterization. Mean transverse diameter of the left atrium was 8.9 +/- 1.4 cm and anteroposterior diameter was 5.1 +/- 1.0 cm, indicating significant enlargement. Homogeneous or inhomogeneous flow-related signals in ventricular diastole were detected in the left atrial cavity in 32 cases (78%), and in the atrial appendage in 35 cases (85%). In 21 patients having a mean wedge pulmonary arterial pressure higher than 20 mm Hg, 20 patients (95%) showed flow-related signals in ventricular diastole. Other MR findings were mitral valve doming in diastole, flow-related signal in the pulmonary artery during systole, and left atrial thrombi.

Adolescent↗
PubMedDate not supplied

Postoperative recurrence of hepatocellular carcinoma: results of transcatheter arterial chemoembolization.

A retrospective analysis was made of the effect of transcatheter arterial chemoembolization (TACE) in 87 patients with recurrent hepatocellular carcinoma (HCC). In contrast to the predominantly single nodular HCC (60.2%) on preoperative angiography, recurrent HCC showed a multinodular pattern in 54.2%. Preoperative TACE had significantly prolonged the interval between surgery and recurrence. One- and 2-year survival rates after TACE of the 87 recurrent HCCs were 74.7% and 55.%, respectively, which were not significantly different from those of a control group of 206 patients with HCC in Child's class A, who were treated with TACE only. We believe that TACE is an effective measure in the management of preoperative and recurrent HCC.

Adolescent↗
PubMedDate not supplied

Embolization of the internal spermatic vein in varicocele: significance of venous pressure.

Embolization of the left internal spermatic vein using spring-coils was performed in 20 patients with varicocele following pressure measurement of the left renal vein and inferior vena cava. During the follow-up of 16-24 months, there was no recurrence in 16 patients with pressure difference less than 3 mmHg; however, there were two recurrences in 4 patients with pressure difference greater than 4 mmHg and opacified adrenal or ureteral veins on venography. We conclude that a significant pressure difference between left renal vein and inferior vena cava, and opacification of adrenal or ureteral veins on left renal venography may be poor prognostic signs of recurrence of varicocele following embolization.

Adolescent↗
PubMedDate not supplied

Iatrogenic dissection of the celiac artery and its branches during transcatheter arterial embolization for hepatocellular carcinoma: outcome in 40 patients.

PURPOSE: To study the sequelae of iatrogenic dissection of the celiac axis and its branches in a large patient population. METHODS: We analyzed 40 patients with hepatocellular carcinoma (HCC) whose celiac artery or its branches were dissected during transcatheter arterial embolization (TAE) and underwent follow-up angiography within 2 months. RESULTS: The two most common sites of dissection were the celiac artery in 13 patients (32.5%) and the proper hepatic artery in 11 patients (27.5%). Follow-up angiography revealed complete recanalization in 32.5% (13/40), irregularity and narrowing of the lumen in 40% (16/40), and complete obstruction in 27.5% (11/40). Therefore, 72.5% (29/40) of the dissected arteries recanalized. Pseudoaneurysm formation of the dissected artery was observed in 32.5% (13/40). Subsequent TAE was possible via the dissected arteries in 79% (27/34) of patients in this series. CONCLUSION: Iatrogenic dissection of the celiac and proximal hepatic arteries heals spontaneously in the majority of patients, and in most instances allows subsequent TAE.

Adult↗
PubMedDate not supplied

Focal eosinophilic infiltration in the liver: radiologic findings and clinical course.

BACKGROUND: We investigated the radiologic findings and clinical course of focal eosinophilic infiltration in the liver. METHODS: We retrospectively reviewed computed tomographic (CT) and sonographic scans in 20 patients (18 male, two female; mean age, 50 years) with pathologically or clinically proven focal eosinophilic infiltration in the liver by two experienced radiologists in our institute from August 1995 to June 1999. We also correlated radiologic findings with peripheral eosinophil count. Radiologic and clinical findings during the follow-up (range, 2-49 months; mean, 19.5 months) also were analyzed. RESULTS: Clinical symptoms and signs included abdominal pain (n = 4), easy fatigability (n = 3), weight loss (n = 1), and peripheral eosinophilia (n = 19). Twelve patients were asymptomatic. On sonographic examinations, all lesions were seen as focal, low echoic nodules. On CT, the lesions appeared isoattenuated or low attenuated in the arterial phase and low attenuated in the portal phase, except one case that showed high attenuation in the arterial phase. The margins of most lesions appeared poorly defined. Lesions were single (n = 9) and multiple: two to five (n = 6), six to 10 (n = 3), and more than 10 (n = 2). Each lesion was smaller than 2 cm; only one was 4 cm in diameter. The distribution of the lesion was subcapsular in 14 patients and central in five. Diffuse dissemination was observed in one. Eosinophil-associated abnormality was not present in other abdominal organ in all cases. The peripheral eosinophil count correlated closely with the number but not with the size of lesions. Sixteen patients who had follow-up images showed complete (n = 14) or partial regression of the lesions with a decrease in size (n = 1) or number (n = 1) after 2-22 months (mean, 6.4 months). CONCLUSION: Focal eosinophilic infiltration in the liver had somewhat characteristic radiologic findings on sonography and CT. In the correct clinical context of peripheral eosinophilia and self-limited course, these radiologic findings may be helpful in differentiating this condition from other focal hepatic lesions.

Contrast Media↗
PubMedDate not supplied

Preoperative evaluation of Klatskin tumor: accuracy of spiral CT in determining vascular invasion as a sign of unresectability.

BACKGROUND: To assess the accuracy of spiral computed tomography (CT) in predicting the resectability of Klatskin tumor as determined by vascular invasion. METHODS: Twenty-one consecutive patients with Klatskin tumor who had undergone laparotomy were included in this study. The preoperative thin-section (5-mm-thick) spiral CT scans of these patients were assessed for the surgical resectability of tumor by evaluating the vascular invasion. The criterion for vascular invasion indicating unresectability was the tumoral invasion of the proper hepatic artery or main portal vein or simultaneous invasion of one side of the hepatic artery and the other side of the portal vein. RESULTS: All nine patients with tumors thought to be unresectable on the basis of CT findings had tumors that were unresectable at surgery (positive predictive value, 100%). Of 12 patients with tumors thought to be resectable, six had resectable tumors (negative predictive value, 50%). Spiral CT failed to detect small hepatic metastasis (n = 1), lymph node metastasis (n = 1), extensive tumor (n = 2) and variation of bile duct (n = 2), which precluded surgical resection. CONCLUSION: Spiral CT is a reliable method for detecting vascular invasion and unresectable tumors. However, it has limitations in detecting variations of the bile duct or the intraductal extent of tumor.

Adult↗
PubMedDate not supplied

Focal hepatic nodules after transcatheter oily chemoembolization; detection with spiral CT versus conventional CT.

BACKGROUND: The objective of this study was to determine if spiral computed tomography (CT) results in increased rate of detection of focal hepatic nodules containing iodized oil after transcatheter oily chemoembolization when compared with conventional CT. METHODS: Spiral CT with single 24-s breath-hold technique was compared with conventional sequential CT in 42 patients with suspected hepatocellular carcinomas. Two sets of CT scans obtained after transcatheter oily chemoembolization were independently reviewed by two radiologists. The slice thickness was 10 mm for both data sets. The number and sizes of focal hepatic nodules containing iodized oil were documented. All 42 patients had at least hepatic nodule. The lesion size varied from 2 mm to 12 cm. RESULTS: In six of the 42 patients, more hepatic nodules could be identified on spiral CT compared with conventional CT. When scans with spiral CT were used, 107 nodules were detected, whereas 98 nodules were detected with conventional CT. Overall, nine (9%) more nodules were detected with spiral CT (p = .002). If lesions larger than 2 cm are excluded, nine (15%) more lesions were detected with spiral CT (p = .002). CONCLUSION: Spiral CT results in increased rate of detection of focal hepatic nodules after transcatheter oily chemoembolization, particularly in lesions smaller than 2 cm.

Antibiotics, Antineoplastic↗
PubMedDate not supplied

Iodized-oil retention within hepatic hemangioma: characteristics on iodized-oil CT.

OBJECTIVE: The purpose of this study was to describe the characteristic computed tomographic (CT) appearance of iodized-oil retention in hepatic hemangioma and to evaluate the duration of the retention of iodized oil on follow-up CT. METHODS: Seventeen hepatic hemangiomas of 14 patients were studied with CT performed 1-3 weeks after injection of 2-9 ml of iodized oil (iodized-oil CT) for the characterization of focal hepatic lesions, which needed differential diagnosis with hepatocellular carcinoma in 10 patients, for therapy in two patients, and for chemoembolization therapy of accompanying hepatocellular carcinomas in two. Twelve patients had 1-7 follow-up CT scans within an interval of 1-38 months. RESULTS: In all cases, iodized-oil CT showed iodized-oil retention within the tumor, regardless of tumor size, shape, location, and amount of injected iodized oil. The distribution was incomplete and predominantly peripheral in all cases. Central retention was also seen in seven cases, in which a relatively large amount of iodized oil was injected, but retention of iodized oil in the tumor was incomplete even in two cases in which a large amount of iodized oil was injected to relieve symptoms and in three cases in which prominent uptake of surrounding liver parenchyma was seen. Patterns of retention were predominantly spotty in five, predominantly nodular in four, and mixed in eight patients. Retention materials slowly washed out but persisted for at least 3 months and up to 38 months (mean = 18.1 months), and complete washout was not seen in any cases at follow-up CT. CONCLUSION: In all cases of hepatic hemangiomas, iodized oil was retained, and retention persisted over several months. Distribution and patterns of retention were characteristically peripheral, spotty, and nodular at iodized-oil CT. Knowledge of the iodized-oil CT appearance of hepatic hemangioma would be helpful to interpret follow-up CT studies of patients who have undergone iodized-oil chemoembolization procedures.

Adult↗
PubMedDate not supplied

Spiral CT for the detection of hepatocellular carcinomas:relative value of arterial- and late-phase scanning.

BACKGROUND: Spiral computed tomography (CT) can image the liver during arterial and late phases of contrast and optimize the evaluation of hypervascular tumor. The objective of this study was to evaluate the relative value of arterial- and late-phase spiral CT in the detection of hepatocellular carcinomas. METHODS: Fifty-eight patients with hepatocellular carcinomas underwent two-phase spiral CT examination with 10-mm collimation at 10 mm/s table speed (Siemens Somatom Plus S), and 120 mL of contrast material (36 g iodine) was injected at the rate of 3 mL/s. CT images of hepatic arterial and late phases were obtained with a 35-s and 180-s delay, respectively. RESULTS: In 58 patients, 111 hepatocellular carcinoma lesions were seen. The arterial phase detected 93 (84%) and the late phase 75 (68%) lesions (p < 0.01). The arterial phase detected more lesions in 11 patients, and the late phase detected more in two patients and an equal number in 45 patients. If lesions larger than 2 cm are excluded, the arterial phase detected 40 (74%) and the late phase 21 (39%) of 54 lesions (p < 0.001). CONCLUSION: The arterial phase of spiral CT greatly improves the detection of hepatocellular carcinoma when compared with the late phase.

Adult↗
PubMedDate not supplied

Helical CT anatomy of pancreatic arteries.

BACKGROUND: To assess the frequency of visualization of pancreatic arteries in the arterial phase of helical computed tomography (CT). METHODS: The visibility of pancreatic and peripancreatic arteries in helical CT images was evaluated in 20 consecutive patients who had no evidence of pancreatic disease. CT examinations were performed by using a continuously rotating CT scanner and intravenous injection of contrast media. The scans were taken 35 s after the start of injection and with a table speed of 3 mm/s. Images were reconstructed in 3-mm section increments. RESULTS: Frequently visualized arteries were the gastroduodenal, anterior and posterior superior pancreaticoduodenal, and right gastroepiploic arteries. Infrequently visualized arteries were the dorsal pancreatic, pancreatica magna, caudal pancreatic, transverse pancreatic, and common, anterior, and posterior inferior pancreaticoduodenal arteries. CONCLUSION: Helical CT enabled us to recognize small pancreatic arteries, and the evaluation of these arteries should be considered in the staging of pancreatic carcinoma.

Arteries↗
PubMedDate not supplied

Detection of pancreatic adenocarcinoma: relative value of arterial and late phases of spiral CT.

BACKGROUND: Spiral computed tomography (CT) allows the pancreas to be imaged during peak contrast levels owing to the capability of fast data acquisition. The objective of this study was to evaluate the relative value of the arterial and late phases of spiral CT for detecting pancreatic adenocarcinomas. METHODS: Twenty-two patients with pathologically proved pancreatic adenocarcinomas underwent two-phase spiral CT. The CT scans were performed with 5 mm collimation and 5 mm/s table speed. Images during the arterial and late phases were obtained at 30- and 180-second delays, respectively. The images of the arterial phase were compared with those of the late phase in terms of tumor conspicuity from surrounding pancreatic parenchyma and tumor detectability by means of a 3-point grading system: 1 (poor), 2 (fair), and 3 (good). RESULTS: In terms of tumor conspicuity from surrounding pancreatic parenchyma, 16 lesions (73%) were good, 5 lesions (23%) were fair, and 1 lesion (4%) was poor during the arterial phase, whereas 6 lesions (27%) were good, 9 lesions (41%) were fair, and 7 lesions (32%) were poor during the late phase (p = 0.0007). The arterial phase was superior to the late phase in 16 patients (73%) and equal in 6 patients (27%). For tumor detectability, 18 lesions (82%) were good, 3 lesions (14%) were fair, and 1 lesion (4%) was poor during the arterial phase, whereas 10 lesions (45%) were good, 7 lesions (32%) were fair, and 5 lesions (23%) were poor during the late phase (p = 0.0033). For detectability, the arterial phase was superior to the late phase in 14 patients (64%) and equal in 8 patients (36%). CONCLUSION: The arterial phase of spiral CT is superior to the late phase, which is equivalent to conventional CT for detecting pancreatic adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Dysplastic nodules of the liver: imaging findings.

BACKGROUND: To verify characteristic features of hepatic dysplastic nodules at different imaging modalities. METHODS: Twenty-eight patients with 37 dysplastic nodules of the liver (0.8-3.0 cm) underwent sonography (28 patients), computed tomography (CT; 24 patients), magnetic resonance (MR; 11 patients), and angiography (12 patients). Each nodule was analyzed for echogenicity, attenuation, signal intensity, and vascularity. RESULTS: Echogenicity of nodules was high in 16 (43%), homogeneous in two (6%), and low in 19 (51%) of 37 nodules. Attenuation of nodules was high in one (7%), homogeneous in four (26%), and low in 10 (67%) of 15 nodules on the arterial-phase CT images; homogeneous in five (33%) and low in 10 (67%) of 15 nodules on the portal-phase CT images; and high in four (17%), homogeneous in six (26%), and low in 13 (57%) of 23 nodules on the delayed-phase CT images. Signal intensity of nodules was high in 15 (94%) and homogeneous in one (6%) of 16 nodules on T1-weighted MR images and was homogeneous in seven (44%) and low in nine (56%) of 16 nodules on T2-weighted MR images. Vascularity of nodules was avascular in 14 (88%) and slightly vascular in two (12%) of 16 nodules. CONCLUSIONS: Hepatic dysplastic nodules show diverse imaging characteristics with different imaging techniques; however, common imaging findings of hepatic dysplastic nodules are low echo, low attenuation, and high, low, or homogeneous intensity on T1- and T2-weighted MR, and avascularity.

Adult↗
PubMedDate not supplied

Hepatic hemangioma: contrast-enhancement pattern during the arterial and portal venous phases of spiral CT.

The objective of the present study was to evaluate contrast-enhancement patterns of hepatic hemangioma according to size during hepatic arterial (30-s delay) and portal venous (65-s delay) phases of spiral computed tomography (CT). During a 10-month-period, 73 patients with 118 hemangiomas underwent two-phase spiral CT examination. The enhancement patterns of tumors were divided into four types based on the attenuation of surrounding liver parenchyma: peripherally nodular high, uniform high, iso, and low. The diameter of the tumors were <10 mm (n = 39), 11-20 mm (n = 33), and >21 mm (n = 46). Overall, the most common enhancement patterns of hemangioma were peripherally nodular high (66/118, 55. 9%) during the arterial and portal venous phases. The second most common contrast-enhancement patterns of hemangioma were uniform high (15/118, 12.7%) during the arterial and portal venous phases. In tumors smaller than 20 mm, 11 (9.3%) had low-low attenuation and two (1.7%) had iso-low attenuation during the arterial and portal venous phases, respectively. In conclusion, at two-phase spiral CT, the most common contrast-enhancement patterns of hemangioma are peripherally nodular high and/or uniform high during the arterial and portal venous phases. However, hemangiomas smaller than 2 cm may have atypical enhancing patterns including low and iso-attenuation.

Adult↗