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Biomedical subjects

B I Choi

Publications and source records attributed to B I Choi.

At least 73 records · Page 4Linked to original sources
PubMed1996

Power versus conventional color Doppler sonography: comparison in the depiction of vasculature in liver tumors.

PURPOSE: To compare power and conventional color Doppler sonography in the depiction of the intratumoral vasculature of hemangiomas, hepatocellular carcinomas (HCCs), and metastases of the liver. MATERIALS AND METHODS: Thirty-two patients with liver tumors (12 hemangiomas, 11 HCCs, and nine metastases) were prospectively evaluated with power and conventional color Doppler sonography by using a 2-4-MHz convex probe with 2-MHz Doppler frequency. Power Doppler sonography was performed with a 75%-88% gain. Conventional color Doppler sonography was performed with a 55%-75% gain and a pulse repetition frequency of 700 Hz. Power Doppler signals and color Doppler signals interrogated in one plane were analyzed by two radiologists, who subjectively rated power Doppler sonography as superior, equal, or inferior to color Doppler sonography. RESULTS: Overall, power Doppler sonography was superior to color Doppler sonography in 18 patients and equal in 14 (P < .01). In hemangiomas, power Doppler sonography was superior to color Doppler sonography in 10 patients and equal in two (P < .01). In HCCs, power Doppler sonography was superior to color Doppler sonography in four patients and equal in seven (P > .05). In metastases, power Doppler sonography was superior to color Doppler sonography in four patients and equal in five (P < .05). CONCLUSION: Power Doppler sonography is more sensitive than color Doppler sonography in the depiction of the vasculature of liver tumors, particularly in hemangiomas.

Adult↗
PubMed1995

Characterization of focal hepatic tumors. Value of two-phase scanning with spiral computed tomography.

BACKGROUND: Spiral computed tomography (CT) allows imaging of the liver during the peak contrast material levels due to the capability of fast data acquisition. The objective of this study was to evaluate the usefulness of two-phase spiral CT in the differential diagnosis of focal hepatic tumors. METHODS: One hundred two patients who had hepatic tumors (211 nodules; 149 hepatocellular carcinomas [HCCs], 36 metastases, and 26 hemangiomas) underwent two-phase spiral CT with 10-mm collimation at 10 mm/second table speed and 120 mL of contrast material injected at the rate of 3 mL/second. Computed tomography images of the hepatic arterial phase and late (equilibrium) phase were obtained at 35-second and 180-second delays, respectively. The enhancement patterns of tumors were divided into six types and were compared with the attenuation of surrounding liver parenchyma: totally high, peripherally high, centrally high, mixed, iso, and low. RESULTS: The common enhancement patterns of HCC in two-phase spiral CT were totally high in the arterial phase and low (n = 63, 42%) or iso (n = 28, 19%) in the late phase. Metastasis showed peripherally nonnodular high attenuation (n = 9, 25%) or low attenuation (n = 9, 25%) in the arterial phase and low attenuation in the late phase, followed by totally high attenuation in the arterial phase and iso in the late phase (n = 6, 17%). Hemangiomas showed totally or peripherally nodular enhancement in the arterial and late phases (n = 23, 89%). In distinguishing hemangiomas from malignant tumors, totally high or peripherally nodular high attenuation in the late phase was the most useful contrast enhancement pattern (96% of hemangioma vs. 0% of malignant tumors). In distinguishing HCCs from metastases, a combination of contrast enhancement pattern of totally high attenuation in the arterial phase and low in the late phase was the most useful contrast enhancement pattern (42% of HCCs vs. 0% of metastases). The predictability of differentiation between hemangiomas and malignant tumors and between HCCs and metastases was 99% and 90% with spiral CT, respectively. CONCLUSIONS: Two-phase spiral CT is useful in the differential diagnosis of focal hepatic tumors with evaluation of contrast enhancement patterns.

Adult↗
PubMed1995

Hepatocellular carcinoma and portal vein invasion: results of treatment with transcatheter oily chemoembolization.

OBJECTIVE: Our objective was to evaluate the efficacy and safety of transcatheter oily chemoembolization therapy in a series of patients with hepatocellular carcinoma and portal vein invasion. MATERIALS AND METHODS: We retrospectively analyzed the results of transcatheter oily chemoembolization for 110 patients with hepatocellular carcinoma invading major portal branches. The Child's classes were A for 94 patients and B for 16. The main portal vein was partially (n = 33) or completely (n = 15) invaded in 48 patients, the right portal vein was invaded in 36, and the left portal vein was invaded in 26. Oily chemoembolization was performed with an emulsion of iodized oil and doxorubicin hydrochloride. Gelatin sponge particle embolization was added for 78 patients. Seventy-one patients underwent multiple treatment sessions. RESULTS: Our initial findings showed that 31 patients had complete or partial remission, with an overall median survival time of 6 months. The cumulative survival rates were 48% (6 months), 30% (1 year), 18% (2 years), and 9% (3 years). The parenchymal tumor extent was the most significant predicting factor for complications and efficacy of therapy. Of 33 patients with a parenchymal tumor limited to one or two segments of a hepatic lobe, 22 had complete or partial remission, with a median survival time of 22 months; this survival time was significantly longer than that (5 months) for 77 patients with a more extensive tumor (p < .0001). Hepatic insufficiency developed in 10 patients, and three of them died within 1 month after chemoembolization. All 10 patients had an extensive parenchymal tumor involving more than two hepatic segments, and four had impaired hepatic functional reserve of Child's class B. CONCLUSION: When a tumor is limited in extent and hepatic function is preserved, transcatheter oily chemoembolization is effective and safe for the palliation of hepatocellular carcinoma and major portal vein invasion. However, when a parenchymal tumor is extensive, chemoembolization is associated with a poor response and a risk of hepatic failure.

Adolescent↗
PubMed1994

Undifferentiated embryonal sarcoma of the liver: US and CT findings.

Six cases of undifferentiated embryonal sarcoma (UES) were reviewed to determine their characteristic features on ultrasonography (US) (n = 5) and computed tomography (CT) (n = 6). US demonstrated a single large, echogenic mass with some anechoic spaces. Contrast-enhanced CT scan revealed a well-demarcated low-attenuation mass with hyperdense septations of variable shape and thickness. Discrepancy of internal architecture on US and CT was one of the important characteristics of UES. CT numbers were 25-47 HU in low-attenuation areas. Enhancing peripheral rim was found in four cases and some solid portions at the periphery or adjacent to the septa were found in all cases. Two patients who had follow-up US and CT without treatment showed enhancing solid portions, changing to hypodense as the tumor grew. When compared with the pathologic findings, US showed a more accurate representation of internal architecture than did CT. Familiarity with these US and CT findings of UES of the liver will be helpful in the differential diagnosis of primary hepatic tumors in childhood.

Adult↗
PubMed1994

Uterine cervical carcinoma: evaluation of pelvic lymph node metastasis with MR imaging.

PURPOSE: To assess accuracy of magnetic resonance (MR) imaging in detection of pelvic node metastasis from uterine cervical carcinoma. MATERIALS AND METHODS: In 136 patients (aged 26-71 years [mean, 49 years]) with uterine cervical carcinoma seen between October 1990 and July 1992, maximum axial diameter (MAAD), minimum axial diameter (MIAD), and signal intensity enhancement ratio of positive nodes were measured. RESULTS: With MAAD of 1.0 cm, MR imaging had an accuracy of 90.4%, sensitivity of 62.2%, and specificity of 94.9% in detection of pelvic node metastasis. Mean MAAD and MIAD were 1.43 and 1.30 cm for true-positive nodes and 1.18 and 0.75 cm for false-positive nodes, respectively. Mean MAAD/MIAD was 1.09 for true-positive and 1.76 for false-positive nodes. With MIAD of 1.0 cm, MR imaging had an accuracy of 93.0% with 62.2% sensitivity and 97.9% specificity. No significant differences were noted in the degree of contrast enhancement between true-positive and false-positive nodes. CONCLUSION: The accuracy of MR imaging was fairly high in detection of pelvic node metastasis from uterine cervical carcinoma, and MIAD was a more accurate size criterion than MAAD.

Carcinoma↗
PubMed1994

Exophytic adenocarcinoma of the stomach: CT findings.

OBJECTIVE: Exophytic adenocarcinomas of the stomach are tumors that have large extraluminal portions. Exophytic growth of gastric carcinoma is rare, and such tumor may be confused with gastric leiomyosarcoma. The purpose of this study was to assess the CT findings of exophytic adenocarcinoma of the stomach and to determine their value in distinguishing between it and gastric leiomyosarcoma. MATERIALS AND METHODS: Twenty patients with exophytic adenocarcinomas of the stomach confirmed by surgery or endoscopic biopsy were included in the study. CT scans were assessed retrospectively for the size, location, and character of the mass and the presence of adjacent thickening of the gastric wall and outlet obstruction. RESULTS: The masses were from 5 to 14 cm in diameter (mean, 9 cm). The mass was in the gastric antrum in 11 cases, the body of the stomach in six cases, the body and antrum in two cases, and the gastric fundus and body in one case. CT showed an exogastric mass with a variable degree of internal low density or necrosis in all 20 cases. Thickening of the gastric wall adjacent to the mass appeared to be a specific finding of exogastric adenocarcinoma (n = 14); it was not seen in reported cases of leiomyosarcoma. Gastric outlet obstruction was seen in four cases, and ulcer was detected in eight cases. The degree of low density or necrosis within the mass was minimal in eight cases, moderate in seven cases, and severe in five cases. CONCLUSION: Our results suggest that CT findings of thickening of the gastric wall adjacent to an exogastric mass, representing spread of cancer to adjacent gastric wall, and/or gastric outlet obstruction are typical of exophytic adenocarcinoma of the stomach and allow distinction between it and gastric leiomyosarcoma.

Adenocarcinoma↗
PubMed1994

Correlation of sonographic findings with histopathological changes of the bile ducts in rabbits infected with Clonorchis sinensis.

Clonorchiasis is an important parasitic disease of humans in Korea. The present study intended to compare sonographic findings with histopathological changes in experimental clonorchiasis. Eighteen New Zealand white rabbits were infected with metacercariae of Clonorchis sinensis, and examined 4, 10, and 22 weeks post-infection (PI). Four infected rabbits were treated with praziquantel 10 weeks PI and were examined 12 weeks after treatment. Sonography revealed mild to severe dilatation of the intrahepatic ducts (IHDD) and slightly increased periductal echoes in 12 out of 14 rabbits at 4 weeks PI, and all of the animals after 10 and 22 weeks PI and 12 weeks after treatment. The histopathological lesions were duct dilatation, mucosal hyperplasia, and periductal fibrosis, which progressed from 4 weeks to 22 weeks PI and even in treated rabbits. The dilated intrahepatic ducts over 1 mm diameter were detected by sonography. The present results indicate that sonographic findings are well correlated with histopathological lesions in rabbit clonorchiasis except for early phase of light burden of infection. The sonography has a limitation in discriminating residual sequelae of the ducts after praziquantel treatment.

Animals↗
PubMed1994

Doppler sonography of deep cavernosal artery of the penis: variation of peak systolic velocity according to sampling location.

To determine if there are significant variations in the peak systolic velocity of cavernosal arteries according to the Doppler sampling location, Doppler sonography was performed in 32 patients with erectile dysfunction and 15 control patients. Doppler spectral waveforms were obtained at proximal and distal locations in cavernosal artery. The peak systolic velocity of the cavernosal artery was 39.0 +/- 11.2 cm/sec in proximal portion and 20.0 +/- 5.6 cm/sec in distal portion in patients with erectile dysfunction. In control patients, the peak systolic velocity was 39.8 +/- 8.0 cm/sec in proximal portion and 21.3 +/- 5.5 cm/sec in distal portion. The peak systolic velocity of the cavernosal artery varies significantly according to the sampling location in patients with erectile dysfunction as well as in control patients. Our study demonstrated that the sampling location needs to be standardized in performing Doppler sonography of the cavernosal arteries, and we propose the proximal cavernosal artery where it angles posteriorly as the standardized sampling location.

Adult↗
PubMed1994

Primary angiosarcoma of the spleen. CT and MR imaging.

The CT and MR findings in 2 patients with surgically proven splenic angiosarcoma are presented. Two distinctive radiologic and pathologic patterns were observed: total tumor replacement of the spleen with preservation of normal contour or multiple nodular masses in the spleen. The various findings on CT and MR imaging reflected the hemorrhagic nature of the lesions with increased iron content. MR imaging appeared to be superior to CT in demonstrating these features. In the case of focal lesions, radiologic differentiation from lymphoma or metastasis was impossible.

Adult↗
PubMed1993

Radiological findings of human fascioliasis.

Fasciola hepatica is a trematode of herbivorous mammals. Humans are accidentally infected by the ingestion of water or raw aquatic vegetables contaminated with the metacercaria. Radiological findings of six patients with fascioliasis (five hepatic fascioliasis, one biliary fascioliasis) were analyzed. The diagnosis was based on serological testing and/or histopathologic findings of eosinophilic abscess in five patients and identification of the adult worm in one patient. The characteristic radiological features of hepatic fascioliasis were (1) cluster of microabscesses arranged in tract-like fashion (burrow tract), (2) subcapsular location of the hepatic lesions, and (3) very slow evolution of the lesion on follow-up examinations. In biliary fascioliasis, there were multiple conglomerated filling defects in the common bile duct. The authors believe that the demonstration of these features, together with peripheral eosinophilia or eosinophilic aspirate from the hepatic lesion, is very helpful in making the correct diagnosis.

Adolescent↗
PubMed1993

Endodermal sinus tumour associated with benign teratoma of the common bile duct.

We report a 5-year-old boy with endodermal sinus tumour associated with benign cystic teratoma of the common bile duct (CBD). To our knowledge, there has been one case of teratoma of the CBD in the English literature with no morphological or radiological description. Our case presented a lobulated polypoid mass obstructing the distal CBD on sonography and computed tomography, which resembled the botryoid masses of rhabdomyosarcoma.

Child, Preschool↗
PubMed1993

Necrotic areas in VX2 carcinoma of rabbits. Correlation of magnetic resonance imaging and pathologic appearance.

RATIONALE AND OBJECTIVES: To assess the potential of magnetic resonance imaging (MRI) for evaluating the evolution of tumor necrosis, the authors evaluated 28 VX2 carcinomas inoculated in the thigh muscles of rabbits. METHODS: MRI of VX2 carcinomas at 2.0 T was done with spin-echo technique 1 week (14 tumors) and 3 weeks (14 tumors) after the inoculation of tumor cells. T1- and T2-weighted images were obtained with 500/30 and 2,500/80 sequences; the authors also performed enhanced T1-weighted images with contrast medium. MRI and histopathologic findings were compared. RESULTS: Enhanced T1-weighted images with gadolinium-DTPA (Gd-DTPA) (dimeglumine gadopentetate) could depict necrosis in almost all tumors (27/28) and were the most sensitive technique followed by T2- and T1-weighted images. T2-weighted images best permitted the evaluation of the characteristics of necrotic areas in VX2 carcinomas, followed by T1-weighted images with contrast enhancement, and unenhanced T1-weighted images. On T2-weighted images, low-intensity areas of necrotic areas correspond to areas of early necrosis, isointense areas corresponded to areas of intermediate necrosis, and high-intensity areas corresponded to the late phase of necrosis. CONCLUSIONS: MRI is useful in depicting necrosis and characterizing different phases of necrosis in VX2 carcinomas.

Animals↗
PubMed1993

Small hepatocellular carcinomas and associated nodular lesions of the liver: pathology, pathogenesis, and imaging findings.

Hepatocellular carcinomas frequently occur in association with liver cirrhosis, as chronic liver disease is one of the most important factors in carcinogenesis. In addition to small hepatocellular carcinomas (less than 3 cm in diameter), recent reports of pathologic studies of resected specimens from cirrhotic liver describe associated small nodular lesions (i.e., regenerating nodule, adenomatous hyperplasia, and early hepatocellular carcinoma). In hepatocarcinogenesis of the cirrhotic liver, a regenerating nodule might be the first step in the development of hepatocellular carcinoma, going through phases of adenomatous hyperplasia and early hepatocellular carcinoma in a multistep fashion. We describe the pathologic characteristics of small hepatocellular carcinomas and associated nodular hepatic lesions and review the current concepts of the role of these associated lesions in carcinogenesis. We also discuss the imaging findings of these abnormalities, the efficacy of various imaging techniques for diagnosing them, and the importance of imaging in treatment planning.

Carcinoma, Hepatocellular↗
PubMed1993

A case of intestinal capillariasis in the Republic of Korea.

In 1991, we observed a Korean man infected by Capillaria philippinensis who had no history of traveling in known endemic areas. He had year-long diarrhea with severe loss of body weight. He enjoyed hunting and fishing and eating raw meat of game animals and fish. An open full-thickness biopsy of the ileum showed flat mucosal surface and sections of the round worm, and fecal examination revealed numerous elliptical helminth eggs. The worms and eggs were consistent with features of C. philippinensis. He was treated with albendazole and was cured. This is the first known case of intestinal capillariasis in the Republic of Korea.

Adult↗
PubMed1993

Piezoelectric lithotripsy of radiopaque gallstones: results and six-month follow-up.

Sixty-eight patients with radiopaque gallbladder stones (38 with a single stone, 30 with multiple stones) were treated with piezoelectric extracorporeal shock wave lithotripsy (ESWL) and results were compared with those of 69 patients with radiolucent stones (28 with a single stone, 41 with multiple stones). Stones were fragmented to 4 mm or less in 76.8% after 41,466 +/- 36,504 shock waves in the radiolucent stone group and 77.9% after 54,686 +/- 51,024 shock waves in the radiopaque stone group (p = 0.876 and 0.130, respectively). In 137 patients, ten patients were lost to follow-up. Average period of follow-up was 220 +/- 198 days. Six-month clearance rate of the radiolucent stone group was 43.5% and that of the radiopaque stone group was 16.4% (p less than 0.05) Figure 1. Six-month clearance rate of patients with single stones smaller than 2 cm was also significantly higher in the radiolucent stone group than in the radiopaque stone group (69.5% vs 18.6%; p less than 0.01). However, in patients with multiple stones, the presence of calcification did not affect rates of successful fragmentation or 6-month clearance. There was no statistically significant difference in incidence of complications between the radiolucent and radiopaque stone groups. Although the number of cases are small and the follow-up period is short, our results of ESWL on radiopaque gallstones are so far not satisfactory in terms of stone clearance. Strict patient selection is needed unless there is an improvement in the lithotripsy procedure or post-lithotripsy management.

Adult↗
PubMed1992

Calcified gastric carcinoma: CT findings.

The computed tomographic (CT) findings of 13 cases of calcified gastric carcinoma were analyzed retrospectively. Eleven cases were confirmed as a mucinous adenocarcinoma by surgery (three cases), or endoscopic biopsy (eight cases). Two cases were diagnosed as adenocarcinoma by endoscopic biopsy. In all cases the calcifications were of the punctate or miliary shape and the size varied from 1-3 mm in diameter. The calcifications were located in the thickened gastric wall in all cases, and were seen in metastatic lesions such as lymph nodes and the liver in two cases. In 10 cases, some tumor portions showed lower attenuation number than that of the muscle on CT scans, and corresponded to mucin pool in tumor portions histologically. Twelve cases were in inoperable advanced stage.

Adenocarcinoma, Mucinous↗
PubMed1992

Duplex Doppler US in patients with medical renal disease: resistive index vs serum creatinine level.

The relationship between resistive index of arterial Doppler waveform of the native kidney and serum creatinine level has been studied using duplex Doppler sonography in 40 patients with medical renal disease and 28 normal controls. The resistive index of the normal control group and the medical renal disease group was 0.627 +/- 0.042 and 0.823 +/- 0.237, respectively, with statistically significant difference. In the group with medical renal disease, there was a statistically significant correlation between the resistive index and the level of serum creatinine. The study suggests that duplex Doppler sonography may be helpful in evaluation of renal functional status in patients with medical renal disease.

Adolescent↗