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Biomedical subjects

Ah Young Kim

Publications and source records attributed to Ah Young Kim.

At least 19 recordsLinked to original sources
PubMed2006

Diagnosis of intrahepatic and common duct stones: combined unenhanced and contrast-enhanced helical CT in 1090 patients.

BACKGROUND: We determined the accuracy of combined unenhanced and contrast-enhanced helical computed tomography (CT) for diagnosis of bile duct stones. METHODS: During a 12-month period, 1090 patients who underwent combined CT and endoscopic retrograde cholangiography (ERC) or percutaneous transhepatic cholangioscopy (PTC) were enrolled in this study. The results of prospective CT interpretation regarding the presence of bile duct stones were compared with results of endoscopic stone removal, PTC and with surgical results. In 70 patients, detectability of stones on CT was evaluated depending on stone types. RESULTS: Of 1090 study patients, 175 and 299 patients were confirmed to have intrahepatic and common duct stones, respectively. The sensitivity and specificity of combined CT were 73% and 98% for diagnosis of intrahepatic stones and 71% and 97% for common duct stones. Of 70 patients 24, 25, and 21 patients had cholesterol, black pigment, and brown pigment stones, respectively. Eleven of 24 cholesterol stones, 21 of 25 black pigment stones, and 15 of 21 brown pigment stones were detected on combined CT. CONCLUSION: Combined CT is of limited sensitivity for detection of bile duct stones, especially in Western countries where cholesterol stones predominate. It may be of greater value in populations with a higher incidence of pigment stones. Other complementary imaging modalities are needed for patients with negative CT findings who are highly suspected to have biliary stones.

Adult↗
PubMed2006

MDCT of small-bowel disease: value of 3D imaging.

OBJECTIVE: Our objective is to show the various clinical applications of MDCT enterography for evaluating small-bowel disease, with a focus on the added value of 3D imaging. CONCLUSION: MDCT and refined 3D imaging processes can offer a full examination of the small bowel as well as powerful information about the bowel and its surrounding structures.

Acute Disease↗
PubMed2006

Flat polyps of the colon: detection with 16-MDCT colonography--preliminary results.

OBJECTIVE: This study evaluates the ability of contrast-enhanced, 16-MDCT colonography to display flat colonic lesions when a very narrow slice thickness (1 mm) is used. CONCLUSION: Less than 50% of flat lesions in our population could be visualized by blinded and unblinded review. Before they could be visualized, flat lesions were 2 mm or greater in height and 7 mm or greater in diameter. Lesions with a height of 1 mm or less were not seen on CT colonography. Contrast enhancement, location on a haustral fold, and abnormal 2D and 3D morphology contributed to lesion conspicuity.

Aged↗
PubMed2006

Bloodborne metastatic tumors to the gastrointestinal tract: CT findings with clinicopathologic correlation.

OBJECTIVE: In this essay, we illustrate the CT features of bloodborne metastases to the gastrointestinal tract from various malignancies with an emphasis on clinicopathologic correlation. CONCLUSION: Familiarity with CT findings of bloodborne metastases to the gastrointestinal tract and an understanding of the disease spread pattern in common primary cancers will be helpful not only in detecting metastatic disease but also in minimizing the possibility of mistaking metastasis for another metachronous malignancy.

Adult↗
PubMed2006

Unusual malignant tumors of the gallbladder.

OBJECTIVE: The purpose of this pictorial essay is to review the spectrum of unusual malignant tumors of the gallbladder and to illustrate their radiologic features. CONCLUSION: Radiologic findings of unusual malignant gallbladder tumors are varied and overlap with those of ordinary gallbladder carcinoma. Despite their rarity, being familiar with the wide spectrum of radiologic findings of these unusual tumors is helpful to improve diagnostic accuracy.

Adult↗
PubMed2006

Hepatic hemangiomas with arterioportal shunt: sonographic appearances with CT and MRI correlation.

OBJECTIVE: The purpose of this study was to summarize and illustrate the sonographic appearance of hepatic hemangiomas with arterioportal shunt and to correlate them with CT and MRI findings. CONCLUSION: High-flow hepatic hemangiomas tend to be seen as hypoechoic lesions at sonography. In the presence of fatty infiltration in the liver, they may accompany peritumoral low-echoic areas presumably caused by peritumoral sparing of fatty infiltration similar to a hyperattenuating or hyperintense peritumoral rim on unenhanced CT or MR chemical shift imaging. Color Doppler sonography may reveal intratumoral flows, large feeding arteries, and reversal of portal flow around the tumor. Knowledge of such sonographic findings may ensure an accurate sonographic diagnosis of these tumors.

Adult↗
PubMed2006

Inferior phrenic arterial bleeding after adult liver transplantation: incidence, clinical manifestations, and predictive CT features.

OBJECTIVE: The purpose of this study was to determine the incidence of inferior phrenic arterial bleeding after liver transplantation in adult patients and to describe its clinical manifestations and predictive CT features. CONCLUSION: Inferior phrenic arterial bleeding occurs frequently and is one of the major postoperative bleeding sites in patients undergoing liver transplantation. Awareness of its common clinical manifestations and predictive CT features is essential for prompt diagnosis and treatment of this early vascular complication, and this knowledge can help to avoid unnecessary reoperation and catastrophic hypotension.

Adolescent↗
PubMed2006

Assessment of the therapeutic response of hepatocellular carcinoma treated with transcatheter arterial chemoembolization: comparison of contrast-enhanced sonography and 3-phase computed tomography.

OBJECTIVE: The purpose of this study was to compare contrast-enhanced sonography with 3-phase computed tomography (CT) in assessing the therapeutic response of hepatocellular carcinomas (HCCs) treated with transcatheter arterial chemoembolization (TACE). METHODS: Twenty-nine nodular HCCs treated with TACE were examined with contrast-enhanced sonography, 3-phase helical CT, and conventional angiography. Contrast-enhanced sonographic and CT findings were interpreted separately and prospectively for the presence or absence of contrast enhancement in the treated HCCs. Conventional angiography served as the reference standard. RESULTS: Intratumoral enhancement was seen in 19 HCCs (61%) on contrast-enhanced sonography and 12 HCCs (39%) on CT. Enhancement patterns on sonography were blush in 8 (42%), branching in 2 (11%), nodular in 4 (21%), and stippled in 5 (26%). Of the 19 HCCs with intratumoral enhancement on contrast-enhanced sonography, 13 (68%) showed tumor staining on angiography. Of the 12 HCCs without intratumoral enhancement on sonography, 1 (8%) showed tumor staining on angiography. The sensitivity and specificity of contrast-enhanced sonography in depicting flow in HCCs treated with TACE were 93% and 65%, respectively. The sensitivity and specificity of 3-phase CT were 64% and 100%. CONCLUSIONS: Contrast-enhanced sonography is a more sensitive imaging method than 3-phase CT in depicting vascularity in HCCs treated with TACE.

Adult↗
PubMed2006

[Multidetector-row CT of the gastrointestinal tract].

Recently, the availability of multidetector-row CT (MDCT) and continuous refinement in three-dimensional (3D) imaging process have greatly expanded the role of CT in evaluating patients with gastrointestinal diseases. MDCT is the latest advancement in CT technology and is now more readily available. This imaging modality can offer full examination of the entire intestinal tract as well as powerful information about the bowel itself and its surrounding structures, which are inherent advantages of CT over conventional barium or optical endoscopic studies. In most cases, MDCT with various 3D technologies can make an easy, rapid, and accurate diagnosis by one-stop imaging, and enables to avoid other examinations. Therefore, knowledge and awareness of valuable clinical applications and proper scan technique of MDCT imaging is essential to achieve the diagnostic goal of one-step imaging.

Adult↗
PubMed2005

Biliary ductal evaluation of hilar cholangiocarcinoma: three-dimensional direct multi-detector row CT cholangiographic findings versus surgical and pathologic results--feasibility study.

The study was conducted, with institutional review board approval and informed patient consent, to assess the feasibility and diagnostic effectiveness of three-dimensional direct multi-detector row computed tomographic (CT) cholangiography for determining the extent of bile duct invasion by hilar cholangiocarcinoma. Eleven patients underwent contrast material-enhanced direct multi-detector row CT cholangiography of the primary and secondary biliary confluence levels and then surgical resection. In most patients, CT cholangiography was tolerable and yielded excellent or good opacification of the biliary tree. CT cholangiography enabled a correct diagnosis of the extent of ductal involvement at all 11 primary confluence levels and at 18 of the 19 secondary confluence levels. Three secondary confluences, which could not be analyzed owing to nonopacification or poor opacification, proved to be involved by hilar cholangiocarcinoma. The authors conclude that three-dimensional direct multi-detector row CT cholangiography is accurate and feasible for defining the extent of ductal invasion by hilar cholangiocarcinoma, especially in patients with preliminary biliary drainage.

Adult↗
PubMed2005

Gastric cancer staging at multi-detector row CT gastrography: comparison of transverse and volumetric CT scanning.

PURPOSE: To prospectively evaluate the accuracy of multi-detector row computed tomography (CT) gastrography for preoperative staging of gastric cancer, with pathologic and surgical results as the reference standard. MATERIALS AND METHODS: This study was approved by the institutional review board, and patients gave written informed consent. One hundred six patients (72 male, 34 female; mean age, 56 years) with endoscopically proved gastric cancer underwent unenhanced and contrast material-enhanced multi-detector row CT gastrography, with effervescent granules used as oral contrast material. Two experienced radiologists independently evaluated the depth of tumor invasion into the gastric wall (tumor staging), the involvement of regional lymph nodes (nodal staging), and the presence or absence of metastasis (metastatic staging) on transverse and volumetric CT images, which included images produced with multiplanar reformation and a virtual endoscopic technique. TNM staging of each tumor was compared with the pathologic and surgical results. Diagnostic accuracy in TNM staging was analyzed. RESULTS: Gastric cancer was detected in 92 (87%) of 106 study patients with transverse CT imaging and in 104 (98%) with volumetric CT imaging. The overall accuracy of the tumor staging was 77% with transverse CT imaging and 84% with volumetric CT imaging (P < .001). The overall accuracy for lymph node staging was 62% with transverse CT imaging and 64% with volumetric CT imaging (P = .057). For staging of metastases, there was no difference between transverse and volumetric CT imaging (86% for both) (P > .99). CONCLUSION: Multi-detector row CT gastrography with multiplanar reformation and virtual endoscopy, compared with transverse CT imaging, can improve the accuracy of preoperative staging of gastric cancer. This difference was significant for tumor staging but not for the staging of lymph nodes and metastases.

Adult↗
PubMed2005

False-negative results at multi-detector row CT colonography: multivariate analysis of causes for missed lesions.

PURPOSE: To determine causes of false-negative results at multi-detector row computed tomographic (CT) colonography and determine presumptive causes with logistic regression analysis. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. The study included 394 colonic segments in 31 men and 25 women at high risk for colorectal cancer (mean age +/- standard deviation, 60.2 years +/- 9.3 for men and 56.8 years +/- 13.3 for women). Multi-detector row CT colonography and colonoscopy (reference standard) were performed in a blinded manner, and the results were compared. CT colonographic findings were interpreted in consensus by two readers using a primary two-dimensional with three-dimensional problem-solving approach. Adequacy of colonic preparation and distention was recorded. Sensitivity and specificity were obtained with 95% confidence intervals (CIs). Lesions missed at CT colonography were retrospectively reassessed to identify why they were missed, and, if the causes were not apparent, logistic regression analysis was performed to determine the presumptive causes. RESULTS: Colonic preparation and distention were optimal in 17 patients (30%) but suboptimal in 37 (66%) and poor enough to make the results nondiagnostic in two (4%). Twenty-nine of 63 lesions were missed at CT colonography. When all flat, sessile, and pedunculated lesions (n = 63) were included, sensitivities were 75% (nine of 12; 95% CI: 48%, 100%) for lesions 10 mm or larger and 79% (19 of 24; 95% CI: 65%, 93%) for those 6 mm or larger. When only sessile and pedunculated lesions (n = 60) were included, corresponding sensitivities were 100% (nine of nine; 73%, 100%) and 90% (19 of 21; 78%, 100%), respectively. All three missed lesions larger than 10 mm were flat, and all three flat lesions were missed. Two 3-mm high lesions, including one invasive adenocarcinoma, were misinterpreted as feces at blinded image review; one 1-mm high tubular adenoma with adenocarcinoma foci could not be visualized even in retrospect. Sessile or pedunculated polyps 5 mm or smaller were significantly more likely to be missed than those 6 mm or larger (adjusted odds ratio, 11.6; P = .027). CONCLUSION: Aside from inadequate bowel preparation and/or distention, flat lesions and small polyps are the two main causes for missed lesions at multi-detector row CT colonography.

Adenocarcinoma↗
PubMed2005

Superficial esophageal cancer: esophagographic findings correlated with histopathologic findings.

PURPOSE: To retrospectively determine and evaluate the findings of superficial esophageal cancer at esophagography and to correlate the esophagographic findings with the depth of tumor invasion. MATERIALS AND METHODS: The institutional review boards required neither their approval nor informed patient consent for this retrospective study. One hundred thirteen patients with superficial esophageal cancer who underwent esophagectomy at three institutions were included in this study. Double-contrast esophagograms were reviewed independently by two reviewers. For assessment of histopathologic findings, pathology reports were reviewed. Findings at esophagography, including morphologic type of the lesion, lesion extent, presence or absence of elevated or depressed component, margin and extent of elevated or depressed component, presence or absence of nodularity, extent of nodularity, esophageal luminal narrowing, and esophageal wall rigidity, were compared between mucosal and submucosal cancers by using chi2, Fisher exact, and independent-sample t tests. RESULTS: Of 122 histopathologically proved superficial esophageal cancers in 113 patients, 100 (82%) were detected at esophagography. The most common morphologic type was the plaquelike form; 50 (50%) such lesions were depicted at esophagography. Morphologic types were significantly different between the mucosal and submucosal cancers (P < .001). Protruded and plaquelike lesions were more frequent among submucosal cancers, whereas most flat lesions were mucosal cancers. An elevated component (P < .001), a rigid esophageal wall (P < .001), and a lobulated or irregular margin of the elevated component (P = .023) were significantly more frequent among submucosal cancers. Also, total extent of the lesion (P < .001), size of the largest nodule (P < .001), and extent of nodularity (P = .036) were significantly larger in the submucosal cancers. CONCLUSION: In the evaluation of patients with superficial esophageal cancer, esophagography appears to be helpful for diagnosing the tumor and differentiating mucosal from submucosal cancers.

Adult↗
PubMed2005

Hepatic artery pseudoaneurysms in adult living-donor liver transplantation: efficacy of CT and Doppler sonography.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of contrast-enhanced CT and Doppler sonography in the diagnosis of hepatic artery pseudoaneurysm after adult living-donor liver transplantation (LDLT). CONCLUSION: Because patients with hepatic artery pseudoaneurysm after LDLT can have diverse clinical presentations, routine imaging follow-up is important for early detection. Although Doppler sonography is limited in showing the pseudoaneurysm, contrast-enhanced CT, especially MDCT with CT arteriography, is effective in showing it in most patients.

Adult↗
PubMed2004

Differentiation of extrahepatic bile duct cholangiocarcinoma from benign stricture: findings at MRCP versus ERCP.

PURPOSE: To retrospectively evaluate criteria for differentiating extrahepatic bile duct cholangiocarcinoma from benign cause of stricture at magnetic resonance cholangiopancreatography (MRCP) and to compare diagnostic accuracy with this modality versus endoscopic retrograde cholangiopancreatography (ERCP). MATERIALS AND METHODS: MRCP and ERCP images in 50 patients (27 with cholangiocarcinoma [18 men, nine women; mean age, 58 years] and 23 with benign cause of stricture [13 men, 10 women; mean age, 60 years]) were retrospectively reviewed to assess the appearance of bile duct strictures. Final diagnosis was based on surgical or biopsy findings. Strictures were described according to their imaging appearance (irregular or smooth margins, asymmetric or symmetric narrowing, abrupt narrowing or gradual tapering, and presence or absence of double-duct sign). Sensitivity, specificity, and accuracy of MRCP and ERCP were calculated by using ratings of confidence in image-based diagnosis. Lengths of stricture were electronically measured and compared by using the Student t test. RESULTS: Among cholangiographic criteria for malignant biliary stricture, irregular margins and asymmetric narrowing were more common in cholangiocarcinomas (24 [89%] of 27 patients) than in benign strictures (six [26%] and eight [35%] of 23 patients, respectively). Sensitivity, specificity, and accuracy of the two methods for differentiation of malignant from benign causes of biliary stricture were 81% (22 of 27), 70% (16 of 23), and 76% (38 of 50), respectively, for MRCP and 74% (20 of 27), 70% (16 of 23), and 72% (36 of 50), respectively, for ERCP. Mean length (+/- standard deviation) of cholangiocarcinomas was 30.0 mm +/- 8.5, and that of benign strictures was 13.6 mm +/- 9.1 (P <.001). CONCLUSION: Accuracy of MRCP is comparable with that of ERCP. Regardless of modality, a lengthy segment of extrahepatic bile duct stricture with irregular margin and asymmetric narrowing suggests cholangiocarcinoma, and a short segment with regular margin and symmetric narrowing suggests benign cause.

Adult↗
PubMed2004

Arterioportal shunt: prevalence in small hemangiomas versus that in hepatocellular carcinomas 3 cm or smaller at two-phase helical CT.

PURPOSE: To compare the prevalence of arterioportal (AP) shunting associated with (a) small (< or =3 cm) hemangiomas and (b) hepatocellular carcinomas (HCCs) (< or =3 cm) at two-phase helical computed tomography (CT). MATERIALS AND METHODS: Two-phase helical liver CT was performed in 107 patients (61 men, 46 women; age range, 25-73 years; mean, 48.6 years) with 169 small hemangiomas and in 384 patients (292 men, 92 women; age range, 18-82 years; mean, 58.3 years) with 598 HCCs 3 cm or smaller. Diagnosis of HCC was verified with histologic findings (n = 30) or typical imaging and clinical findings (n = 568); that of all hemangiomas was verified with typical imaging and clinical findings. Three radiologists retrospectively reviewed all CT images in consensus. Contrast material-enhanced CT scans were obtained during the hepatic arterial and portal venous phases. AP shunt was considered to be present when wedge-shaped or irregularly shaped homogeneous enhancement peripheral to tumor appeared at hepatic arterial phase CT and isoattenuation or slight hyperattenuation in that area appeared at portal phase CT. The prevalence of AP shunting associated with hemangiomas and that associated with HCCs were compared with multivariate model testing. Speed of lesion enhancement (rapid enhancement, when extent of intratumoral enhancement at hepatic arterial phase CT was >50%; slow enhancement, when extent of intratumoral enhancement was < or =50%) and presence of AP shunt were correlated with chi2 or Fisher exact testing. RESULTS: AP shunts were more frequently found in hemangiomas (36 lesions [21.3%]) than in HCCs (25 lesions [4.2%]) (P <.001). Twenty-four (38%) of the 64 hemangiomas with rapid enhancement had AP shunts, whereas only 12 (11.4%) of the 105 hemangiomas with slow enhancement had AP shunts (P <.001). There was no significant difference between prevalence of AP shunt in the 573 HCCs with rapid enhancement (24 lesions, 4.2%) and that in the 25 HCCs with slow enhancement (one lesion, 4.0%). CONCLUSION: AP shunts were more frequently seen at two-phase helical CT in small hepatic hemangiomas than in HCCs and thus represent a suggestive but not specific finding of hemangioma. Small hemangiomas with AP shunts tend to show rapid rather than slow enhancement.

Adolescent↗
PubMed2004

Pyogenic hepatic abscesses: distinctive features from hypovascular hepatic malignancies on contrast-enhanced ultrasound with SH U 508A; early experience.

The aim of this study was to investigate the feasibility of contrast-enhanced US (conE US) in differentiating pyogenic hepatic abscesses (PyHAs) from hypovascular hepatic malignancies. conE US images of 16 PyHAs in 12 patients were evaluated retrospectively and were compared with those of 22 hypovascular hepatic malignancies in 12 patients. The conE US images were obtained at 30, 90, 150 and 270 s after a bolus injection of 4 g of SH U 508A (Levovist, Schering; 300 mg/mL). The images were specifically analyzed for the shape (round or ovoid, lobulating or coalescent according to the complexity), the margin (sharp or ill-defined), and the pattern of contrast agent enhancement of the lesion (internal and rim enhancement). In our experience, as to the shape of the lesion, PyHAs were usually coalescent (94%), and hepatic malignancies were more frequently round or ovoid (36%) or lobulating (50%) (p < 0.0001). The margin of the lesion was usually sharp in PyHAs (81%), whereas it was more commonly ill-defined (59%) in hepatic malignancies (p = 0.02). Whereas PYHAs usually produced no internal enhancement (94%), diffuse (73%) or peripheral (27%) hypoechoic intratumoral enhancement was seen in hepatic malignancies (p < 0.0001). This study shows that conE US is potentially useful in differentiation of PyHAs from hypovascular hepatic malignancies. PyHAs usually produce characteristic features, such as coalescent appearance, sharp boundary of necrotic cavity, and lack of internal enhancement on conE US.

Adult↗