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ABSTRACT: Secretin-stimulated magnetic resonance cholangiopancreatography not only facilitate the depiction of anatomic variations or morphologic changes of the pancreatic duct in the normal and diseased pancreas but also help assessing functional abnormalities of the exocrine pancreas. In this article, we illustrate findings of normal pancreas and various pancreatic diseases on magnetic resonance cholangiopancreatography after secretin stimulation.
Abdominal Imaging 04/2012; 31(5):575-81. · 1.73 Impact Factor
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Abdominal Imaging 02/2011; · 1.73 Impact Factor
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ABSTRACT: To describe the radiological, endoscopic, and pathological findings of gastric schwannomas in 16 patients.
The radiological, endoscopic, and pathological findings of 16 surgically proven cases of gastric schwannoma were retrospectively reviewed. All patients underwent computed tomography (CT) and four patients were evaluated with upper gastrointestinal series. Two radiologists reviewed the CT and upper gastrointestinal series images by consensus with regard to tumour size, contour, margin, and growth pattern, the presence or absence of ulcer, cystic change, and the CT enhancement pattern. Endoscopy was performed in eight of these 16 patients. Six patients underwent endoscopic ultrasonography. Pathological specimens were obtained from and reviewed in all 16 patients. Immunohistochemistry was performed for c-kit, CD34, smooth muscle actin, and S-100 protein.
On radiographic examination, gastric schwannomas appeared as submucosal tumours with the CT features of well-demarcated, homogeneous, and uncommonly ulcerated masses. Endoscopy with endoscopic ultrasonography demonstrated homogeneous, submucosal masses contiguous with the muscularis propria in all six examined cases. On pathological examination, gastric schwannomas appeared as well-circumscribed and homogeneous tumours in the muscularis propria and consisted microscopically of interlacing bundles of spindle cells. Strong positivity for S-100 protein was demonstrated in all 16 cases on immunohistochemistry.
Gastric schwannomas appear as submucosal tumours of the stomach and have well-demarcated and homogeneous features on CT, endoscopic ultrasonography, and gross pathology. Immunohistochemistry consistently reveals positivity for S-100 protein in the tumours.
Clinical Radiology 06/2008; 63(5):536-42. · 1.95 Impact Factor
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ABSTRACT: Sclerosing lipogranuloma is a rare, benign disease which is a peculiar granulomatous reaction of fatty tissue. This disease affects multiple organs and the majority of cases are secondary to exogenous foreign bodies. The authors report a case of primary sclerosing lipogranuloma of the rectum mimicking a submucosal rectal tumour.
The British journal of radiology 12/2006; 79(947):e190-2. · 2.11 Impact Factor
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ABSTRACT: The role of computed tomography (CT) in the preoperative staging of gastric cancer, even if controversial, may be fundamental for evaluating the local extent and nodal involvement of the disease, especially in locally advanced cases. However, previous results of CT staging have not been satisfactory for predicting the invasive depth of the tumor or possible nodal metastases. Recently introduced multidetector row CT (MDCT) and three-dimensional (3D) imaging are expected to overcome the limitations in cancer staging by offering rapid and accurate information for space perception, detailed hemodynamics, and real-time 3D processing of volumetric data sets. In particular, virtual endoscopic imaging may be helpful for detecting early gastric cancer. In our experience, T and N stagings of gastric cancer were improved with 3D MDCT when using volume rendering and virtual endoscopic imaging compared with conventional axial two-dimensional (2D) CT (accuracy of T staging with 3D vs. 2D CT images, 84% vs. 77%; accuracy of N staging, 63% vs. 61% with 3D vs. 2D images, respectively). In particular, the detection rate of early gastric cancer was markedly increased up to 96% when using 3D MDCT. Therefore, we believe that 3D MDCT of the stomach may enhance the performance of CT in the preoperative evaluation of patients who have gastric cancer by offering easy early detection of lesions and accurate tumor staging through the 3D imaging process.
Abdominal Imaging 07/2005; 30(4):465-72. · 1.73 Impact Factor
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D H Park,
M H Kim,
S S Lee,
S K Lee,
K P Kim,
J M Han,
S Y Kim,
M H Song,
D W Seo, A Y Kim,
T K Kim,
Y I Min
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ABSTRACT: Magnetic resonance cholangiopancreatography (MRCP) is rapidly replacing diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in various pancreaticobiliary diseases. This study was designed to evaluate the accuracy of MRCP in detection of hepatolithiasis and accompanying biliary strictures.
A prospective study over 2 years was conducted in 66 patients with primary intrahepatic stones. All patients with hepatolithiasis underwent percutaneous transhepatic cholangioscopy (PTC) within 2 weeks of the MRCP examination. The MRCP findings were compared with those of PTC as the reference standard for assessing the location of intrahepatic stones and the presence or absence of accompanying biliary strictures.
The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic stones were 97 %, 99 %, and 98 %, respectively. The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic bile duct strictures were 93 %, 97 %, and 97 %, respectively. During PTC, six of the 66 patients (9 %) were found on histology to have intraductal cholangiocarcinoma in stone-bearing ducts, which had not been suspected on MRCP.
In this study, MRCP allowed intrahepatic stones and accompanying biliary strictures to be located accurately. MRCP may therefore be able to replace diagnostic ERCP in patients with primary intrahepatic stones. However, MRCP had a limited ability to reveal concurrent intraductal cholangiocarcinoma associated with hepatolithiasis.
Endoscopy 12/2004; 36(11):987-92. · 5.21 Impact Factor
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ABSTRACT: To assess the usefulness of volume measurement using 3D US for depicting metastatic cervical lymph nodes.
Thirty-five cervical lymph nodes in 13 patients with primary head and neck malignancy were included in this study. US with volume acquisition was prospectively performed with a 5-10 MHz linear mechanical volume probe. Volume measurement of the node was calculated using a 3D automatic volume calculation program. The excised nodes matched on US were examined histopathologically.
The volume of malignant nodes ranged from 0.444 to 4.442 cm3, the volume of the benign nodes from 0.143 to 1.176 cm3. Combinations of high positive (>80%) and negative (>90%) predictive values were obtained at a cut-off value of 0.7 cm3.
Volume measurement of cervical nodes using 3D US can be a useful tool for differentiating metastatic from benign nodes in patients with primary head and neck malignancy.
Acta Radiologica 11/2002; 43(6):571-4. · 1.37 Impact Factor
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ABSTRACT: Purpose: To assess the usefulness of volume measurement using 3D US for depicting metastatic cervical lymph nodes.Material and Methods: Thirty-five cervical lymph nodes in 13 patients with primary head and neck malignancy were included in this study. US with volume acquisition was prospectively performed with a 5–10 MHz linear mechanical volume probe. Volume measurement of the node was calculated using a 3D automatic volume calculation program. The excised nodes matched on US were examined histopathologically.Results: The volume of malignant nodes ranged from 0.444 to 4.442 cm3, the volume of the benign nodes from 0.143 to 1.176 cm3. Combinations of high positive (>80%) and negative (>90%) predictive values were obtained at a cut-off value of 0.7 cm3.Conclusion: Volume measurement of cervical nodes using 3D US can be a useful tool for differentiating metastatic from benign nodes in patients with primary head and neck malignancy.
Acta Radiologica 10/2002; 43(6):571 - 574. · 1.37 Impact Factor
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B S Kim,
H K Ha,
I-J Lee,
J H Kim,
H W Eun,
I Y Bae, A Y Kim,
T K Kim,
M H Kim,
S K Lee,
W Kang
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ABSTRACT: To evaluate the accuracy of CT for staging gallbladder cancers, especially the T-factor of the TNM staging system.
CT investigations of 100 patients with surgically proven gallbladder cancers were retrospectively analyzed. Dynamic helical CT was performed in 16 patients and conventional CT in the remaining 84. On CT, three radiologists attempted tumor staging for these patients; the majority opinion was used for final decision. According to CT protocols (dynamic helical CT vs. conventional CT) and each tumor type (thickened wall/intraluminal mass/massive), the accuracy of CT staging was compared. The CT staging was correlated with the surgico-pathologic results.
The overall accuracy of CT for staging gallbladder cancers was 71%; it was 79% for T1 and T2 tumors, 46% for T3 tumors, and 73% for T4 tumors. For all three readers, the poorest accuracy was obtained in T3 tumors. No statistically significant difference was noted in the accuracy between the groups undergoing conventional CT and dynamic helical CT. A statistically significant difference was noted in the accuracy for staging thickened wall and intraluminal mass types of tumors (p<0.05); the highest accuracy was obtained in the intraluminal mass type (89%) and the massive type (83%), while it was 54% in the thickened wall type.
The accuracy of tumor staging with CT in patients with gallbladder cancer depends on the morphological type of tumor. The poorest result is obtained in the thickened wall type.
Acta Radiologica 01/2002; 43(1):71-6. · 1.37 Impact Factor
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ABSTRACT: To investigate the feasibility of recent contrast-specific ultrasound techniques in depicting vascular flow and the effects of changing the output power of the transducer and insonation mode on contrast enhancement, the authors performed an experimental study with a flow phantom.
While changing the mechanical index and the sound insonation mode (continuous and intermittent), images were obtained with three contrast-enhanced ultrasound techniques: fundamental, second-harmonic, and pulse-inversion harmonic imaging (PIHI) after a bolus injection of microbubble contrast agent. The images were compared on a time-intensity curve.
In assessing fixed flow (10 cm/s), PIHI showed the best depiction of flow signal. In intermittent scanning, increases in the mechanical index caused stronger flow signals and longer enhancement duration in all techniques. However, continuous scanning revealed poor depiction of flow signal regardless of the technique or changes in the mechanical index because of significant bubble destruction.
Microbubble-enhanced PIHI with intermittent scanning at a high mechanical index can depict vascular flow highly effectively without shortening the duration of enhancement.
Investigative Radiology 11/2001; 36(10):582-8. · 4.59 Impact Factor
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ABSTRACT: The purpose of this study was to compare observer performance for detecting urinary calculi using abdominal computed radiography with hard-copy versus soft-copy images and with a high-resolution video monitor versus a liquid-crystal-display (LCD) monitor.
We compared observer performance for detecting urinary calculi using three sets of radiographs-hard-copy images, soft-copy images displayed on a LCD monitor (1280 x 1024 bits), and soft-copy images displayed on a high-resolution video monitor using receiver operating characteristic curve analysis with a continuous rating scale. Computed radiography was archived with a 2140 x 1760 pixel resolution and a 10-bit depth. The selected data set included 62 images: 27 images showing proven urinary calculi smaller than 6 mm and three in number, and 35 images containing no proven abnormalities. Eleven radiologists (three genitourinary radiologists and eight general radiologists) participated in the study. Interpretations of three sets of randomly distributed radiographs were performed individually in three separate sessions at 1-week intervals.
No statistically significant differences were found in the area under the receiver operating characteristic curve for detecting urinary calculi or in the interpreting times between soft-copy and hard-copy images; the mean areas under the receiver operating characteristic curve of hard-copy images, soft-copy images displayed on an LCD monitor, and soft-copy images displayed on a high-resolution video monitor were 0.579, 0.610, and 0.732, respectively. However, soft-copy images showed relatively improved diagnostic accuracy among less experienced radiologists (p < 0.05).
For detecting urinary calculi, soft-copy images offered a diagnostic accuracy similar to or slightly more accurate than that of hard-copy images obtained in a laser-printed film-based environment. The diagnostic performance with soft-copy images viewed on an LCD monitor was comparable to that of soft-copy images viewed on a high-resolution video monitor.
American Journal of Roentgenology 09/2001; 177(2):331-5. · 2.78 Impact Factor
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ABSTRACT: To determine the prevalence of arterioportal shunt associated with hepatic hemangiomas, describe the two-phase spiral computed tomographic (CT) findings, and correlate the presence of arterioportal shunt with the size and rapidity of enhancement of hemangiomas.
The study group consisted of 109 hepatic hemangiomas in 69 patients who underwent two-phase spiral CT during 1 year. CT scans were obtained during the hepatic arterial (30-second delay) and portal venous (65-second delay) phases after injection of 120 mL of contrast material (3 mL/sec). Arterioportal shunts were diagnosed when hepatic arterial phase CT scans showed a wedge-shaped or irregularly shaped homogeneous enhancement in the liver parenchyma adjacent to the tumor and when portal venous phase CT scans showed isoattenuation or slight hyperattenuation, compared with normal liver in that area, and when there was no demonstrable cause of these attenuation differences. The presence of arterioportal shunt in hemangioma was correlated with the size of the tumor and the rapidity of intratumoral enhancement.
Arterioportal shunt was found in 28 (25.7%) of 109 hemangiomas. There was no statistically significant relationship between lesion size and presence of the arterioportal shunt (P =.653). Arterioportal shunt was more frequently found in hemangiomas with rapid enhancement (P <.01).
Arterioportal shunts are not uncommonly seen in hepatic hemangiomas at two-phase spiral CT. Hemangiomas with arterioportal shunts tend to show rapid enhancement.
Radiology 06/2001; 219(3):707-11. · 5.73 Impact Factor
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ABSTRACT: The purpose of this study was to analyze the incidence and primary causes of distal ileal wall thickening in 131 patients with right-sided colon cancer.
During a 2-year period, 131 patients underwent surgical resection for right-sided colon cancer. Of these patients, we analyzed 13 who had distal ileal wall thickening on CT before surgery and also had the cause determined at pathology. CT findings were analyzed with regard to the morphologic features of colonic tumors, bowel wall involvement patterns of the distal ileum, and changes in the pericolic space.
Distal ileal wall thickening occurred in 13 (10%) of the 131 patients who had right-sided colon cancer. Three patients had polypoid colon cancer, whereas the other 10 had infiltrative colon cancer. The mean thickness of the involved colonic segments was 1.6 cm (range, 1.0-2.2 cm) with a mean length of 5.2 cm (range, 2.5-10.0 cm). Pericolic infiltration was mild in six patients and moderate in four patients. The mean length and thickness of the affected ileal segments were 3.2 cm (range, 1.5-6.0 cm) and 1.1 cm (range, 0.7-2.0 cm), respectively. On histopathologic examination, neoplastic processes involved the distal ileum in nine (69%) of the 13 patients. This involvement was caused by either direct tumor invasion in seven patients or lymphatic spread in two. In four patients (31%), nonneoplastic processes with edema and congestion involved the distal ileum.
The distal ileum may be abnormally thickened in about 10% of patients with right-sided colon cancer; this thickening results from tumor extension (69%) or a nontumorous process (31%).
American Journal of Roentgenology 12/2000; 175(5):1439-44. · 2.78 Impact Factor
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ABSTRACT: Most inflammatory, neoplastic and vascular disorders manifest bowel wall thickening on computed tomography (CT). Therefore, it is very important to understand the patterns of bowel wall involvement (degree, length, symmetry and contrast enhancement patterns) in each category to make a correct diagnosis. Observing extraluminal changes also help to classify the primary causes of pathological conditions involving the gastrointestinal tract. Adequate CT examinations with optimal opacification of the gastrointestinal tract are essential not only to avoid false positive findings but also to detect subtle or minimal lesions. If findings for establishing a diagnosis are equivocal, the use of combined findings increases the diagnostic accuracy of CT.
Journal of Korean Medical Science 03/2000; 15(1):13-24. · 0.99 Impact Factor
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ABSTRACT: To compare contrast material-enhanced harmonic power Doppler ultrasonography (US) with conventional power Doppler US in depicting the vascularity of hepatocellular carcinoma (HCC).
Twenty patients with nodular HCCs (2.6-13.2 cm in diameter; mean diameter, 4.8 cm) were prospectively examined with both conventional and harmonic power Doppler US. US was performed with a 2-4-MHz curved linear-array transducer according to a standard examination protocol (1,000-Hz pulse repetition frequency, medium wall filter, and power gain of 55%-84% for conventional power Doppler US; 700-Hz pulse repetition frequency, low wall filter, and power gain of 95%-98% for harmonic power Doppler US). Serial, dynamic scans were obtained before intravenous injection of the contrast agent (SH U 508A) and at 30, 60, 90, 120, 180, 240, and 300 seconds after injection with both techniques.
The number of intratumoral power Doppler US signals was similar with both techniques at 30-90 seconds after contrast agent injection; however, after 90 seconds, conventional power Doppler US depicted significantly more signals than did harmonic power Doppler US. Harmonic power Doppler US was superior to conventional power Doppler US in terms of power Doppler artifacts such as "blooming" or motion-related artifacts.
Although the effective enhancement duration is relatively short compared with that for conventional power Doppler US, contrast-enhanced harmonic power Doppler US can be effective in evaluating the vascularity of HCCs because of the advantage of fewer power Doppler artifacts.
Radiology 03/2000; 214(2):381-6. · 5.73 Impact Factor
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ABSTRACT: Despite the advantages of depicting slow flow in small vessels, conventional power Doppler ultrasound (US) has a basic limitation, specifically that artifactual power Doppler signals mimic blood flow, especially in hyperechoic tissue. The purpose of this study was to compare harmonic power Doppler US with power Doppler US using a Doppler phantom under various parameter settings, focusing on the assessment of slow flow in the hyperechoic tissue.
While controlling the flow velocity (5 and 10 cm/s), pulse repetition frequency (500, 700, and 1,000 Hz), wall filter (low and medium), and Doppler gain (90%, 96%, and 100%), the authors performed both harmonic Doppler US and power Doppler US by using a Doppler phantom/flow control system. We measured and compared the relative intensities of the Doppler signals (0-250 scale) in both the vessels and hyperechoic tissue-mimicking materials with the two different imaging modalities.
Power Doppler US with any combination of the four parameters evaluated depicted strong flow signals (mean, 213) that were superior to harmonic Doppler US (mean, 61). Relatively strong artifactual signals within the hyperechoic tissue-mimicking materials were noted on all power Doppler US studies (mean, 106) but nearly none on harmonic Doppler US (mean, 3). The contrast-to-noise ratio of harmonic Doppler US was significantly greater than that of power Doppler US.
Harmonic Doppler US is more useful in assessing slow flow in hyperechoic tissue than power Doppler US because it produces fewer artifactual Doppler signals originating from stationary hyperechoic tissues, which can be misjudged as true signals on power Doppler US.
Investigative Radiology 03/2000; 35(2):105-10. · 4.59 Impact Factor
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ABSTRACT: CT and MR imaging have an important role in establishing the diagnosis of mesenteric ischemia. However, without specific signs such as thromboembolism in the mesenteric vessel, intramural or portal venous gas, and the absence of bowel wall enhancement, mesenteric ischemia can be confused with inflammatory or neoplastic gastrointestinal diseases. Arterial or venous occlusion or low-flow state are the main direct causes of mesenteric ischemia. Delayed diagnosis in equivocal cases can be avoided through an understanding of the patholophysiological aspects of mesenteric ischemia as they occur in a variety of other conditions, including: thromboembolism, bowel obstruction, neoplasm, vasculitis, inflammatory diseases, trauma, and drug or radiation therapy.
Seminars in Ultrasound CT and MRI 03/2000; 21(1):40-55. · 1.24 Impact Factor
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ABSTRACT: Power Doppler ultrasonography using a sonographic contrast agent (Levovist) was evaluated in 20 patients with hepatic hemangiomas with a 2-4 MHz convex transducer according to a standardized examination protocol (pulse repetition frequency, 1000 Hz; medium wall filter; power Doppler gain, 50 to 85%). Enhancement patterns were assessed and were compared with those on dynamic magnetic resonance imaging (n = 11) or computed tomography (n = 9). The most common enhancement pattern was dotlike or linear enhancement located predominantly at the periphery of the tumor (15 cases, 75%). Diffuse homogeneous enhancement was seen in one case (5%). No definite contrast enhancement was evident in four cases (20%). The enhanced area on ultrasonograms was smaller than that on dynamic MR images or CT scans in 18 cases (90%). A transient centripetal fill-in pattern was identified in six cases (30%). Persistent enhancement until 300 s was not seen in any case. Therefore, specific diagnosis of hemangioma with power Doppler ultrasonography and contrast agent may not be possible.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 12/1999; 18(11):737-43. · 1.25 Impact Factor
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ABSTRACT: The objective of this study was to describe CT findings of changes in the liver associated with benign obstruction of the hepatic inferior vena cava (IVC).
For a 10-year period, 35 patients with benign obstruction of the hepatic IVC underwent contrast-enhanced CT of the abdomen. These patients were included in this retrospective study. CT scans were analyzed for morphologic changes and abnormal enhancement of the liver, changes in intrahepatic vessels, and additional findings that might be related to obstruction of the IVC.
Morphologic changes of the liver included hypertrophy of the caudate lobe (91%) and the left lobe (57%), atrophy of the right lobe (49%), and a nodular surface (74%). The most common pattern of attenuation change was areas of linear, irregular, or wedge-shaped hypoattenuation predominantly located in the peripheral portion of the liver (63%). Diffuse hypoattenuation was seen in six patients (19%) and was frequently found in areas in which hepatic veins filled with hypoattenuated thrombosis (67%). On CT, segmental IVC obstruction (80%) was seen as an obliterated segment of the hepatic IVC. However, membranous IVC obstruction (20%) was not seen on CT. The IVC below the level of obstruction was often revealed as rounded (89%) and occasionally contained thrombus (37%) or calcification (26%).
CT shows a broad spectrum of morphologic and attenuation changes of the liver and of the hepatic vessels in benign obstruction of the hepatic IVC.
American Journal of Roentgenology 12/1999; 173(5):1235-42. · 2.78 Impact Factor
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ABSTRACT: To describe imaging findings of hepatic hemangiomas on power Doppler (PD) ultrasound (US) with revised Doppler parameters for preventing PD artefacts from stationary hyperechoic tissue, we prospectively evaluated 48 hemangiomas by PD US with predetermined PD settings to prevent artefactual signals from stationary hyperechoic tissue (pulse repetition frequency of 1000 Hz, medium wall filter, and PD gain of 60-85%). Intratumoral PD signals were not seen in 32 lesions (67%). Minimal (n = 15) or moderate (n = 1) intratumoral PD signals were seen in 16 lesions (33%) and were distributed in the peripheral portion only in 12 lesions (75%) and in the peripheral and central portion in 4 lesions (25%). Due to the lack of sensitivity of PD to detect slow flow in hemangiomas, PD US should no longer be used for the evaluation of echogenic liver masses caused by hemangiomas from other hypovascular malignant lesions of the liver.
Ultrasound in Medicine & Biology 10/1999; 25(7):1055-61. · 2.29 Impact Factor
