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ABSTRACT: To evaluate the reliability of virtual non-contrast (VNC) images reconstructed from contrast-enhanced, dual-energy scans compared with true non-contrast (TNC) images in the assessment of high CT attenuation or calcification of mediastinal lymph nodes.
A total of 112 mediastinal nodes from 45 patients who underwent non-contrast and dual-energy contrast-enhanced scans were analyzed. Node attenuation in TNC and VNC images was compared both objectively, using computed tomography (CT) attenuation, and subjectively, via visual scoring (0, attenuation ≤ the aorta; 1, > the aorta; 2, calcification). The relationship among attenuation difference between TNC and VNC images, CT attenuation in TNC images, and net contrast enhancement (NCE) was analyzed.
CT attenuation in TNC and VNC images showed moderate agreement (intraclass correlation coefficient, 0.612). The mean absolute difference was 7.8 ± 7.6 Hounsfield unit (HU) (range, 0-36 HU), and the absolute difference was equal to or less than 10 HU in 65.2% of cases (73/112). Visual scores in TNC and VNC images showed fair agreement (κ value, 0.335). Five of 16 nodes (31.3%) which showed score 1 (n = 15) or 2 (n = 1) in TNC images demonstrated score 1 in VNC images. The TNC-VNC attenuation difference showed a moderate positive correlation with CT attenuation in TNC images (partial correlation coefficient [PCC] adjusted by NCE: 0.455) and a weak negative correlation with NCE (PCC adjusted by CT attenuation in TNC: -0.245).
VNC images may be useful in the evaluation of mediastinal lymph nodes by providing additional information of high CT attenuation of nodes, although it is underestimated compared with TNC images.
Korean journal of radiology: official journal of the Korean Radiological Society 01/2013; 14(3):532-539. · 1.32 Impact Factor
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ABSTRACT: The purpose of our study was to identify extrahepatic soft tissue mimicking applicator-tract implantation after percutaneous radiofrequency ablation of hepatic malignancy on triple-phase dynamic CT.
A database was reviewed for 131 patients who underwent percutaneous radiofrequency ablation for treatment of a hepatic tumor over a 3-year period. Patients who developed extrahepatic soft tissue adjacent to the previous ablation zone mimicking applicator-tract implantation were identified. The clinical features of patients, characteristics of extrahepatic soft tissue on CT, soft-tissue changes on follow-up CT, and histopathologic results were evaluated.
Extrahepatic soft tissue developed in five patients (3.8%) at 2-8 months after percutaneous radiofrequency ablation. Extrahepatic soft tissue showed progressive enhancement during the delayed phase of dynamic CT. Four lesions were completely resolved without any treatment. However, one lesion was enlarged and xanthogranulomatous inflammation was diagnosed by percutaneous biopsy. Univariate analysis showed that an index tumor with a subcapsular location and a prior biopsy had high odds ratios.
The possibility of a benign inflammatory lesion should be considered when extrahepatic soft tissue showing radiologic findings similar to applicator-tract implantation develops after radiofrequency ablation of a hepatic tumor.
American Journal of Roentgenology 08/2012; 199(2):453-7. · 2.78 Impact Factor
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ABSTRACT: To evaluate the diagnostic efficacy of ultrasonographically (US) guided percutaneous core biopsy of reticular infiltrations alone without mass in the mesentery and omentum at contrast material-enhanced abdominal computed tomography (CT).
This study was approved by the institutional review board, and the need for obtaining signed informed consent was waived for this retrospective analysis. From March 2004 to May 2009, 45 patients (mean age, 52.3 years; age range, 21-89 years) with reticular infiltrations alone without mass in the mesentery and omentum at contrast-enhanced abdominal CT underwent US-guided percutaneous core biopsy. Twenty-one men and 24 women were included. The area with the severest infiltrations at CT was targeted during real-time US-guided percutaneous biopsy. Biopsy results were compared with the final results of surgery or follow-up. The diagnostic accuracy of US-guided percutaneous biopsy was then calculated.
One patient had an insufficient biopsy specimen. Among the 44 patients with sufficient biopsy specimens, 17 patients had malignancy, 12 had tuberculosis, and 15 had nonspecific inflammation. All 29 patients with malignancy and tuberculosis at biopsy had that confirmed with surgery or follow-up results. Two of 15 patients with nonspecific inflammation at percutaneous biopsy were confirmed as having malignancy at surgery and four as having tuberculosis after improvement with empirical antituberculosis therapy. The diagnostic accuracy of US-guided percutaneous biopsy of reticular infiltrations in the mesentery and omentum was 84%; the sensitivity and specificity was, respectively, 89% and 100% for malignancy, 75% and 100% for tuberculosis, and 90% and 83% for nonspecific inflammation.
US-guided percutaneous core biopsy is a feasible diagnostic method with high specificity for confirmative diagnosis of reticular infiltrations alone in the mesentery and omentum at contrast-enhanced CT.
Radiology 08/2011; 261(1):311-7. · 5.73 Impact Factor
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ABSTRACT: To evaluate the accuracy of a computer-aided evaluation program (CAE) of breast MRI for the assessment of residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy.
Fifty-seven patients with breast cancers who underwent neoadjuvant chemotherapy before surgery and dynamic contrast enhanced MRI before and after chemotherapy were included as part of this study. For the assessment of residual tumor extent after completion of chemotherapy, the mean tumor diameters measured by radiologists and CAE were compared to those on histopathology using a paired student t-test. Moreover, the agreement between unidimensional (1D) measurement by radiologist and histopathological size or 1D measurement by CAE and histopathological size was assessed using the Bland-Altman method. For chemotherapy monitoring, we evaluated tumor response through the change in the 1D diameter by a radiologist and CAE and three-dimensional (3D) volumetric change by CAE based on Response Evaluation Criteria in Solid Tumors (RECIST). Agreement between the 1D response by the radiologist versus the 1D response by CAE as well as by the 3D response by CAE were evaluated using weighted kappa (k) statistics.
For the assessment of residual tumor extent after chemotherapy, the mean tumor diameter measured by radiologists (2.0 ± 1.7 cm) was significantly smaller than the mean histological diameter (2.6 ± 2.3 cm) (p = 0.01), whereas, no significant difference was found between the CAE measurements (mean = 2.2 ± 2.0 cm) and histological diameter (p = 0.19). The mean difference between the 1D measurement by the radiologist and histopathology was 0.6 cm (95% confidence interval: -3.0, 4.3), whereas the difference between CAE and histopathology was 0.4 cm (95% confidence interval: -3.9, 4.7). For the monitoring of response to chemotherapy, the 1D measurement by the radiologist and CAE showed a fair agreement (k = 0.358), while the 1D measurement by the radiologist and 3D measurement by CAE showed poor agreement (k = 0.106).
CAE for breast MRI is sufficiently accurate for the assessment of residual tumor extent in breast cancer patients receiving neoadjuvant chemotherapy. However, for the assessment of response to chemotherapy, the assessment by the radiologist and CAE showed a fair to poor agreement.
Korean journal of radiology: official journal of the Korean Radiological Society 01/2011; 12(1):34-43. · 1.32 Impact Factor
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ABSTRACT: The objective of our study was to evaluate the usefulness of superparamagnetic iron oxide (SPIO)-enhanced MRI in experimental models of infectious disease and to analyze the intracellular uptake of SPIO.
Nine rats with infectious arthritis of the knee or soft-tissue infection were imaged on an MRI unit on days 4-6 after i.v. injection of a bacterial suspension. All animals were imaged on a T2-weighted fast spin-echo sequence before and 24 hours after administration of SPIO. The nine rats were classified into two groups according to the dose of SPIO. We calculated the relative signal-to-noise ratio (SNR) change and compared the relative SNR change with the histologic findings. We analyzed iron-loaded cells and the intracellular uptake of iron particles according to the dose of SPIO.
The SNR value decreased in proportion to the increase in the number of iron-laden macrophages or fibroblasts in the wall of the soft-tissue abscess (p < 0.01). The intracellular uptake of iron particles was shown in fibroblasts as well as in macrophages, and their uptake in the fibroblasts was greater than that in the macrophages (p < 0.05). There was no statistically significant difference in the intracellular uptake of iron particles according to the dose of SPIO (p > 0.1).
SPIO-enhanced MRI can be useful in evaluating infectious disease of the joint or soft tissue and is influenced by the uptake of iron particles in fibroblasts as well as macrophages.
American Journal of Roentgenology 10/2007; 189(3):542-8. · 2.78 Impact Factor
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American Journal of Roentgenology 11/2003; 181(4):1055-7. · 2.78 Impact Factor
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ABSTRACT: This study analyzed the color and power Doppler signals in solid breast masses and assessed their value in differentiating malignant from benign lesions.
One hundred twenty-nine biopsy-proven solid breast masses (54 malignant and 75 benign) were evaluated with color and/or power Doppler sonography using a 7-MHz linear-array transducer. We retrospectively analyzed the location, shape, and penetration of the Doppler vascular signals in the breast masses. The location of the vascular signals was categorized as central, peripheral, or both. The shape of the signals was categorized as linear, irregular, branching, or a single dot. A penetrating vessel was defined as a continuous vascular signal extending from outside the lesion to inside it. In 43 cases, power and color Doppler sonograms were compared.
Doppler features suggestive of malignant lesions were the presence of both peripheral and central vascularity (odds ratio, 6.0), presence of penetrating vessels (odds ratio, 5.4), and presence of branching vessels (odds ratio, 13.7). Power Doppler sonography was more sensitive than color Doppler sonography in detecting vascular signals in 49% of cases.
Color (power) Doppler imaging is a valuable adjunct to conventional sonography in differentiating between malignant and benign breast lesions.
Journal of Clinical Ultrasound 11/2002; 30(8):459-64. · 0.81 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the role of preoperative sonography in predicting technical difficulties during laparoscopic cholecystectomy in patients with acute cholecystitis.
Sonographic assessment of 14 parameters was performed in 55 patients during a 9-month period: volume of gallbladder (GB), thickness of GB wall, pattern of GB wall thickening, size of largest gallstone, gallstone mobility, adhesion of GB to its bed, fat plane between GB and hepatoduodenal ligament, free fluid in GB fossa, common bile duct (CBD) dilatation, CBD stone(s), color and power Doppler signals in GB wall, and increased color and power Doppler signals in adjacent liver. Each of the 5 operative steps of laparoscopic cholecystectomy was scored as being difficult (1) or not (0). The scores for each step were added to obtain the overall difficulty score (0-5). We evaluated prospectively whether there were significant associations among the preoperative sonographic findings and the overall difficulty score, scores for each of the 5 operative steps, and operation time.
The overall difficulty score was significantly associated with a GB volume of 50 cm(3) or more, GB wall thickness of 3 mm or more, and presence of color Doppler signals in the GB wall. Increased GB volume also made dissection of adhesions from the GB and dissection of Calot's triangle more difficult. Extraction of the GB from the abdomen was more difficult with a thickened GB wall or adhesion of the GB to its bed. The presence of a CBD stone, dilatation of the CBD (> or = 8 mm), color Doppler signals in the GB wall, and increased power Doppler signals in the adjacent liver were significantly associated with increased operation time.
Based on our experience, preoperative determination of GB volume, GB wall thickness, and presence of color Doppler signals in the GB wall in patients with acute cholecystitis helps predict technical difficulties during laparoscopic cholecystectomy.
Journal of Clinical Ultrasound 32(3):115-22. · 0.81 Impact Factor
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ABSTRACT: Purpose: To determine the frequency with which ultrasonography (US) provides a correct diagnosis and suggests appropriate guidance for the treatment of patients with right lower quadrant abdominal pain. Materials and Methods: During an 11-month period, US was consecutively performed in 84 patients who were presented with right lower quadrant abdominal pain. In the 76 [M ; F=16 ; 60, age range 14-87 (mean, 41) years] who formed the study popula-tion, final diagnoses were made surgically or clinically. For US, a 5-7-MHz convex-ar-ray, 4-MHz vector-array, and/or 7-MHz linear-array transducer was used, according to the patient¡¯s body habitus. To determine how often our US reports had provided a cor-rect diagnosis and suggested appropriate guidance for surgical or medical treatment, and to calculate their diagnostic value, the reports were retrospectively compared with final diagnoses. Results: US diagnoses were acute appendicitis in 40 patients (53%), diseases other than this in 25 patients (33%), and no abnormality in 11 (14%). In 38 of the 40 patients (95%), the diagnosis of acute appendicitis was surgically confirmed as correct, and for other diseases, diagnoses based on the findings of US proved to be correct in 21 of 25 patients (84%). Overall, diagnosis was correct in 67 (88%). As regards appropriate guidance for treatment, 46 (61%) and 30 (39%) patients were diagnosed by US to have surgical and medical diseases, respectively. In 44 of the 46 (96%), it was confirmed guidance was appropriate, and for the 30 with medical disease, this was so in all but one case (97%). Overall, the treatment plan was appropriate in 72 patients (95%). Conclusion: Our study revealed that US was able to provide a correct diagnosis in 88% of patients with right lower quadrant abdominal pain, and in 95% of these, the treatment plan suggested was appropriate. US is, therefore, a valuable screening tool in the diagnosis and therapeutic guidance of such patients.
