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Kyoung-Sik Cho

Publications and source records attributed to Kyoung-Sik Cho.

At least 19 recordsLinked to original sources
PubMed2006

Preoperative diagnosis of mature cystic teratoma with malignant transformation: analysis of imaging findings and clinical and laboratory data.

PURPOSE: To evaluate the factors including the imaging findings and clinical and laboratory data that were useful for diagnosing mature cystic teratomas with malignant transformation. MATERIALS AND METHODS: In 11 patients, we analyzed the imaging findings by the CT and MR focused on the soft tissue components for the following characteristics: size; the angle between the soft tissue components and the inner wall of the cyst (acute or obtuse); the configuration of the inner border (regular or irregular); and enhancement as well as tumor size. Clinical and laboratory data such as age, serum SCC, CA-125, CA 19-9, and AFP, were also determined. RESULTS: In the analysis of the imaging findings, nine (82%) of all tumors had soft tissue components and eight (89%) of nine soft-tissue-containing tumors showed an obtuse angle between the soft tissue components and the inner wall of the cyst as well as enhancement. In nine (82%) of the study patients it was shown that the largest diameter of the tumor was larger than 9.9 cm and the patients were older than 45 years. In the results of the laboratory data, six (67%) of performed nine patients had a CA-125 elevation greater than 35 U/ml and three (75%) of performed four patients had a CA 19-9 elevation greater than 37 U/ml. CONCLUSION: We suggest that preoperative diagnosis may be improved and available in cases of synthesized imaging findings with clinical and laboratory data.

Adult↗
PubMed2006

Renal angiomyolipoma with minimal fat: differentiation from other neoplasms at double-echo chemical shift FLASH MR imaging.

PURPOSE: To prospectively evaluate the diagnostic performance of double-echo gradient-echo (GRE) chemical shift magnetic resonance (MR) imaging in the differentiation of angiomyolipoma (AML) with minimal fat from other renal neoplasms, with pathologic examination or follow-up data serving as the reference standard. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained. Double-echo GRE chemical shift MR imaging was performed in 55 patients (29 men and 26 women; mean age, 49 years +/- 14 [standard deviation]) with 55 renal tumors, including 37 (67%) pathologically proved tumors (23 renal cell carcinomas, nine AMLs, two oncocytomas, two lymphomas, and one reninoma) and 18 (33%) clinically diagnosed tumors (17 AMLs and one indeterminate malignancy). All tumors showed no intratumoral fat and had homogeneous enhancement and a prolonged or gradual enhancement pattern on biphasic helical computed tomographic scans. Signal intensity was measured in the renal tumor and spleen on in-phase and opposed-phase images. The signal intensity index and tumor-to-spleen ratio in AMLs and non-AMLs were calculated and compared with the Student t test. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic accuracy of the signal intensity index and tumor-to-spleen ratio and to extract the optimal cut-off values in the differentiation of AMLs and non-AMLs. RESULTS: The signal intensity index and tumor-to-spleen ratio were different between AMLs (42% +/- 11 and -43% +/- 17, respectively) and non-AMLs (5% +/- 14 and -4% +/- 16, respectively) (P < .001). The area under the ROC curve was 0.975 for the signal intensity index and 0.952 for the tumor-to-spleen ratio. For differentiation of AMLs from non-AMLs, sensitivity and specificity were (a) 96% and 93%, respectively, with a signal intensity index of 25% and (b) 88% and 97%, respectively, with a tumor-to-spleen ratio of -32%. CONCLUSION: Double-echo GRE chemical shift MR imaging can be used to differentiate AML with minimal fat from other renal neoplasms.

Adult↗
PubMed2006

Contrast-enhanced sonography for prostate cancer detection in patients with indeterminate clinical findings.

OBJECTIVE: The purpose of our study was to evaluate the usefulness of contrast-enhanced sonography for prostate cancer detection in patients with an indeterminate prostate-specific antigen (PSA) level (4-10 ng/mL) and negative findings on digital rectal examination. SUBJECTS AND METHODS: Forty-eight patients underwent gray-scale, color Doppler, and contrast-enhanced sonography examinations and then sonographically guided biopsy. Contrast-enhanced sonography was performed using Levovist at a mechanical index of 1.1-1.4. The performances of the three methods for cancer detection were compared according to biopsy site and patient. RESULTS: Sensitivity by biopsy site was greater on contrast-enhanced sonography (68%) than on gray-scale (39%) and color Doppler (41%) sonography (p > or = 0.05), whereas the specificity and overall accuracy by biopsy site (82% and 77% for gray-scale sonography, 84% and 79% for color Doppler sonography, and 83% and 81% for contrast-enhanced sonography, respectively) were not different for the three methods (p > 0.05). The concordance score for sonography and biopsy results by patient was not different for gray-scale (6.4 +/- 1.8), color Doppler (6.3 +/- 0.6), and contrast-enhanced sonography (6.5 +/- 0.7) (p = 0.281). CONCLUSION: Contrast-enhanced sonography could improve only the sensitivity for cancer detection in analysis by biopsy site but did not improve the overall performance of sonography in patients with an indeterminate PSA level and negative digital rectal examination.

Aged↗
PubMed2006

MDCT Findings of renal trauma.

OBJECTIVE: The purposes of this pictorial essay are to show MDCT findings of renal trauma and describe the indications and protocol for MDCT. CONCLUSION: CT is indicated when patients have gross hematuria, hypotension, lumbar spinal injury, and fractures of lower ribs or the transverse process. The CT examination must be designed specifically for urinary tract evaluation, and MDCT is especially useful for this purpose. Injury to the kidney is graded I to V according to degree of laceration and amount of hematoma.

Adult↗
PubMed2005

Collecting duct carcinoma of the kidney: CT and pathologic correlation.

PURPOSE: We characterized CT findings of collecting duct carcinoma of the kidney and correlated these with the histopathologic findings. MATERIALS AND METHODS: CT scans of 18 patients with pathologically proven collecting duct carcinoma of the kidney were retrospectively reviewed. We analyzed CT findings of collecting duct carcinoma and also correlated CT findings with the histopathologic findings. RESULTS: The mean size of the tumors was 6.9 cm and all cases were solid. Seventeen (94%) tumors had a medullary location. Nine (69%) and 11 (85%) cases showed weak and heterogeneous enhancement, respectively. A cystic component (50%) was frequently seen within the tumors. Lymphadenopathy and metastasis were noted in 10 (56%) and 6 (33%) cases, respectively. Perinephric stranding and vascular invasion were present in 10 (56%) and 5 (28%) cases, respectively. In 17 (94%) of the 18 cases, involvement of the renal sinus was present. Infiltrative growth (67%) and preservation of the renal contour (61%) were more common than expansile growth (33%) and exophytic configuration (39%), respectively. These CT features were well correlated with the histopathologic findings. CONCLUSION: Medullary location, weak and heterogeneous enhancement, involvement of the renal sinus, infiltrative growth, preserved renal contour, and a cystic component are CT findings frequently seen in patients with collecting duct carcinoma of the kidney. CT findings are nevertheless nonspecific and do not allow collecting duct carcinoma to be easily differentiated from the other subtypes of renal cell carcinoma. However, when CT demonstrates a renal tumor with these findings, collecting duct carcinoma can be considered in the differential diagnosis.

Adult↗
PubMed2005

Wash-in rate on the basis of dynamic contrast-enhanced MRI: usefulness for prostate cancer detection and localization.

PURPOSE: To evaluate the usefulness of the wash-in rate based on dynamic contrast-enhanced (DCE) MRI for the detection and localization of prostate cancer. MATERIALS AND METHODS: In 53 patients, the wash-in rate was measured in the cancer area and in three normal areas (the peripheral zone, inner portion of the transitional zone, and outer portion of the transitional zone). On the basis of these data, parametric imaging was generated and then its accuracy for cancer detection and location was evaluated compared to that of T2-weighted imaging without the use of an endorectal coil. For that purpose the entire prostate was divided into 18 segments. RESULTS: The wash-in rate value was greater in cancer tissue (9.2/second) than in three normal tissues (3.3/second, 6.7/second, and 3.2/second, respectively; P<0.001). The sensitivity and specificity were greater on parametric imaging of the wash-in rate compared to T2-weighted imaging in the entire prostate (96% and 82% vs. 65% and 60%, respectively) and the peripheral zone (96% and 97% vs. 75% and 53%; P<0.05). In the transitional zone, the sensitivity was greater on parametric imaging (96%) than on T2-weighted imaging (45%; P=0.016), but the specificity was similar (51% vs. 73%; P=0.102). CONCLUSION: The wash-in rate based on DCE-MRI is a useful parameter for prostate cancer detection and localization.

Aged↗
PubMed2005

Comparison of virtual cystoscopy, multiplanar reformation, and source CT images with contrast material-filled bladder for detecting lesions.

OBJECTIVE: The objective of our study was to compare the diagnostic accuracy of virtual cystoscopy, multiplanar reformation, and source CT images for lesion detection in the contrast material-filled bladder. SUBJECTS AND METHODS: Two observers independently evaluated 47 patients (28 men and 19 women; mean age +/- SD, 59 +/- 16 years) with virtual cystoscopy, multiplanar reconstruction, and source CT images acquired with contrast material-filled bladder using an MDCT scanner (detector array, 4 x 1.25 mm; beam pitch, 0.75). Agreement between the two observers was evaluated for the three reconstruction methods using kappa statistics. Using the conventional cystoscopic findings as a reference, we compared the results of the three reconstruction techniques both by bladder site and by patient using the McNemar test. RESULTS: The interobserver agreement for the number of positive sites was excellent for virtual cystoscopy (kappa = 0.816), fair for multiplanar reconstruction (kappa = 0.461), and good for source CT images kappa = 0.676). For both observers, the sensitivity for lesion detection by bladder site was significantly greater with virtual cystoscopy (observer 1, 95%; observer 2, 90%) than with multiplanar reconstruction (78% and 60%) and source CT (68% and 65%) images (p < 0.05), whereas the specificity by bladder site and the sensitivity and specificity by patient did not differ with the three methods (p > 0.05). For determining the presence or absence of lesion at each site, virtual cystoscopy was more accurate than multiplanar reconstruction and source CT images for both observers (p < 0.05). CONCLUSION: Virtual cystoscopy is more accurate than multiplanar reconstruction and source CT images for the detection of lesions in the bladder.

Adult↗
PubMed2004

Renal cell carcinoma: analysis of postoperative recurrence patterns.

PURPOSE: To retrospectively analyze the recurrence patterns of renal cell carcinoma (RCC) and the factors affecting tumor recurrence. MATERIALS AND METHODS: The institutional review board approved this study; patient informed consent was not required. There were 162 men (mean age, 54 years +/- 13 [standard deviation]) and 32 women (mean age, 56 years +/- 11) who had undergone complete surgical resection of RCC. Mean follow-up period was 45 months (range, 7-92 months). In consensus, two radiologists determined the presence or absence of tumor recurrence and recorded the time and sites of tumor recurrence. The relationships between tumor recurrence and tumor factors, including greatest diameter (> or =5 cm or <5 cm), T stage, N stage, stage group, histologic subtype, and nuclear grade, were evaluated by using Kaplan-Meier statistics. RESULTS: Tumor recurred in 41 (21%) patients. The mean time of tumor recurrence was 17 months (range, 3-50 months). Tumor recurred within 2 years after surgery in 34 (83%) patients. Tumor recurrence sites included lung (n = 29), bone (n = 13), the nephrectomy site (n = 7), brain (n = 6), liver (n = 5), mediastinal lymph nodes (n = 5), the contralateral kidney (n = 4), and the neck muscles (n = 2). The recurrence rate was greater for tumors 5 cm or larger than for those smaller than 5 cm, greater for T3a or T3b tumors than for T1 tumors, greater for stage III tumors than for stage I tumors, and greater for tumors with a nuclear grade of 3 or 4 than for those with a nuclear grade of 1 or 2 (P < .05 for all). CONCLUSION: RCC usually recurs within 2 years after surgery, with the lung being the most vulnerable site; greatest tumor diameter, T stage, stage group, and nuclear grade are important factors for recurrence.

Adolescent↗
PubMed2004

Bladder cancer: analysis of multi-detector row helical CT enhancement pattern and accuracy in tumor detection and perivesical staging.

PURPOSE: To evaluate the enhancement pattern of bladder cancer and the accuracy of multi-detector row helical computed tomography (CT) in the detection and staging of bladder cancer. MATERIALS AND METHODS: In 20 patients, the attenuation value of bladder cancer was measured on dynamic contrast material-enhanced multiphasic CT images obtained with scanning delays of 40, 60, 80, and 100 seconds. In 67 patients, CT data were obtained with a 60-second scanning delay that covered the bladder (section thickness, 2.5 mm; beam pitch, 1.5) and a 180-second scanning delay that covered the abdomen (section thickness, 5 mm; beam pitch, 1.5). We prospectively evaluated CT images and compared findings at CT with findings at histologic examination. We evaluated cancer detection rate, positive predictive value of cancer detection, and sensitivity and specificity in the diagnosis of perivesical invasion. RESULTS: The attenuation value of bladder cancers was significantly higher on 60- (105 HU +/- 16) and 80-second (97 HU +/- 15) delayed CT images than on the other images (P <.05). The cancer detection rate and positive predictive value for cancer detection were 97% and 95%, respectively, in 67 patients and increased to 100% and 100%, respectively, in 44 patients with a time interval of 7 or more days between transurethral resection of the bladder (TURB) and CT examination. Sensitivity and specificity in the diagnosis of perivesical invasion were 89% and 95%, respectively, in 67 patients and increased to 92% and 98%, respectively, in 44 patients with a time interval of 7 or more days between TURB and CT examination. CONCLUSION: Bladder cancer tends to show peak enhancement with the 60-second scanning delay. Multi-detector row helical CT is useful in the detection and staging of bladder cancer.

Aged↗
PubMed2004

Angiomyolipoma with minimal fat: differentiation from renal cell carcinoma at biphasic helical CT.

PURPOSE: To compare various computed tomographic (CT) features of angiomyolipoma (AML) with minimal fat with those of size-matched renal cell carcinoma (RCC). MATERIALS AND METHODS: Eighty-one patients (19 with AML with minimal fat [mean diameter, 2.8 cm; range, 1.5-4.5 cm] and 62 with RCC [mean diameter, 3.1 cm; range, 1.8-4.5 cm]) who had undergone biphasic CT (ie, CT with unenhanced, corticomedullary, and early excretory phase scanning) were evaluated. Two reviewers who were unaware of the diagnosis retrospectively recorded tumor attenuation on unenhanced scans, enhancement characteristics (ie, homogeneity of enhancement, amount of enhancement, enhancement pattern over time), tumor margin, location of tumor center, intratumoral calcification, perinephric changes, and patient age and sex. The predictive value of each CT finding was determined by using multivariate logistic regression analysis. RESULTS: Homogeneous enhancement (observed in 79% of AMLs vs 5% of RCCs; odds ratio, 37) and prolonged enhancement pattern (observed in 58% of AMLs vs 10% of RCCs; odds ratio, 42) were valuable predictors for differentiating AML with minimal fat from RCC at multivariate analysis (P <.05 for both). When both CT findings were used as a criterion for differentiating AML from RCC, positive and negative predictive values were 91% (10 of 11 tumors) and 87% (61 of 70 tumors), respectively. Fifty-three percent of AMLs versus 13% of RCCs showed high tumor attenuation on unenhanced scans (P =.04), whereas RCCs showed greater mean enhancement than AMLs (114 HU +/- 44 [SD] vs 73 HU +/- 30 in corticomedullary phase and 66 HU +/- 24 vs 49 HU +/- 20 in early excretory phase) and a male predominance (male-to-female ratio, 50:12 vs 8:11; P =.001). CONCLUSION: Biphasic helical CT may be useful in differentiating AML with minimal fat from RCC, with homogeneous tumor enhancement and prolonged enhancement pattern being the most valuable CT findings.

Adipose Tissue↗
PubMed2004

MRI of small cell carcinoma of the uterine cervix with pathologic correlation.

OBJECTIVE: The purpose of this study was to evaluate the MRI features of small cell carcinoma of the uterine cervix and to correlate those features with pathologic findings. CONCLUSION: Small cell carcinoma of the uterine cervix can be characterized by frequent parametrial invasion and extensive lymphadenopathy, although the tumor morphology seems to be nonspecific on MRI.

Adult↗
PubMed2004

CT angiography for evaluation of living renal donors: comparison of four reconstruction methods.

OBJECTIVE: We sought to compare various reconstruction methods for CT angiographic images in evaluating living renal donors. MATERIALS AND METHODS: In 76 patients who underwent donor nephrectomy, vascular phase CT data were obtained using an MDCT scanner (detector array, 1.25 mm x 4; beam pitch, 1.5). Two radiologists independently reconstructed CT angiographic images using thick-slab volume rendering, thick-slab maximum intensity projection (MIP), sliding thin-slab volume rendering, and sliding thin-slab MIP. The radiologists counted the number of renal arteries, early branching arteries, and renal veins. We compared the accuracy rates for the detection of vessels achieved with the four types of reconstructed images, using the surgical findings as the gold standard. Agreement between the two observers and between the surgical and CT angiographic findings was evaluated. RESULTS: The sensitivity for detecting the supernumerary artery was significantly greater with sliding thin-slab volume rendering and sliding thin-slab MIP (97%) than with thick-slab volume rendering (59%) (p = 0.039). No significant difference between the other comparison pairs of reconstruction methods was found. The interobserver agreement for detecting supernumerary and early branching arteries with sliding thin-slab volume rendering and MIP was excellent (kappa = 0.820-0.859) and good for renal veins (kappa = 0.698-0.724), whereas the agreement of thick-slab volume rendering and MIP was good for arteries (kappa = 0.706-0.791) and moderate for veins (kappa = 0.443-0.579). The agreement between CT angiographic reconstructed images and surgical findings for detection of vessels was better with sliding thin-slab volume rendering and MIP (kappa = 0.793-1.000) than in thick-slab volume rendering and MIP (kappa = 0.306-0.613). CONCLUSION: For CT angiographic evaluation of living renal donors, sliding thin-slab reconstruction is superior to thick-slab reconstruction.

Adult↗
PubMed2004

CT features of serous surface papillary carcinoma of the ovary.

OBJECTIVE: The purpose of this study was to determine the CT appearance of serous surface papillary carcinoma of the ovary. MATERIALS AND METHODS: CT scans of 17 patients with histologically proven serous surface papillary carcinoma of the ovary were retrospectively reviewed. We evaluated the ovary size, omental or mesenteric involvement (none, mild, or severe), ascites (none, small, moderate, or large), and peritoneal thickening (none, smooth, or nodular). We also noted the presence of a cul-de-sac mass, lymphadenopathy, and calcification within the peritoneal mass. The preoperative serum level of cancer antigen (CA)-125 was assessed in all patients. RESULTS: The diameter of ovaries was 3 cm or smaller in 14 patients (82%). All patients had omental or mesenteric involvement by the tumor (mild, n = 2; severe, n = 15) and ascites (small, n = 1; moderate, n = 3; large, n = 13). Peritoneal thickening (smooth, n = 5; nodular, n = 10) was noted in 15 patients (88%) and a cul-de-sac mass in 10 (59%). Lymphadenopathy was noted in five patients (29%) and calcification within the peritoneal mass in one (6%). Serum CA-125 level was elevated in all patients (168-63,300 U/mL). CONCLUSION: Serous surface papillary carcinoma of the ovary should be suggested as a diagnosis in patients who have peritoneal carcinomatosis, relatively normal-sized ovaries, and a highly elevated serum CA-125 level.

Adult↗
PubMed2003

Living donor kidneys: usefulness of multi-detector row CT for comprehensive evaluation.

PURPOSE: To evaluate in living renal donors the usefulness of multi-detector row computed tomography (CT) in the assessment of renal vasculature and the upper urinary tract. MATERIALS AND METHODS: Four-channel multi-detector row CT scans were obtained in 77 patients. Vascular phase scans were used for CT angiography; excretory phase scans, for CT urography. At CT angiography, two independent observers evaluated the number of arteries and veins and the presence of early-branching arteries. CT urographic images were evaluated with regard to the opacification of the urinary tract and for abnormalities. Findings of CT angiography and urography were compared with surgical findings. Interobserver agreement between CT angiographic and surgical findings was quantified with weighted kappa statistics. Sensitivity and specificity of CT angiography in identifying supernumerary vessels and early-branching arteries were also evaluated. To evaluate the radiation dose to patients, weighted CT dose index (DI) was assessed for each scan. RESULTS: Agreement between CT angiographic and surgical findings was excellent for the number of renal arteries (kappa = 0.896) and veins (kappa = 0.843). Detection rate of CT angiography was 98% (89 of 91) for arteries and 98% (83 of 85) for veins. The respective sensitivity and specificity of CT angiography were 86% (12 of 14) and 100% (65 of 65) for supernumerary arteries, 100% (11 of 11) and 100% (66 of 66) for early-branching arteries, and 75% (six of eight) and 100% (69 of 69) for supernumerary veins. At CT urography, collecting systems and proximal ureters were well opacified in all patients; two patients had underrotated kidneys without obstruction. The weighted CT DI was 10.19 mGy for unenhanced and excretory phase scans and 12.88 mGy for the vascular phase scan. CONCLUSION: Multi-detector row CT can help assess well the renal vasculature and the urinary tract of living renal donors.

Adult↗
PubMed2003

CT and MRI findings of cystadenofibromas of the ovary.

The aim of this study was to assess imaging findings on CT or MR images of histologically proven ovarian cystadenofibromas. In the period 1995-2001, 32 histologically proven ovarian cystadenofibromas were identified in 28 women. Of the 32 ovarian cystadenofibromas, 16 tumors were purely cystic and the remaining 16 were complex cystic on CT or MR images. Solid components of 16 complex cystic tumors were seen as nodular ( n=8) or trabecular ( n=9) solid areas. One tumor had both nodular and trabecular solid components. Among 16 complex cystic tumors, 14 had thick or irregular septa; thus, half of ovarian cystadenofibromas had morphological imaging features of malignancy on CT or MR images. On histology, solid components in the cystic tumors were correlated with fibrous stromas that occasionally made a false-positive result for malignancy on imaging.

Adolescent↗
PubMed2003

The urethra and its supporting structures in women with stress urinary incontinence: MR imaging using an endovaginal coil.

OBJECTIVE: The objective of this study was to evaluate the urethra and its supporting structures in patients with stress urinary incontinence using MR imaging with an endovaginal coil. SUBJECTS AND METHODS: We reviewed MR images obtained using an endovaginal coil in 63 patients with stress urinary incontinence and in 16 continent women. We compared the two groups for the thickness of the striated muscle, smooth muscle, and mucosa-submucosa of the urethra; degree of asymmetry of the puborectalis muscle; frequency of distortion in the periurethral, paraurethral, and pubourethral ligaments; degree of the vesicourethral angle; and dimension of the retropubic space. Using the status of the urethra and its supporting structures as our basis, we scored the risk of stress urinary incontinence for each woman on a scale of 0-5. RESULTS: The striated muscle layer of the urethra was thinner in the group with stress urinary incontinence (mean +/- SD, 1.9 +/- 0.5 mm) than that in the continent group (2.6 +/- 0.4 mm) (p < 0.001). A high degree of asymmetry of puborectalis muscle (>1.5) was more frequent in the group with stress urinary incontinence (29%) than in the continent group (0%) (p = 0.015). Supporting ligaments were more frequently distorted in the incontinent group than in the continent group. Distorted periurethral ligaments were found in 56% of the patients with stress urinary incontinence versus 13% of the women who were continent; distorted paraurethral ligaments were found in 83% of the patients with stress urinary incontinence versus 19% of the women who were continent; and distorted pubourethral ligaments were found in 54% of the patients with stress urinary incontinence versus 19% of the women who were continent (p < 0.05). The group with stress urinary incontinence had a greater vesicourethral angle (148 degrees vs 125 degrees ) and larger retropubic space (7.5 vs 5.1 mm) than did the women who were continent (p < 0.05). The score for the risk of stress urinary incontinence was higher in the group with stress urinary incontinence (3.3 +/- 1.4) than in the women who were continent (1.0 +/- 1.2) (p < 0.001). CONCLUSION: MR imaging with an endovaginal coil revealed significant morphologic alterations of the urethra and supporting structures in patients with stress urinary incontinence.

Adult↗