Jongmee Lee

Gadoxetic Acid–Enhanced MRI Versus Triple-Phase MDCT for the Preoperative Detection of Hepatocellular Carcinoma

OBJECTIVE We compared the diagnostic performance of gadoxetic acid-enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC). SUBJECTS AND METHODS Sixty-two consecutively registered patients (54 men, eight women; age range, 31-67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid-enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated. RESULTS For each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05). CONCLUSION Gadoxetic acid-enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

Preoperative staging of rectal cancer: accuracy of 3-Tesla magnetic resonance imaging

The purpose of this study was to evaluate the accuracy of 3-Tesla magnetic resonance imaging (MRI) for the preoperative staging of rectal cancer. Thirty-five patients with a primary rectal cancer who underwent preoperative 3-T MRI using a phased-array coil and had a surgical resection were enrolled in the study group. Preoperatively, three experienced radiologists independently assessed the T and N staging. A confidence level scoring system was used to determine if there was any perirectal invasion, and receiver operating characteristic (ROC) curves were generated. The interobserver agreement was estimated using κ statistics. The overall accuracy rate of T staging for rectal cancer was 92%. The diagnostic accuracy was 97% for T1, 89% for T2 and 91% for T3, respectively. The predictive accuracy for perirectal invasion by the three observers was high (Az>0.92). The interobserver agreement for T staging was moderate to substantial. The overall sensitivity, specificity, and accuracy for the detection of mesorectal nodal metastases were 80%, 98%, and 95%, respectively. In conclusion, preoperative 3-T MRI using a phase-array coil accurately indicates the depth of tumor invasion for rectal cancer with a low variability.

Preoperative Staging of Rectal Cancer: Comparison of 3-T High-Field MRI and Endorectal Sonography

OBJECTIVE The aim of this study was to compare phased-array 3-T MRI and endorectal sonography in the preoperative staging of rectal cancer. MATERIALS AND METHODS During an 8-month period, 24 patients with rectal cancer underwent both 3-T MRI performed with phased-array coils and 7.5- to 10-MHz endorectal sonography in the 3 weeks before surgical resection. Three radiologists independently reviewed the MR and endorectal sonographic images. The histopathologic findings in resected specimens were used to evaluate the sensitivities and specificities of these techniques for invasion of the muscularis propria and perirectal tissue and for lymph node involvement. Receiver operating characteristic (ROC) analysis was used to compare the diagnostic accuracies of the techniques. RESULTS For muscularis propria invasion, the mean sensitivities of both MRI and endorectal sonography were 100%, and the mean specificities were 66.7% and 61.1%, respectively. The differences in the mean sensitivities and specificities were not statistically significant (p > 0.05 in each case). For perirectal tissue invasion, MRI and endorectal sonography had comparable sensitivities and specificities (91.1% vs 100%, 92.6% vs 81.5%; p > 0.05 in each case). They also had similar sensitivities and specificities for lymph node involvement (63.6% vs 57.6%, 92.3% vs 82.1%; p > 0.05 in each case). ROC curves for muscularis propria invasion and lymph node involvement showed no differences in diagnostic accuracy. The mean area under the ROC curve for endorectal sonography (A(Z) = 0.996) for perirectal tissue invasion, however, showed higher accuracy than that of MRI (A(Z) = 0.938, p = 0.028). CONCLUSION The sensitivity, specificity, and accuracy of 3-T MRI were similar to those of endorectal sonography for muscularis propria invasion and lymph node involvement, but for perirectal tissue invasion, 3-T MRI was less accurate than endorectal sonography.

Ascending retrocecal appendicitis: clinical and computed tomographic findings.

Objective: To describe the clinical presentation and computed tomographic (CT) features of ascending retrocecal appendicitis. Methods: During the past 8 years, 1670 patients with surgically proven appendicitis were identified by a retrospective investigation. Thirty-three patients who underwent contrast-enhanced abdominal CT before surgery and had ascending retrocecal appendicitis at surgery were included in the patient cohort. The clinical and CT findings of these 33 patients were analyzed. Results: Patients presented with right lower abdominal pain (49%, 16/33), right flank pain (24%, 8/33), right upper abdominal pain (18%, 6/33), and periumbilical pain (15%, 5/33). Inflamed ascending retrocecal appendices were visualized completely in 70% (23/33), partially in 21% (7 of 33), and not detected in the remaining 9% (3/33). Periappendiceal inflammatory changes were most commonly observed in the retrocolic space in 88% (29/33), followed by paracolic gutter (30%, 10/33), pararenal space (27%, 9/33), mesentery (24%, 8/33), perirenal space (18%, 6/33), and subhepatic space (3%, 1/33). Inflammatory thickening of Gerota fascia (70%, 23/33) and the lateroconal fascia (64%, 21/33) was observed as well. Perforation of the appendix with the formation of an abscess was present in 49% (16/33). The abscesses were most commonly located in the retrocolic space (88%, 14/16). Diffuse wall thickenings of the cecum (67%, 22/33) and the ascending colon (64%, 21/33) were often observed also. Appendicoliths were found in 33% (11/33). Conclusions: More than half of patients with ascending retrocecal appendicitis presented with atypical clinical presentation. At CT, ascending retrocecal appendicitis was associated with a high incidence of retroperitoneal inflammatory changes and appendiceal perforation.

Overlapping Ablation Using a Coaxial Radiofrequency Electrode and Multiple Cannulae System: Experimental Study in ex-Vivo Bovine Liver

Objective To assess the sizes and configurations of thermal zones after overlapping ablations using a coaxial radiofrequency (RF) electrode and multiple cannulae in ex-vivo bovine liver. Materials and Methods For ablation procedures, a coaxial RF electrode and introducer set was used. Employing real-time ultrasound guidance and overlapping techniques in explanted, fresh bovine liver, we created five kinds of thermal zones with one (n=10), two (n=8), four (n=3), and six ablation spheres (n=3). Following ablation, MR images were obtained and the dimensions of all thermal zones were measured on the longitudinal or transverse section of specimens. The shape of the composite ablation zones was evaluated using three-dimensional MR image reconstruction. Results At gross pathologic examination of ten single-ablation zones (spheres), the long-axis (transverse) and short-axis lengths of zones ranged from 3.7 to 4.4 (mean, 4.1) cm and from 3.5 to 4.0 (mean, 3.7) cm, respectively. The long-axis (transverse) and short-axis lengths of double-ablation zones (cylinders) with 23% overlap ranged from 7.0 to 7.7 (mean, 7.3) cm and from 3.0 to 3.9 (mean, 3.5) cm, respectively; those with 58% overlap ranged from 6.0 to 6.4 (mean, 6.2) cm and from 3.8 to 4.6 (mean, 4.3) cm, respectively. The long-axis (diagonal) and short-axis lengths on a transverse section of four-ablation zones (cakes) ranged from 8.5 to 9.7 (mean, 9.1) cm and from 3.0 to 4.1 (mean, 3.7) cm, respectively. Gross pathologic examination of three composite six-ablation zones (spheres) showed that the long-axis (diagonal) and short-axis lengths of zones ranged from 9.0 to 9.9 (mean, 9.4) cm and from 6.8 to 7.5 (mean, 7.2) cm, respectively. T2-weighted MR images depicted low-signal thermal zones containing multiple curvilinear and spotty regions of hyperintensity. Conclusion Using a coaxial RF electrode and multiple cannulae, together with ultrasound guidance and precise overlapping ablation techniques, we successfully created predictable thermal zones in ex-vivo bovine liver.

Ferucarbotran-enhanced magnetic resonance imaging versus gadoxetic acid-enhanced magnetic resonance imaging for the preoperative detection of hepatocellular carcinoma: initial experience.

We compared the diagnostic performance of ferucarbotran-enhanced magnetic resonance imaging (MRI) with that of gadoxetic acid-enhanced MRI for the preoperative detection of hepatocellular carcinoma (HCC) of 27 consecutive patients (male-female, 21:6; 33-76 years) with 38 surgically proven HCCs (mean diameter, 2.8 cm; range, 0.8-10.2 cm) on a 3.0-T unit. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC, sensitivity, positive and negative predictive values was evaluated. For each observer, the values of the area under the receiver operating characteristic curve (Az) were 1.000, 1.000, and 0.974 for ferucarbotran-enhanced MRI and 1.000, 0.987, and 1.000 for gadoxetic acid-enhanced MRI, and the differences were not statistically significant between 2 techniques for each observer (P > 0.05). For each observer, sensitivities were 100%, 100%, and 92.1% for ferucarbotran-enhanced MRI and 100%, 94.7%, and 100% for gadoxetic acid-enhanced MRI with no statistical significance (P > 0.005). The differences of the positive and negative predictive values of 2 techniques for each observer were not statistically significant (P > 0.05). Ferucarbotran-enhanced MRI and gadoxetic acid-enhanced MRI show a similar diagnostic performance for the preoperative detection of HCCs.

Ferucarbotran-Enhanced 3.0-T Magnetic Resonance Imaging Using Parallel Imaging Technique Compared With Triple-Phase Multidetector Row Computed Tomography for the Preoperative Detection of Hepatocellular Carcinoma

Objective: To compare diagnostic performance of ferucarbotran-enhanced 3.0-T magnetic resonance (MR) imaging using parallel imaging technique with that of triple-phase multidetector row computed tomography (MDCT) for the preoperative detection of hepatocellular carcinoma (HCC). Methods: Eighty-six consecutive patients with a total of 128 surgically proven HCCs were enrolled in this study. All patients underwent ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique and triple-phase MDCT before hepatic resection. Three experienced radiologists independently analyzed each images on a segment-by-segment basis. The accuracy of these techniques for the detection of HCC was assessed by performing a receiver operating characteristic (ROC) analysis of 104 resected hepatic segments with at least 1 HCC and 113 resected hepatic segments without HCC. Results: The mean value of the area under the ROC curve (Az) of the ferucarbotran-enhanced 3.0-T MR imaging (0.990) was significantly higher than that of the triple-phase MDCT (0.964) (P = 0.00). The mean sensitivity of the ferucarbotran-enhanced 3.0-T MR imaging (98.1%) was significantly higher than that of the triple-phase MDCT (92.9%) (P = 0.00). The higher sensitivity was largely attributable to a greater ability of the 3.0-T MR imaging to detect small HCC (≤1 cm) (92.6% in 3.0-T MR imaging and 37.0% in MDCT; P = 0.00). No significant difference was found for their mean specificities (98.2% in 3.0-T MR imaging and 97.6% in MDCT; P = 0.86). Conclusions: Ferucarbotran-enhanced 3.0-T MR imaging using parallel imaging technique is a more accurate diagnostic tool than triple-phase MDCT for the preoperative detection of HCC. Ferucarbotran-enhanced 3.0-T MR imaging has a higher sensitivity than triple-phase MDCT, especially for small HCCs (≤1 cm).

Depiction of Viable Tumor in Hepatocellular Carcinoma Treated with Transarterial Chemoembolization: Multiphasic Helical CT with Review of the Previous Serial CT Images

Objective The purpose of our study was to assess whether a review of multiphasic helical CT combined with the previous serial CT images could be helpful to depict a viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization. Materials and Methods Twenty-four consecutive patients with 35 hepatocellular carcinomas underwent transarterial chemoembolization followed by hepatic resection. First, three radiologists independently analyzed the last CT images taken before resection for the presence of viable tumor. A second analysis was then performed using the last CT combined with the previous serial CT images. The CT analyses were then compared with the pathologic results. The added value of the review of the previous serial CT images was evaluated by performing a receiver operating characteristic analysis. The sensitivity, specificity and diagnostic accuracy for the depiction of viable tumor were also assessed, and the characteristics of the false-negative lesions were pathologically evaluated. Results The mean diagnostic accuracies (Az values) for the depiction of viable tumor with using the last CT alone and with the review of the previous serial CT images for all observers were 0.885 and 0.901, respectively, which were not significantly difference (p > 0.05). However, the additional review of the previous serial CT images allowed the observers to render a correct diagnosis for three lesions that had been incorrectly diagnosed with the review of last CT alone. The sensitivity, specificity and diagnostic accuracy of the last CT along with the review of the previous serial CT images were 78%, 97% and 84%, respectively. All of the 16 false-negative lesions diagnosed by each observer showed 90% or greater necrosis on the pathologic examination. Conclusion For the depiction of viable tumor in hepatocellular carcinoma treated with transarterial chemoembolization, although the difference in the diagnostic accuracies was not statistically significant, a review of the multiphasic helical CT combined with the previous serial CT images could help reach a correct diagnosis for those lesions incorrectly diagnosed with the review of the last CT alone.

Follicular cholangitis mimicking hilar cholangiocarcinoma

A 61-year-old man with intermittent periumbilical pain and high liver enzyme levels underwent spiral computed tomography of the abdomen with intravenous contrast medium enhancement. Abdominal computed tomogram showed wall thickening of both intrahepatic ducts and proximal common hepatic duct with enhancement. Direct cholangiogram showed severe smooth strictures from the common hepatic duct to both intrahepatic ducts. The findings were interpreted as hilar cholangiocarcinoma. The pathologic findings after surgical resection were consistent with follicular cholangitis.

Comparison of Transvaginal Ultrasonography with Hysterosonography as a Screening Method in Patients with Abnormal Uterine Bleeding

Objective To assess the utility of hysterosonography (HS) as a screening method in patients with abnormal uterine bleeding. Materials and Methods We retrospectively reviewed transvaginal ultrasonography (TVS) and HS for 105 patients whose diagnosis was confirmed pathologically. All 105 patients were initially evaluated on the same day with both TVS and HS. On TVS and HS examination, endometrial cavitary lesions were classified as diffuse hyperplasia, endometrial polyp, endometrial cancer, uterine synechia and submucosal leiomyoma. Hysteroscopy with biopsy (n=35), curettage (n=60) or hysterectomy (n=10) was performed, and the results of TVS and HS examination were correlated with the pathological findings. Results The sensitivity and specificity were 79.0% and 45.8% for TVS, and 95.1% and 83.3% for HS, respectively. The positive and negative predictive values were 83.0% and 39.3% for TVS, and 95.1% and 83.3% for HS, respectively. Twenty-seven showed a discrepancy between the TVS and HS, and eight cases showed a discrepancy between HS and the pathologic diagnosis. Conclusion TVS is a sensitive method to evaluate the endometrial cavitary lesions, but it often does not provide the physician with sufficient diagnostic information. With its higher sensitivities, specificities and positive and negative predictive values, HS can be better used than TVS in evaluating those patients with abnormal uterine bleeding.