Test-bolus injection for optimization of arterial phase imaging during contrast-enhanced hepatic MR imaging

Contrast enhancement during the dynamic MR imaging is important for the detection and characterization of focal liver lesions. The purpose of this study was to determine whether or not a timing examination with a injection of a 1.0-mL bolus of gadopentetate dimeglumine into the antecubital vein followed by rapid dynamic scanning and measurement of signal intensity of the aorta could help to obtain proper arterial-dominant phase images for the characterization of focal hepatic lesions during subsequent multiphase dynamic MR imaging. The imaging delay to acquisition of the first gadolinium-enhanced image for multiphase dynamic MR imaging was set to equal the time to peak aortic enhancement during the test examination. The first contrast-enhanced images of 80 patients with 160 focal liver lesions (hepatocellular carcinoma, n = 79; cavernous hemangioma, n = 51; metastatic tumor, n = 30) were then retrospectively reviewed. Peak aortic enhancement occurred between 10 and 28 seconds (mean, 16.5 seconds +/- 3.1) after starting the infusion of contrast material in 80 patients during the test-examination. Depending on the findings of intrahepatic vascular enhancement on the full-scale dynamic images, hepatic arterial phase (n = 11, 14%) or sinusoid phase (n = 65, 81%) imaging was obtained during the first gadolinium-enhanced acquisition in 76 (95%) of 80 patients. Three different lesions were well characterized and easily distinguished from each other (p < .0001) on the first-phase images depending on their enhancement pattern. In the majority of patients, timing examination with test-bolus injection was helpful in obtaining qualified images for the characterization of various focal lesions.

A Case of Bile Leak from the Accessory Bile Duct after Laparoscopic Cholecystectomy / 대한소화기내시경학회지

Bile leak is one of the complications of both open and laparoscopic cholecystectomy. The majority of postcholecystectomy leaks occur from the cystic duct stump. Due to their location and small size, accessory ducts are vulnerable to injury during cholecystectomy. A clinical significant leak from the injured accessory bile duct is rare and has rarely been reported in Korea. Endoscopic retrograde cholangiopancreatography (ERCP) has a major role both in detecting such a leak, determining its site, and in managing it. A case was experienced involving a significant bile leak after laparoscopic cholecystectomy from the accessory bile duct in a 49 year-old man. The site of the leak was diagnosed by ERCP and the leak was successfully treated endoscopically by using biliary stenting. However, the diagnosis of the accessory bile duct was established only by a follow-up ERCP done after the healing of the bile leak. This case in herein reported with a review of the related literature.

Focal Hepatic Nodules with High Signal Intensity on T1-weighted MR Imaging: Differentiation of Small Hepatocellular Carcinoma from Dysplastic Nodule by Quantitative Analysis of Multi-phase Contrast-enhanced DynamicMR Imaging

PURPOSE: To evaluate the usefulness of quantitative analysis of the degree of enhancement in dynamic MRimaging used to differentiate dysplastic nodule (DN) from small hepatocellular carcinoma (HCC), both of which showhigh signal intensity on T1-weighted images. MATERIALS AND METHODS: From 26 small HCCs and 71 DNs, all of whichshowed homogeneous high signal intensity on T1-weighted images among 42 patients with liver cirrhosis, weselected 16 small HCCs and 10 DNs of more than 1cm in diameter which were diagnosed by biopsy and follow-up imaging. Dynamic MR imaging of the entire liver was obtained using the breath-hold technique at postinjection 10sec. (phase 1), 35 sec. (phase 2), 60 sec. (phase 3), and 5 min. (delayed) after intravenous manual injection ofGd-DTPA (0.1 mmol/kg) at a velocity of 3-4 cc/sec. Nodule-to-liver contrast-to-noise ratios (CNR) during eachphase were calculated by measurement of the region of interest. RESULTS: On precontrast T1-weighted images, themean CNR of small HCCs was 2.873, and that of DNs was 3.854, there was thus no significant statistical difference(p>0.01). On postcontrast images, the CNR of small HCCs during each phase was 5.565, 3.790, 1.704, and 1.282, withpeak CNR phase 1 and a mostly decreasing trend thereafter. However, the CNR of DNs during each phase was 3.053,1.561, 0.919, and 1.038 ; there was thus showed no significant increase during phase 1 in comparison with the CNRsseen on precontrast images. During the precontrast stage and phase 1, the average difference in CNR was 2.691 forsmall HCCs and 0.801 for DNs the difference was thus significant (p<0.01). CONCLUSION: Quantitative analysis ofCNR, reflecting the degree of nodule-to-liver enhancement in dynamic MR imaging, was found to be useful for thedifferentiation of small HCCs from DNs, both of which show high signal intensity on T1-weighted images.

Early homogeneously enhancing hemangioma versus hepatocellular carcinoma: differentiation using quantitative analysis of multiphasic dynamic magnetic resonance imaging

The aim of this study was to determine the usefulness of quantitative analysis of multiphasic dynamic contrast-enhanced magnetic resonance (MR) imaging in differentiating early homogeneously enhancing hemangiomas from hepatocellular carcinomas (HCCs). Four-phased dynamic MR imaging at 10 sec (first phase of dynamic contrast-enhanced imaging, P1), 35 sec (second phase, P2), 60 sec (third phase, P3) and 300 sec (delay phase, P4) immediately after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA was obtained with 1.5-T unit with breath-hold multisection FLASH (fast low angle-shot) sequence (TR/TE, 113-130 msec/4.1 msec; flip angle, 80 degrees). Thirty-three HCCs and 18 hemangiomas, homogeneously enhanced on P1, were included in the study. The images were evaluated quantitatively (SNR, signal-to-noise ratio; and CNR, contrast- to- noise ratio of lesions). Quantitatively, mean CNR was higher for hemangiomas than for HCCs on all phases, and the difference in CNRs between hemangioma and HCCs was statistically significant on P3 and P4 (p < 0.0001). When the cutoff for CNR was set at a value of 7.00 on P3 and 1.00 on P4, sensitivity, specificity and accuracy were 94.4%, 93.9%, and 94.1% on P3, and 94.4%, 81.8%, and 86.3% on P4, respectively. There was no statistically significant difference in SNRs between HCC and hemangioma. The differential diagnosis between early, homogeneously enhancing hemangiomas and HCCs was more confidently made with CNRs of lesions on P3 and P4 in dynamic contrast-enhanced MR imaging.

Radiologic Findings of Tubular Adenoma of the Breast

PURPOSE: Tubular adenoma (TA) is known as a rare lesion of the breast which is difficult to diagnosis preoperatively because of its rarity and similarity to fibroadenoma. Hence, our purpose is to suggest the characteristic sonographic features for its correct diagnosis. MATERIALS AND METHODS: We retrospectively analyzed the clinical data and mammographic and sonographic findings. of seven patients(mean age, 23) who during theprevious five years had presented at our hospital with pathologically-proven tubular adenomas. RESULTS: TA was misdiagnosed as fibroadenoma, since on physical examination of these young females, the lesions presented apalpable, non-tender mass. Mammographically, they showed a well defined mass similar to fibroadenoma. however, Sonographic findings were characteristic of TA and compared to fibroadenoma, showed a well demarcated and smooth bordered mass with transverse long axis, posterior enhancement and homogeneous lower internal echogenecity. Nocase showed lateral wall refractive shadowing. CONCLUSION: In young females, the clinical and mammographic findings of TA are similar to those of fibroadenoma. However, sonographic findings of TA can, be helpful in the differential diagnosis of this entity and fibroadenoma.

CT-Discography: Diagnostic Accuracy in Lumbar Disc Herniation and Significance of Induced Pain During Procedure

PURPOSE: To evaluate the usefulness and the accuracy of CT-discography in lumbar disc disease by analyzing the findings of CT-discogram and types of evoked pain during the procedure. MATERIALS AND METHODS: CT-discograms were retrospectively evaluated in 47 intervertebral discs of 20 patients with multilevel involvement of lumbardisc diseases. In 28 herniated discs confirmed at surgery, the findings of CT-discogram (28 disc levels/20 patients), MRI(23/16) and CT(21/15) were comparatively analysed. The type of pain after infusion of contrast mediaduring CT-discography was compared with that prior to the procedure. RESULTS: The accuracy for determining typesof the herniated lumbar disc when compared with postoperative results was 96.4%(27 discs/28 discs) in the CT-discogram, 82.6%(19 discs/23 discs) in MRI and 71.4%(15 discs/21 discs) in the CT scan. Pains encountered during discography were radiating pain in 12 discs and back pain in 24 discs. CT-discography was especially helpful in 10 patients with multilevel involvement of the lumbar disc diseases to evaluate the exact location of diseased disc(s) that provoked the pain. CONCLUSION: CT-discography is a highly accurate method in diagnosis ofthe herniated lumbar intervertebral discs and is very useful in determining the precise location related to the development of pain in such cases.

The Effect of Hormonal Replacement Therapy on Breast

PURPOSE: To evaluate mammographic and sonographic breast parenchymal changes and the risk of breast cancer in women on hormonal replacement therapy (HRT). MATERIAL AND METHODS: The study group consisted of 50 patients examined with serial mammograms and/or ultrasonograms during HRT. The control group consisted of 50 patients examined with serial mammogram for a routine health check. Mammographic parenchymal changes in both the study and control groups and so- nographic findings of 27/50 patients in study group were evaluated. RESULTS: Follow-up mammogram of the control group showed no interval change or slight evolution of parenchyma with increasing age, but the study group showed increasing parenchymal densities. Most frequently encountered finding on SOhogram in 11 women treated by estrogen alone, was ductal dilatation (7cases ;64%), whereas in 16 women treated by estrogen and progesteron it was ductal epithelial hyperplasia (8 cases; 50%). Overall, four breast cancers developed;one infiltrating ductal carcinoma and three ductal carcinoma in situ. CONCLUSION: HRT causes the changes of breast parenchyma on mammogram and sonogram of postmenopausal women, and increases the risk of developing breast cancer. Therefore, careful and regular examination should be followed in those on postmenopausal HRT.