Ran-Chou Chen

Blood perfusion of vertebral lesions evaluated with gadolinium-enhanced dynamic MRI: In comparison with compression fracture and metastasis

To investigate blood perfusion of vertebral lesions using dynamic Gd‐DTPA‐enhanced MRI.

Dynamic Contrast-Enhanced Folate-Receptor-Targeted MR Imaging Using a Gd-loaded PEG-Dendrimer-Folate Conjugate in a Mouse Xenograft Tumor Model

PurposeThe purpose of this study is to validate a folate-receptor (FR)-targeted dendrimer, PEG-G3-(Gd-DTPA)11-(folate)5, for its ability to detect FR-positive tumors, by using dynamic contrast-enhanced MRI.ProceduresKB cells, FR siRNA knockdown KB cells, and FR negative HT-1080 cells, were incubated with fluorescein-labeled dendrimer and their cellular uptake was observed. Dynamic contrast-enhanced MRI was performed on mice-bearing KB and HT-1080 tumors and the enhancement patterns and parameters were analyzed.ResultsGreen fluorescence was found in the KB cells in the cellular uptake experiment, but was not seen in other settings. In the dynamic contrast-enhanced MRI, the 30-min washout percentage was −4 ± 18% in the KB tumors and 39 ± 23% in the HT-1080 tumors. A 17% cut-off point gave a sensitivity of 94.4% and a specificity of 93.8%.ConclusionsWe have demonstrated the targeting ability of PEG-G3-(Gd-DTPA)11-(folate)5 in vitro and in vivo. A 17% cut-off point for a 30-min washout percentage can be a useful parameter for the diagnosis of FR-positive tumors.

Magnetic resonance imaging appearance of well-differentiated hepatocellular carcinoma

Objective: To investigate the magnetic resonance imaging (MRI) features of well-differentiated hepatocellular carcinoma (HCC). Methods: We reviewed the MRI of 32 patients with 33 pathologically confirmed well-differentiated HCC. The MRI protocol included T2-weighted imaging with and without fat saturation, dual-phase T1-weighted imaging, and gadolinium-enhanced dynamic study. The signal intensity of each lesion was categorized as hyperintense, isointense, and hypointense with reference to the surrounding liver parenchyma. Results: Thirty-one (93.9%) of 33 well-differentiated HCC were demonstrated on the MRI. The remaining 2 were isointense in all magnetic resonance sequences and, therefore, could not be identified. Most of them were hyperintense (n = 15 [45.4%]) or isointense (n = 16 [48.5%]) on T1-weighted imaging, and hyperintense (n = 12 [36.4%]) or isointense (n = 17 [51.5%]) on T2-weighted imaging. On the dynamic study, 17 lesions (51.5%) were enhanced. Conclusions: MRI may identify most well-differentiated HCC; however, the imaging appearance is diverse. Biopsy should be performed if magnetic resonance study is inconclusive.

The value of ultrasound measurement of gallbladder wall thickness in predicting laparoscopic operability prior to cholecystectomy

We prospectively analysed 51 consecutive cases who underwent laparoscopic cholecystectomy from June 1992 to February 1993. There were 35 cases of chronic cholecystitis and 16 cases of acute cholecystitis. All underwent pre-operative ultrasonography, complete blood cell count, liver function test and endoscopic retrograde cholangiopancreatography. Of those 44 had post-operative ultrasound within the first 2 d and again on the seventh day. In 35 cases of chronic cholecystitis, 31 of 32 cases with a pre-operative gallbladder (GB) wall thickness of less than 6 mm were successfully resected laparoscopically. All three cases with a GB wall thicker than 6 mm were converted to open cholecystectomy. In acute cholecystitis, the wall thickness of the laparoscopic cholecystectomy group ranged from 2 to 9 mm (average 4 mm) and the wall thickness of the conversion group was 4-7 mm (average 6 mm). Post-operative fluid accumulation was noted in 28 (63.6%) cases. There was no correlation between post-operative pyrexia, duration of post-operative pain, clinical complications and the presence of fluid accumulation in the GB fossa. However, of four cases with increasing fluid on the seventh day, three developed complications. We conclude that ultrasonography is valuable in chronic cholecystitis for selecting cases for laparoscopic cholecystectomy.

Intra-arterial carbon dioxide-enhanced ultrasonogram of hepatocellular carcinoma treated by transcatheter arterial embolization and percutaneous ethanol injection therapy

The purpose of this study was to investigate the value of carbon dioxide‐enhanced ultrasonography (CO2‐US) in the evaluation of viable hepatocellular carcinomas (HCC) which were treated by transcatheter arterial embolization (TAE), percutaneous ethanol injection (PEI), or a combination treatment (TAE and PEI). Forty‐one patients with 66 HCC were included in the study. They underwent CO2‐US and angiography were performed in all tumours after they were treated by TAE, PEI or a combination treatment. Forty‐six tumours were positively enhanced by CO2‐US and 40 of them were positive by angiography. These 46 tumours were proved to be viable tumours either by biopsy or by follow‐up studies. The positive predictive value was 100% for CO2‐US and 87.8% in angiography. Twenty tumours were negative by CO2‐US and these were also negative by angiography. Carbon dioxide‐enhanced ultrasonography is a more reliable method for detecting the viable portion of the treated HCC compared with conventional angiography.

T2-weighted and T1-weighted dynamic superparamagnetic iron oxide (ferucarbotran) enhanced MRI of hepatocellular carcinoma and hyperplastic nodules.

BACKGROUND/PURPOSE Iron oxide contrast medium (ferucarbotran) shortens both T1 and T2 relaxation time. We used the T2- and the T1-weighted dynamic ferucarbotran-enhanced magnetic resonance (MR) imaging to predict the histologic grade of hepatocellular carcinoma (HCC) and to distinguish HCC from hyperplastic nodules. METHODS Forty-three patients with 48 representative hepatic lesions (13 well differentiated HCC, 19 moderately differentiated HCC, 4 poorly differentiated HCC, 12 hyperplastic nodules) were included in the study. T1-weighted image, T2-weighted turbo spin echo, and T2*EPI (echo-planar) images were obtained before and after ferucarbotran injection. The percentage T2 signal intensity loss (T2 PSIL) of the tumors was calculated at 5 minutes and 25 minutes after contrast injection. The enhancement in dynamic T1 images was interpreted by two independent radiologists. RESULTS The T2 PSIL of well differentiated HCC was 39.5 +/- 8.23%, moderately differentiated HCC was 26.4 +/- 13.78%, poorly differentiated HCC was 4.4 +/- 9.42%, and hyperplastic nodules was 44.3 +/- 11.04%. Comparison of T2 PSIL showed significant differences in the three histologically graded HCCs (p < 0.001), but not between the well differentiated HCCs and hyperplastic nodules (p > 0.05). Delayed post-contrast (25 minutes) T2-weighted images were not necessary and shortened the examination time. In the post contrast dynamic T1 study, no significant differences between all the groups was seen. CONCLUSION Ferucarbotran MR images help in differentiating the different histologic grades of HCC but T2 PSIL could not differentiate hyperplastic nodules from well differentiated HCC. Dynamic post contrast T1-weighted images provide no additional information.

Integrin αvβ3–Targeted Dynamic Contrast–Enhanced Magnetic Resonance Imaging Using a Gadolinium-Loaded Polyethylene Gycol–Dendrimer–Cyclic RGD Conjugate to Evaluate Tumor Angiogenesis and to Assess Early Antiangiogenic Treatment Response in a Mouse Xenograft Tumor Model

The purpose of this study was to validate an integrin αvβ3–targeted magnetic resonance contrast agent, PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2, for its ability to detect tumor angiogenesis and assess early response to antiangiogenic therapy using dynamic contrast–enhanced (DCE) magnetic resonance imaging (MRI). Integrin αvβ3–positive U87 cells and control groups were incubated with fluorescein-labeled cRGD-conjugated dendrimer, and the cellular attachment of the dendrimer was observed. DCE MRI was performed on mice bearing KB xenograft tumors using either PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 or PEG-G3-(Gd-DTPA)6-(cRAD-DTPA)2. DCE MRI was also performed 2 hours after anti–integrin αvβ3 monoclonal antibody treatment and after bevacizumab treatment on days 3 and 6t. Using DCE MRI, the 30-minute contrast washout percentage was significantly lower in the cRGD-conjugate injection groups. The enhancement patterns were different between the two contrast injection groups. In the antiangiogenic therapy groups, a rapid increase in 30-minute contrast washout percentage was observed in both the LM609 and bevacizumab treatment groups, and this occurred before there was an observable decrease in tumor size. The integrin αvβ3 targeting ability of PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 in vitro and in vivo was demonstrated. The 30-minute contrast washout percentage is a useful parameter for examining tumor angiogenesis and for the early assessment of antiangiogenic treatment response.

Long-Term Survival of Taiwanese Patients with Hepatocellular Carcinoma after Combination Therapy with Transcatheter Arterial Chemoembolization and Percutaneous Ethanol Injection

BACKGROUND AND PURPOSE Several studies have shown a superior effect of combination therapy with transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) compared with either monotherapy for the treatment of advanced hepatocellular carcinoma (HCC), but there have been no reports on combination treatment from Taiwan. This study investigated the long-term survival and prognostic factors of HCC patients treated with TACE/PEI combination therapy. METHODS A total of 153 consecutive HCC patients, with tumor sizes between 2 and 3 cm in 47 patients, between 3 and 5 cm in 66 patients, and between 5 and 13 cm in 40 patients, who received TACE/PEI combination therapy were included in this retrospective study. The mean follow-up duration was 23 +/- 17 months (range, 1 to 78 months). RESULTS The 1-, 2-, 3-, 4-, 5-, and 6-year cumulative survival rates for the patients were 78%, 54%, 40%, 22%, 12%, and 5%, respectively. Multivariate analysis using Coxs proportional hazards model showed that the stage of cirrhosis (Childs class B or C vs class A) was the only factor that significantly affected the survival rate (p = 0.02) [relative risk, 2.10; 95% confidence interval, 1.12 to 3.96]. Univariate analysis showed that survival was poorer in patients with tumors greater than 5 cm than in patients with tumors 2 to 5 cm in largest dimension; this difference was not significant in the multivariate analysis. No serious complications were observed during or after treatment. CONCLUSIONS TACE combined with PEI is an alternative treatment for patients with larger HCC who are not suitable for surgical resection. A superior outcome can be expected in patients with Childs class A cirrhosis.

MR cholangiopancreatography: prospective comparison of 3-dimensional turbo spin echo and single-shot turbo spin echo with ERCP.

BACKGROUND AND PURPOSE Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive technique for examination of the biliopancreatic tract. Respiratory-triggered 3-dimensional turbo spin echo (3DTSE RT) and breath-hold thick slab single-shot turbo spin echo (ssTSE BH) are both useful MRCP techniques. The purpose of this study was to compare these 2 sequences with endoscopic retrograde cholangiopancreatography (ERCP) in patients with biliary tract disease. METHODS Forty four patients with suspected biliary obstruction were recruited to receive MRCP within 3 days before ERCP. MRCP was performed using both 3DTSE RT with maximum intensity projection images and ssTSE BH. ERCP was performed and assessed by 2 endoscopists. RESULTS MRCP was successfully performed in all patients, whereas ERCP failed in 6 patients (13.6%). MRCP was effective in detecting the presence of choledocholithiasis in 13 of 14 patients, ERCP in 12 of 12, and 2 failed ERCP. MRCP was effective in detecting benign biliary obstruction in 18 of 19 patients, and ERCP in 15 of 15, but 4 patients failed ERCP and choledocholithiasis was misdiagnosed by MRCP in 1 patient. Both MRCP and ERCP correctly diagnosed malignant bile duct obstruction in 10 of 11 patients, and both misdiagnosed that condition as benign obstruction in 1 patient. There was no significant difference between MRCP and successful ERCP in detecting lesions. MRCP was significantly better than ERCP when both successful and failed ERCP were encountered (p = 0.0498). Both 3DTSE RT and ssTSE BH produced the same results in depicting the biliary ducts and lesions in 37 patients (84.1%). Four patients (9.1%) showed better images on 3DTSE RT, whereas 3 patients (6.8%) showed better images on ssTSE BH. CONCLUSIONS 3DTSE RT and the ssTSE BH were complementary to each other in MRCP studies. Using these 2 techniques, MRCP has a high successful rate and diagnostic accuracy when compared with ERCP in detecting bile duct disease.

Detection of hepatocellular carcinoma by ferucarbotran-enhanced magnetic resonance imaging: the efficacy of accumulation phase fat-suppressed T1-weighted imaging

AIM To evaluate the effectiveness of accumulation phase, fat-suppressed, T1-weighted imaging (FS-T1WI) when detecting hepatocellular carcinoma (HCC) by ferucarbotran-enhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS Thirty patients who underwent ferucarbotran-enhanced MRI, which resulted in 35 confirmed HCCs, were included in this prospective study. Two image sets were prepared and two radiologists independently reviewed these in two reading sessions; set A was without contrast-enhanced accumulation phase FS-T1WI and set B included contrast-enhanced accumulation phase FS-T1WI. All HCCs had been confirmed by operation (n=4), by biopsy (n=28), and by follow-up study for at least 1 year (n=3). RESULTS The contrast-to-noise ratio significantly increased from -1.2+/-7.5 to 12.7+/-7.3 with contrast-enhanced accumulation phase FS-T1WI, but was only slightly increased from 12.2+/-10.3 to 15.5+/-12.2 with contrast-enhanced T2WI (p<0.001). The signal-to-noise ratio (SNR) was decreased with T1WI and T2WI for liver parenchyma. With T2WI, the SNR for HCCs was decreased; however, it was slightly increased with T1WI (p<0.001). Overall, 29 HCCs were detected using set A, and 35 nodules were identified using set B, which included the contrast-enhanced accumulation phase FS-T1WI. Thus, the detection rate significantly increased using post-contrast medium accumulation phase FS-T1WI (p<0.05). CONCLUSION Due to the improved CNR with the post-contrast medium accumulation phase FS-T1WI, which helped to increase HCC detection, accumulation phase FS-T1WI is recommended as one of the routine protocols for inclusion in HCC detection.