Biomedical subjects

Fu-Hua Yan

Publications and source records attributed to Fu-Hua Yan.

8 recordsLinked to original sources

PubMed2006

Utilizing generalized autocalibrating partial parallel acquisition (GRAPPA) to achieve high-resolution contrast-enhanced MR angiography of hepatic artery: initial experience in orthotopic liver transplantation candidates.

OBJECTIVE: To evaluate feasibility of using GRAPPA to acquire high-resolution 3D contrast-enhanced MR angiography (CE-MRA) of hepatic artery and value of GRAPPA for displaying vessels anatomy. MATERIALS AND METHODS: High-resolution CE-MRA using GRAPPA was performed in 67 orthotopic liver transplantation recipient candidates. Signal intensity (SI) and relative SI, i.e., Cv-ro (vessel-to-liver contrast) of the aorta and the hepatic common artery (HCA), were measured. The SI and the relative SI were compared and analyzed using T-test. For purpose of qualitative evaluation, the vessel visualization quality and the order of depicted hepatic artery branches were evaluated by two radiologists independently and assessed by weighted kappa analysis. The depiction of hepatic arterial anatomy and variations was evaluated, and results were correlated with the findings in surgery. RESULTS: The mean SI values were 283.29+/-65.07 (mean+/-S.D.) for aorta and 283.16+/-64.07 for HCA, respectively. The mean relative SI values were 0.698+/-0.09 for aorta and 0.696+/-0.09 for HCA, respectively. Homogeneous enhancement between aorta and HCA was confirmed by statistically insignificant differences (p-values were 0.89 for mean SI values and 0.12 for mean relative SI values, respectively). The average score for vessel visualization ranged from good to excellent for different artery segments. Overall interobserver agreement in the visualization of different artery segments was excellent (kappa value>0.80). The distal intrahepatic segmental arteries were well delineated for majority of patients with excellent interobserver agreement. Normal hepatic arterial anatomy was correctly demonstrated in 53 patients, and arterial anomalies were accurately detected on high-resolution MRA image of all 14 patients. CONCLUSION: High-resolution hepatic artery MRA acquired using GRAPPA in a reproducible manner excellently depicts and delineates small vessels and can be routinely used for evaluating OLT candidates.

Adult↗

PubMed2004

Multiphase hepatic scans with multirow-detector helical CT in detection of hypervascular hepatocellular carcinoma.

BACKGROUND: Multirow-detector helical CT (MDCT) allows faster Z-axis coverage and improves longitudinal resolution to scan the entire liver. This study was to evaluate the value of multiphase hepatic CT scans using MDCT in diagnosing hypervascular hepatocellular carcinoma (HCC). METHODS: Multiphase hepatic CT scans in 40 patients were carried out with a Marconi Mx8000 MDCT scanner. The scans of early arterial phase (EAP), late arterial phase (LAP) and portal venous phase (PVP) were started at 21, 34 and 85 seconds after injection of contrast medium, respectively. The number of detected lesions was calculated in each phase. The density of the liver and tumor was greater than 1 cm for HCC, and the density of the liver and tumor in each phase was statistically calculated. RESULTS: A total of 61 lesions were found in the 40 patients, and lesions greater than 1 cm were seen in 47 cases. The density differences between the liver and tumor were statistically significant (P<0.05) at the LAP and EAP and between the LAP, EAP and PVP. In the 61 lesions, the detectability in the EAP, LAP and the double arterial phases (DAP) was 32%, 87%, and 94%, respectively. Significant difference was found between the LAP plus PVP and the EAP plus PVP; but no significant difference was observed between the DAP plus PVP and the LAP plus PVP. CONCLUSIONS: The utility of MDCT scan in the liver has optimized the protocol of arterial phase scan. MDCT is possible to scan the entire liver in a real arterial phase and it is very valuable in the detection of small HCC.

Carcinoma, Hepatocellular↗

PubMed2003

Role of multiphase scans by multirow-detector helical CT in detecting small hepatocellular carcinoma.

AIM: To evaluate the role of multiphasic scanning by multirow-detector helical CT (MDCT) in detecting small hypervascular hepatocellular carcinoma (SHCC). METHODS: Multiphasic scanning was carried out in 75 patients with SHCC with Marconi MX8000 CT scanner. The early arterial phase (EAP), late arterial phase (LAP) and the portal venous phase (PVP) scans were started at 21 s, 34 s and 85 s respectively. The mean difference of CT values between tumor and liver parenchyma for each scanning phase was measured, and the sensitivity of detection of SHCC in each of these phases and in the combined phase was calculated and statistically analyzed. RESULTS: The mean difference of CT values between tumor and liver parenchyma was significant in 71 lesions > or =1 cm in three phases (P<0.05). In 91 tumor foci, the detectability of SHCC was 45.1%, 83.5% and 92.3% in EAP, LAP and double arterial phases (DAP), respectively. The early arterial phase plus the portal venous phase and the double arterial phase plus the portal venous phase were 94.5%, 97.8%, respectively. Whereas the detectability in LAP plus PVP and in DAP plus PVP had no statistical difference. CONCLUSION: The utility of faster speed and thinner slice MDCT and multiphase scanning protocol can improve the detectability of hypervascular small hepatocellular carcinoma. Among which LAP is superior to EAP in depicting the lesions.

Carcinoma, Hepatocellular↗

PubMed2002

Role and limitation of FMPSPGR dynamic contrast scanning in the follow-up of patients with hepatocellular carcinoma treated by TACE.

AIM: To evaluate the role and limitation of fast multiplanar spoiled gradient-recalled (FMPSPGR) MR dynamic contrast scanning in the follow-up of patients with HCC treated by transarterial chemoembolization (TACE). METHODS: Twenty-two patients with 24 HCC lesions confirmed by biopsy or surgical resection underwent MR imaging in 4-9wks after TACE with a superconducting 1.5 T MR scanner, including SE T(1)WI, T(2)WI and FMPSPGR dynamic contrast scanning. The signal intensities of all lesions on SE T(1)WI,T(2)WI and the enhancement patterns on FMPSPGR dynamic contrast scanning were observed, and the comparison was made between MRI findings and pathological results in all the cases. RESULTS: Of the 24 lesions, the signal intensities were various on SE T(1)WI and T(2)WI. On T(1)WI, 13 lesions appeared as hyperintense, 4 lesions were isointense and the other 7 lesions were hypointensese. Histologically, hyperintense lesions showed on T(1)WI were viable tumor or hemorrhage; isointensities were coagulative necrosis or inflammatory infiltration; hypointensities were tumor, liquified necrosis, coagulative necrosis or inflammatory infiltration. On T(2)WI, 15 lesions appeared as hyperintense, 3 lesions were isointense and the other 6 lesions were hypointensese. Hyperintense lesions showed on T(2)WI were residuals of viable tumor, hemorrhage, liquefied necrosis or inflammatory infiltration; isointense lesions were residuals of viable tumor or inflammatory infiltration; hypointense lesions were coagulative necrosis. On FMPSPGR dynamic contrast scanning, 18 of the 24 lesions enhanced on early-phase dynamic scanning corresponding to residuals of viable tumor and the other 6 lesions had no enhancement at this phase because complete necrosis were seen in the histologic examination. On delayed-phase dynamic scanning, 6 lesions had permanent enhancement appeared as inhomogeneous hyperintensity and both residuals of viable tumor and inflammatory infiltration were found by histologic examination. 18 lesions were hypointense at this phase and 8 of them coexisted with peripheral ring-like enhancement of the lesions resulting from viable tumors or inflammatory infiltration. CONCLUSION: FMPSPGR MR dynamic contrast scanning can reflect the pathologic changes of HCC treated by TACE. Especially, early-phase dynamic scanning can evaluate accurately residuals of viable tumor and necrosis in HCC lesions. FMPSPGR dynamic contrast scanning is useful in the follow-up of patients with HCC treated by TACE combined with SE T(1)WI and T(2)WI, but it is difficult to differentiate peripheral viable tumors from inflammatory infiltration.

Carcinoma, Hepatocellular↗

PubMed2002

Arterial phase of biphase enhancement spiral CT in diagnosis of small hepatocellular carcinoma.

OBJECTIVES: To evaluate the value of the arterial Phase (AP) of biphase enhanced spiral CT (SCT) in the diagnosis of small HCC and to investigate the criteria, initial time, ending time and duration of AP. METHODS: From May 1995 to March 1999, patients with small HCC proved surgically and pathologically including 49 patients (n=53) in group A, 148 (n=186) in group B and 52 (n=52) in group C were collected. Biphase dynamic enhanced SCT scans were performed in all patients of the three groups and additional single-level dynamic scans only done in the group C. The detectability, diagnostic accuracy of lesions and enhancement of the lesions in AP were analyzed statistically. In addition, the initial time, ending time and duration of AP were measured. RESULTS: The results of the group A showed the detectability of small HCC was 88.68% in AP and 90.57% in both Phases, higher than those by ultrasound. Markedly enhanced lesions in AP accounted for 76% and 78% in the groups B and C respectively. The initial time, ending time and duration of AP measured on single-level dynamic scans were 16.9 s, 39.6 s and 22.7 s on average respectively. CONCLUSIONS: The biphase dynamic SCT especially its arterial phase appears to be very valuable in diagnosing small HCCs. In light of short duration of AP, understanding and strict control of AP is obviously imperative.

Adult↗

PubMed2002

Enhancement patterns of small hepatocellular carcinoma shown by dynamic MRI and CT.

OBJECTIVES: To study prospectively the enhancement features of small hepatocellular carcinoma (SHCC) with multi-phase scanning of dynamic MRI and spiral CT, and discuss the superiority of dynamic MRI to spiral CT. METHODS: Multi-phase dynamic contrast scanning of high field MRI and spiral CT were performed in 53 patients with SHCC. The arterial phase, portal venous phase and delayed phase scanning of spiral CT was done after the pre-contrast scanning of the entire liver. MRI was performed with SE sequence and fast multiplanar spoiled gradient-recalled sequence dynamic multi-phase contrast scanning. RESULTS: Seventy-six lesions were found in all 53 patients. Sixty-nine and 54 of the 76 lesions enhanced obviously in MRI and spiral CT arterial phase scanning respectively. The typical enhancement patterns of SHCC in the arterial phase, portal venous phase and delayed phase scanning of MRI and spiral CT were hyper-hypo-hypointense (dense) and hyper-iso-hypointense (dense). Atypical enhancement patterns were hyper-hyper-hyperintense (dense), hyper-iso-isointense (dense) and hypo-hypo-hypointense (dense). CONCLUSIONS: Both MRI and spiral CT multi-phase dynamic contrast-enhanced scanning could demonstrate the enhancement features of SHCC, and arterial phase scan of MRI was superior to spiral CT in reflecting the hypervascular characterization of SHCC. In addition, MRI was better than spiral CT in characterization of hepatic lesions combined with SE sequence.

Adult↗

PubMed2002

MR dynamic Gadolinium-enhanced fast multiplanar spoiled gradient-echo and spin-echo T1-weighted fat-suppressed techniques in diagnosis of pancreatic carcinoma.

OBJECTIVE: To evaluate the value of MR dynamic Gadolinium-enhanced fast multiplanar spoiled gradient-echo (FMPSPGR) and spin-echo (SE) T1-weighted fat-suppressed techniques in the diagnosis of pancreatic carcinoma. METHODS: Eighteen cases of pancreatic carcinoma verified by surgical and pathologic results were examined by MR, and the MR sequences included SE T1WI, FSE T2WI, SE T1-weighted fat-suppressed and dynamic Gadolinium-enhanced FMPSPGR. RESULTS: Of 18 pancreatic carcinomas, 10, 6, and 2 tumors showed respectively hypo-intensity, iso-intensity and hyper-intensity on SE T1WI, meanwhile, 8, 6, and 4 tumors displayed hyper-intensity, iso-intensity and hypo-intensity on FSE T2WI in comparison with the normal pancreatic tissue. All of the tumors showed hypo-intensity on SE T1-weighted fat-suppressed and also obvious non-enhancement or slight enhancement on MR dynamic Gadolinium-enhanced FMPSPGR images during the arterial dominant phase scanning. CONCLUSION: SE T1-weighted fat-suppressed and MR dynamic Gadolinium-enhanced FMPSPGR sequences could evidently improve the sensitivity and specificity in the diagnosis of pancreatic carcinoma.

Adult↗

PubMed1998

Role and pitfalls of hepatic helical multi-phase CT scanning in differential diagnosis of small hemangioma and small hepatocellular carcinoma.

AIM:To compare and analyze the contrast enhancement appearance of small hemangioma (SHHE) and small hepatocellular carcinoma (SHCC) with helical multi-phase CT scanning so as to determine their roles and pitfalls in the differential diagnosis of SHHE and SHCC.METHODS:The pre and postcontrast CT scanning of the liver in 73 cases (38 SHHE, 35 SHCC) were carried out. The first phase scan of the entire liver began at 30s after the injection of contrast medium, the second and third phases began at 70s, and 4min respectively. The contrast enhancement patterns and characteristics of all lesions were observed and compared.RESULTS In SHHE, 64.29% (27/42) had typical manifestations in two-phase dynamic scanning, such as peripheral dramatic high-density enhancement of the lesions with progressive opacification from the periphery toward the center, 30.95% (13/42) were hyperdense in both phases and 4.76% (2/42) were hypodense in both phases. In the third phase scanning, 96.67% (28/30) of SHHE were hyperdense and isodense.In SHCC 59.52% (25/42) presented typical appearances, such as hyperdense in the first phase and hypodense in the second phase, 23.81% (10/42) were hyperdense in the first phase and isodense in the second phase with 4.76% (2/42) of hypodense in both phases. In the third phase scanning, 85.71% (24/28) of SHCC were hypodense.CONCLUSION:According to the contrast enhancement patterns of SHHE and SHCC in the two-phase or multi-phase scanning by helical CT, diagnosis can be established in the majority of lesions, while some atypical cases needed MRI for further investigation.

Journal Article↗