磁共振扩散成像技术及其在肝癌的临床应用分析

目的:分析研究磁共振扩散成像技术在肝癌的临床应用中的临床效果,为诊断治疗肝癌提供临床参考依据。方法:选择20例肝癌患者,分为试验组与对照组,每组10例。针对试验组患者采用本院的西门子avanto 1.5T机器、西门子sensation16螺旋CT进行磁共振扩散成像技术检查治疗,针对对照组的患者采用正常的检查诊断方式。对比两组的诊断结果和临床效果。结果:经过两组的诊断结果对比分析,发现试验组的医学影像诊断优于对照组,两者差异有统计学意义(P<0.05)。结论:呼吸系统或者消化系统的CT或磁共振诊断具有临床推广价值,在临床中具有医学意义。

Perivascular epithelioid cell tumor of the liver:A report of two cases and review of the literature

Perivascular epithelioid cell tumor (PEComa) is a rare tumor which arises from mesenchymal tissues. It is predominant in the uterus,but very rare in the liver. To the best of our knowledge,less than 5 cases of PEComa of the liver have been reported. Herein we present two pathologically proven cases of PEComa of the liver,retrospectively analyze their clinical and imaging features,and review the literature.

IN VIVO ~1 H MAGNETIC RESONANCE SPECTROSCOPY IN EVALUATION OF HEPATOCELLULAR CARCINOMA AND ITS EARLY RESPONSE TO TRANSCATHETER ARTERIAL CHEMOEMBOLIZATION

Objective To investigate the value of in vivo proton magnetic resonance spectroscopy （MRS） in the assessment of hepatocelhilar carcinoma （HCC） and monitor its metabolic change shortly after transcatheter arterial chemoembolization （TACE）. Mothoda In this prospective study, 28 consecutive patients with large HCC （ ≥3 cm in diameter） confirmed by fine needle aspiration biopsy were recruited. The ^1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. The technical success rate of IH MRS in liver was high （33/41, 80% ）, closely related to breath motion, location of lesion, and size of voxeL In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended （ choline-to-lipid ratios from 0.352±0. 080 to 0. 167±0. 030, P = 0. 026; from 0. 205±0. 060 to 0. 070±0. 020, P = 0. 042, respectively ） ; yet lipid resonance peak ascended. Conclusions In vivo tH MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. IH MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.

Characteristics and pathological mechanism on magnetic resonance diffusion-weighted imaging after chemoembolization in rabbit liver VX-2 tumor model

AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software. RESULTS: Under b-value of 100 s/mm2, ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value. CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.

MRI versus 64-row MDCT for diagnosis of hepatocellular carcinoma

AIM： To compare the diagnostic capability of multidetector computed tomography （MDCT） and magnetic resonance imaging （MRI） for the detection of hepatocellular carcinoma （HCC） tumour nodules and their effect on patient management. METHODS： A total of 28 patients （25 male, 3 female, mean age 67 ± 10.8 years） with biopsy-proven HCC were investigated with 64-row MDCT （slice 3 mm native, arterial and portal-venous phase, 120 mL Iomeprol, 4 mL/s, delay by bolus trigger） and MRI （Tlfs fl2d TE/ TR 2.72/129 ms, T2tse TE/TR 102/4000 ms, 5-phase dynamic contrast-enhanced Tlfs fl3d TE/TR 1.56/4.6, Gadolinium-DTPA, slice 4 mm）. Consensus reading of both modalities was used as reference. Tumour nodules were analyzed with respect to number, size, and location. RESULTS： In total, 162 tumour nodules were detected by consensus reading. MRI detected significantly more tumour nodules （159 vs 123, P 〈 0.001） compared to MDCT, with the best sensitivity for early arterial phase MRI. False-negative CT findings included nodules ≤ 5 mm （n = 5）, ≤ 10 mm （n = 17）, ≤ 15 mm （n= 12）,≤20mm（n=4）,andlnodule〉20mm.MRI missed 2 nodules ≤ 10 mm and 1 nodule ≤ 15 mm. On MRI, nodule diameters were greater than on CT （29.2 ≤25.1 mm, range 5-140 mm vs 24.1 ± 22.7 mm, range 4-129 mm, P 〈 0.005）. In 2 patients, MDCT showed only unilobar tumour spread, whereas MRI revealed additional nodules in the contralateral lobe. Detection of these nodules could have changed the therapeutic strategy. CONCLUSION： Contrast-enhanced MRI is superior to 64-row MDCT for the detection of HCC nodules. Patients should be allocated to interventional or operative treatment according to a dedicated MRI-protocol.

Hepatocellular carcinoma in Budd-Chiari syndrome:A single center experience with long-term follow-up in South Korea

AIM:To evaluate long-term clinical course of BuddChiari syndrome(BCS) and predictive factors associated with the development of hepatocellular carcinoma(HCC) and survival.METHODS:We analyzed 67 patients with BCS between June 1988 and May 2008.The diagnosis of BCS was confirmed by hepatic venous outflow obstruction shown on abdominal ultrasound sonography,computed tomography,magnetic resonance imaging,or venography.The median follow-up period was 103 ± 156 [interquartile range(IQR)] mo.RESULTS:The median age of the patients was 47 ± 16(IQR) years.At diagnosis,54 patients had cirrhosis,25(37.3%) Child-Pugh class A,23(34.3%) Child-Pugh class B,and six(9.0%) patients Child-Pugh class C.During the follow-up period,HCC was developed in 17 patients,and the annual incidence of HCC in patients with BCS was 2.8%.Patients in HCC group(n = 17) had higher hepatic venous pressure gradient(HVPG) than those in non-HCC group(n = 50)(21 ± 12 mmHg vs 14 ± 7 mmHg,P = 0.019).The survival rate of BCS patients was 86.2% for 5 years,73.8% for 10 years,and 61.2% for 15 years.In patients with BCS and HCC,survival was 79% for 5 years,43.1% for 10 years,and 21.5% for 15 years.CONCLUSION:The incidence of HCC in patients with BCS was similar to that in patients with other etiologic cirrhosis in South Korea.The HVPG is expected to provide additional information for predicting HCC development in BCS patients.

Value of MR perfusion imaging after intervention treatment of hepatic cancer

Objective： To investigate the value of MR perfusion imaging in evaluating the curative effect of intervention treatment of hepatic cancer. Methods： 36 patients underwent MR perfusion imaging after intervention treatment. The quantization results were differed between carcinoma residue and benign tissue. And the diagnosis accuracy was judged, Results： There was a significant difference in mean MSI between residue tumor after surgery and the benign enhancement area. The timeintension curve of residue tumor was observed to ascend rapidly to reach the peak, whereas that of the enhancement tissue ascended slowly to reach the peak. The sensitivity and specificity of PWl on detection of residuary or recurrent tumor were 0.89 and 0.73 respectively. Conclusion： PWl is a very sensitive imaging technique that can be used to distinguish liver tissue condition after surgery. PWI contributed to early stage diagnosis and dynamic monitoring following HCC surgery.

Complete response to radiation therapy of orbital metastasis from hepatocellular carcinoma

The incidence of hepatocellular carcinoma(HCC)is increasing in the United States,and 50%-75%o patients with HCC will develop metastatic disease Orbital metastases from HCC are extremely rare.We report the case of a 52-year-old male with known metastatic HCC,who presented with severe proptosis and diplopia.An orbital mass was identified on magnetic resonance imaging(MRI)and confirmed to have hypermetabolic activity on positron emission tomography/computed tomography.He received a palliative course of external beam radiation therapy to the right orbit.Intensity modulated radiation therapy (IMRT)was used to allow sparing of critical norma tissues in close proximity to the tumor.One month after completion of IMRT to 58 Gray in 30 fractions delivered over 6 wk,the patient had a complete clinical,radiologic(MRI)and symptomatic response The patient continues to have local control in the orbi 1.7 years after therapy completion.All critical norma structures were kept below the tolerance dose using IMRT,and no toxicities were observed.

MR-arterioportography: A new technical approach for detection of liver lesions

AIM: To evaluate the benefit and effectiveness of MRarterioportography (MR-AP) to achieve the highest sensitivity for detection and evaluation of hepatocellular carcinoma (HCC). METHODS: Twenty liver cirrhosis patients with suspected HCC were included before transarterial chemoembolization. In all patients double-enhanced Magnetic resonance imaging (MRI) was performed. A bolus of 10 mL Magnevist was injected through a selectively placed catheter in the superior mesenteric artery and MRI of the liver was performed in arterioportographic phase. Two independent readers evaluated number, size and localization of detected lesions. Diagnostic quality was determined using a 4-point scale. Differences were analyzed for significance using a t -test. Interobserver variability was calculated. RESULTS: In all 20 patients (100%), MR-AP was feasible. Diagnostic quality was, in all cases, between 1 and2 for both modalities and readers. MR-AP detected significantly more lesions than double-enhanced MRI (102.5 vs 61, respectively, P < 0.0024). The inter-observer variability was 0.881 for MRI and 0.903 for MR-AP. CONCLUSION: Our study confirmed that the MR-AP as an additional modality for detection of HCC is beneficial, as significantly more lesions were detected compared to MRI with liver-specific contrast.