时间-空间标记反转脉冲非增强肝门静脉TRANCE与bFFE成像对比研究

目的:应用Time-SLIP技术结合3D TRANCE和3D Balanced FFE进行非增强肝门静脉成像,评估两种方法在肝门静脉成像中的各自优势。方法:22名健康志愿者进行Time-SLIP 3D TRANCE和Time-SLIP 3D Balanced FFE肝门静脉血管成像,测量血管信噪比(SNR)、对比噪声比(CNR),并对图像质量进行主观评分。结果:Time SLIP 3D TRANCE和Time SLIP 3D Balanced FFE图像测量的脾静脉、肠系膜.上静脉、门静脉主于、肝内两个主要分支的信噪比(SNR)和对比噪声比(CNR)统计学上均有显著性差异(P<0.01)。Time-SLIP 3D TRANCE图像中肝内门静脉右主干显示4级分支计数优于Time-SLIP 3D Balanced FFE(P<0.05)。两种成像方法图像质量评分有统计学显薯差异(P<0.05)。结论:时间-空间标记反转脉冲3D TRANCE和3D Balanced FFE两种成像方法均可用于肝门静脉成像,3D TRANCE获得的图像质量优于3D Balanced FFE.

Contrast-enhanced endoscopic ultrasonography

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest,to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures.We review the mechanisms of action of first,second and third generation contrast agents and their use in various endoscopic procedures in the gastrointestinal tract.Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy,assessment of depth of invasion of esophageal,gastric and gall bladder cancers and visualization of the portal venous system and esophageal varices.In addition,contrast agents can be used to differentiate pancreatic lesions.The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies.The sensitivity of power Doppler sonography to depict tumor neovascularization can be increased by contrast agents.Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion.In the future,these techniques could potentially be used to quantify tumor perfusion,to assess and monitor the efficacy of antiangiogenic agents,to assist targeted drug delivery and allow molecular imaging.

Application of T2~*-weighted first-pass perfusion imaging in the diagnosis of breast tumors

Objective:To study the diagnostic value of T2*-weighted first-pass perfusion imaging in breast tumors.Methods: We analyzed the magnetic resonance imaging(MRI)information along with the pathological and immunohistochemistry re- sults.Magnetic resonance imaging was performed in 28 patients with breast tumor.The time to signal intensity curves were generated according to the T2*-weighted first-pass perfusion imaging.The curve’s maximal signal intensity drop rate and maximal signal intensity decrease time were analyzed and compared with the pathological diagnoses after surgery.Results: Malignant breast lesions showed higher maximal signal intensity drop rate(44.69%±17.07 vs.17.22%±7.49,P<0.001) than benign lesions,but there was no significant difference of maximal signal decrease time between those two lesions(23.94 s±4.92 vs.20.02 s±6.83,P>0.05).Conclusion:The T2*-weighted first-pass perfusion imaging has enough sensitivity and specificity in breast tumor diagnosis.

Diffusion tensor imaging of the brain in patients with Alzheimer's disease and cerebrovascular lesions

Background:Recent autopsy study showed a high incidence of cerebrovascular lesions in Alzheimer's disease(AD).To assess the impact of cerebrovascular pathology in AD,we used diffusion tensor imaging(DTI) to study AD patients with and without cerebrovascular lesions.Materials and Methods:Conventional and DTI scans were obtained from 10 patients with probable AD,10 AD/V patients(probable AD with cerebrovascular lesions) and ten normal controls.Mean diffusivity(D) and fractional anisotropy(FA) values of some structures involved with AD pathology were measured.Results:D value was higher in AD patients than in controls in hippocampus and the cingulate gyrus.In AD/V patients,increased D value was found in the same structures and also in the thalamus and basal ganglia compared to controls.There was a significant difference of D value between AD and AD/V patients.FA value reduced in the white matter of left inferior temporal gyrus and in the bilateral middle cingulate gyrus in patients with AD/V compared with controls.The MMSE(mini-mental state examination) score significantly correlated with FA value in the right hippocampus(r=0.639,P<0.019),in the right anterior cingulate gyrus(r=0.587,P<0.035) and in left parahippocampal gyrus(r=0.559,P<0.047).Conclusion:Cerebrovascular pathology had stronger impact on the D value than the AD pathology alone did.Elevated D value in thalamic and basal ganglia may contribute to cognitive decline in AD/V patients.Reduced FA values in AD/V patients may indicate that cerebrovascular pathology induced more severe white matter damage than the AD pathology alone did.

Contrast-enhanced ultrasonographic imaging diagnosis on assessment of vascularity in liver metastatic lesions

AIM: To investigate the vasculature of rabbit liver metastatic lesions by color Doppler imaging and power Doppler imaging (PDI) techniques.METHODS: Eight New Zealand rabbits with implanted VX2 liver tumors were used. All ultrasound examinations were performed with a HP 5500 color Doppler ultrasound scanner. Before and after the injection of contrast agent, the changes of gray scale and the periphery and intralesional blood flow of the liver metastatic lesion were carefully observed by B mode ultrasound, color Doppler flow imaging (CDFI)and PDI.RESULTS: Twelve lesions were found in the eight rabbits with implanted VX2 liver tumors, whose diameter rangedfrom 1.6 to 4.8 cm. Echoes of these lesions were not characterized and has lack of specificity. After the injectionof contrast agent, the numbers of dot or strip-like flow messages increased both at the periphery and inside of these lesions under the mode of CDFI and PDI, and were more pronounced under PDI. Morphology of intralesional vessels extended, even branched and some signals were clearly found encircling the lesion. And some vessels were found penetrating into the center of the lesion.CONCLUSION: PDI after injection of self-made echo contrast agent can show a pronounced sensitivity than that of B mode ultrasound and CDFI in diagnosis of vascularity of a metastatic lesion.

Gd-EOB-DTPA-enhanced magnetic resonance imaging features of hepatic hemangioma compared with enhanced computed tomography

AIM:To clarify features of hepatic hemangiomas on gadolinium-ethoxybenzyl-diethylenetriaminpentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared with enhanced computed tomography (CT). METHODS:Twenty-six patients with 61 hepatic hem- angiomas who underwent both Gd-EOB-DTPA-enhanced MRI and enhanced CT were retrospectively reviewed. Hemangioma appearances (presence of peripheral nodular enhancement, central nodular enhancement, diffuse homogenous enhancement, and arterioportal shunt during the arterial phase, fill-in enhancement during the portal venous phase, and prolonged enhancement during the equilibrium phase) on Gd-EOB-DTPA-enhanced MRI and enhanced CT were evaluated.The degree of contrast enhancement at the enhancing portion within the hemangioma was visually assessed using a five-point scale during each phase. For quantitative analysis, the tumor-muscle signal intensity ratio (SIR), the liver-muscle SIR, and the attenuation value of the tumor and liver parenchyma were calculated. The McNemar test and the Wilcoxon's signed rank test were used to assess the significance of differences in the appearances of hemangiomas and in the visual grade of tumor contrast enhancement between Gd-EOB-DTPA-enhanced MRI and enhanced CT. RESULTS:There was no significant difference between Gd-EOB-DTPA-enhanced MRI and enhanced CT in the presence of peripheral nodular enhancement (85% vs 82%), central nodular enhancement (3% vs 3%), diffuse enhancement (11% vs 16%), or arterioportal shunt (23% vs 34%) during arterial phase, or fill-in enhancement (79% vs 80%) during portal venous phase. Prolonged enhancement during equilibrium phase was observed less frequently on Gd-EOB-DTPA-enhanced MRI than on enhanced CT (52% vs 100%, P < 0.001). On visual inspection, there was significantly less contrast enhancement of the enhancing portion on Gd-EOB-DTPA-enhanced MRI than on enhanced CT during the arterial (3.94 ± 0.98 vs 4.57 ± 0.64, respectively, P < 0.001), portal venous (3.72 ± 0.82 vs 4.36 ± 0.53, respectively, P < 0.001), and equilibrium phases (2.01 ± 0.95 vs 4.04 ± 0.51, respectively, P < 0.001). In the quantitative analysis, the tumor-muscle SIR and the liver-muscle SIR observed with Gd-EOB-DTPA-enhanced MRI were 0.80 ± 0.24 and 1.28 ± 0.33 precontrast, 1.92 ± 0.58 and 1.57 ± 0.55 during the arterial phase, 1.87 ± 0.44 and 1.73 ± 0.39 during the portal venous phase, 1.63 ± 0.41 and 1.78 ± 0.39 during the equilibrium phase, and 1.10 ± 0.43 and 1.92 ± 0.50 during the hepatobiliary phase, respectively. The attenuation values in the tumor and liver parenchyma observed with enhanced CT were 40.60 ± 8.78 and 53.78 ± 7.37 precontrast, 172.66 ± 73.89 and 92.76 ± 17.92 during the arterial phase, 152.76 ± 35.73 and 120.12 ± 18.02 during the portal venous phase, and 108.74 ± 18.70 and 89.04 ± 7.25 during the equilibrium phase, respectively. Hemangiomas demonstrated peak enhancement during the arterial phase, and both the SIR with Gd-EOB-DTPA-enhanced MRI and the attenuation value with enhanced CT decreased with time. The SIR of hemangiomas was lower than that of liver parenchyma during the equilibrium and hepatobiliary phases on Gd-EOB-DTPA-enhanced MRI. However, the attenuation of hemangiomas after contrast injection was higher than that of liver parenchyma during all phases of enhanced CT. CONCLUSION:Prolonged enhancement during the equilibrium phase was observed less frequently on Gd-EOB-DTPA-enhanced MRI than enhanced CT, which may exacerbate differentiating between hemangiomas and malignant tumors.

Role of SPECT/CT in diagnosis of hepatic hemangiomas

AIM: To investigate the role of SPECT/CT in the diagnosis of hepatic hemangiomas whose anatomical positions are not ideal, situated adjacent to the heart, the inferior cava,hepatic vessels or abdominal aorta, etc.METHODS: The hepatic perfusion, blood pool, and fusion imaging were carried out using SPECT/CT in 54 patients,who were suspected for hepatic hemangiomas. When the anatomical positions were not ideal, the diagnosis was difficult by SPECT only. So the information of computed tomography (CT) was applied to help in diagnosing. The results were recorded as hemangiomas or not.RESULTS: Of the 54 patients, 31 patients were diagnosed as suffering from hepatic hemangiomas. The anatomical positions of eight patients' hepatic hemangiomas (25.81%)were not ideal. Among these lesions of the eight patients,three patients' hepatic lesions were located near to the abdominal aorta, one to the heart, and four to the inferior cava. In addition, six abnormal radioactivity accumulation regions, adjacent to the heart and inferior cava, with the help of CT, were confirmed to be the imaging of inferior cava other than hepatic hemangiomas.CONCLUSION: When the anatomical positions of hepatic hemangiomas are not good enough for diagnosis, the fusion imaging of SPECT/CT is a simple and efficient method for differential diagnosis.

Hemorrhagic hepatic cysts mimicking biliary cystadenoma

The hemorrhagic simple hepatic cyst is extremely rare and can sometimes be confused with biliary cystadenoma or cystadenocarcinoma.Here we present two cases of huge hemorrhagic simple hepatic cysts. Case 1 was a 43-year-old man with a cystic lesion measuring 13 cm×12 cm in the right hepatic lobe. Ultrasound and computed tomography showed several mural nodules on the irregularly thickened wall and high-density straps inside the cyst.Case 2 was a 60-year-old woman with a huge cyst measuring 15 cm ×14 cm in the central liver.Ultrasound and magnetic resonance imaging showed the cystic wall was unevenly thickened and there were some flame-like prominences on the wall.The iconographic representations of the two cases mimicked biliary cystadenoma.Cystectomy and left hepatectomy were performed for the two patients, respectively.Both patients recovered quickly after their operations and showed no recurrence.

Contrast-enhanced and targeted ultrasound

Ultrasonic imaging is becoming the most popular medical imaging modality,owing to the low price per examination and its safety.However,blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies.For perfusion imaging,markers have been designed to enhance the contrast in B-mode imaging.These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells.In this review,the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described.Furthermore,an outline of clinical imaging applications of contrast-enhanced ultrasound is given.It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition,and how these phenomena may be utilized in ultrasonic imaging.Aided by high-speed photography,our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques.More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves,and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs.These are beginning to be accepted into clinical practice.In the long term,targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

Hybrid ultrasound imaging techniques(fusion imaging)

Visualization of tumor angiogenesis can facilitate noninvasive evaluation of tumor vascular characteristics to supplement the conventional diagnostic imaging goals of depicting tumor location,size,and morphology.Hybrid imaging techniques combine anatomic [ultrasound,computed tomography(CT),and/or magnetic resonance imaging(MRI)] and molecular(single photon emission CT and positron emission tomography) imaging modalities.One example is real-time virtual sonography,which combines ultrasound(grayscale,colour Doppler,or dynamic contrast harmonic imaging) with contrast-enhanced CT/MRI.The benefits of fusion imaging include an increased diagnostic confidence,direct comparison of the lesions using different imaging modalities,more precise monitoring of interventional procedures,and reduced radiation exposure.

Imaging techniques used for the real-time assessment of angiogenesis in digestive cancers

Angiogenesis has a critical role in primary tumor growth and the development of metastases.Several angiogenesis inhibitors were recently developed,being a very attractive target for digestive tumor therapy.However,individualized therapy should not only be based on the pre-treatment imaging evaluation,but also on sensitive monitoring of microvascular changes during treatment.State-of-theart imaging techniques have the potential to visualize and characterize angiogenesis,although the technology and methodologies employed are recent and need further validation.The aim of this series of reviews was to analyze and enhance current knowledge and future perspectives about the real-time assessment of angiogenesis in digestive cancers,used for the longitudinal monitoring of the effects of chemo-radiotherapy(including anti-angiogenic therapies),as well as for the precise targeting of drugs through molecular-based drug-delivery systems.

MRI manifestations of enlarged superior ophthalmic vein

Objective:To assess MRI in the evaluation of enlarged superior ophthalmic vein (SOV). Methods: MRI manifestations and etiology of forty-six patients with enlarged SOV were analyzed. Results: SOV enlargement was noted to occur in carotid-cavernous fistula, ophthalmic Graves'disease, Tolosa-Hunt syndrome, inflammation at the apex of the orbit, orbital pseudotumor and thrombosis of cavernous sinus. The dilated vein appeared as signal void tubular shadows on both T1 and T2 weighted images. The diameter of the enlarged vein was 3.5-6.0 mm. Extraocular muscle enlargement, orbital pathologies, enlarged carotid cavernous sinus etc were also revealed by MRI. Conclusion: The dilated SOV may be well demonstrated by MRI. The etiological diagnosis of enlarged SOV can be made in combination with the associated findings.

APPLICATION OF MAGNETIC RESONANCE ANGIOGRAPHY IN PORTAL HYPERTENSIVE SURGERY

Objective To compare magnetic resonance angiography （MRA） with traditional angiography and doppler ultrasonography （DUS） in the assessment of portal venous anatomy and its hemodynamics. Methods Three dimensional dynamic contrast-enhanced （ 3 D-DCE） MRA and two dimensional phase-contrast （2D-PC） MR were used for the study of portal venous system in the patients with portal hypertension and those without liver cirrhosis. The comparison of the portal blood flow （PBF） measured with 2D-PC MR and DUS was made. Results The portal vein, splenic vein, superior mesenteric vein, cephalic collateral veins and anastomotic stoma of surgical shunting were clearly displayed in 3D-DCE MRA. There was no significant difference between PBF measured with 2D-PC MR and DUS. Conclusion The results of present study indicate that the anatomical imaging of the portal venous system can be dearly revealed in MRA and the PBF can be accurately measured with 2D-PC MR. It is believed that MRA is a useful tool in the management of the patients with portal hypertension.

Evaluation of the tumor angiogenesis in benign prostate hyperplasia and prostatic cancer with MR perfusion-weighted imaging

Objective： To explore the application of MR perfusion-weighted imaging （PWI） in the benign and malignant prostate diseases, and evaluate the correlations of PWl features with vascular endothelial growth factor （VEGF） and microvessel density （MVD）. Methods： Seventy-four consecutive patients who were diagnosed clinically for the prostate diseases, including forty-four cases with benign prostate hyperplasia and thirty cases with prostatic cancer proved pathologically, were examined by PWI. MVD and VEGF were stained with immunohistochemical methods. Some parameters of PWl, including the steepest slope of signal intensity-time curve （SSmax） and the change in relaxation rate （ΔR2^＊ peak） at lesions, were analyzed. Correlation analysis was used to determine the relationship between the results of PWl and immunohistochemistry. Results： （1） In the benign prostate hyperplasia （BPH）, SSmax and ΔR2^＊ peak of perfusion curve were 34.2 ± 2.9 and 1.49 ± 0.11, respectively; however, in the prostatic cancer （Pca）, they were 58.6± 4.8 and 3.18 ±0.49 respectively; there were statistical differences （t = 2.16 and 2.31, P 〈 0.05）. （2） The VEGF and MVD expressions of thirty Pca patients were significantly higher than those of forty-four BPH patients （x2 = 28.64, P 〈 0.01; t = 21.2, P 〈 0.01）. MVD expressions of Pca and BPH groups showed positive associations with VEGF expressions （P 〈 0.01）. On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak showed associations with MVD and VEGF expressions （P 〈 0.01）. Conclusion： On MR perfusion-weighted imaging, SSmax and ΔR2^＊ peak can reflect MVD and VEGF expression levels in the benign and malignant prostate diseases and might be implied the tumor angiogenesis so as to distinguish benign from malignant and provide the important information for the surgeon to diagnose and treat the prostatic diseases.

Three-dimensional CT angiography and surgical correlation in the evaluation of intracranial aneurysms

OBJECTIVE: To evaluate the diagnostic accuracy of three-dimensional CT angiography in the surgical treatment of intracranial aneurysms. METHODS: Twenty-four patients suspected of intracranial aneurysms underwent routine catheter four-vessel angiography, three dimensional CT angiography (3D-CTA), magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA). RESULTS: A total of 28 aneurysms were detected by CT angiography in this study. Twenty-one patients each had a single aneurysm, two patients each had two aneurysms, and one had three aneurysms. The shapes of aneurysms revealed by 3D-CTA were round in 20 lesions, elliptical in 5, and 1 obulated in 3. Of the 24 lesions which were completely disclosed during surgery, the shapes correlated well with the 3D-CT angiograms. The mean diameter of the aneurysmal neck was 5.9 mm in 3D-CTA images, with the smallest being 1.6 mm and the largest 13.7 mm. The size was very close to the actual size measured at surgery (P

Effect of cilostazol on cerebral arteries in secondary prevention of ischemic stroke

Objective To compare the effects of cilostazol on cerebral arteries and cerebrovascular blood flow in secondary prevention of ischemic stroke, with those of aspirin. Methods Sixty-eight patients who had ischemic stroke during the recent 1-6 months were recruited and randomized into cilostazol or aspirin group. Cerebrovascular condition was assessed by magnetic resonance angiography （MRA） and transcranial doppler ultrasonography （TCD） at the beginning of the study and after 12-month medication. Results During the clinical follow-up, ischemic stroke recurred in 2 patients in cilostazol group, while in aspirin group, one case of ischemic stroke recurrence and one case of acute myocardial infarction were found. MRA revealed that in aspirin group, the percentages of patients experiencing aggravation and attenuation of cerebrovascular condition were 3.3% and 6.7%, respectively, while in aspirin group, they were 3.3% and 10%, respectively. Moreover, TCD revealed that 26.9% of the patients in aspirin group and 14.3% of the patients in cilostazol group experienced aggravation of cerebrovascular condition. However, the systolic peak flow velocity of the previously abnormal arteries increased by 42.9% after 12-month medication of cilostazol, which was significantly higher than that after aspirin medication （27.5%） （P = 0.04）. Furthermore, as a major side effect of antiplatelet therapy, the frequrency of bleeding was much less in cilostazol group （0 case in cilostazol group vs 5 in aspirin, P 〈 0.05）. Conclusion Cilostazol is as effective as aspirin in preventing the aggravation of cerebral arteries in secondary prevention of ischemic stroke. Besides, it is more safe. Cilostazol can increase the systolic peak flow velocity of cerebral arteries, which may improve the blood supply of focal ischemia.

Contrast enhanced MR angiography in pulmonary sequestration

Objective To evaluate the feasibility of contrast enhanced three-dimensional(3D)magnetic resonance angiography(MRA)in identifying the systemic blood supply in pulmonary sequestration.Methods Three patients who were suspected of pulmonary sequestration were examined by contrast enhanced 3D MRA.MR images were compared with surgical findings.Results Contrast enhanced 3D MRA clearly demonstrated systemic arteries from the descending thoracic aorta supplying the basilar segments of the lower lobe in each case.Pulmonary veins from these segments,which drained into the left atrium in two cases,were also detected.MRA images were consistent with those observed in surgery.Conclusion Contrast enhanced 3D MRA allows accurate diagnosis of pulmonary sequestration and may obviate the need for more invasive investigations.

Cerebral angiography and MR perfusion images in patients with ischemic cerebral vascular disease

OBJECTIVE: To evaluate the value of perfusion MR imaging and angiographic evidence of collateral circulation in symptomatic patients with ischemic cerebrovascular diseases (ICVD). METHODS: Cerebral angiography and perfusion MR were performed in 16 patients with symptoms of ICVD. Qualitative perfusion maps were calculated for regional cerebral blood volume (rCBV) and mean transit time (MTT). RESULTS: A total of 27 lesions were seen on the perfusion MR maps (6 infarcts and 21 ischemic lesions) and most of them (26/27) showed a prolonged MTT. MTT is sensitive to the presence of ischemic lesions, but not sufficient in distinguishing infarct from ischemia. All of the infarcts showed a decreased rCBV, while most of the ischemic lesions showed a normal or increased rCBV. When collateral circulation was identified on angiography, most ischemic lesions were not infarcts and had a normal or increased rCBV. The absence of angiographically identifiable cerebral collaterals may not always result in an infarct; 50% had decreased rCBV. Despite the absence of angiographic collaterals, the other half had normal or increased rCBV. CONCLUSION: Cerebral angiographic evidence of collateral circulation is important in identifying a favorable outcome in patients with ICVD. However, a lesion with a normal or increased rCBV suggests a sufficient collateral circulation even without angiographic collaterals. Perfusion images may be a potentially useful adjunctive tool in the prediction of the outcome of ICVD, particularly where no apparent collateral macrocirculation is seen on CA.

MRI and magnetic resonance angiography in evaluating simultaneous pancreas-kidney transplantation

OBJECTIVE: To evaluate the value of magnetic resonance imaging (MRI) and three dimensional (3D) contrast magnetic resonance angiography (MRA) in the diagnosis of complications of simultaneous pancreas-kidney transplantation (SPKT), as confirmed by biopsy and digital subtraction angiography (DSA). METHODS: Five MR examinations of five patients were performed within 28 days to 2 years after surgery on GE 1.5T MR system. Imaging techniques included axial and sagittal chemical fat-suppressed T1-weighted image (T1WI) and T2-weighted image (T2WI), additional contrast axial or saggital chemical fat-suppressed T1WI were obtained after 3D contrast MRA for calculating the mean percentage of the parenchymal enhancement (MPPE) of the pancreas and kidney. 3D contrast MRA was performed with Smartprep technique. MRA data were analyzed with maximum intensity projection (MIP) and multi-planner reformat (MPR). RESULTS: In five cases of transplant pancreases, MRI found two normal pancreas grafts, one case of acute rejection, one case of chronic rejection with 70% fibrosis and one case of late pancreatitis. In five transplant kidneys, MRI detected four normal kidney grafts and one case of acute rejection with infarction. MPPE could distinguish infarction from other complications. 3D contrast MRA could display vascular complications of SPKT, such as stenosis or occlusion, aneurysm formation of transplanted vessels and narrowing at the site of anastomosis, as confirmed by DSA. CONCLUSION: With combined application of MRI and 3D contrast MRA, complications of SPKT can be clearly identified.

Relationship between Framingham risk score and subclinical atherosclerosis in carotid plaques： an in vivo study using multi-contrast MRI

The assessment and management of early-stage atherosclerosis are important for the prevention of cardiovascular disease(CVD).In this study,we used multi-contrast magnetic resonance imaging(MRI) to investigate the carotid plaque feature in asymptomatic,at-risk subjects;we also evaluated the correlation between MRI findings and Framingham risk score(FRS).One hundred sixty-six asymptomatic individuals with risk factors for CVD underwent multi-contrast MRI.After the arterial morphology and plaque components were outlined,the differences in carotid plaque burden among the various risk categories were analyzed.The FRS analysis showed that high-risk individuals had thicker vessel wall and higher plaque lipid content than did low risk participants.A substantial proportion of advanced carotid plaques occurred in low and intermediate-risk groups.Multi-contrast MRI may provide incremental value to the FRS in managing asymptomatic at-risk population.