Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries.Electronic SupplementaryMaterial Supplementary material is available for this article at .     

Time-of-flight MR angiography of kidney transplants

The aim of the study was to apply time-of-flight MR angiography to renal transplant arteries with comparison of two- and three-dimensional (2D and 3D) sequences and to correlate the findings with colour flow sonography (CFS) and digital subtraction angiography (DSA). A total of 102 MR studies were performed in 101 patients: 87 with the 2D-FLASH sequence (18 repeated after Gd-DOTA administration), 49 with the 3D-FISP (both in 34). All patients were also studied with CFS and 15 with intra-arterial DSA. The 3D sequence produced good-quality MR angiograms in 94% of cases (82% in 2D). Gd-DOTA infusion improved the quality of the 2D angiograms in 7 of 18 cases. Only these patients were included in the remainder of the evaluation (90 patients with 103 arteries). CFS showed 72 normal and 10 abnormal arteries. In this group, the 2D sequence led to 7 (12%) false positives of stenosis and the 3D sequence yielded 1 (3%). Correlation between MR angiography and DSA was obtained for 21 arteries (15 patients) with suspicion of arterial complications. The 2D-FLASH (n = 13) and the 3D-FISP (n = 12) MR sequences allowed the correct diagnosis of all main artery complications (14 stenoses and 4 thromboses) without any false negatives and without discordance when both sequences were performed (n = 4). In the 3 other cases with a normal main artery, 2 segmental thromboses were correctly identified by both sequences and 1 stenosis of a segmental branch was correctly identified by the 2D sequence only but misdiagnosed as a thrombosis with the 3D sequence. Grading of the severity of stenoses was inaccurate with both sequences. It is concluded that the 3D time-of-flight MR sequence provides better MR angiograms than the 2D, with fewer false positives for stenosis. No false-negative arterial complications were noted. Correspondence to: N. Grenier     

Contrast-enhanced 3D MR angiography of the carotid artery: comparison with conventional digital subtraction angiography

BACKGROUND AND PURPOSE: Since 1996, several preliminary studies have shown the usefulness of contrast material-enhanced MR angiography for imaging supraaortic vessels. The aim of this study was to compare the accuracy of contrast-enhanced 3D MR angiography with that of digital subtraction angiography (DSA) in the evaluation of carotid artery stenosis. METHODS: A blinded comparison of first-pass contrast-enhanced MR angiography with conventional DSA was performed in 120 patients (240 arteries). MR angiography was performed with a 1.5-T magnet with gradient overdrive equipment, by using a coronal radiofrequency-spoiled 3D fast low-angle-shot sequence after the intravenous injection of gadodiamide. The guidelines of the North American Symptomatic Carotid Endarterectomy Trial for measuring stenosis of the internal carotid artery were applied on maximum intensity projection (MIP) images and conventional catheter angiograms. RESULTS: Grading of stenoses on MR angiograms agreed with grading of stenoses on DSA images in 89% of arteries. In the severe stenosis group (70-99%), agreement was 93%. All internal carotid occlusions (n = 28) and seven of nine pseudo-occlusions were accurately detected with contrast-enhanced MR angiography. The correlation between MR angiography and DSA for determination of minimal, moderate, and severe stenoses and occlusion was statistically significant (r = 0.91, P<.001). CONCLUSIONS: This investigation with a large number of patients confirms that contrast-enhanced MR angiography could become a diagnostic alternative to DSA in the treatment of patients with carotid artery disease.     

Internal carotid artery stenosis: accuracy of subjective visual impression for evaluation with digital subtraction angiography and contrast-enhanced MR angiography

PURPOSE: To prospectively determine, for both digital subtraction angiography (DSA) and contrast material-enhanced magnetic resonance (MR) angiography, the accuracy of subjective visual impression (SVI) in the evaluation of internal carotid artery (ICA) stenosis, with objective caliper measurements serving as the reference standard. MATERIALS AND METHODS: Local ethics committee approval and written informed patient consent were obtained. A total of 142 symptomatic patients (41 women, 101 men; mean age, 70 years; age range, 44-89 years) suspected of having ICA stenosis on the basis of Doppler ultrasonographic findings underwent both DSA and contrast-enhanced MR angiography. With each modality, three independent neuroradiologists who were blinded to other test results first visually estimated and subsequently objectively measured stenoses. Diagnostic accuracy and percentage misclassification for correct categorization of 70%-99% stenosis were calculated for SVI, with objective measurements serving as the reference standard. Interobserver variability was determined with kappa statistics. RESULTS: After exclusion of arteries that were unsuitable for measurement, 180 vessels remained for analysis with DSA and 159 vessels remained for analysis with contrast-enhanced MR angiography. With respect to 70%-99% stenosis, SVI was associated with average misclassification of 8.9% for DSA (8.9%, 7.8%, and 10.0% for readers A, B, and C, respectively) and of 11.7% for contrast-enhanced MR angiography (11.3%, 8.8%, and 15.1% for readers A, B, and C, respectively). Negative predictive values were excellent (92.3%-100%). Interobserver variability was higher for SVI (DSA, kappa = 0.62-0.71; contrast-enhanced MR angiography, kappa = 0.57-0.69) than for objective measurements (DSA, kappa = 0.75-0.80; contrast-enhanced MR angiography, kappa = 0.66-0.72). CONCLUSION: SVI alone is not recommended for evaluation of ICA stenosis with both DSA and contrast-enhanced MR angiography. SVI may be acceptable as an initial screening tool to exclude the presence of 70%-99% stenosis, but caliper measurements are warranted to confirm the presence of such stenosis.     

Aneurysms of proximal pulmonary arteries: CT diagnosis and preoperative assessment

We reviewed our experience with proximal pulmonary artery aneurysm (PPAA) to determine whether accurate preoperative evaluation (crucial to differential diagnosis and surgical planning) had been obtained on the basis of CT study alone. Three patients with PPAA were studied with contrast-enhanced CT. We evaluated the size and shape of PPAAs, their proximal and distal extent, eventual presence of intraluminal thrombi, dissection, perianeurysmal fibrosis, and rupture. The results were compared with surgical findings. In two patients the aneurysm involved the pulmonary trunk and both the right and left arteries origin. In one patient the aneurysm extended from the left artery origin to the hilum of the left lung. Contrast-enhanced CT alone allows detection of aneurysm in the pulmonary trunk, in right or left pulmonary arteries with precise preoperative evaluation of the extent, size, shape, and complications. The CT imaging was unable to establish the etiologic origin and presence of small intimal tears in PPAA. Correspondence to: G. Iula     

移床-血管示踪MR血管成像在下肢动脉疾病中的临床应用

目的研究移床-血管示踪MRA在下肢动脉疾病中的应用价值,探讨移床技术的优势。方法对36例临床疑有下肢动脉疾病的患者行移床-血管示踪三维动态增强MRA检查,其中急性下肢动脉闭塞症5例,检查后行急诊手术,慢性下肢动脉闭塞31例,其中10例行DSA检查。15例可评价病例以DSA或手术结果作为金标准进行效果评价。结果36例病人均满意地显示了完整的下肢动脉血管。将每条下肢分为14个血管节段观察,15例可评价病例共观察420段血管节段,显示可比动脉节段102段。与DSA或手术结果比较,两者诊断符合率为93.14%(95/102),MRA诊断的敏感度为100%,特异度为100%。5例急性下肢动脉闭塞症与手术结果比较,MRA对血管闭塞长度的评价与手术无统计学差异(t=2.251,P>0.05)。结论移床-血管示踪MRA与DSA或手术比较,具有很好的一致性,能全面、准确地评价下肢动脉病变,是一种可靠的、无创的、有应用价值的检查方法。     

Takayasu arteritis: diagnosis with breath-hold contrast-enhanced three-dimensional MR angiography

The purpose of the study was to determine the diagnostic accuracy of breath-hold contrast-enhanced three-dimensional (3D) magnetic resonance (MR) angiography in Takayasu arteritis. Thirty patients suspected of having Takayasu arteritis were examined with MR angiography and conventional angiography. Takayasu arteritis was diagnosed in 20 of these patients. MR angiography was performed using a 1.5-T system after bolus injection of 0.1 mmol/kg of gadodiamide. MR angiography clearly depicted various vascular lesions in the aorta and its major branches in all 20 patients with Takayasu arteritis. It also depicted pulmonary artery lesions in 10 (50%) of the 20 patients. MR angiography accurately depicted 323 (98%) of 330 arteries, but 7 (2%) stenotic arteries were overestimated as occluded. The sensitivity and specificity of MR angiography for the diagnosis of Takayasu arteritis were both 100%. Breath-hold contrast-enhanced 3D MR angiography clearly depicts various vascular lesions in both the systemic and pulmonary arteries in Takayasu arteritis, thus allowing a definitive diagnosis of Takayasu arteritis.     

Early onset of retrograde flow in the main pulmonary artery is a characteristic of pulmonary arterial hypertension

Purpose:

To evaluate if early onset of retrograde flow in the main pulmonary artery is a characteristic of pulmonary arterial hypertension (PAH).

Materials and Methods:

Fifty‐five patients with suspected pulmonary hypertension (PH) underwent right‐sided heart catheterization and retrospectively ECG‐gated MR phase‐contrast velocity quantification in the main pulmonary artery. Pulmonary hypertension was defined by a mean pulmonary artery pressure being larger than 25 mmHg. The onset time of the retrograde flow relative to the cardiac cycle duration (Relative Onset Time = ROT) was compared with mean pulmonary artery pressure.

Results:

By the catheterization, 38 patients were identified as having PAH. The ROT for these PAH patients was significantly different from those found in the 17 non‐PH subjects (0.14 ± 0.06 versus 0.37 ± 0.06, P < 0.001). The mean pulmonary artery pressure was related to the ROT (r² = 0.62, P < 0.001) and could be estimated from the ROT with a standard deviation of 11.7 mmHg. With a cutoff value of 0.25, the ROT distinguished PAH patients from non‐PH subjects.

Conclusion:

Early onset of retrograde flow in the main pulmonary artery is a characteristic of pulmonary arterial hypertension and is visible by standard MR phase‐contrast velocity quantification. J. Magn. Reson. Imaging 2011;33:1362–1368. © 2011 Wiley‐Liss, Inc.     

肺癌血管造影表现及临床意义

目的：研究肺癌的肿瘤血管形态，指导肺癌的诊断和介入治疗。材料和方法：对１００例肺癌病人在治疗前行支气管动脉ＤＳＡ，其中２０例同时作了肺动脉ＤＳＡ。结果：①肺癌的血供来自支气管动脉；②供血的支气管动脉增粗；③出现肿瘤血管和肿瘤染色；④少数病例可见支气管动脉与肺动脉或肺静脉直接交通；⑤纵膈或肺门淋巴结显影。表现与原发癌相似。结论：肺癌的介入治疗应选择支气管动脉为靶血管，不但要进行灌注化疗，而且要栓塞支气管动脉以阻断肿瘤的血供和异常交通，不但要栓塞原发瘤的供血动脉也要栓塞转移淋巴结的供血动脉。     

Value of image subtraction in 3D gadolinium-enhanced MR angiography of the renal arteries

The objective of this study was to evaluate quantitatively and qualitatively the effect of image subtraction on the image quality of three-dimensional (3D) gadolinium-enhanced MR angiograms of the renal arteries. Breath-hold 3D gadolinium MR angiography (MRA) as well as conventional contrast angiography of the renal arteries was performed on 20 patients with suspected renovascular hypertension. MR angiograms were acquired before and during dynamic infusion of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA). Contrast-enhanced images were compared with images that had undergone voxel-by-voxel signal intensity subtraction of contrast-enhanced data from precontrast data. One false positive finding for significant renal artery stenosis was recorded with MRA using conventional angiography as the gold standard. Image subtraction did not alter the diagnosis at MRA in any case. The mean contrast-to-noise ratio (CNR) was significantly higher (P < .05) on the subtraction MR angiograms compared to the nonsubtracted MR angiograms. There was no significant difference in the signal-to-noise ratio (SNR). Qualitative analysis revealed a significant improvement in image quality after image subtraction with respect to visualization of the distal renal arteries. In conclusion, image subtraction improves the quality of renal MRA in terms of both CNR and visualization of the distal renal arteries.     

18F-FDG accumulation in atherosclerosis: use of CT and MR co-registration of thoracic and carotid arteries

Purpose The purpose of this study was to depict ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) accumulation in atherosclerotic lesions of the thoracic and carotid arteries on CT and MR images by means of automatic co-registration software. Methods Fifteen hospitalised men suffering cerebral infarction or severe carotid stenosis requiring surgical treatment participated in this study. Automatic co-registration of neck MR images and FDG-PET images and of contrast-enhanced CT images and FDG-PET images was achieved with co-registration software. We calculated the count ratio, which was standardised to the blood pool count of the superior vena cava, for three arteries that branch from the aorta, i.e. the brachial artery, the left common carotid artery and the subclavian artery (n=15), for atherosclerotic plaques in the thoracic aorta (n=10) and for internal carotid arteries with and without plaque (n=13). Results FDG accumulated to a significantly higher level in the brachial artery, left common carotid artery and left subclavian artery at their sites of origin than in the superior vena cava (p=0.000, p=0.000 and p=0.002, respectively). Chest CT showed no atherosclerotic plaque at these sites. Furthermore, the average count ratio of thoracic aortic atherosclerotic plaques was not higher than that of the superior vena cava. The maximum count ratio of carotid atherosclerotic plaques was significantly higher than that of the superior vena cava but was not significantly different from that of the carotid artery without plaque. Conclusion The results of our study suggest that not all atherosclerotic plaques show high FDG accumulation. FDG-PET studies of plaques with the use of fused images can potentially provide detailed information about atherosclerosis.     

肺癌16层螺旋CT支气管动脉血管成像与DSA对比分析

目的:探讨16层螺旋CT血管三维重组对诊断与评价肺癌支气管动脉供血血管和血供的临床应用价值.方法:10例肺癌同时行16层螺旋CT支气管动脉血管三维重组和DsA检查,并对16层螺旋cT支气管动脉血管三维重组和DSA资料进行对比分析.结果:10例肺癌16层螺旋CT血管成像显示11支支气管动脉,其中图像质量优5支、良好6支;DSA显示10支支气管动脉.10例肺癌16层螺旋CT血管成像显示肿瘤供血支气管动脉起源、形态及分支状况与DSA一致.10例肺癌16层螺旋CT血管VR彩色成像与DSA显示肿瘤染色及肿瘤内血供状况一致率为90%.结论:16层螺旋CT血管成像可克服DSA一次检查不能显示其全部供血血管的缺点;对诊断和评价肺癌供血血管和血供状况有较大临床价值.     

Supraaortic arteries: contrast-enhanced MR angiography at 3.0 T--highly accelerated parallel acquisition for improved spatial resolution over an extended field of view

PURPOSE: To prospectively use 3.0-T breath-hold high-spatial-resolution contrast material-enhanced magnetic resonance (MR) angiography with highly accelerated parallel acquisition to image the supraaortic arteries of patients suspected of having arterial occlusive disease. MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study. Eighty patients (44 men, 36 women; age range, 44-90 years) underwent contrast-enhanced MR angiography of the head and neck at 3.0 T with an eight-channel neurovascular array coil. By applying a generalized autocalibrating partially parallel acquisition algorithm with an acceleration factor of four, high-spatial-resolution (0.7 x 0.7 x 0.9 mm = 0.44-mm(3) voxels) three-dimensional contrast-enhanced MR angiography was performed during a 20-second breath hold. Two neuroradiologists evaluated vascular image quality and arterial stenoses. Interobserver variability was tested with the kappa coefficient. Quantitation of stenosis at MR angiography was compared with that at digital subtraction angiography (DSA) (n = 13) and computed tomographic (CT) angiography (n = 12) with Spearman rank correlation coefficient (R(s)). RESULTS: Arterial stenoses were detected with contrast-enhanced MR angiography in 208 (reader 1) and 218 (reader 2) segments, with excellent interobserver agreement (kappa = 0.80). There was a significant correlation between contrast-enhanced MR angiography and CT angiography (R(s) = 0.95, reader 1; R(s) = 0.87, reader 2) and between contrast-enhanced MR angiography and DSA (R(s) = 0.94, reader 1; R(s) = 0.92, reader 2) for the degree of stenosis. Sensitivity and specificity of contrast-enhanced MR angiography for detection of arterial stenoses greater than 50% were 94% and 98% for reader 1 and 100% and 98% for reader 2, with DSA as the standard of reference. Vascular image quality was sufficient for diagnosis or excellent for 97% of arterial segments evaluated. CONCLUSION: By using highly accelerated parallel acquisition, the described 3.0-T contrast-enhanced MR angiographic protocol enabled visualization and characterization of the majority of supraaortic arteries, with diagnostic or excellent image quality (97% of arterial segments) and diagnostic values comparable with those obtained by using CT angiography and DSA for detection of arterial stenoses.     

Acute pulmonary embolus mimicked on V/Q scan by sarcoidosis

Acute pulmonary embolus is a common problem requiring evaluation in the emergency setting. Following the initial chest radiograph, the most common imaging test requested is the ventilation perfusion lung scan. We describe a patient with sarcoidosis and a false positive ventilation perfusion lung scan caused by bilateral hilar adenopathy compressing the proximal pulmonary arteries. This case illustrates that patients with hilar adenopathy and suspected pulmonary embolus may have unreliable ventilation perfusion scans, and should be referred to arteriography or CT for evaluation, rather than for a ventilation perfusion lung scan.     

Flow velocity quantification in human coronary arteries with fast,breath-hold MR angiography

Measurement of coronary artery flow velocities has, until now, largely required the use of invasive technologies. The authors have implemented a breath-hold magnetic resonance (MR) angiography technique for depicting the coronary arteries and for quantifying flow velocities. The method was tested in flow phantoms and then applied to a series of subjects: 11 subjects were studied at rest, and four were studied before and during pharmacologic stress induced by intravenous adenosine. Flow velocities at rest in the midportion of the right coronary artery were 9.9 cm/sec ± 3.5 (n = 12); in the proximal left anterior descending coronary artery, they were significantly higher, measuring 20.5 cm/sec ± 5.2 (n = 6). With adenosine, flow velocities typically increased at least fourfold. The authors conclude that noninvasive measurement of coronary artery flow velocities is feasible with MR angiography; this method may prove useful for determining the physiologic significance of coronary artery stenosis.     

MRI of the breast in patients with metastatic disease of unknown primary

The objective of this study was to assess the value of contrast-enhanced dynamic breast imaging in patients with carcinoma of unknown primary (CUP). Fourteen patients presenting with metastatic disease compatible with breast cancer (axillary lymph node metastasis: n = 6; supraclavicular lymph node metastasis: n = 1; bone metastasis: n = 3; liver metastasis: n = 3; lung metastasis: n = 1), who had no evidence of tumor in X-ray mammograms and ultrasound, underwent bilateral dynamic breast MR imaging. Suspicious lesions were localized preoperatively using a stereotactic device for MR-guided localization procedures. Magnetic resonance imaging revealed suspicious lesions in 9 of 14 patients. Histopathology revealed invasive carcinoma of the breast in 6 of these patients. Two enhancing lesions were fibroadenomas; one proved to be sclerosing adenosis. In 5 patients MR imaging showed no abnormality. Follow-ups performed up to 1 year after initial treatment revealed no breast cancers in these 5 patients. In patients with metastatic disease of unknown primary, MRI of the breast depicts the primary in a considerable number of cases with normal conventional evaluation. Received: 20 February 1998; Revision received: 2 June 1998; Accepted: 10 July 1998     

肾动脉狭窄的三维增强磁共振血管成像诊断

目的:评价高分辨力三维增强磁共振血管成像术(3DCEMRA)对肾动脉狭窄的显示准确性。方法:对30例临床诊断或怀疑肾动脉狭窄患者进行高分辨力肾动脉3DCEMRA检查,分析所有患者的肾动脉和副肾动脉显示质量和病变显示情况,并与DSA做对照。结果:3DCEMRA显示了30例患者总共59支肾动脉主干(1例为单支移植肾动脉),显示率为100%。3DCEMRA显示4支副肾动脉,显示率100%。肾动脉段级分支的显示率为49%。所有病例在动脉显示区域内静脉均未显影或显影淡,对诊断不构成影响。DSA共显示59支肾动脉主干和4支副肾动脉(以63支计算),59支主干中2支闭塞,8支重度狭窄,11支中度狭窄,10支轻度狭窄,28支肾动脉主干和4支副肾动脉都正常。3DCEMRA除把2支轻度狭窄估为中度狭窄,1支中度狭窄估为重度狭窄外,其它结果都同DSA一致,故3DCEMRA显示肾动脉主干和副肾动脉狭窄程度超过50%的有血液动力学意义的明显狭窄的敏感性和特异性分别为100%和95%,阳性预测值为91%,阴性预测值为100%。结论:高分辨力肾动脉3DCEMRA能准确检出肾动脉主干和副肾动脉狭窄,并能较好判断其狭窄程度。     

Multiphase ECG-triggered 3D contrast-enhanced MR angiography: utility for evaluation of hilar and mediastinal invasion of bronchogenic carcinoma

The purpose of this study was to evaluate the usefulness of cardiac synchronized magnetic resonance angiography [electrocardiographically (ECG)-triggered MRA] for improving image quality and detection of hilar and mediastinal invasion of bronchogenic carcinoma. Fifty patients, suspected of having hilar or mediastinal invasion of bronchogenic carcinoma, underwent contrast-enhanced computed tomography and MR imaging including conventional and ECG-triggered MRA. Twenty patients subsequently also underwent surgical resection. Vascular enhancement-to-background ratio (VBR), vascular enhancement-to-tumor ratio (VTR), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality scores of thoracic vessels obtained with both MRA techniques were determined and compared. In addition, the diagnostic accuracy of tumor invasion of pulmonary vessels was compared. VBRs and VTRs of both MRA techniques were not significantly different. ECG-triggered MRA significantly improved SNRs and CNRs (P < 0.05). Two readers judged that overall image quality of ECG-triggered MRA was better than that of conventional MRA (kappa > or = 0.41). In conclusion, ECG-triggered MRA improves the image quality and the detection of hilar and mediastinal invasion of bronchogenic carcinoma.     

肾动脉纤维肌层发育不良的高分辨力三维增强MR血管成像

目的:评价高分辨力三维增强磁共振血管成像术(3D CE MRA)诊断肾动脉纤维肌层发育不良(FMD)的价值.方法:5例经临床和DSA造影确诊的肾动脉FMD患者行肾动脉高分辨力3D CE MRA检查,扫描同时使用透视触发和并行采集技术.分析所有患者的肾动脉和FMD显示情况,并与DSA对照.结果:肾动脉3D CE MRA清楚显示5例患者10支肾动脉主干及其近端段级分支,且静脉均未显影或显影很淡.5例FMD均为单侧肾动脉受累,2例表现为肾动脉主干和近端段级分支串珠状改变,3例表现为肾动脉中段局限性狭窄.3D CE MRA显示结果与DSA一致.结论:高分辨力肾动脉3D CE MRA能较好检出肾动脉主干和近端分支的FMD.     

肝门区肿瘤的MRI诊断及临床应用价值

目的:探讨MRI(包括平扫、动态增强、MRCP和3D DCE-MRA)对肝门区肿瘤的诊断及术前评估的价值。方法:回顾性分析60例肝门区肿瘤的MR表现,其中肝细胞癌(HCC)8例,胆管癌(HC)30例,转移性病变18例,血管瘤4例,并与手术或病理结果对照。结果:MRCP对肝门部胆管梗阻水平定位准确率达93.3%(56/60),平扫联合动态增强对病变定性诊断准确率为81.7%(49/60)。3D DCE-MRA显示病变供血动脉1例、动静脉瘘1例、肝动脉受累1例、门静脉瘤栓2例、门静脉受浸润9例,门静脉受推移3例、下腔静脉受累2例。结论:MRI一系列检查方法对肝门区肿瘤定性诊断及外科手术方案制订具有重要意义。