64层螺旋CT对周围血管性疾病的诊断价值:与DSA的对照研究

目的 通过与DSA比较评估64层螺旋CT血管成像诊断周围血管性疾病(peripheral vascular disease,PVD)的准确性及特异性.方法 30例PVD患者同时接受DSA及CT血管造影检查.血管狭窄程度分为5级:Ⅰ正常(无狭窄);Ⅱ轻度狭窄(1%～49%狭窄);Ⅲ中度狭窄(50%～74%狭窄);Ⅳ重度狭窄(75%～99%);Ⅴ闭塞.以DSA结果为金标准,分析64层螺旋CT的灵敏度、特异度等指标.结果 30例患者中,共有720支血管均有DSA及CTA成像.进行分析比较后发现,64层螺旋CT诊断下肢动脉有意义狭窄的灵敏度98.5%、特异度99.2%、阳性预测值99.1%、阴性预测值98.7%.结论 64层螺旋CT血管成像是诊断周围血管狭窄程度的一种准确、安全、无创的影像学诊断技术.     

Aortoiliac and lower extremity arteries assessed with 16-detector row CT angiography: prospective comparison with digital subtraction angiography

PURPOSE: To prospectively compare the accuracy of 16-detector row computed tomographic (CT) angiography with conventional digital subtraction angiography (DSA) as the reference standard in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease. MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained. A total of 39 consecutive patients (27 men [mean age, 66 years] and 12 women [mean age, 64 years]) with peripheral arterial disease underwent both conventional DSA and 16-detector row CT angiography. For data analysis, the arterial vascular system was divided into 35 segments. A total of 1365 arterial segments were analyzed for arterial stenosis by two independent blinded readers using a four-point grading system (grade 1, <10% luminal narrowing; grade 2, 10%-49% luminal narrowing; grade 3, 50%-99% luminal narrowing; grade 4, occlusion). Interobserver agreements were calculated by using kappa statistics. A third independent blinded reader assessed possible reasons for disagreements between 16-detector row CT angiographic findings and conventional DSA findings. Effective radiation dose was calculated for both imaging modalities. RESULTS: Sixteen-detector row CT angiographic and conventional DSA findings were diagnostic in all vascular segments. Compared with conventional DSA, the sensitivity and specificity of 16-detector row CT angiography with regard to detection of hemodynamically significant stenosis in all 35 arterial segments were 96% and 97%, respectively, for both readers. Readers 1 and 2 overestimated arterial stenosis in 42 (3%) and 34 (2%) arterial segments, respectively, and underestimated arterial stenosis in 13 (1%) and 10 (1%) arterial segments, respectively. Interobserver agreement was excellent (kappa = 0.84-1.00). Presence of anteroposteriorly located luminal narrowing and extensive vascular wall calcification were considered main reasons for disagreements between imaging modalities. Effective radiation dose was lower for 16-detector row CT angiography (1.6-3.9 mSv) than for conventional DSA (6.4-16.0 mSv). CONCLUSION: Sixteen-detector row CT angiography is an accurate and reliable noninvasive alternative to conventional DSA in the assessment of aortoiliac and lower extremity arteries in patients with peripheral arterial disease.     

Comparison between 64-row CT angiography and digital subtraction angiography in the study of lower extremities: personal experience

Purpose

This study was undertaken to evaluate the potential of 64-row multislice computed tomography (CT) versus digital subtraction angiography (DSA) in detecting significant lesions of lower-extremity inflow and runoff arteries.

Materials and methods

Fifty-three patients underwent 64-row multislice CT and DSA over a mean of 36 days. The vascular tree was divided into 33 segments. Three readers independently reviewed the axial CT scans and multiplanar oblique and two- and three-dimensional reconstructions (maximum intensity projection and volume rendering) images to assess degree of stenosis according to four categories: 1 (0%–49% stenosis); 2 (50%–99% stenosis); 3 (occluded); 4 (not evaluable). In all cases, DSA was performed by arterial catheterisation.

Results

In 53 patients, 1,440 segments were evaluated (infrarenal aorta and 16 arterial segments for each leg; 42 bilateral studies, 11 unilateral studies). Compared with DSA, CT angiography yielded 97.2% sensitivity, 97% specificity, 92.5% positive predictive value, 98.9% negative predictive value, 97.1% diagnostic accuracy and 95.4% concordance on the degree of stenosis.

Conclusions

Sixty-four-row multislice CT proved to be helpful in detecting haemodynamically significant lesions in peripheral arterial occlusive disease and improved the results obtained with 4- and 16-slice multidetector CT. In addition, owing to the high spatial resolution and rigorous technique, no variations in the data obtained below the knee were detected, overcoming a limitation of earlier generations of CT scanners.     

Peripheral arterial disease. Contrast-enhanced 3D MR angiography of the lower leg and foot compared with conventional angiography

PURPOSE: To determine whether contrast-enhanced 3D MR angiography (CE MRA) could replace digital subtraction angiography (DSA) for the evaluation of atherosclerotic peripheral vascular disease of the lower leg and foot. MATERIAL AND METHODS: Thirty-five patients with symptoms of atherosclerotic disease of the leg were examined prospectively with CE MRA of the foot and the lower legs as well as with DSA from the aorta to the pedal arches. The MRA technique was focused on optimal imaging of the arteries of the foot. RESULTS: The agreement between CE MRA and DSA for grading of stenosis was moderate to good (weighted kappa-values 0.48-0.80). The sensitivity of CE MRA for detection of significant stenosis (> or = 50%) was 92% and the specificity was 64% with DSA as gold standard. CONCLUSION: CE MRA is a fairly accurate method for the demonstration of atherosclerotic disease below the knee including the pedal arches. It can replace DSA for the assessment of distal arteries in patients with impaired renal function. However, image quality and resolution still needs to be improved before CE MRA can become the method of choice in all patients.     

Infrarenal aortic and lower-extremity arterial disease: diagnostic performance of multi-detector row CT angiography

PURPOSE: To compare multi-detector row spiral computed tomographic (CT) angiography with digital subtraction angiography (DSA) in evaluation of the infrarenal aorta and lower-extremity arterial system. MATERIALS AND METHODS: Fifty patients with peripheral arterial occlusive disease were evaluated with multi-detector row CT angiography and DSA. Arteries depicted at CT angiography and DSA were graded separately for degree of stenosis as 23 anatomic segments (infrarenal aorta, right and left common iliac artery, internal iliac artery, external iliac artery, common femoral artery, superficial femoral artery, deep femoral artery, popliteal artery, anterior tibial artery, tibioperoneal trunk, posterior tibial artery, and peroneal artery). Grades included the following: 1, normal patency; 2, moderate (< or =50%) stenosis; 3, focal severe (>50%) stenosis; 4, multiple severe stenoses; and 5, occlusion. Three readers independently interpreted the images, and statistical analysis was performed. The results of image interpretation were evaluated for strength of agreement by using Cohen kappa statistics. On the basis of consensus readings, sensitivity, specificity, and accuracy for detection of stenotic lesions were calculated, with findings at DSA used as the reference standard. RESULTS: Substantial to almost perfect interobserver agreement was achieved in all cases. At DSA, 349 diseased segments were found among the 1,137 segments evaluated. Sensitivity, specificity, and accuracy, based on a consensus reading of multi-detector row CT angiograms, were 96%, 93%, and 94%, respectively. A statistically significant difference (P <.05) between DSA and multi-detector row CT angiography was present only in arteries graded 1 or 2. Interobserver agreement was almost perfect among the three readers for treatment recommendations based on findings at CT angiography and DSA. CONCLUSION: Multi-detector row CT angiography appears consistent and accurate in the assessment of patients with peripheral arterial occlusive disease.     

Prospective evaluation of suspected stenoocclusive disease of the intracranial artery: combined MR angiography and CT angiography compared with digital subtraction angiography

BACKGROUND AND PURPOSE: MR angiography is primarily and increasingly used to assess intracranial arterial stenoocclusion. However, MR angiography can cause overestimation of stenosis. Although CT angiography is accurate, it has limitations. Our purpose was to determine whether the accuracy of combined MR angiography and CT angiography is equal to that of digital subtraction angiography (DSA) in measuring stenosis and detecting major intracranial arterial occlusion. METHODS: CT angiography and intraarterial DSA were prospectively performed in 18 patients with suspected intracranial stenoocclusive disease, as revealed with MR angiography. Before DSA, two reviewers independently assessed MR intracranial angiograms. Subsequently, they assessed CT angiograms with MR angiograms. Results were compared with DSA results. The degree of stenoocclusion was categorized; stenosis of 50% or more indicated stenoocclusive disease. After the blinded study, two radiologists retrospectively reviewed the angiographic findings. RESULTS: Stenoocclusive disease was identified in 18 of 198 intracranial arteries at DSA. MR angiography had a sensitivity of 92%, a specificity of 91%, and an accuracy of 91% for the identification of stenosis of 50% or more; the addition of CT angiography yielded values of 100%, 99%, and 99%, respectively. Stenotic grades with combined CT angiography and MR angiography agreed with those of DSA in 98% of cases. In the retrospective study, CT angiography did not always correctly delineate arterial lumina with circumferential calcification and cavernous portions of the internal carotid artery. CONCLUSION: In this investigation, the evaluation of suspected stenoocclusive diseases in major intracranial arteries, the accuracy of combined MR angiography and CT angiography is equal to that of DSA in most cases.     

Prospective evaluation of carotid artery stenosis: elliptic centric contrast-enhanced MR angiography and spiral CT angiography compared with digital subtraction angiography

BACKGROUND AND PURPOSE: Although digital subtraction angiography (DSA) is the reference standard for assessing carotid arteries, it is uncomfortable for patients and has a small risk of disabling stroke and death. These problems have fueled the use of spiral CT angiography and MR angiography. We prospectively compared elliptic centric contrast-enhanced MR angiography and spiral CT angiography with conventional DSA for detecting carotid artery stenosis. METHODS: Eighty carotid arteries (in 40 symptomatic patients) were assessed. Elliptic centric MR and spiral CT angiographic data were reconstructed with maximum intensity projection and multiplanar reconstruction techniques. All patients had been referred for DSA evaluation on the basis of findings at Doppler sonography, which served as a screening method (degree of stenosis > or = 70% or inconclusive results). Degree of carotid stenosis estimated by using the three modalities was compared. RESULTS: Significant correlation with DSA was found for stenosis degree for both elliptic centric MR and spiral CT angiography; however, the correlation coefficient was higher for MR than for CT angiography (r = 0.98 vs r = 0.86). Underestimation of stenoses of 70-99% occurred in one case with elliptic centric MR angiography (a 70% stenosis was underestimated as 65%) and in nine cases with spiral CT angiography, in comparison to DSA findings. Overestimation occurred in two cases with MR angiography (stenoses of 65-67% were overestimated as 70-75%). With CT, overestimation occurred in seven cases; a stenosis of 60% in one case was overestimated as 70%. Both techniques confirmed the three cases of carotid occlusion. With elliptic centric MR angiography, carotid stenoses of 70% or greater were detected with high sensitivity, 97.1%; specificity, 95.2%; likelihood ratio (LR) for a positive test result, 20.4; and ratio of LR(+) to LR(-), -0.3. With spiral CT angiography, sensitivity, specificity, LR(+), and LR(+):LR(-) were 74.3%, 97.6%, 31.2, and 0.3, respectively. CONCLUSION: Elliptic centric contrast-enhanced MR angiography is more accurate than spiral CT angiography to adequately evaluate carotid stenosis. Furthermore, elliptic centric contrast-enhanced MR angiography appears to be adequate to replace conventional DSA in most patients examined.     

Multi-detector row CT angiography in the assessment of carotid artery disease in symptomatic patients: comparison with rotational angiography and digital subtraction angiography

BACKGROUND AND PURPOSE: Compared with the single-detector technique, multi-detector row CT angiography permits larger anatomic coverage that includes both the epiaortic and entire carotid circulations. We evaluated the accuracy of multi-detector row CT angiography by using multiplanar reformation (MPR) for measuring carotid artery diameters compared with that of rotational angiography. We also evaluated the diagnostic performance of CT angiography compared with digital subtraction angiography (DSA). METHODS: In 35 patients, CT angiograms of 70 carotid arteries were compared with DSA images, and CT angiograms of 33 carotid arteries were compared with rotational angiograms. CT angiographic interpretation was performed first interactively at a workstation. Diameter measurements of normal and stenosed carotid arteries were performed on cross-sectional and oblique sagittal MPRs. Degree of stenosis was calculated per North American Symptomatic Carotid Endarterectomy Trial criteria independently by two observers for each technique. RESULTS: Degree of stenosis was slightly underestimated with CT angiography, with mean differences (+/- SD) per observer of 6.9 +/- 17.6% and 10.7 +/- 16.1% for cross-sectional and 2.8 +/- 19.2% and 9.1 +/- 16.8% for oblique sagittal MPRs compared with rotational angiography. CT angiography was somewhat inaccurate for measuring the absolute minimal diameter of high-grade stenoses. On symptomatic sides (n = 35), interactive CT angiographic interpretation combined with MPR measurements for lesions with a visual estimate of 50% or greater stenosis achieved a sensitivity of 95% (20/21) and specificity of 93% (13/14) in the detection of carotid stenosis (>/= 50%) verified with DSA. CONCLUSION: Regardless of slight underestimation of carotid stenosis with CT angiography compared with rotational angiography, diagnostic performance of CT angiography with interactive interpretation proved to be good. Also, the method is highly sensitive for detection of carotid artery stenosis, indicating the suitability of CT angiography as a screening method for symptomatic patients. For hemodynamically significant stenoses revealed by CT angiographic screening, conventional angiography still seems to be necessary.     

Aortoiliac and renal arteries: prospective intraindividual comparison of contrast-enhanced three-dimensional MR angiography and multi-detector row CT angiography

PURPOSE: To compare contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography and multi-detector row computed tomographic (CT) angiography in the same patients for assessment of the aortoiliac and renal arteries, with digital subtraction angiography (DSA) as the standard of reference. MATERIALS AND METHODS: DSA, 3D MR angiography, and multi-detector row CT angiography were performed in 46 consecutive patients. A total of 769 arterial segments were analyzed for arterial stenosis by using a four-point grading system. Aneurysmal changes were noted. The time required for performing 3D reconstructions and image analysis of both MR and CT data sets was measured. Patient acceptance for each modality was assessed with a visual analogue scale. Statistical analysis of data was performed. RESULTS: Sensitivity of MR angiography for detection of hemodynamically significant arterial stenosis was 92% for reader 1 and 93% for reader 2, and specificity was 100% and 99%, respectively. Sensitivity of CT angiography was 91% for reader 1 and 92% for reader 2, and specificity was 99% and 99%, respectively. Differences between the two modalities were not significant. Interobserver and intermodality agreement was excellent (kappa = 0.88-0.90). The time for performance of 3D reconstruction and image analysis of CT data sets was significantly longer than that for MR data sets (P <.001). Patient acceptance was best for CT angiography (P =.016). CONCLUSION: There is no statistically significant difference between 3D MR angiography and multi-detector row CT angiography in the detection of hemodynamically significant arterial stenosis of the aortoiliac and renal arteries.     

Assessment of critical limb ischemia in patients with diabetes: comparison of MR angiography and digital subtraction angiography

OBJECTIVE: The purpose of our study was to evaluate the diagnostic accuracy of hybrid MR angiography by comparison with digital subtraction angiography (DSA) in diabetic patients with critical limb ischemia. SUBJECTS AND METHODS: Thirty-one patients prospectively underwent both hybrid MR angiography and DSA. The hybrid MR angiography study consisted of high-resolution MR angiography of a single calf and foot using a contrast-enhanced 3D gradient-echo volumetric interpolated breath-hold examination with surface coils, followed by three-station bolus chase MR angiography with a dedicated peripheral vascular coil. Two blinded reviewers separately analyzed maximum-intensity-projection hybrid MR angiograms and DSA images. The peripheral vessels were divided into 10 anatomic segments for review. The status of each segment was graded as normal, stenosis less than 50% in diameter, stenosis greater than 50%, or occluded. The sensitivity and specificity of hybrid MR angiography were determined using DSA as the gold standard. Treatment options were considered separately from the results of each examination. RESULTS: Among 310 analyzed segments, the sensitivities of hybrid MR angiography for stenosis and occlusion were, respectively, 95% and 95% for reviewer 1 and 96% and 90% for reviewer 2. The specificities of hybrid MR angiography for stenosis and occlusion were, respectively, 98% and 98% for reviewer 1 and 98% and 99% for reviewer 2. In 25 patients (81%), the quality of bolus chase MR angiography images was insufficient to assess runoff arteries. All treatments proposed on the basis of DSA findings were endorsed by hybrid MR angiography findings. Eleven more treatments were formulated on the basis of hybrid MR angiography findings. Of these, four were due to overestimation of stenosis on MR angiography and seven were due to the detection of patent infrageniculate arteries on hybrid MR angiography that were not detected on DSA. CONCLUSION: Hybrid MR angiography depicts runoff arteries not seen on DSA. Hybrid MR angiography may be useful for treatment planning in selected diabetic patients with critical limb ischemia.     

Peripheral vascular occlusive disease: evaluation with contrast-enhanced moving-bed MR angiography versus digital subtraction angiography in 106 patients

OBJECTIVE: The purpose of our study was to compare contrast-enhanced moving-bed MR angiography and digital subtraction angiography in the evaluation of peripheral vascular occlusive disease. MATERIALS AND METHODS: This retrospective report includes 106 patients (45 women, 61 men) with known or suspected peripheral vascular occlusive disease who underwent MR angiography and intraarterial digital subtraction angiography of the peripheral arteries. MR angiography was performed on a 1.0-T unit using a moving-bed technique. Every leg was divided into 14 vascular segments, and severity of disease was scored in four categories. Digital subtraction angiography was the standard of reference. RESULTS: In the 106 patients, 2378 vessel segments were evaluated with both imaging modalities. In 2156 segments, MR angiography and digital subtraction angiography were concordant for stenosis classification, in 188 segments the two modalities differed in one category, and in 24 segments they differed in two categories. MR angiography achieved sensitivity and specificity of 96.7% and 95.8%, respectively, for differentiating nonsignificant from hemodynamically significant stenosis (kappa = 0.91). CONCLUSION: This study indicates that MR angiography is an accurate imaging modality in clinical practice. Our data support the concept that MR angiography can modify the diagnosis of suspected peripheral vascular occlusive disease.     

Carotid arterial stenosis: evaluation at CT angiography with the volume-rendering technique.

PURPOSE: To determine whether computed tomographic (CT) angiography with the volume-rendering technique (VRT) can be used to accurately quantify carotid arterial stenosis and to identify occlusions. MATERIALS AND METHODS: Spiral CT was performed in 23 patients who were referred for carotid stenosis evaluation. VRT images and shaded-surface display (SSD) images of 46 carotid arterial bifurcations were compared with findings from digital subtraction angiography (DSA). RESULTS: Agreement on stenosis category between VRT CT angiography and DSA was found in 39 (85%) of the 46 carotid arteries studied. VRT CT angiography was 92% (49 of 53) sensitive and 96% (82 of 85) specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). Agreement on stenosis category between SSD CT angiography and DSA was found in 38 (83%) of the 46 carotid arteries studied. SSD CT angiography was 91% (48 of 53) sensitive and 93% (79 of 85) specific for the detection of grade 2-3 stenoses. Calcified stenoses were correctly graded at VRT CT angiography in 10 of the 10 cases with heavy mural calcified plaques, while eight of the 10 stenoses were accurately quantified at SSD CT angiography. CONCLUSION: These results indicate that VRT CT angiography is as accurate as SSD CT angiography in the evaluation of carotid arterial bifurcations.     

Multidetector CT angiography of the aortoiliac system and lower extremities: a prospective comparison with digital subtraction angiography

OBJECTIVE: Our objective was to determine whether multidetector CT (MDCT) angiography is an accurate and reliable method of revealing atheroocclusive disease of the aortoiliac system and the lower extremities compared with digital subtraction angiography (DSA). SUBJECTS AND METHODS: Forty-one patients with ischemic legs underwent both MDCT angiography and DSA of the aortoiliac system and the legs. The arterial supply of the legs was divided into 35 segments. Three independent observers rated each segment according to the maximal degree of arterial stenosis. Consensus interpretation was used to calculate the sensitivity and specificity of MDCT angiography in showing arterial occlusions and stenoses of at least 75%. Intertechnique agreement was measured for each anatomic segment, and interobserver agreement was calculated for both techniques. Agreement was quantified using the kappa statistic. RESULTS: The sensitivity and specificity of MDCT angiography for depicting arterial occlusions and stenoses of at least 75% were 88.6% and 97.7%, and 92.2% and 96.8%, respectively. Substantial intertechnique agreement (kappa > 0.4) was present in 102 (97.1%) of 105 arterial segments. Substantial interobserver agreement was present in 104 (99.0%) of 105 comparisons for both MDCT angiography and DSA with an average kappa value of 0.84 for CT and 0.78 for DSA. MDCT angiography showed more patent segments than DSA (1192 vs 1091). All nine segments seen on DSA and not seen on MDCT angiography were in the calves. Of 110 segments seen on MDCT angiography and not seen on DSA, 100 (90.9%) were in the calves. CONCLUSION: MDCT angiography was accurate in showing arterial atheroocclusive disease with reliability similar to DSA. MDCT angiography showed more vascular segments than DSA, particularly within calf vessels.     

Routine Use of Three-Dimensional Contrast-Enhanced Moving-Table MR Angiography in Patients with Peripheral Arterial Occlusive Disease: Comparison with Selective Digital Subtraction Angiography

Purpose To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease. Methods Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA. Results Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, κ = 0.9 ± 0.03) and moderate stenosis (96.5% and 94.3%, κ = 0.9 ± 0.03). Conclusion Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.     

MR angiography of the pedal arteries with gadobenate dimeglumine, a contrast agent with increased relaxivity, and comparison with selective intraarterial DSA

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced MR angiography (i.e., contrast-enhanced MRA [CE-MRA]) of the pedal vasculature with selective digital subtraction angiography (DSA) in patients with peripheral arterial occlusive disease (PAOD). MATERIALS AND METHODS: A total of 22 patients with PAOD were prospectively examined at 1.5T. For contrast enhancement, 0.1 mmol/kg body weight of Gd-BOPTA were applied. MRA consisted of dynamic imaging with acquisition of six consecutive data sets. Acquisition time for each data set was 24 seconds, voxel size was 1.0 x 1.0 x 1.3 mm(3). A total of 20 out of 22 patient underwent selective DSA, two patients fine-needle DSA. DSA and MRA were performed within seven days. Image analysis was independently done by two observers with assessment of overall image quality, motion artifacts, detection of patent vessel segments of the distal calf and pedal vessels, and the number of patent metatarsal arteries. After four weeks, a consensus reading of DSA images was done. A second consensus reading of CE-MRA was performed after a further six weeks. RESULTS: Consensus readings of MRA and DSA revealed higher image quality and fewer motion artifacts for MRA (P = 0.021 and P = 0.008, respectively, sign test); interobserver agreement was good (kappa = 0.78) for image quality, and moderate (kappa = 0.46) for motion artifacts. There were no differences between CE-MRA and DSA in detecting patent vessel segments with a high degree of agreement (kappa = 0.89), and interobserver agreement for MRA was substantial (kappa = 0.89). Significantly more vessels were assessed as partially occluded on DSA than on CE-MRA (P = 0.004). There was a good agreement between DSA and CE-MRA for assessment of relevant vessel stenosis (kappa = 0.61); interobserver agreement for MRA was good (kappa = 0.65). CE-MRA detected significantly more patent metatarsal arteries than did DSA (P < 0.001). CONCLUSION: Gd-BOPTA-enhanced MRA is comparable to DSA for assessment of the pedal vasculature, and is able to delineate significantly more patent vessels without segmental occlusions and more metatarsal arteries than selective DSA.     

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.     

Multidetector row CT angiography of the lower limb arteries: a prospective comparison of volume-rendered techniques and intra-arterial digital subtraction angiography

AIM: To assess whether multi-detector CT angiograms (MDCTA) of the lower limb arteries, compared with conventional digital subtraction angiograms (DSA), could replace invasive arteriography in patients with symptomatic peripheral arterial disease. MATERIALS AND METHODS: In a prospective comparative analysis of MDCTA and DSA in 44 patients, MDCTA was analyzed using volume-rendered images acquired at a workstation and viewed in tandem with the original axial data. Designated arterial segments were graded according to their degree of stenosis. RESULTS: We found agreement for the degree of stenosis in 88.8% and 85.4% of 1024 segments analysed for two observers. The sensitivity for treatable lesions (>50% stenosis) was 79.1% and 72% with a specificity of 93.3% and 92.6%. DSA failed to visualize 7.3% of segments that were visible with MDCTA. These segments were exclusively downstream to long segment occlusions. CONCLUSION: MDCTA using 4-slice machines is insensitive to detecting significant arterial stenoses in the lower limb arteries. MDCTA is superior to DSA in its visualization of arterial territories downstream to significant occlusive disease.     

Whole-body 3D MR angiography of patients with peripheral arterial occlusive disease

OBJECTIVE: We assessed the diagnostic performance of whole-body 3D contrast-enhanced MR angiography in comparison with digital subtraction angiography (DSA) of the lower extremities in patients with peripheral arterial occlusive disease. SUBJECTS AND METHODS. Fifty-one patients with clinically documented peripheral arterial occlusive disease referred for DSA of the lower extremity arterial system underwent whole-body MR angiography on a 1.5-T MR scanner. Paramagnetic gadobutrol was administered and five contiguous stations were acquired with 3D T1-weighted gradient-echo sequences in a total scanning time of 72 sec. DSA was available as a reference standard for the peripheral vasculature in all patients. Separate blinded data analyses were performed by two radiologists. Additional vascular disease detected by whole-body MR angiography was subsequently assessed on sonography, dedicated MR angiography, or both. RESULTS: All whole-body MR angiography examinations were feasible and well tolerated. AngioSURF-based whole-body MR angiography had overall sensitivities of 92.3% and 93.1% (both 95% confidence intervals [CIs], 78-100%) with specificities of 89.2% and 87.6% (both CIs, 84-98%) and excellent interobserver agreement (kappa = 0.82) for the detection of high-grade stenoses. Additional vascular disease was detected in 12 patients (23%). CONCLUSION: Whole-body MR angiography permits a rapid, noninvasive, and accurate evaluation of the lower peripheral arterial system in patients with peripheral arterial occlusive disease, and it may allow identification of additional relevant vascular disease that was previously undetected.     

Spiral CT angiography and selective digital subtraction angiography of internal carotid artery stenosis.

PURPOSETo determine whether spiral CT angiography allows accurate, quantitative evaluation of anatomic abnormalities, including detection of additional lesions, delineation of plaque morphology, and estimation of degree of internal carotid artery stenosis.METHODSSpiral CT angiography with a maximum intensity projection technique was compared with selective digital subtraction angiography (DSA) in 92 carotid arteries. The category of stenosis was determined according to the North American Symptomatic Carotid Endarterectomy Trial: mild (0% to 29%), moderate (30% to 69%), severe (70% to 99%), and occlusion (100%).RESULTSIn 78 (85%) of the 92 cases, spiral CT angiography and selective DSA demonstrated the same degree of stenosis. All occlusions (n = 19) were diagnosed correctly with spiral CT angiography. Spiral CT angiography agreed with selective DSA in the classification of stenosis in 59% of the group with mild stenosis, in 82% of the group with moderate stenosis, and in 90% of the group with severe stenosis. In the groups with mild (n = 13), moderate (n = 9), and severe (n = 27) stenosis, correlation of spiral CT angiography with selective DSA was significant. Calcified plaques were readily diagnosed with the use of spiral CT angiography but delineation of ulcers was poor. Tandem lesions were not visible owing to the limited coverage.CONCLUSIONSpiral CT angiography is useful for the detection of proximal internal carotid stenoses that are greater than 30%. Depiction of mild stenoses appears to be limited. CT is superior for the detection of calcified plaques but it is not useful for the detection of ulcers.     

多层螺旋CT血管成像与外周动脉疾病治疗方案选择

目的：探讨以多层螺旋CT血管成像（MDCTA）为依据制定外周动脉闭塞性疾病（PAOD）治疗方案的可靠性。方法：对38例PAOD患者的MDCTA检查资料和其中20例数字减影血管造影（DSA）资料进行回顾性分析。由血管外科专家采用盲法分别根据MDCTA和DSA诊断结果为主要依据并结合临床症状、体征进行分析,对病变血管段制定出治疗方案。结果：通过CTA和DSA两种检查方法共评价了402段血管,两种方法选择的治疗方案差异无统计学意义,χ2=3.4,P=0.493。结论：MDCTA大范围血管成像是准确、无创的检查技术,以MDCTA发现为主要依据制定治疗方案是非常准确的。