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PubMed1996

Lower extremity angiography: improved image quality and outflow vessel detection with bilaterally antegrade selective digital subtraction angiography. A blinded prospective intraindividual comparison with aortic flush digital subtraction angiography.

RATIONALE AND OBJECTIVES: To introduce routine bilaterally antegrade selective stationary digital subtraction angiography (DSA), and prospectively compare it with unselective stationary DSA in the detection of calf arteries and assess additional time and complication rate. METHODS: Twenty-five patients received one unselective and two separate antegrade selective studies of each calf. Images were evaluated for image quality, number of depicted run-off vessels, and potential crural bypass recipient arteries. RESULTS: Bilaterally antegrade selective DSA was significantly superior in image quality and motion artifacts (P < 0.01). The number of adequately depicted run-off arteries per calf increased from 79% (2.37 of 3) to 96% (2.89 of 3) for legs with advanced peripheral vascular disease (PVD). Seventy-nine instead of 62 potential bypass recipients were identified (P = 0.002). Mean procedure time needed for selective catheterizations was 7 minutes. No adverse events were seen. CONCLUSIONS: Bilaterally antegrade selective DSA clearly is superior to aortic run-off DSA depicting tibial arteries. It requires comparatively small additional effort. Outflow vessel detection essentially is independent of advanced PVD.

Aged↗

PubMed1988

[Angiography in peripheral arterial occlusive disease. Comparison between large-format angiography, digital subtraction angiography and intermediate-format technic].

With peripheral venous injection of contrast medium, DSA serves to diagnose occlusive peripheral arterial disease in some 90% of cases. Indications for iv-DSA are occlusions and stenoses in the area of the iliac and femoral arteries, as well as in the proximal lower leg. Intraarterial DSA with fine needle is additionally indicated in some 10% of patients for examination of the distal lower leg arteries. In non-diagnostic DSA, conventional angiography using 100-mm technique may be performed with the same angiographic unit.

Angiography↗

PubMed2000

Idiopathic ischemic cerebral infarction in childhood: depiction of arterial abnormalities by MR angiography and catheter angiography.

BACKGROUND AND PURPOSE: We report our experience with MR imaging, MR angiography, and catheter angiography in children with acute idiopathic cerebral infarction and suggest that catheter angiography may still play an important role in this setting. METHODS: During the past 8 years, 18 children with idiopathic cerebral infarction underwent MR imaging and catheter angiography; 17 were also studied with MR angiography. MR imaging was done within 34 hours after onset of hemiplegia or seizures or both. Sixteen patients underwent catheter angiography within 36 hours of MR imaging; 12 studies were performed within 22 hours. Two patients underwent catheter angiography, in both cases within 72 hours. Infarcts were compared with arterial abnormalities seen at catheter angiography, and the results of MR angiography were compared with those seen at catheter angiography. RESULTS: Comparing MR angiography with catheter angiography, we found the positive predictive value of MR angiography for arteriopathy was 100%, with a negative predictive value of 88%. MR angiography was equivalent to catheter angiography in the detection and depiction of proximal middle cerebral artery disease; however, depiction of disease in the internal carotid artery (ICA) and detection of peripheral embolic disease were better with catheter angiography than MR angiography. CONCLUSION: Basal ganglia lesions associated with ICA disease by MR angiography should probably be studied with digital subtraction angiography, as MR angiography did not depict the length and severity of ICA disease as well as catheter angiography did. Hemispheric infarcts should be studied with catheter angiography, as emboli may occur in the absence of heart disease; the circle of Willis may be uninvolved with embolic disease, and MR angiography is not sensitive to emboli in small peripheral intracranial arteries.

Acute Disease↗

PubMed2002

High-resolution multiphase contrast-enhanced three-dimensional MR angiography compared with two-dimensional time-of-flight MR angiography for the identification of pedal vessels.

PURPOSE: The authors prospectively evaluated optimized multiphase high-resolution (HR) Gadolinium (Gd)-enhanced three-dimensional (3D) magnetic resonance (MR) angiography and standard two-dimensional (2D) time-of-flight (TOF) MR angiography for their ability to delineate distal calf and pedal vessels. MATERIALS AND METHODS: Twelve patients (20 limbs) with limb-threatening peripheral arterial occlusive disease underwent HR Gd-enhanced and 2D TOF MR angiography to identify targets for distal bypass. Imaging of the region of the ankle and foot was performed on a 1.5 T system with a head coil. A standard 2D TOF MR angiography sequence was performed first. The HR Gd-enhanced MR angiography sequence was then performed after injection of 0.01-0.2 mmol/kg of gadodiamide, allowing the acquisition of multiple consecutive coronal partitions, each in 18-25 seconds. Two experienced angiographers independently analyzed both studies. Comparison with intraoperative conventional angiography was available in 10 limbs. RESULTS: HR Gd-enhanced MR angiography allowed significantly faster imaging time (P <.0001) and larger coverage area (P <.0001) than 2D TOF MR angiography. All segments seen on 2D TOF MR angiography were visualized on HR Gd MR angiography, and significantly more suitable targets were seen well on HR Gd-enhanced MR angiography than on 2D TOF MR angiography (mean targets per limb: 3.9 +/- 1.9 vs 2.6 +/- 1.5, respectively; P =.02). In addition, HR Gd-enhanced MR angiography allowed better visualization of the arcuate pedal branch than 2D TOF MR angiography (P <.0001). Excellent correlation was demonstrated between HR Gd-enhanced MR angiography and intraoperative angiography in 29 segments (binary similarity coefficient, 0.90). A significantly higher percentage of artifacts adversely affected image interpretation with 2D TOF MR angiography than with HR Gd-enhanced MR angiography (14 limbs vs five limbs, P <.001). Artifacts on HR Gd-enhanced MR angiography included suboptimal mask in two limbs, venous contamination in one patient (two limbs), and motion artifact in one limb, although the studies remained diagnostic in all cases. CONCLUSION: HR Gd-enhanced MR angiography identified more distal target vessels with greater confidence than 2D TOF MR angiography. Optimized HR Gd-enhanced MR angiography may replace 2D TOF MR angiography as the gold standard examination for evaluation of distal runoff.

Ankle↗

PubMed2002

Comparison of intraarterial and IV gadolinium-enhanced MR angiography with digital subtraction angiography for the detection of renal artery stenosis in pigs.

OBJECTIVE: Catheter-based intraarterial injections of gadolinium are useful during MR imaging-guided endovascular procedures to generate rapid vascular road maps. Using an animal model of renal artery stenosis, we tested the hypothesis that intraarterial gadolinium-enhanced MR angiography is as accurate as IV gadolinium-enhanced MR angiography and digital subtraction angiography (DSA). We also tested the hypothesis that intraarterial MR angiography uses less gadolinium than IV MR angiography. MATERIALS AND METHODS: We induced bilateral renal artery stenosis in five pigs. All pigs underwent comparative imaging with DSA, IV MR angiography, and aortic catheter-directed intraarterial MR angiography. For IV and intraarterial MR angiography, we used the same three-dimensional acquisition. We assessed differences in quantitative stenosis measurements among DSA, IV MR angiography, and intraarterial MR angiography using the Wilcoxon's signed rank test. RESULTS: Mean stenosis measurements (+/-SD) were as follows: DSA, 58% +/- 12%; IV MR angiography, 63% +/- 9.3%; and intraarterial MR angiography, 64% +/- 11%. There were no statistically significant differences in accuracy between DSA and IV MR angiography (p = 0.06), DSA and intraarterial MR angiography (p = 0.16), or IV and intraarterial MR angiography (p = 0.70). Intraarterial MR angiography used a mean gadolinium dose of 5.6 mL, compared with 9 mL for IV MR angiography. CONCLUSION: In swine, IV and intraarterial MR angiography have a similar accuracy for detecting renal artery stenosis. Intraarterial MR angiography uses smaller doses of injected gadolinium.

Angiography, Digital Subtraction↗

PubMed1993

Treatment of arteriovenous malformations with stereotactic radiosurgery employing both magnetic resonance angiography and standard angiography as a database.

Twenty-one arteriovenous malformations were prospectively evaluated using magnetic resonance angiography and compared with stereotactic angiography. The goals were to establish the feasibility of magnetic resonance angiography, compare it to stereotactic angiography, employ magnetic resonance angiography in follow-up, and semiquantify flow. A correlative evaluation between flow and response to stereotactic radiosurgery was carried out. Phase contrast angiograms were obtained at flow velocities of 400, 200, 100, 60, and 20 cm/sec. The fractionated velocities provided images that selectively demonstrated the arterial and venous components of the arteriovenous malformations. Qualitative assessment of the velocity within the arteriovenous malformations and the presence of fistulae were also determined by multiple velocity images. In addition, 3-dimensional time-of-flight magnetic resonance angiograms were obtained to define the exact size and shape of the nidus. This technique also permitted evaluation of the nidus and feeding arteries for the presence of low flow aneurysms. Correlation between the two imaging modalities was carried out by subjective and semiquantitative estimation of flow velocity and estimation of nidus size. The following velocity parameters were employed: fast, intermediate, slow, and none (arteriovenous malformation obliterated). In 19 of 21 (90.5%) arteriovenous malformations, magnetic resonance angiography was equal or superior to stereotactic angiography for flow quantification and visualization of the nidus. Only 2 of 21 arteriovenous malformations were better demonstrated by stereotactic angiography than by magnetic resonance angiography (failure rate of 9.5%). The nidus size in one case was clearly underestimated by stereotactic angiography and would have resulted in a geographic miss without magnetic resonance angiography. Seven post-radiosurgery arteriovenous malformations were evaluated for follow-up with both magnetic resonance angiography and stereotactic angiography. In 6 of 7 arteriovenous malformations, magnetic resonance angiography response matched stereotactic angiography response. Correlation of flow with outcome was carried out for 14 arteriovenous malformations using magnetic resonance angiography only. Interestingly, all nine arteriovenous malformations with intermediate or slow flow demonstrated partial or complete obliteration; whereas only 3 of 5 fast flow arteriovenous malformations achieved a response with a median follow-up of 10 months. This early analysis suggests that slower flowing arteriovenous malformations may obliterate faster after stereotactic radiosurgery and flow parameters could be employed to predict response. In conclusion, magnetic resonance angiography permits semiquantitative flow velocity assessment and may therefore be superior to stereotactic angiography. An additional advantage of magnetic resonance angiography is the generation of serial transverse images which can replace the conventional CT scan employed for stereotactic radiosurgery treatment planning.(ABSTRACT TRUNCATED AT 400 WORDS)

Cerebral Angiography↗

PubMed2005

Interobserver agreement for the interpretation of contrast-enhanced 3D MR angiography and MDCT angiography in peripheral arterial disease.

OBJECTIVE: The objective of our study was to compare interobserver agreement for interpretations of contrast-enhanced 3D MR angiography and MDCT angiography in patients with peripheral arterial disease. SUBJECTS AND METHODS: Of 226 eligible patients, 69 were excluded. The remaining 157 consecutive patients were prospectively randomized to either MR angiography (n = 78) or MDCT angiography (n = 79). Two observers independently evaluated for arterial stenosis or occlusion on MR angiography (2,157 segments) and MDCT angiography (2,419 segments) using a 5-point ordinal scale. Vessel wall calcifications were noted. Interobserver agreement for each technique was evaluated with a weighted kappa (kappa(w)) statistic. RESULTS: Although interobserver agreement for both was excellent, the interobserver agreement for MR angiography (kappa(w) = 0.90; 95% confidence interval [CI], 0.89-0.92) was higher than that for MDCT angiography (kappa(w) = 0.85; 95% CI, 0.83-0.86) for reporting the degree of arterial stenosis or occlusion in all segments. For the different anatomic locations, the interobserver agreement for MR angiography versus MDCT angiography was as follows: aortoiliac (kappa(w) =0.91 vs 0.84, respectively), femoropopliteal (kappa(w) = 0.91 vs 0.87), and crural (kappa(w) = 0.90 vs 0.83) segments. The interobserver agreement of MDCT angiography significantly decreased in the presence of calcifications but was still good for all anatomic locations. The lowest agreement was found for crural segments in the presence of calcifications (kappa(w) = 0.67). With MR angiography, there were 12 times more nondiagnostic segments than with MDCT angiography (81 vs 7, respectively). CONCLUSION: Interpretations of MR angiography and MDCT angiography for peripheral arterial disease have an excellent interobserver agreement. MR angiography has a higher interobserver agreement than MDCT angiography, and the presence of calcified segments significantly decreases interobserver agreement for MDCT angiography.

Adult↗

PubMed2003

Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests.

OBJECT: The aim of this study was to assess the diagnostic yield of imaging tests performed in patients in whom the cause of subarachnoid hemorrhage (SAH) had not been demonstrated on initial angiography. METHODS: By reviewing medical records of 806 patients with SAH who had been admitted during a 6.5-year period, the authors identified 86 in whom initial transfemoral catheter angiography failed to reveal the cause of SAH. Clinical and radiological data were analyzed to determine the diagnostic yield of subsequent catheter angiography, computerized tomography (CT) angiography, magnetic resonance (MR) angiography, and MR imaging of the brain and spine for various subtypes of SAH (bleeding not visualized on CT studies [CT-negative SAH], perimesencephalic SAH, and nonperimesencephalic SAH). Of 41 patients with nonperimesencephalic SAH, 36, 32, and 21 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 23 patients (18 with Gd and 15 with susceptibility contrast sequences), and spine MR imaging in 17. Of 36 patients with perimesencephalic SAH, 31, 23, and 17 underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in 18 patients (17 with Gd and 11 with susceptibility contrast sequences), and spine MR imaging in 14. Of nine patients with SAH not visualized on CT scanning, three, one, and six underwent repeated catheter angiography, CT angiography, and MR angiography, respectively; brain MR imaging was performed in eight patients (five with Gd and three with susceptibility contrast sequences), and spine MR imaging in seven. The cause of SAH could be determined in only four patients, all with nonperimesencephalic SAH. The only test that yielded a diagnosis was catheter angiography (three aneurysms on the second and one on the third angiography, all surgically secured). Diffusion-weighted MR imaging demonstrated small, deep infarcts in five patients. CONCLUSIONS: Repeated catheter angiography remains the most sensitive test to determine the cause of SAH that is not demonstrated on initial angiography, particularly in the subtype of nonperimesencephalic SAH. Newer, noninvasive imaging techniques provide little diagnostic yield.

Adult↗

PubMed2000

Multidirectional depiction of internal carotid arterial stenosis: three-dimensional time-of-flight MR angiography versus rotational and conventional digital subtraction angiography.

PURPOSE: To evaluate whether and to what extent greater number of projection images obtained at three-dimensional (3D) time-of-flight (TOF) magnetic resonance (MR) angiography versus conventional digital subtraction angiography (DSA) causes overestimation of internal carotid arterial (ICA) stenosis. MATERIALS AND METHODS: DSA (two or three projections), rotational angiography (16 or 32 projections), and 3D TOF MR angiography (12 projections) were performed in 47 stenotic ICAs of 38 symptomatic patients. Two observers independently measured maximum stenosis, and the mean differences among MR angiography, DSA, and rotational angiography were compared. RESULTS: Three rotational and five MR angiograms were nondiagnostic. Seven MR angiograms of ICA stenoses showed a signal void and were excluded from analysis. On the remaining 32 angiograms, mean differences in maximum stenosis for observers 1 and 2, respectively, were 7% (95% CI: 3%, 12%) and 8% (95% CI: 3%, 13%) at MR angiography versus DSA and 2% (95% CI: -2%, 7%) and -1% (95% CI: -5%, 3%) at MR angiography versus rotational angiography. ICA stenosis was graded significantly higher at MR angiography versus DSA, whereas, it was not overestimated at MR angiography versus rotational angiography. The difference in maximum stenosis at MR angiography versus DSA was significantly different from that of MR angiography versus rotational angiography. CONCLUSION: Apparent overestimation of ICA stenosis at 3D TOF MR angiography versus conventional DSA may be partly explained by the greater number of projection images available at 3D TOF MR angiography.

Aged↗

PubMed2001

Intracranial aneurysms: CT angiography and MR angiography for detection prospective blinded comparison in a large patient cohort.

PURPOSE: To compare computed tomographic (CT) angiography and magnetic resonance (MR) angiography with intraarterial digital subtraction angiography (DSA) in the detection of intracranial aneurysms. MATERIALS AND METHODS: One hundred forty-two patients underwent intraarterial DSA to detect aneurysms. CT angiography, three-dimensional time-of-flight MR angiography, and intraarterial DSA were performed contemporaneously. Film hard-copy images and maximum intensity projection reconstructions of the CT angiograms and MR angiograms were reviewed at different times. RESULTS: The accuracy per patient for the best observer was 0.87 at CT angiography and 0.85 at MR angiography. The accuracy per aneurysm for the best observer was 0.73 at CT angiography and 0.67 at MR angiography. Differences between readers and modalities were not significant. Interobserver agreement was good: kappa value of 0.73 for CT angiography and of 0.74 for MR angiography. The sensitivity for detection of aneurysms smaller than 5 mm was 0.57 for CT angiography and 0.35 for MR angiography compared with 0.94 and 0.86, respectively, for detection of aneurysms 5 mm or larger. The accuracy of both CT angiography and MR angiography was lower for detection of internal carotid artery aneurysms compared with that at other sites. With low observer confidence, the likelihood of correct interpretation was significantly poorer. CONCLUSION: CT angiography and MR angiography have limited sensitivity in the detection of small aneurysms but good interobserver agreement. There is no significant difference in diagnostic performance between the noninvasive modalities.

Adult↗

PubMed2005

Preoperative cerebral aneurysm assessment by three-dimensional magnetic resonance angiography: feasibility of surgery without conventional catheter angiography.

OBJECTIVE: In this study, we aimed to assess whether surgery could be performed in patients with cerebral aneurysms by using three-dimensional (3-D) magnetic resonance (MR) angiography alone, without conventional catheter angiography. METHODS: A total of 108 patients who had undergone MR angiography and aneurysm surgery between January 1998 and January 2004 were enrolled in this study. The study subjects included 49 patients without subarachnoid hemorrhage (SAH) and 59 patients with SAH. RESULTS: In our preliminary study, 13 patients without SAH were diagnosed using 3-D MR angiography compared with catheter angiography and 3-D computed tomographic angiography before surgery. The 3-D MR angiography demonstrated all 18 unruptured aneurysms that were detected by catheter angiography. Thirty-six patients without SAH and 59 patients with SAH were examined using 3-D MR angiography. In 33 patients (91.6%) without SAH and 56 patients (94.9%) with SAH, we were able to reach a diagnosis on the basis of 3-D MR angiography alone. A majority of aneurysms were regular-sized and located in the anterior part of the circle of Willis. A total of 89 patients (93.7%) who underwent surgery with the aid of 3-D MR angiography alone were treated successfully and had no complications related to the lack of information that might have been gathered by catheter angiography. The 3-D MR angiography provided the authors with the aneurysm locations as well as with surgically important information regarding the configuration of the aneurysmal sac and neck and its relationship with the surrounding vessels. In the remaining 6 patients, 3-D MR angiography was followed by catheter angiography to acquire additional diagnostic confirmation. CONCLUSION: The results of this study support the notion that 3-D MR angiography can replace conventional catheter angiography for preoperative assessment in the majority of regular-sized anterior circulation aneurysms.

Carotid Artery, Internal↗

PubMed1996

Cardiac-gated MR angiography of the entire lower extremity: a prospective comparison with conventional angiography.

OBJECTIVE: The purpose of this study was to prospectively evaluate cardiac-gated two-dimensional (2D) time-of-flight MR angiography in patients with peripheral arterial occlusive disease (PAOD). SUBJECTS AND METHODS: Twenty-three patients with PAOD were studied using cardiac-gated 2D time-of-flight MR angiography in the body coil from each patients' aortic bifurcation to the pedal arches. Blinded comparison with conventional angiograms was used to determine sensitivity, specificity, and positive and negative predictive values of this MR angiography technique. Kappa statistics were used to compare treatment plans of these patients studied with MR angiography and with conventional angiography. RESULTS: In the aortoiliac region, MR angiography had a correlation coefficient of .89 for all degrees of narrowing. For hemodynamically significant lesions, MR angiography had an 89% sensitivity, 98% specificity, 84% positive predictive value, and 99% negative predictive value. In the femoral region, MR angiography had a correlation coefficient of .91 for all degrees of narrowing. For hemodynamically significant lesions, MR angiography had an 89% sensitivity, 98% specificity, 93% positive predictive value, and 97% negative predictive value. In the popliteal region, MR angiography had a correlation coefficient of .93 for all degrees of narrowing. For hemodynamically significant lesions, MR angiography had an 89% sensitivity, 98% specificity, 94% positive predictive value, and 95% negative predictive value. In the tibioperoneal and foot regions, MR angiography had a correlation coefficient of 88% for all degrees of narrowing. For hemodynamically significant lesions, MR angiography had an 86% sensitivity, 93% specificity, 89% positive predictive value, and 91% negative predictive value. When the treatment planning data were classified into one of four outcomes (no intervention, surgery, percutaneous angioplasty, or further diagnostic study), MR angiography and conventional angiography had excellent agreement, with a Cohen's kappa value of .78. CONCLUSION: Cardiac-gated 2D time-of-flight MR angiography that uses the body coil provides a useful examination for PAOD with reasonable resolution. This imaging technique is potentially more time-efficient than techniques using extremity coils.

Aged↗

PubMed2005

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.

Adult↗

PubMed2000

Use of spiral computerized tomography angiography in patients with subarachnoid hemorrhage in whom subtraction angiography did not reveal cerebral aneurysms.

OBJECT: Patients with subarachnoid hemorrhage (SAH) in whom angiography does not demonstrate diagnostic findings sometimes suffer recurrent disease and actually harbor undetected cerebral aneurysms. The management strategy for such cases remains controversial, but technological advances in spiral computerized tomography (CT) angiography are changing the picture. The purpose of this prospective study was to examine how spiral CT angiography can contribute to the detection of cerebral aneurysms that cannot be visualized on angiography. METHODS: In 134 consecutive patients with SAH, a prospective search for the source of bleeding was performed using digital subtraction (DS) and spiral CT angiography. In 21 patients in whom initial DS angiography yielded no diagnostic findings, spiral CT angiography was performed within 3 days. Patients in whom CT angiography provided no diagnostic results underwent second and third DS angiography sessions after approximately 2 weeks and 6 months, respectively. Six patients with perimesencephalic SAH were included in the 21 cases. Six of the other 15 patients had small cerebral aneurysms detectable by spiral CT angiography, five involving the anterior communicating artery and one the middle cerebral artery. Two patients in whom initial angiograms did not demonstrate diagnostic findings proved to have a ruptured dissecting aneurysm of the vertebral artery; in one case this was revealed at autopsy and in the other during the second DS angiography session. A third DS angiography session revealed no diagnostic results in 13 patients. CONCLUSIONS: Spiral CT angiography was useful in the detection of cerebral aneurysms in patients with SAH in whom angiography revealed no diagnostic findings. Anterior communicating artery aneurysms are generally well hidden in these types of SAH cases. A repeated angiography session was warranted in patients with nonperimesencephalic SAH and in whom initial angiography revealed no diagnostic findings, although a third session was thought to be superfluous.

Adult↗

PubMed1997

[Diagnosis of unruptured cerebral aneurysms using magnetic resonance angiography and three dimensional computed tomographic angiography].

The purpose of this study is to confirm the use of magnetic resonance (MR) angiography and three-dimensional computed tomographic (3D CT) angiography, in the screening of unruptured cerebral aneurysms. Sixty-six unruptured cerebral aneurysms in forty-eight patients were examined by MR angiography, 3D CT angiography and digital subtraction angiography (DSA). All cases underwent surgery. Three out of sixty-six (4.5%) cerebral aneurysms detected by MR angiography and 3D CT angiography were false positive. The false aneurysms were located at the region of the internal carotid artery and the posterior communicating artery, and were under 2.0mm in size. The diagnosis of the infundibular dilatation at the junction of the internal carotid artery and the posterior communicating artery remained difficult. The true positive diagnosis of aneurysms using MR angiography or 3D CT angiography was 95.5%, in our hospital. All unruptured cerebral aneurysms over 2.0mm in size were detected correctly by using MR angiography and 3D CT angiography, as well as DSA. The inadequate diagnosis of aneurysms caused by MR angiography was due to the overlapping of vessels and the surrounding noise. Superselective maximum intensity projection (MIP) and interactive vascular imaging (IVI) were adopted for exact diagnosis. Furthermore, the three slab method of MR angiography was used for containing the limits between the vertebral artery and the distal anterior cerebral artery, and the triple method was able to decrease surrounding noise. Using MR angiography, we diagnosed and operated on about 100 cases of unruptured cerebral aneurysm in one year. Our conclusion is that we can diagnose any unruptured cerebral aneurysm, over 2.0mm in size, using MR angiography and 3D CT angiography.

Adult↗

PubMed1996

MR angiography of renal artery stenosis: value of the combination of three-dimensional time-of-flight and three-dimensional phase-contrast MR angiography sequences.

OBJECTIVE: It has been reported and also has been our preliminary experience that many false ostial stenoses are attributable to a loss of signal intensity at the origin of the renal arteries when three-dimensional (3D) phase-contrast MR angiography is used. Our objective was to add a 3D time-of-flight MR angiography sequence to the 3D phase-contrast MR angiography sequence to better analyze the origin of the main renal arteries. We assessed the value of the combination of these two MR angiography sequences for the depiction of renal artery stenosis. SUBJECTS AND METHODS: Forty-six patients suspected of having renal artery stenosis on the basis of clinical history, physical examination, and laboratory data were prospectively enrolled. Intraarterial digital subtraction angiography findings were available for all patients. Using intraarterial digital subtraction angiography, we considered stenosis to be significant when the vessel was narrowed more than 50%. During MR angiography, half of the data were reconstructed by interpolation to avoid long acquisition times. Total acquisition times were less than 15 min. MR angiography findings were interpreted independently by two radiologists who were unaware of the findings of intraarterial digital subtraction angiography. With 3D phase-contrast MR angiography, any cutoff in signal intensity or any narrowing of the vessel diameter of more than 50% from the renal ostium to the renal hilum was considered to represent significant stenosis. With 3D time-of-flight MR angiography, our image analysis was focused on the origin of the arteries. Any cutoff in signal intensity in the first centimeter of the renal artery was considered to represent significant stenosis. RESULTS: Intraarterial digital subtraction angiography showed 105 renal arteries, including 15 supernumerary renal arteries. Eleven stenoses were localized to the main hilar renal arteries. Using time-of-flight MR angiography, we found that polar supernumerary renal arteries of small caliber and intrarenal branches of renal arteries were not adequately displayed. Using phase-contrast MR angiography to evaluate only whether the main hilar renal arteries were stenotic, we calculated the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy to be 100%, 65%, 28%, 100%, and 69%, respectively. Using a combination of the two imaging sequences, we found that the specificity, positive predictive value, and accuracy were increased to 90%, 58%, and 92%, respectively. CONCLUSION: For detecting stenoses of the main renal arteries but not for visualizing small accessory renal arteries or distal branches, our results support the use of a combination of the two MR angiography sequences. For now, this combination of sequences should be viewed primarily as a technique for screening patients.

Adult↗

PubMed2001

[Comparison of digital subtraction angiography, CT angiography, and ultrasonic Doppler examination in the evaluation of penile arterial lesions].

BACKGROUND: CT angiography reconstructed by a multidetector-row helical CT scanner is a newly developed form of imaging. We compared CT angiography and ultrasonic Doppler examination with digital subtraction angiography (DSA) in the diagnosis of arterial lesion. METHOD: Eighteen patients with arteriogenic erectile dysfunction (ED) underwent color Doppler study, DSA, and CT angiography after providing informed consent. The CT angiography images were obtained by a multidetector-row helical CT scanner, Asteion TSX021A (TOSHIBA). We injected prostaglandin E1 into the penile cavernous body, and then rapidly infused nonionic contrast medium into the antecubital vein. DSA and CT angiography images of the bilateral internal pudendal arteries and cavernous arteries were examined for stenotic lesions or occlusion. We also compared the peak systolic blood flow velocity in the cavernous artery measured by color Doppler ultrasound with CT angiography and DSA. RESULTS: The CT angiography and color Doppler studies were performed on an outpatient basis, but DSA required hospitalization. In the 36 internal pudendal arteries, DSA represented 22 normal arteries and 14 stenosis or occlusions. CT angiography showed 15 normal arteries and 21 occlusions. For the diagnosis of stenosis or occlusion in the internal pudendal artery, the CT angiography image had a good agreement, with a sensitivity of 1.00, specificity of 0.68, and accuracy of 0.81. For diagnosis in the cavernous artery, CT angiography image also showed a good agreement with DSA; however, the quality of the images of fine arteries was better in the DSA images. The inferior view and internal view of the pelvis in CT angiography were helpful for visualizing the internal pudendal artery, especially at the pubic bone. There was insufficient correlation between peak systolic blood flow velocity and DSA findings. There were no serious complications involved in either examination. CONCLUSIONS: CT angiography has not yet reached the same level as DSA in the evaluation of fine arteries. However, CT angiography can produced images sufficient for the diagnosis of arteriogenic ED with some advantages. We believe that with improvement, CT angiography will become an adequate replacement for DSA in the diagnosis of penile arterisl lesion.

Adult↗

PubMed2000

Utility of CT angiography and MR angiography for the follow-up of experimental aneurysms treated with stents or Guglielmi detachable coils.

BACKGROUND AND PURPOSE: Previous studies have depicted arterial and aneurysmal anatomy with three-dimensional time-of-flight (3D-TOF) MR angiography before and after treatment with Guglielmi detachable coils (GDCs) and with CT angiography before and after treatment with stents and stent-grafts. We investigated the ability of time-resolved contrast-enhanced 3D MR angiography (3D MR digital subtraction angiography [DSA]) to accurately depict the anatomy of experimental lateral aneurysms before and after treatment with GDCs and a variety of stents or stent-grafts, and compared these findings with 3D-TOF MR angiography without and with contrast enhancement and CT angiography. METHODS: Two nitinol stents, two nitinol-polytetrafluoroethylene (PTFE) stent-grafts, and two stainless steel stents were deployed in three dogs with experimental carotid aneurysms. In a fourth animal, one of three aneurysms was completely occluded with GDCs. The other two aneurysms were loosely packed to ensure persistence of some residual aneurysmal lumen. Cut-film angiography, CT angiography, 3D-TOF MR angiography without and with contrast enhancement, and 3D MR DSA were performed in all dogs before and 3 weeks after treatment. RESULTS: 3D MR DSA was superior to conventional 3D-TOF MR angiography without and with contrast enhancement in accurately depicting experimental lateral aneurysms and superior to CT angiography in depicting aneurysms treated by GDCs. 3D MR DSA and CT angiography were comparable in depicting vessels treated with nitinol stents and stent-grafts, whereas CT angiography was superior for showing vessels treated by stainless steel stents. CONCLUSION: We recommend further development and clinical evaluation of 3D MR DSA for imaging cerebral aneurysms before and after treatment with GDCs. 3D MR DSA or CT angiography may be useful for evaluating vessels containing nitinol stents or nitinol-PTFE stent-grafts, whereas CT angiography should be used for follow-up of vessels treated by stainless steel stents.

Animals↗