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[Comparative assessment of helical CT-angiography, 2D TOF MR-angiography and 3D gadolinium enhanced MRA in aorto-iliac occlusive disease].

PURPOSE: To compare helical CT-angiography (CTA) and two techniques of MR angiography (MRA) to conventional angiography in aorto-iliac occlusive disease. MATERIALS AND METHODS: The abdominal aorta and iliac arteries in 22 patients (4 for preoperative assessment of abdominal aortic aneurysm and 18 for peripheral vascular disease) were imaged using four techniques: digital subtraction angiography ("gold standard"), 2D TOF MR angiography, 3D Gd-enhanced MR angiography and helical CT angiography. Source (CTA and 2D TOF MRA) and MIPed images (after subtraction measures before and after gadolinium injection for 3D Gd-MRA) were reviewed. RESULTS: Sensitivity, specificity and accuracy for the detection of significant (>50%) stenosis and occlusion of aorto-iliac arteries were respectively: 38%, 89%, 77% for 2D TOF MRA; 75%, 71%, 72% for 3D Gd-MRA and 95%, 90%, 92% for CTA. Excluding the internal iliac arteries, results were 54%, 96%, 88% for 2D TOF MRA; 96%, 80%, 83% for 3D Gd-MRA and 92%, 93%, 95% for CTA. CONCLUSION: 3D Gd-MRA, a technique with potential for further improvement, is superior to 2D TOF MRA for detecting significant stenosis and occlusion of aorto-iliac arteries. Results at Gd-MRA are nearly similar to those at CTA (after excluding internal iliac arteries). Results at Gd-MRA are not affected by calcified plaque.

Adult↗

Multisection CT angiography compared with catheter angiography in diagnosing vertebral artery dissection.

BACKGROUND AND PURPOSE: Multisection CT angiography is a minimally invasive technique that can provide high-resolution and high-contrast images of the arterial lumen and wall. To our knowledge, the ability of multisection CT angiography in detecting vertebral artery (VA) dissection has never been evaluated. We assessed the sensitivity and specificity of a routine, standardized, multisection CT angiographic protocol for the detection of VA dissection. METHODS: We retrospectively reviewed multisection CT angiograms of 17 patients with VA dissection and 17 control subjects. The acquisition protocol for multisection CT angiography was 1.25-mm nominal section thickness, a table speed of 7.5 mm per rotation (9.4 mm/s), and a 0.8-second gantry rotation period. Two radiologists assessed the maximum intensity projection and axial source images. The sensitivity and specificity of this technique in depicting VA dissection were determined. RESULTS: Conventional angiography depicted 15 normal and 19 dissected VAs (including five stenotic, seven occlusive, and seven aneurysmal dissections) in the patient group and 28 normal and six atherosclerotic VAs in the control group. Multisection CT angiography enabled successful diagnosis of all 19 dissected VAs and 48 (98%) of 49 nondissected VAs but misidentified a severe atherosclerotic lesion as an aneurysmal-type dissection. The sensitivity, specificity, accuracy, and positive and negative predictive values of multisection CT angiography in diagnosing VA dissection were 100%, 98%, 98.5%, 95%, and 100%, respectively. CONCLUSION: Multisection CT angiography was a sensitive and accurate technique for the diagnosis of VA dissection.

Adult↗

[Digital thermo-coronary angiography--development and validation of the method in comparison with conventional cine-coronary angiography].

We describe the technique-thermal coronary angiography (TCA)-for real-time assessment of coronary anatomy and flow. The goal of this study was to compare thermal coronary angiography to cine coronary angiography and to validate its value for detecting stenoses. We studied the exposed LAD both in beating and arrested hearts in 11 open-chest pigs by TCA and cine angiography. We used an AGA 782 Thermovision system combined with a TIC 8000 digital image processor providing coronary images with 0.1-0.2 mm spatial and 0.1 degrees C thermal resolution, and a CFR x-ray system. The coronary arteries were catheterized via the right carotid artery, using standard 5F catheters. The thermal camera was focused at a 1m-distance to the heart surface and the x-ray was angled to LAO position. We performed simultaneous thermal and cine angiography using Angiovist 370 at different temperatures (10-40 degrees C) and injection rates (1-2.5 ml/s). Different grades of stenoses were created by snares. Thermistor probe readings of the epimyocardium and the left atrial blood were performed to reference the thermal camera measurements. We obtained high resolution TCA images of both the coronaries and of the myocardial perfusion beds whenever there was greater than 4 degrees C difference between injectate and epicardial temperature. The TCA detection of stenoses as compared to cine angiography was 29/30 (96.6%) in arrested and 36/42 (85.7%) in beating hearts. Coronary occlusion produced immediate and dramatic perfusion defects as detected by TCA. TCAs were highly reproducible. Injection rate of 2 ml/s provided optimal thermal coronary images. Thermal angiograms of the LAD were sometimes affected by large crossing coronary veins, myocardial bridges, and excess of fat pretending nonexistent coronary stenosis. TCA is a highly sensitive and reproducible method as compared to standard coronary angiography and allows for detection of coronary stenoses. The image quality was best in arrested hearts.

Animals↗

[Transvenous digital subtraction angiography for the diagnosis of renal artery stenosis in arterial hypertension. A comparison with conventional angiography].

Venous digital subtraction angiography was performed in 248 patients for the diagnosis of renal arterial stenosis. In 88% of the investigations the digital subtraction angiograms were of diagnostic value. Comparison of digital angiography and conventional angiography was made for 57 renal arteries (25 investigations). In 52 renal arteries we found the same results with both methods, in 5 renal arteries the digital angiography showed false positive results. The spatial resolution of digital subtraction angiography is sufficient for the correct diagnosis of significant renal arterial stenosis. With regard to the lower invasion of digital subtraction angiography compared to conventional angiography the first method should be used for clarification of renal arterial hypertension.

Angiography↗

Comparison of MR angiography with X-ray angiography in patients with ischemic cerebrovascular diseases.

MRI angiography and x-ray conventional angiography was performed in 10 patients with ischemic cerebral diseases. In 3 patients, MRI angiography showed narrowing or occlusion of main intracranial arterial trunks, but x-ray angiography confirmed these findings only in one patient. In two other patients, narrowing or occlusion was not observed. Also, no narrowing or occlusion was observed on x-ray angiography, when MRI angiography showed normal findings. It was concluded that MRI angiography was sensitive investigation, when intracerebral occlusive disease was suspected.

Aged↗

Rating the urgency of coronary angiography: results of an expert panel process. Ontario Coronary Angiography Panel.

OBJECTIVE: To rate the urgency of coronary angiography for patients with ischemic heart disease. Ratings were made for patients with varying degrees of symptoms and noninvasive cardiac test results. DESIGN: A panel of 10 cardiologists rated 354 case scenarios which presented varying combinations of clinical factors that may affect urgency. MEASUREMENTS: The case scenarios were rated by each panelist on a waiting time scale consisting of six categories which ranged from the requirement for emergency angiography to a delay of up to three months. A seventh category represented the lack of urgent need for angiography. The contribution of each clinical factor to urgency of coronary angiography was determined. MAIN RESULTS: Symptom class as defined by a modification to the Canadian Cardiovascular Society grading scale for angina pectoris, results of exercise stress tests and results of imaging studies were the major determinants of urgency. In cases of unstable angina, rest electrocardiography is of importance. These factors explained at least 95% of the variance in the case urgency scores. There was agreement by at least five of the panelists on urgency score in 84% of cases. The assigned urgency varied from 6.7, representing no urgent need for angiography, for minimally asymptomatic angina with no positive noninvasive test results, to immediate angiography for cardiogenic shock. Other factors had minimal or negligible effects on urgency. CONCLUSIONS: The urgency of need for coronary angiography was addressed by an explicit method incorporating the judgements of a panel of expert cardiologists, permitting derivation of a scoring system for rating priority of individual patients in the face of waiting lists. These methods illustrate an approach to problems presented by procedure waiting lists.

Adult↗

Accuracy of computed tomographic angiography and magnetic resonance angiography for diagnosing renal artery stenosis.

BACKGROUND: Timely, accurate detection of renal artery stenosis is important because this disorder may be a potentially curable cause of hypertension and renal impairment. OBJECTIVE: To determine the validity of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) compared with digital subtraction angiography (DSA) for detection of renal artery stenosis. DESIGN: Prospective multicenter comparative study conducted from 1998 to 2001. Two panels of 3 observers judged CTA and MRA image data and were blinded to all other results. Digital subtraction angiography images were evaluated by consensus. SETTING: 3 large teaching hospitals and 3 university hospitals in the Netherlands. PATIENTS: 402 hypertensive patients with suspected renal artery stenosis were included. A group of 356 patients who underwent all 3 diagnostic tests was used for analysis. MEASUREMENTS: Reproducibility was assessed by calculating interobserver agreement. Diagnostic performance was evaluated in terms of sensitivity, specificity, and other diagnostic variables. Atherosclerotic stenoses of 50% or greater and fibromuscular dysplasia were considered clinically relevant. RESULTS: Twenty percent of patients who underwent all 3 tests had clinically relevant renal artery stenosis. Moderate interobserver agreement was found, with kappa values ranging from 0.59 to 0.64 for CTA and 0.40 to 0.51 for MRA. The combined sensitivity and specificity were 64% (95% CI, 55% to 73%) and 92% (CI, 90% to 95%) for CTA and 62% (CI, 54% to 71%) and 84% (CI, 81% to 87%) for MRA. LIMITATIONS: Eighteen percent of the patients were included nonconsecutively. Digital subtraction angiography may be an imperfect reference test. CONCLUSION: Computed tomographic angiography and MRA are not reproducible or sensitive enough to rule out renal artery stenosis in hypertensive patients. Therefore, DSA remains the diagnostic method of choice. *For a list of the other investigators and research coordinators who participated in RADISH, see the Appendix.

Adult↗

Evidence against the widespread use of angiography of noncoronary arteries during coronary artery angiography and cardiac catheterization.

PURPOSE: Although the most widely used screening techniques for extracardiac atherosclerotic distributions are noninvasive, in patients undergoing coronary arteriography, the question as to whether angiography of extracardiac arteries at the time of cardiac catheterization is really effective or if it should be considered malpractice is still open. We sought to determine the safety and real usefulness of angiography of extracardiac arteries performed by trained invasive cardiologists during cardiac catheterization. METHODS: Medical records of all patients undergoing combined coronary and noncoronary angiography between May 1998 and December 2002 were retrospectively reviewed. Moderate to severe arterial stenosis (>50% stenosis), vessel occlusion, aneurysmal, or severe ectasia were noted as significant angiographic findings. RESULTS: Two hundred and seventy patients (165 males, mean age = 67.7+/-9.2 years, mean serum creatinine = 1.1+/-0.8 mg/dl) underwent combined cardiac catheterization and angiography of extracardiac arteries following specific indications. Significant findings were reported in 66 (24.4%) patients. Logistic regression analyses revealed three-vessel coronary artery disease [CAD; odds ratio (OR)=9.917; 95% confidence interval (CI) = 2.2 to 43.8; P = .002) and hypercholesterolemia (OR = 2.851; 95% CI=1.03 to 7.9; P = .044) to be independent predictors of extracardiac atherosclerotic involvement. Complications rate was negligible. The detection of significant angiographic findings led to endovascular treatment in 37.8% and surgical vascular repair in 33.3% of cases. CONCLUSIONS: Angiography of extracardiac arteries at the time of coronary angiography appears justified only in patients with specific indications, multivessel CAD, and hypercholesterolemia.

Aged↗

Combining stereotactic angiography and 3D time-of-flight magnetic resonance angiography in treatment planning for arteriovenous malformation radiosurgery.

PURPOSE: This study was initiated to evaluate the advantages of using three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), as an adjuvant to conventional stereotactic angiography, in obtaining three-dimensional information about an arteriovenous malformation (AVM) nidus and in optimizing radiosurgical treatment plans. METHODS AND MATERIALS: Following angiography, contrast-enhanced MRI and MRA studies were obtained in 22 consecutive patients undergoing Gamma Knife radiosurgery for AVM. A treatment plan was designed, based on the angiograms and modified as necessary, using the information provided by MRA. The quantitative analysis involved calculation of the ratio of the treated volume to the MRA nidus volume (the tissue volume ratio [TVR]) for the initial and final treatment plans. RESULTS: In 12 cases (55%), the initial treatment plans were modified after including the MRA information in the treatment planning process. The mean TVR for the angiogram-based plans was 1.63 (range 1.17-2.17). The mean coverage of the MRA nidus by the angiogram-based plans was 93% (range 73-99%). The mean MRA nidus volume was 2.4 cc (range 0. 6-5.3 cc). The MRA-based modifications resulted in increased conformity with the mean TVR of 1.46 (range 1.20-1.74). These modifications were caused by MRA revealing irregular nidi and/or vascular components superimposed on the angiographic projections of the nidi. In a number of cases, the information from MRA was essential in defining the nidus when the projections of the angiographic outlines showed different superior and/or inferior extent of the nidus. In two cases, MRA revealed irregular nidi, correlating well with the angiograms and showed that the angiographically acceptable plans undertreated 27% of the MRA nidus in one case and 18% of the nidus in the other case. In the remaining 10 cases (45%), both MRI and MRA failed to detect the nidus due to surgical clip artifacts and the presence of embolizing glue. CONCLUSIONS: The 3D TOF MRA provided information on irregular AVM shape, which was not visualized by angiography alone, and it was superior to MRI for defining the AVM nidus. However, when imaging artifacts obscured the AVM nidus on MRI and MRA, angiography permitted detection of AVM. Utilizing MRA as a complementary imaging modality to angiography increased accuracy of the AVM radiosurgery and allowed for optimal dose planning.

Cerebral Angiography↗

Assessment of aortocoronary bypass graft patency by intra-arterial digital subtraction angiography compared to selective graft angiography.

The value of digital subtraction angiography (DSA), in assessing aortocoronary bypass graft patency, was evaluated by studying 22 consecutive patients with 54 aortocoronary saphenous vein bypass grafts, who had postoperative angina pectoris. Each patient underwent selective graft angiography and non-gated DSA. The DSA consisted of a run of 15 to 20 frames, taken at 2.3 frames per second during injection of diluted contrast in the ascending aorta, performed after a test exposure was made. Thirty-two of the 54 grafts (59%) were patent. Thirty of the 32 grafts were seen to be patent by both selective graft angiography and DSA. In addition, a further two grafts were found to be patent on DSA, but were not able to be selectively catheterised and were not seen on the conventional aortogram. Selective graft angiography revealed four tight proximal graft stenoses, of which one only was seen on DSA; and poor distal run-off in five grafts, two of which showed up as late filling grafts on DSA. In summary, the accuracy of intra-arterial DSA in assessment of bypass graft patency was excellent. All grafts seen to be patent on selective graft angiography were also seen by DSA alone and in addition two grafts which could not be selectively catheterised were found to be patent. However, in patients with postoperative chest pain, selective graft angiography is probably required as non-gated intra-arterial DSA does not provide sufficient information to assess graft stenoses, distal flow and the native coronary vessels.

Adult↗

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.

Adult↗

Lower extremity: nonstepping digital angiography with photostimulable imaging plates versus conventional angiography.

PURPOSE: To compare nonstepping digital subtraction angiography (DSA) (ie, storage phosphor radiography adapted to a stationary imaging plate changer) with conventional screen-film angiography in the evaluation of the lower extremities. MATERIALS AND METHODS: Fifty-one patients with peripheral vascular disease underwent both nonstepping DSA and screen-film angiography. The angiographic and radiologic techniques of both systems were kept identical for each patient. Three radiologists independently rated the overall quality of each angiogram. In their evaluations for each of 12 arterial segments on all 102 angiograms, they also rated the degree of opacification, the diameter reduction of the most severe stenosis, and their level of confidence. RESULTS: Mean overall quality scores and levels of confidence were better for nonstepping DSA than for screen-film angiography (P < .001). Full opacification was reported in 95.6% and 89.2% of all 1,836 segments with nonstepping DSA and screen-film angiography, respectively (P < .0001). The difference between the mean stenosis grades obtained with screen-film angiography and nonstepping DSA was not statistically significant. Intertechnique agreements were good (kappa = 0.77, 0.81, and 0.81), whereas interobserver agreements were influenced by the observer's experience with the imaging techniques. CONCLUSION: Nonstepping DSA images of the lower extremity were of better diagnostic quality than were screen-film angiograms. The development of dedicated nonstepping DSA equipment is warranted.

Adult↗

Detection of thrombosis in the portal venous system: comparison of contrast-enhanced MR angiography with intraarterial digital subtraction angiography.

PURPOSE: To determine whether intraarterial digital subtraction angiography (DSA) can be replaced by contrast material-enhanced magnetic resonance (MR) angiography in the assessment of patency or thrombosis of the portal venous system in patients with portal hypertension. MATERIALS AND METHODS: Thirty-six patients with portal hypertension underwent contrast-enhanced MR angiography and intraarterial DSA for assessment of the portal venous system. The images were evaluated for vessel patency or thrombosis of the portal, splenic, or superior mesenteric vein. RESULTS: Of the 101 vessels evaluated, 42 were thrombosed. Overall sensitivity, specificity, and accuracy for the detection of thrombosis were 100%, 98%, and 99%, respectively, for MR angiography and 91%, 100%, and 96%, respectively, for DSA; differences between the imaging methods were not statistically significant. Only in four patients with six vessels (6%) were there discordant findings between MR angiography and DSA. CONCLUSION: Noninvasive contrast-enhanced MR angiography has the potential to replace intraarterial DSA as the standard method to assess the whole portal venous system.

Adolescent↗

High-resolution, contrast-enhanced magnetic resonance angiography with elliptical centric k-space ordering of supra-aortic arteries compared with selective X-ray angiography.

BACKGROUND AND PURPOSE: The objective of this study was to evaluate the relative value of high-resolution, contrast-enhanced MR angiography (CE MRA) with elliptical centric k-space ordering compared with intra-arterial x-ray angiography for imaging carotid stenosis. METHODS: Thirty patients with suspected stenosis of the carotid arteries were examined with CE MRA (1.5-T scanner) and x-ray angiography (aortic arch survey and selective imaging of both common carotid arteries). For the first time, not only the extracranial carotid bifurcation but all the vessel segments from the aortic arch to the circle of Willis were assessed by independent investigators. RESULTS: For the internal carotid artery in the region of the extracranial carotid bifurcation, there was a very close correlation between CE MRA and x-ray angiography (sensitivity, 100%; specificity, 92%). The initially suspected overestimation of stenosis on CE MRA in 3 cases was ultimately revealed to be an underestimation on x-ray angiography. CE MRA showed slightly poorer imaging of the basal vessel segments at the level of the aortic arch (because of breathing artifacts) and the intracranial vessel segments (because of small vessel caliber and venous superimposition due to delayed sequence starts). CONCLUSIONS: The MRA technique described here provides reliable results in the diagnosis of carotid stenosis and is thus suitable for replacing the invasive conventional x-ray angiography method in most cases. Further technical developments with regard to spatial resolution are still required for improved visualization of small vessels (terminal carotid branches and intracranial vessels).

Aged↗

Simultaneous preoperative brachiocephalic angiography and coronary angiography to prevent coronary-subclavian steal syndrome in coronary surgery candidates.

BACKGROUND: Whether or not preoperative brachiocephalic angiography with left internal mammary artery (LIMA) visualization should be performed at the time of coronary angiography in patients in whom bypass grafting using LIMA is envisaged is still debated. We sought to assess the role of the routine brachiocephalic angiography artery in preventing the coronary-subclavian steal syndrome in patients who are candidates for bypass grafting using LIMA. METHODS: Medical records of 110 patients (mean age 69.3 +/- 8.4 years) who underwent concomitant coronary angiography and brachiocephalic arteriography between May 1998 and December 2002 were reviewed. Stenosis >50%, vessel occlusion, and aneurysm were noted as significant findings. RESULTS: Significant findings were observed in 23/110 patients (20.9%). Five patients with subclavian artery stenosis and upper limb ischemia underwent subclavian artery angioplasty and stenting and bypass surgery using LIMA. During a mean follow-up of 24.7 +/- 10.7 months, only one patient developed a new subclavian artery disease after bypass grafting using LIMA, and underwent subclavian artery angioplasty. Logistic regression analysis revealed 3-vessel CAD (odds ratio (OR) 9.917 ; 95% confidence interval (CI) 2.2 to 43.8; P = .002), hypercholesterolemy (OR 2.74; CI 95% 1.05 to 7.7; P = .044), and age >65 (OR 3.55; CI 95% 2.2 to 9.2, P = .038) to be predictors of brachiocephalic disease. CONCLUSION: This study suggests that routine angiography of the brachiocephalic arteries at the time of coronary angiography is effective in preventing coronary-subclavian steal syndrome in select patients who are candidates for bypass grafting using LIMA.

Aged↗

Symptomatic middle cerebral artery stenosis and occlusion: comparison of three-dimensional time-of-flight magnetic resonance angiography with conventional angiography.

The usefulness of magnetic resonance (MR) angiography using the three-dimensional time-of-flight method for the characterization of symptomatic middle cerebral artery (MCA) occlusive lesions was evaluated in 10 patients with MCA occlusion and 10 with MCA stenosis. All lesions were symptomatic and documented by conventional angiography. There was no false-negative MR angiogram that failed to demonstrate the MCA occlusive lesion. MR angiography correctly evaluated the location of lesions and the difference between stenosis and occlusion. Stenosis appeared as a focal signal loss (< 1.0 cm) of the MCA at the site of stenosis, and occlusion as a complete signal loss of the MCA distal to the site of occlusion. However, MR angiography could not distinguish diffuse stenosis and one point stenosis demonstrated by conventional angiography. MR angiography is a useful noninvasive diagnostic method for evaluating occlusive lesions of the MCA in symptomatic patients.

Adult↗

Detection of circle of Willis aneurysms in patients with acute subarachnoid hemorrhage: a comparison of CT angiography and digital subtraction angiography.

OBJECTIVE: The purpose of this study was to compare CT angiography with digital subtraction angiography (DSA) in the detection and measurement of intracranial aneurysms in patients with acute subarachnoid hemorrhage. SUBJECTS AND METHODS: Thirty consecutive patients with recent subarachnoid hemorrhage shown by unenhanced CT scanning or lumbar puncture were studied with CT angiography and DSA. Using a shaded surface display format and source images, two reviewers working independently blindly interpreted CT angiograms for presence and size of aneurysms. Sensitivity and specificity for aneurysm detection were calculated for each reviewer. Aneurysm size measurements were compared between reviewers and between the two imaging techniques. RESULTS: Thirty aneurysms were found in 22 patients with DSA; eight patients had no aneurysms. The sensitivity and specificity of CT angiography for reviewer A were 0.97 and 1.0, respectively. For reviewer B, the sensitivity and specificity were 0.77 and 0.87, respectively. All cases with single aneurysms on DSA (18 patients) had surgical confirmation of aneurysm location and rupture. In each case with multiple aneurysms (four patients), the aneurysm thought responsible for the hemorrhage was surgically confirmed. In those cases with no aneurysms found on DSA, follow-up DSA studies did not reveal additional findings. Differences between reviewers in aneurysm size measurements made with CT angiography were not significant (p = .10). Mean aneurysm measurements for reviewer A, reviewer B, and DSA were 6.6 mm, 7.0 mm, and 6.9 mm, respectively. CONCLUSION: CT angiography shows potential in the detection and measurement of aneurysms in patients with acute subarachnoid hemorrhage when compared with DSA.

Acute Disease↗

High-resolution magnetic resonance coronary angiography of the entire heart using a new blood-pool agent, NC100150 injection: comparison with invasive x-ray angiography in pigs.

Recent developments of novel magnetic resonance intravascular contrast agents with low T1 in blood and a long intravascular half-life will rapidly position magnetic resonance coronary angiography (MRCA) at the threshold of clinical application. This article describes the use of one such intravascular contrast agent for noninvasive coronary angiography and comparison with routine invasive x-ray angiography. Six domestic farm pigs with an artificial stenoses at the left circumflex were studied. NC100150 Injection, a new ultra-small superparmagnetic iron oxide (Nycomed Amersham Imaging, Oslo, Norway), was injected using a dose of 5.0 mg Fe/kg body weight. Scanning was done using a 1.5-T Gyroscan ACS-NT. A high-resolution electrocardiogram-triggered scan covering the entire heart was applied. Navigator echoes were used for respiratory triggering. In all animals the location of the stenoses detected with MRCA correlated well with x-ray angiography. The correlation factor between the grade of stenoses determined by MRCA and x-ray angiography was 0.993. MRCA using NC100150 Injection can depict the major coronary arteries and branches well. Decreases in vessel caliber detected by MRCA correlate well with x-ray angiography. The use of such intravascular contrast agents show great promise for clinical applications for noninvasive detection of coronary artery disease in humans.

Animals↗