Radiation Dose from 3D Rotational vs. Conventional 2D Digital Subtraction Angiography in Intracranial Aneurysm Coiling.

PURPOSE: To compare patient effective dose resulting from two alternative imaging protocols for pre-coiling assessment of intracranial aneurysms: a series of 2D Digital Subtraction Angiography (DSA) projections, and a 3D rotational angiography (RA) acquisition. METHODS: In a retrospective analysis, we investigated 44 patients who underwent endovascular coiling in our institution. Images were acquired on a biplane Image Intensifier system not equipped with dose-area product (DAP) meter. Conventional 2D DSA images were simulated with an anthropomorphic skull phantom. Entrance skin dose was measured with a 60 cc ion chamber, and the PCXMC Monte Carlo based software was used to calculate patient effective dose. For the RA protocol, a 16 cm computed tomography (CT) dosimetry phantom and a 100 mm pencil ion chamber were employed to measure the CT dose index. Patient effective dose was calculated with the ImPACT calculator. An unpaired two-tailed t-test was used to determine the significance of differences between patient doses in each group. RESULTS: Sixteen patients underwent the 2D DSA protocol with multiple projections; their mean number of cine runs was 5.1; the mean effective dose was 2.11 millisievert (mSv) (range 1.69-3.43 mSv). Twenty eight patients were assessed using the 3D RA protocol with the effective dose of 1.29 mSv. The difference between the means of two dose distributions was statistically significant (p=0.00028). CONCLUSION: Our study demonstrated that the patient effective dose was significantly lower from the 3D RA protocol than that from the 2D DSA protocol used in the planning of coiling of intracranial aneurysm.

Radiological assessment of vascular access in haemodialysis patients.

Clinical examination is still the most important diagnostic tool and duplex ultrasonography is the imaging method of first choice. Radiological assessment of vascular access for haemodialysis includes preoperative analysis of vessel anatomy and postoperative surveillance for access maturation as well as diagnosis in vascular access insufficiency. Compared to ultrasonography digital subtraction angiography is superior for the evaluation of the central veins and allows diagnosis and treatment in one session. Computed tomography should only be used in patients with inconclusive ultrasonography results, for example, for the assessment of the central veins and visualization of the vascular tree. Gadolinium-enhanced magnetic resonance imaging is no longer recommended in dialysis patients, because it may trigger nephrogenic systemic fibrosis. In patients with a history of previous central venous catheters additional preoperative imaging of the central veins should be performed. In this article we review the different radiological imaging methods for preoperative assessment and suspected vascular access dysfunction.

Safety, efficacy, and cost of intraoperative indocyanine green angiography compared to intraoperative catheter angiography in cerebral aneurysm surgery.

Intraoperative angiography in cerebrovascular neurosurgery can drive the repositioning or addition of aneurysm clips. Our institution has switched from a strategy of intraoperative digital subtraction angiography (DSA) universally, to a strategy of indocyanine green (ICG) videoangiography with DSA on an as-needed basis. We retrospectively evaluated whether the rates of perioperative stroke, unexpected postoperative aneurysm residual, or parent vessel stenosis differed in 100 patients from each era (2002, "DSA era"; 2007, "ICG era"). The clip repositioning rate for neck residual or parent vessel stenosis did not differ significantly between the two eras. There were no differences in the rate of perioperative stroke or rate of false-negative studies. The per-patient cost of intraoperative imaging within the DSA era was significantly higher than in the ICG era. The replacement of routine intraoperative DSA with ICG videoangiography and selective intraoperative DSA in cerebrovascular aneurysm surgery is safe and effective.

Safety of arch aortography for assessment of carotid arteries.

PURPOSE: To retrospectively review the safety of arch aortography and compare complication rates with published figures for selective catheter angiography. METHODS: The medical records of patients undergoing arch aortography over the last 3 years (n=311; 180 male, 131 female; mean+/-SD age 71.0+/-9.2 years, range 42-90 years) were retrospectively reviewed. Any peri-procedural (0-48 h) complications were recorded. A certified neurologist (MSR/GSV) classified all questionable neurological events. RESULTS: There were no focal neurological events or deaths (n=0; 0%; CI: 0-0.96%). Non-focal neurological events included mild disorientation (n=2; 0.6%; CI: 0.176-2.31) and unequal pupils (n=1; 0.3%; CI: 0.056-1.79%). Cardiovascular events included symptomatic hypotension (n=4; 1.3%; CI: 0.50-3.25%), angina (n=1; 0.3%; CI: 0.056-1.79%) and arrhythmia (n=4; 1.3%; CI: 0.50-3.25). There were 27 minor access site complications (8.7%; CI: 6.0-12.3). None of these complications extended hospital stay. None of the arch angiograms had to be followed by selective carotid angiography. CONCLUSION: Arch aortography appears to have a lower neurological complication rate than selective carotid angiography.

Assessment of CE-MRA for the rapid detection of supra-aortic vascular disease.

BACKGROUND: Contrast-enhanced MR angiography (CE-MRA) using a combined head and neck coil permits non-invasive imaging of the vasculature from the aortic arch through to the Circle of Willis in less than 2 minutes. OBJECTIVE: To determine the accuracy of CE-MRA for the detection of vascular pathology, in particular vascular stenoses, using digital subtraction angiography (DSA) as the gold standard. METHODS: In a prospective study of 81 patients referred for DSA, CE-MRA and DSA studies were performed within 72 hours of each other. CE-MRA was performed on a 1.5 Tesla clinical MRI scanner using a five-channel neurovascular array (head and neck coil), with dynamic tracking of the IV gadolinium bolus. CE-MRAs and DSA films were read by two interventional neuroradiologists blinded to the clinical presentation of the patient. RESULTS: On DSA, there were 77 vascular stenoses > or =50% identified, 51 extracranial and 26 intracranial. The overall sensitivity of CE-MRA using the neurovascular array for the detection of vascular stenoses > or =50% was 57% (95% CI: 46 to 68%) with a specificity of 98% (97 to 99%). The sensitivity for the detection of extracranial vascular stenoses > or =50% was 82% (72 to 93%) with a specificity of 97% (96 to 98%). However, the sensitivity for the detection of intracranial vascular stenoses > or =50% was only 8% (0 to 18%), with a specificity of 99% (98 to 100%). CONCLUSIONS: At this stage Contrast-enhanced MR angiography using a neurovascular coil shows promise as a rapid, specific, and noninvasive screening method for extracranial vascular disease, but not for intracranial vascular disease.

[Contrast media in peripheral angiography: does cost reduction mean loss of quality and safety? A reevaluation based on a randomized double-blind comparative study of ioxaglate versus iopromide]. / Kontrastmittel in der peripheren Angiographie: Bedeutet Kostenreduktion Verlust an Qualität und Sicherheit? Eine Reevaluierung anhand einer randomisierten Doppelblind-Vergleichsstudie von Ioxaglat versus Iopromid.

PURPOSE: To evaluate whether meglumine-sodium-ioxaglate (Hexabrix) and iopromide (Ultravist) are identically appropriate for peripheral angiography. Outcome variables were pain, image quality and adverse events. METHODS: Sixty patients were included in a randomised double-blind study. In all patients an intraarterial digital subtraction angiography (i.a. DSA) of iliac and peripheral arteries was performed. RESULTS: Analysis of the study revealed no significant difference between both contrast media in terms of the main and additional outcome variables. In comparison to iopromide, ioxaglate caused milder pain sensations (VAS 4.70 vs. 7.76, p = 0.25). Mild adverse events were observed more frequently in ioxaglate angiography (11% vs. 0%, p = 0.1). CONCLUSION: Both contrast media seem to be appropriate for peripheral angiography using DSA technique. Ioxaglate causes a cost reduction of about 20-35%. However, an increase of mild adverse reactions up to 11% to 15% has to be accepted.

[Cost-effectiveness of and morbidity from digital subtraction angiography. A study of 5,817 cases]. / Coût--effectivité--morbidité de l'angiographie par soustraction numérique. Etude de 5817 cas.

This study was based on 5,817 patients examined by digital subtraction angiography (DSA) between 1984 and 1990. 5,209 patients received an intravenous injection of contrast agent and 608 received an intra-arterial injection. Digital subtraction angiography has become a routine procedure for the diagnosis of vascular disease in the various fields studied, as it provides images of diagnostic quality in 97% of cases: diagnostic quality of 95% after intravenous injection and 99% after intra-arterial injection. The morbidity is 1.65% for the intravenous route and 4.8% for the intra-arterial route. The morbidity of brachial artery catheterization is 5.5% DSA by intravenous injection is a low-risk angiographic technique which represents a major economy in terms of the cost of the examination and the examination time, a reduction of hospital stay and waiting lists; these advantages are very important in the current context of public health.

Perioperative imaging strategies for carotid endarterectomy. An analysis of morbidity and cost-effectiveness in symptomatic patients.

OBJECTIVE: To assess the cost-effectiveness of four diagnostic strategies for the preoperative evaluation of symptomatic patients who are potential candidates for carotid endarterectomy (ie, 70% to 99% stenosis): (1) duplex sonography (DS), (2) magnetic resonance angiography (MRA), (3) contrast angiography (CA), and (4) the combination of DS and MRA supplemented by CA for disparate results. METHODS: Cost-effectiveness analysis based largely on published clinical trial data. Sensitivities and specificities of noninvasive tests were estimated from 81 patients undergoing prospective evaluation with DS, MRA, and CA. OUTCOME MEASURE: Incremental cost per quality-adjusted year of life gained. RESULTS: For a hypothetical cohort of symptomatic patients undergoing evaluation for carotid endarterectomy, the combination of tests resulted in the greatest quality-adjusted life expectancy of the four options considered. After incorporating the costs of testing, surgery, and stroke, we found that neither the MRA nor the CA strategy was cost-effective. The combination of tests was more effective but more costly than DS, resulting in an additional cost of $22,400 per quality-adjusted year of life gained. For centers that do not have adequate MRA, CA resulted in an additional cost of $99,200 per quality-adjusted year of life saved compared with DS. CONCLUSIONS: Our results suggest that for the preoperative detection of a 70% to 99% carotid stenosis, the combination of DS and MRA, supplemented by CA for disparate results, is associated with the lowest long-term morbidity and mortality and has a favorable cost-effectiveness ratio. The combination of tests, or DS alone when MRA is not available, could potentially replace the current practice of using CA alone in the preoperative evaluation of patients with symptomatic carotid stenosis.

[Intra-arterial digital angiography using a trans-humeral approach in the assessment of ambulatory patients]. / Angiografia digitalizzata per via arteriosa con approccio transomerale nello studio dei pazienti ambulatoriali.

The authors report their experience with intraarterial digital subtraction angiography (DSA) performed on outpatients via brachial artery catheterization. A total of 120 outpatients were studied for cerebral and lower limbs vascular diseases. Transbrachial catheterization was performed with 5F or, preferably, with 4F angiographic catheters. Success rate was high and the transbrachial approach was always easy. In the course of cerebral examination (18/120 cases) the catheter was always easily positioned in the ascending thoracic aorta, through right transbrachial approach. In the course of abdominal aorta and lower extremities examination (102/120 cases), the ideal catheter positioning--in the descending aorta--was performed in 95/102 cases, by left transbrachial approach, while in 7/102 patients the catheter was placed in the ascending aorta. The complication rate was low: 7/120 ecchymosis, 4/120 small hematomas spontaneously resorbed, and 2/120 transient spasms of brachial artery. The authors suggest trasbrachial intraarterial DSA as an alternative to intravenous DSA in outpatients.