Complications of cerebral angiography and pneumography

Carotid access for cardiac catheterization: revisiting the past for a complex intra-arterial approach

Historically, multiple arterial access sites have been used for cerebral, peripheral or coronary angiography prior to the widespread utilization of the safer transbrachial and, more recently, transfemoral or transradial approaches. Additionally, alternative sites for arterial access such as the carotid artery are often used in complex pediatric invasive procedures. We describe a case of a patient with severe peripheral arterial occlusive disease with active ischemia who required coronary angiography. In collaboration with cardiothoracic surgery, carotid cutdown was successfully performed in the cardiac catheterization laboratory to allow performance of diagnostic coronary angiography and intravascular ultrasound.

Head and neck vascular lesions: characterization of the flow pattern by the use of three-phase CT

Objective

This study was designed to evaluate the usefulness of three-phase CT to characterize the hemodynamics of vascular lesions in the head and neck area.

Materials and Methods

We analyzed vascular malformations of head and neck regions in 21 patients with the use of three-phase CT, including pre-contrast phase, vascular phase (scan delay: 20-35 seconds after intravenous contrast material injection) and equilibrium phase (scan delay: 3-5 minutes) imaging. The flow characteristic of each lesion was determined and categorized as either a high- or a low-flow lesion according to findings on selective arteriography and/or direct puncture venography. The CT number was acquired from two areas in a vascular lesion, sorted by the enhancement pattern: area 1, a highly enhanced area seen on the vascular phase; area 2, a delayedly enhanced area seen on the equilibrium phase. The CT numbers of each phase were compared between high- and low-flow lesions with use of the unpaired t-test. The flow patterns of high- and low-flow lesions were analyzed by assessment of time-density curves of three phase CT.

Results

High-flow lesions were detected in nine patients and low-flow lesions were detected in 12 patients. On the vascular phase, the CT number of areas 1 and 2 of high-flow lesions was significantly higher than for low-flow lesions (p < 0.05). Contrary to early peaks seen in time-density curves of high-flow lesions, low-flow lesions showed a delayed peak.

Conclusion

Three-phase CT seems to be a valuable non-invasive method to differentiate a high-flow lesion from a low flow lesion of head and neck vascular lesions.

CT and MR imaging features of oral and maxillofacial hemangioma and vascular malformation

PURPOSE

To present CT and MR images and compare CT and MRI features of oral and maxillofacial hemangioma and vascular malformation.

MATERIAL AND METHODS

The clinical materials consisted of nine vascular tumors from nine patients examined by both CT and MR scanners between November 1996 and March 2002. Both CT and MR images were retrospectively evaluated. The following features were evaluated: detectability of the lesion, border of the lesion, tumor margin, inner nature of the lesion, contrast between the lesion and surrounding tissues, degree of CT value or signal intensity of the lesion, enhancement of contrast medium, inner nature of the lesion after contrast medium injection, detectability of phleboliths and detectability of bone resorption.

RESULTS

In two patients, we could not detect lesions in any of the CT images because of artifacts from the teeth and/or dental restorations. In contrast, we could detect all lesions on T2-weighted MR images and contrast enhanced T1-weighted MR images. On T2-weighted images with the fat suppression technique, tumors tended to show higher contrast compared to surrounding tissues.

CONCLUSION

T2-weighted images with the fat suppression technique and contrast enhanced T1-weighted images with the fat suppression technique were very useful for the detection of vascular lesions. Observation from optional directions (axial, coronal and sagittal images) seemed appropriate for delineating the extension of the tumor. Phleboliths detectability on CT images was superior to that on MR images.

Clinical events following neuroangiography: a prospective study

Clinical events following cerebral angiography were prospectively evaluated in 1,002 procedures. The ischemic event rate between 0 and 24 hours was 1.3% (0.1% permanent). This incidence was higher (2.5%) in patients investigated for cerebrovascular disease, but the difference was not significant. In addition, 1.8% of the patients suffered ischemia (0.3% permanent) between 24 and 72 hours after angiography. Cerebral ischemic events occurred as a recurrence or worsening of a preexisting phenomenon. twice as often as de novo. All permanent ischemia was a worsening of a preexisting phenomenon. There was a significant increase in the incidence of neurologic events between 0 and 24 hours when the procedure lasted longer than 60 minutes and when there was systolic hypertension. Trends toward higher incidence were noted with the use of increased volume of contrast, with increased serum creatinine, when transient ischemic attacks or stroke were the indications, and when 3 or more catheters were used. The incidence of neurologic events between 24 and 72 hours increased significantly with the increase in the amount of contrast used, with age, and with diabetes. The occurrence of nonneurologic events (mostly hematomas) was significantly increased by multiple factors. This study shows that events can and do occur beyond the usual observation period of 24 hours but confirms the low risk of cerebral angiography when performed judiciously.

Dynamic computerized tomography in the assessment of hemangioma

Three hemangiomas of the face and orbit are studied with dynamic computerized tomography (CT). This noninvasive technique has the advantage of simultaneous bone and soft tissue visualization at the time of peak contrast enhancement, and it precludes the potential complications of arteriography and biopsy. The hemangiomas are precisely delineated with intense contrast; the sharp peak and rapid uninterrupted runoff of the computer-generated plot of contrast concentration (CT number) versus time is characteristic of this lesion. It is suggested that the progress of hemangioma involution may be documented by the change in contrast distribution in sequential dynamic CT studies. Dynamic CT is recommended for the evaluation of head and neck vascular tumors.

Injury of the carotid and vertebral arteries

A knowledge of the normal anatomy and anatomic relationships of the carotid and vertebral arteries, as well as the biomechanics by which traumatic injury occurs to these vessels, is important both in the interpretation of diagnostic arteriograms and in the clinical assessment of the injured patient.

Diagnosis of carotid body tumors by dynamic computerized tomography

The carotid body tumor, although uncommon, is frequently considered in the differential diagnosis of cervical masses. When this lesion becomes a serious diagnostic possibility, angiography must be considered. Currently angiography is the only nonsurgical modality that can reliably confirm the clinical diagnosis. We describe the case of a patient in whom a carotid body tumor was diagnosed preoperatively by dynamic computerized tomography. Dynamic computerized tomography, a relatively noninvasive technique, should now be deemed the technique of choice for diagnosis of carotid body tumors, thus avoiding the potential morbidity of angiography. In patients for whom tumor removal is indicated, however, preoperative angiography is still mandatory in order to plan the best operative procedure.

Direct percutaneous cerebral angiography in neurosurgical practice

A retrospective analysis of 1171 consecutive percutaneous retrograde brachial and carotid cerebral angiograms was performed on 635 patients, 50.7% of whom were in the sixth decade or older. Symptoms and signs of cerebrovascular disease were the most frequently investigated and diagnosed, accounting for 46.7% of all the angiograms. Despite this relatively high-risk population, we have found direct percutaneous cerebral angiography to have a very low risk. The pros and cons of direct percutaneous versus transfemoral cerebral angiography are discussed. The literature of the previous 10 years is reviewed, and the complication rate of these two techniques is compared.