Intravenous digital subtraction angiography in the investigation of intracranial disease

Opening of the Blood-Brain Barrier by Intravenous Contrast Media in Euvolemic and Dehydrated Rabbits

It has been suggested that intravenous injections of hypertonic contrast media when used in computed tomography and digital subtraction angiography might raise plasma osmolality sufficiently to open the blood-brain barrier (BBB). The current investigation establishes the threshold of plasma osmolality that causes the the opening of the BBB in euvolemic and dehydrated rabbits. Euvolemic rabbits were allowed food and water ad libitum. Dehydrated rabbits received 4.0 mg/kg of furosemide intramuscularly and were deprived of water for 72 hours. Meglumine/sodium diatrizoate 76 per cent (n=28) or mannitol 20 per cent (n= 12) was administrated intravenously, at a rate of 25 mmol/kg body weight/hour for 2, 3 or 4 hours. Plasma osmolality, blood iodine concentration, blood pressure, heart rate and hematocrit were assessed at regular intervals. Evans blue and 99Tcm-DTPA were used simultaneously as tracers for BBB opening. Rating of BBB opening with 99Tcm-DTPA correlated well with Evans blue staining (r=0.863, p<0.001; n=42). BBB opening was related to plasma osmolality and was similar for both contrast media and mannitol. Widespread BBB opening occurred above 400 mmol/kg while focal BBB opening occurred above 370 mmol/kg. Dehydration per se increased plasma osmolality but did not reduce the threshold for BBB opening.

Preoperative superselective embolization of skull-base meningiomas: indications and limitations

We evaluated the clinical significance of preoperative superselective embolization for skull-base meningiomas. The subjects consisted of 20 patients with skull-base meningiomas, and were classified into a preoperative embolized group and a non-embolized group. The volume of blood transfused during the operation, the length of the operative procedure and the neurological outcome were compared between the two groups. The results showed that, in tumors smaller than 6 cm, the blood lost during the operation was significantly less in the embolized group. In tumors larger than 6 cm, there was not difference in blood lost, perhaps because larger meningiomas tend to have tiny blood vessels that are unsuitable for preoperative embolization. There was no difference in the length of the operation between the two groups. The embolized group tended to show a better clinical outcome than the non-embolized group.

Detection of unruptured familial intracranial aneurysms by intravenous digital subtraction angiography. Screening of two affected families

The authors discuss the detection of intracranial aneurysms (IA) by means of intravenous digital angiography (ivDSA) in (a)symptomatic first degree relatives of families in which two or more individuals have IA. ivDSA is an almost noninvasive and low-risk diagnostic procedure. Screening, by means of ivDSA, of two affected families is described. In family I which includes 7 members with proven IA, ivDSA has been carried out in 36 asymptomatic individuals: in one, a 6 X 15 mm aneurysm was found at the left posterior communicating artery (PCoA). In family II, including one member with a proven IA and another with a subarachnoid hemorrhage, ivDSA has been carried out in 4 members: one aneurysm with a diameter of 6 mm was found at the left PCoA. Conventional cerebral angiography (CCA) confirmed both IA's. Neurosurgical treatment followed. The advantages and disadvantages of ivDSA vs. CCA as elective screening procedure in such cases are discussed. Screening of asymptomatic first degree relatives of cases with familial IA by means of ivDSA is strongly advocated.

Vertebral artery injury and cerebellar stroke while swimming: case report

A twenty-five year old woman suffered the acute onset of dysequilibrium followed by headache, nausea, vomiting, vertigo, and slurred speech while swimming. Brain imaging revealed a right cerebellar infarct. Intravenous digital subtraction angiography showed a hypoplastic right vertebral artery and focal narrowing of the dominant left vertebral at the level of the C1-C2 junction. The patient was treated with aspirin and dipyridamole and immobilized for two weeks. She achieved almost complete recovery. Repeat angiography showed resolution of the left vertebral artery defect. Other cases of posterior circulation infarction associated with head turning during sports and ordinary activities are reviewed.

Comparison of digital subtraction arteriography and conventional film screen subtraction arteriography for neuroradiology

Sixty-nine patients with 91 separate abnormal findings were studied by both intra-arterial digital subtraction arteriography (ADSA) and conventional film screen subtraction arteriography (CFSA) in the same projection, with the same magnification. Digital subtraction arteriography has distinct advantages over CFSA in the form of reduced contrast utilization, better patient tolerance of arteriography because of reduced contrast concentration, superior contrast resolution, and rapid, on-line visualization of the abnormalities. Digital subtraction arteriography is limited by its availability in only a single plane, by decreased spatial resolution which affected the image quality for intracranial blood vessels at an image intensifier (I.I.) field of 12 inches, and by relatively limited field of view both intracranially and extracranially for I.I. fields of 6 and 9 inches.

Digital subtraction arteriography

DSA has quickly made the transition from an experimental examination performed in a research institution to a routine procedure performed in a community hospital. Diagnostic quality images for screening applications are obtained in over 90% of patients, and in many instances DSA is the only angiographic study that need be done. The applications of IV DSA have broadened to encompass many angiographic procedures for which selective injections are not mandatory. When IA studies must be performed, digital equipment offers the advantages of speed, safety, and lessened patient discomfort. New technological developments will increase the advantages and applications.

Intravenous digital subtraction angiography (IVDSA) in children

Forty-one intravenous digital subtraction angiographic (IVDSA) studies were performed in 39 patients aged 4 weeks to 19 years (mean: 9.4 years) in order to evaluate the heart, great vessels and palliative shunts. Contrast agents were injected via antecubital vein cannulation in 14 examinations. In the remaining 27, injections were made through centrally-placed catheters inserted via right antecubital or femoral veins. All but one of the centrally-injected procedures resulted in technically satisfactory images. Four of the peripherally-injected IVDSA studies were unsatisfactory or of limited value due to motion artefacts, insufficient contrast, equipment failure or perivenous extravasations. Systemic-pulmonary shunt lesions were difficult to image, but IVDSA of the aorta and pulmonary arteries provided consistently useful information.