Biomedical subjects

R I Aviv

Publications and source records attributed to R I Aviv.

12 recordsLinked to original sources

PubMed2007

Angiography of primary central nervous system angiitis of childhood: conventional angiography versus magnetic resonance angiography at presentation.

BACKGROUND AND PURPOSE: To systematically analyze conventional angiographic (CA) features of children with primary central nervous system angiitis (cPACNS), to compare and correlate CA and MR angiography (MRA) lesion characteristics, and to define the sensitivity and specificity of MRA with CA as a reference standard. METHODS: A retrospective, single-center cohort study of consecutive patients with cPACNS was performed. Patients with CA and MRA studies at diagnosis were included. Imaging studies were blindly reviewed by 2 neuroradiologists using a standard analysis protocol. CA and MRA studies were compared using nonparametric analysis. RESULTS: Of 45 patients with MRA at diagnosis, there were 25 for whom CA and MRA studies were performed within 1 month of each other. These comprised the study group. The CA distribution of lesions was multifocal (76%) and proximal (86%) (P < .05) with a trend toward unilaterality (P = .06) with anterior circulation involvement (P = .08). The sensitivity and specificity of MRA for CA abnormality was 70% and 98%, respectively. There was no significant difference between MRA and CA for lesion detection or characterization (P = .87), and the modalities showed a fair correlation (kappa = 0.4). CONCLUSION: Angiographic lesions are multifocal and occur proximally and unilaterally within the anterior circulation. There is no significant difference in the ability of MRA to detect and characterize lesions when compared with CA.

Adolescent↗

PubMed2006

Seizures during stroke thrombolysis heralding dramatic neurologic recovery.

Seizures during thrombolytic therapy for ischemic stroke have not previously been described as a favorable prognostic sign. We report three patients with severe stroke (NIH Stroke Scale [NIHSS] score 15 to 20) who experienced a seizure during tissue plasminogen activator (tPA) infusion. While initially raising alarm about possible hemorrhage, the seizures heralded dramatic recovery (an immediate 15-point NIHSS score improvement after tPA; NIHSS score 0 or 1 at 24 hours). We propose that the seizures during thrombolysis may indicate cortical reperfusion and/or hyperperfusion due to early recanalization of an acutely occluded intracranial artery.

Adult↗

PubMed2006

Identification of penumbra and infarct in acute ischemic stroke using computed tomography perfusion-derived blood flow and blood volume measurements.

BACKGROUND AND PURPOSE: We investigated whether computed tomography (CT) perfusion-derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients. METHODS: Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9). Penumbra was operationally defined as tissue with an admission CBF <25 mL x 100 g(-1) x min(-1) that was not infarcted on the 5- to 7-day NCCT. Logistic regression was applied to differentiate between infarct and penumbra data points. RESULTS: For recanalized patients, CBF was significantly lower (P<0.05) for infarct (13.3+/-3.75 mL x 100 g(-1) x min(-1)) than penumbra (25.0+/-3.82 mL x 100 g(-1) x min(-1)). CBV in the penumbra (2.15+/-0.43 mL x 100 g(-1)) was significantly higher than contralateral (1.78+/-0.30 mL x 100 g(-1)) and infarcted tissue (1.12+/-0.37 mL x 100 g(-1)). Logistic regression using an interaction term (CBFxCBV) resulted in sensitivity, specificity, and accuracy of 97.0%, 97.2%, and 97.1%, respectively. The interaction term resulted in a significantly better (P<0.05) fit than CBF or CBV alone, suggesting that the CBV threshold for infarction varies with CBF. For patients without recanalization, CBF and CBV for infarcted regions were 15.1+/-5.67 mL x 100 g(-1) x min(-1) and 1.17+/-0.41 mL x 100 g(-1), respectively. CONCLUSIONS: We have shown in a limited sample of patients that CBF and CBV obtained from CTP can be sensitive and specific for infarction and should be investigated further in a prospective trial to assess their utility for differentiating between infarct and penumbra.

Acute Disease↗

PubMed2006

MR imaging and angiography of primary CNS vasculitis of childhood.

BACKGROUND AND PURPOSE: Primary angiitis of the central nervous system of childhood (cPACNS) is a rare and ill-defined disease. In the absence of a brain biopsy, the diagnosis is based on typical clinical and imaging abnormalities. The aim of this study was to analyze systematically the MR imaging and MR angiographic (MRA) abnormalities in a large cohort of children with cPACNS. METHODS: We analyzed the MR imaging features of a single pediatric center cohort of 45 cPACNS patients. MR imaging studies were performed for all patients, and both MR imaging and MRA were performed for 42 patients, who formed the cohort for review of the presence and correlation of lesions. Proportions were calculated by using the Fisher exact test, and agreement between MR imaging and MRA was calculated by using the McNemar test. The sensitivity of each diagnostic technique was established. RESULTS: The most-common pattern of parenchymal abnormality was multifocal, unilateral involvement, each in 42/45 patients (93%). The lateral lenticulostriate artery terrritory was affected in 56% of cases, with involvement of a supratentorial deep gray matter structure in 91%. No infratentorial lesion occurred in the absence of supratentorial abnormality. MRA was normal in 12/42 patients (28.6%). Among the abnormal studies, stenosis was detected on MRA in 83% and was "benign" in appearance in 73% of patients and "aggressive" in 16.7%. Involvement was proximal in 83% and distal in 27% of patients. Multiple ipsilateral lesions were seen in 63%. MR imaging was abnormal in every patient where MRA was abnormal. With the assumption of MR imaging as the gold standard, the sensitivity of MRA was 72%. The agreement between MR imaging and MRA for abnormality was significant (P = .04). CONCLUSION: We have illustrated the MR imaging and MRA appearances of cPACNS in the largest cohort to date. Both parenchymal and vascular lesions were predominantly proximal, unilateral, and multifocal within the anterior circulation. There was good agreement between MR imaging and MRA for lesion location. MR imaging findings were abnormal in all cases at diagnosis, and this remains the most sensitive technique to the detection of vasculitis.

Adolescent↗

PubMed2005

Orbital imaging: Part 1. Normal anatomy.

Advanced imaging techniques enable the radiologist to detect an increasing number of structures within the orbit not previously identifiable. We describe the imaging techniques and orbital anatomy with an emphasis on radiologically identifiable structures. In a second review of orbital pathology we present pathological processes that may involve these structures.

Facial Bones↗

PubMed2005

Orbital imaging: Part 2. Intraorbital pathology.

Several primary and secondary processes may affect the orbit. We present a review of intraorbital pathology utilising a compartmental approach guiding the differential diagnosis. Knowledge of the contents of each compartment facilitates the differential diagnosis. Globe pathology is not dealt with in this review.

Diagnosis, Differential↗

PubMed2003

Embolisation of spinal dural arteriovenous fistulae with Onyx.

Surgery is currently the standard treatment for spinal dural arteriovenous fistulae (DAVF). Endovascular embolisation of these lesions using N-butyl cyanoacrylate (NBCA) has a high success rate. Onyx is a new liquid embolic agent whose viscosity makes it suitable for treatment of spinal DAVF where penetration into the proximal radicular vein is required. It is delivered with greater control than NBCA without the necessity for rapid withdrawal of the catheter and may therefore overcome some of the drawbacks of NBCA. We report two patients who underwent Onyx embolisation of spinal DAVF; to our knowledge this is the first such report.

Angiography↗

PubMed2002

Craniosynostosis.

Craniosynostosis, caused by premature fusion of the sutures, may be syndromic or non-syndromic. Radiology has an important role to play in the assessment, management and follow-up of these patients. Initial investigations may often be undertaken within general radiology departments. An understanding of the terminology and recognition of the predictable patterns of presentation are essential to enable appropriate referral to a craniofacial unit where further investigation and management are undertaken. We present the radiological features of several craniosynostoses with an emphasis on the role of plain radiography. We demonstrate the complementary role of computed tomography in their evaluation within the setting of a specialist centre.

Craniosynostoses↗

PubMed2002

Radiological palliation of malignant colonic obstruction.

PURPOSE: To evaluate the efficacy of colorectal stenting in the palliation of irresectable malignant colonic obstruction. MATERIALS AND METHODS: Fifteen patients underwent colorectal stenting for irresectable colonic malignancy. Sixteen stents were placed successfully in 13 patients. Two stent insertions, one a proximal transverse colon lesion, were unsuccessful. Twelve patients (80%) had clinical or radiological features of imminent obstruction. Three patients were completely obstructed. Eighty-six percent of lesions were within the rectosigmoid colon. RESULTS: Technical and clinical success was 88%. Early, minor complications occurred in two patients (13%). Late complications included migration (13%) and ingrowth (19%). The median survival was 2 months (0.5-12 months). CONCLUSION: Stenting should be considered as definitive treatment in the context of an inoperable malignant stricture of the colon. It has low morbidity and a high technical and clinical success rate and avoids emergency defunctioning surgery in high-risk patients.

Adult↗

PubMed2002

Use of stents in the palliative treatment of malignant gastric outlet and duodenal obstruction.

AIM: To evaluate the efficacy of stenting in the palliation of malignant duodenal and gastric outlet obstruction. MATERIALS AND METHODS: We retrospectively reviewed our series of patients who underwent stenting for malignant upper gastrointestinal obstruction between March 1998 and December 1999. From January 2000 data have been acquired prospectively. Our series comprises 21 stents successfully deployed in 15 patients. RESULTS: The technical and clinical success was 93% (14/15 patients). One patient required endoscopic negotiation of recurrent gastric carcinoma at the gastrojejunostomy site after failure to cross the lesion fluroscopically. Two patients required re-intervention 2 and 5 weeks after initial stent placement, for migration and ingrowth respectively. Eighteen stents were placed transorally, two stents transhepatically and one via a transgastric approach. Early complications (pain < 3 days) occurred in two patients (13%) and late complications (ingrowth, overgrowth and migration) occurred in three patients (20%). The median survival was 2.4 months (range 2-4 months). CONCLUSION: Stenting provides a less invasive palliative option than surgery with the advantage of lower morbidity and complication rates. It has the advantage of high technical and clinical success rates facilitated by alternative routes of access into the upper gastrointestinal tract via transgastric and transhepatic routes in addition to the traditional peroral route.

Adult↗

PubMed2001

Angiomatosis of bone and soft tissue: a spectrum of disease from diffuse lymphangiomatosis to vanishing bone disease in young patients.

The application of cross-sectional imaging in the investigation of patients with angiomatosis reveals that lymphangiomatosis and vanishing bone disease should not be considered as separate entities, but rather as a spectrum of disease. We present a pictorial review of eight patients demonstrating the manifestations of soft tissue and bony involvement. We highlight a subgroup of patients with chyloid pleural effusions who have a poor prognosis.

Adolescent↗

PubMed1993

The prevalence of maternal medication ingestion in the antenatal period.

The prevalence of ingestion of medication by pregnant women was recorded in 236 patients attending the antenatal clinics at New Somerset and Peninsula Maternity Hospitals. Patients were interviewed over two periods, 23-26 July and 2-12 December 1991. Of these women, 168 (71.2%) took a total of 283 drugs from 18 different categories. One hundred and forty women (59%) took prescribed and 68 (28.8%) non-prescribed medications. The most commonly used medicines were analgesics, cough and cold medicines, antibiotics, laxatives and antacids. Analgesics that contain aspirin constituted 13.8% of self-administered medicines and 2% of prescribed medicines. The most common sources of non-prescribed medication were pharmacies (60%), followed by supermarkets (32.5%). One hundred and sixty-two women (68.6%) received no advice on medication during their pregnancy. Of those who received advice, formal sources (doctor/nurse/pharmacist/midwife) accounted for 56.8% and informal sources (family/friends/magazines) for 43.3% of advice; 59.7% of women did not know that certain medicines are unsafe during pregnancy. Our data indicate that pregnant women in Cape Town take a large number of medicines, often without being aware of the potential adverse effects. This study shows the need for education in this regard, especially at antenatal clinics, pharmacies and supermarkets.

Adult↗