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Biomedical subjects

A G Clifton

Publications and source records attributed to A G Clifton.

17 recordsLinked to original sources
PubMed2003

Endolymphatic sac tumours.

We present a case of a papillary tumour of the petrous bone. The established terminology for this rare neoplasm is endolymphatic sac tumour (ELST) but the true origin remains controversial. ELSTs are associated with von Hippel-Lindau disease. They are locally invasive, highly vascular and often require endovascular embolization prior to surgery. Both radiologically and histologically ELSTs are easily mistaken for other more common tumours such as paragangliomas and renal or papillary thyroid carcinoma metastases. This is important because local excision is curative.

Adenoma↗
PubMed2002

The contribution of proton magnetic resonance spectroscopy (1HMRS) to clinical brain tumour diagnosis.

Proton magnetic resonance spectroscopy (1HMRS) provides biochemical information from tissue non-invasively, and has an evolving role in brain tumour diagnosis and management. We present 100 consecutive patients with brain tumours who had single voxel 1HMRS as part of their preoperative investigations. We report the histopathological findings and the diagnostic contribution of spectroscopy in an adjunctive role. On the basis of clinical and radiological information the preoperative diagnosis was unclear or inaccurate in 26 out of 100 cases. The discrepancy was of lesion grade in 17 cases and lesion type in 9 cases. In 6 of 100 patients with brain tumours 1HMRS could have made a significant contribution to the preoperative diagnosis if used as part of the routine assessment. There is therefore a useful role for 1HMRS in the evaluation of intracranial mass lesions.

Adolescent↗
PubMed2000

MR angiography.

The primary use of angiography in the neck, either conventional catheter angiography or non-invasive techniques (MR angiography, CT angiography and ultrasound), is for the evaluation of the presence and severity of carotid stenosis. Other conditions such as vertebral artery stenosis, carotid and vertebral artery dissection and fibromuscular dysplasia are much less common but easily detectable with conventional angiography and are becoming increasingly reliably evaluated by non-invasive imaging. Intracranially, the value of MR angiography is less clear cut. It is certainly of use presurgery to look for vessel occlusion and encasement of vessels by tumour. It is also useful in excluding venous thrombosis as a cause of stroke. MR angiography for the detection and screening of intracranial aneurysms is less clear cut and, at present, it is the author's belief that MR angiography cannot replace conventional catheter angiography. Straight-forward spin echo imaging is the most accurate way of detecting arteriovenous malformations (AVMs) with magnetic resonance.

Carotid Stenosis↗
PubMed1995

Measurement of infarct size using MRI predicts prognosis in middle cerebral artery infarction.

BACKGROUND AND PURPOSE: An accurate measure of the severity of ischemic insult and the resulting prognosis is needed to assess the effectiveness of new treatments for acute stroke. We studied the reproducibility and accuracy of measurements of infarct volume with MRI and correlated the measurements with outcome. METHODS: Infarct volume was measured on T2-weighted images with the Analyze image analysis software. This technique was found to be highly accurate and reproducible. RESULTS: Measurements of infarct volume were found to be highly accurate and reproducible. Twenty-one patients (mean age, 66.5 years; range, 28 to 90 years) with cortical middle cerebral artery territory infarcts in whom adequate data could be obtained were studied within 72 hours from onset (mean delay to MRI, 27.5 hours; range, 5 to 72 hours). The Scandinavian Stroke Scale was used to calculate a prognostic score, and clinical outcome was assessed at 3 months. Infarct volume was found to significantly predict outcome. Mean infarct volume in the independent patients was 35.7 +/- 29.7 cm3 compared with 88.3 +/- 71.3 cm3 in dependent patients and 166.5 +/- 65.9 cm3 in dead patients (F = 10.52, P < .001). Patients with an initial infarct volume less than 80 cm3 were found to have a better outcome than those with larger infarct volumes. Secondary hemorrhage visible on MRI also predicted a poor outcome. In contrast, the Scandinavian Stroke Scale did not significantly predict outcome. CONCLUSIONS: The results demonstrate that measurement of the size of middle cerebral artery infarction with MRI is a useful tool in assessing prognosis and will have a valuable role in assessing new therapeutic agents.

Adult↗
PubMed1993

Invasive aspergilloma of the skull base.

Aspergillus infection originating in the nasal cavity or paranasal sinuses is a rare cause of benign, locally invasive disease affecting the skull base. We describe a case in which extensive disease led to bilateral proptosis and invasion of the anterior cranial fossa.

Adult↗
PubMed1993

Appearances of posterior osteophytes after sound anterior interbody fusion in the cervical spine: a high-definition computed myelographic study.

Whether posterior osteophytes in the cervical spine resorb after anterior interbody fusion is controversial. Previous studies have only used plain films. In order to study remodelling, a retrospective study of 53 patients using high-definition CT was performed. There was no evidence of remodelling or resorption of osteophytes and persistent osteophytes continued to deform the spinal cord for up to 12 years after fusion. The importance of this in relation to cervical spinal surgery is that every effort should be made to remove posterior osteophytes during anterior interbody fusion.

Bone Remodeling↗
PubMed1992

Intracranial extension of orbital pseudotumour.

Radiologically demonstrable intracranial extension of orbital pseudotumour is rare, and only four cases appear to have been reported previously in the literature. A review of the computed tomographic (CT) images of 90 biopsy proven cases of orbital pseudotumour seen over a 10 year period revealed eight cases with intracranial meningeal spread.

Adult↗
PubMed1991

The investigation of acoustic neuroma.

Gadolinium-enhanced magnetic resonance (GdMR) is the long awaited, easy and definitive investigation for imaging or excluding small acoustic neuromas. However, on the grounds of cost alone it is unrealistic to submit every patient with mild unilateral sensorineural deafness to GdMR. A screening regime is described which combines simple but effective imaging studies of the internal auditory meatus with clinical testing of vestibular function and objective audiometry. The 'two out of three positive' approach based on these tests has proved to be a reliable screening regime for selecting patients for GdMR.

Audiometry, Evoked Response↗
PubMed1991

Case report: renal lymphoma in a patient with Waldenstrom's macroglobulinaemia.

A case of lymphoma confined solely to the kidneys in a patient with Waldenstrom's macroglobulinaemia is described. Primary lymphomatous involvement of the kidney is very rare in this condition. Ultrasound showed enlarged kidneys partially encased by tumour masses. The radiological features are described and the literature reviewed.

Humans↗
PubMed1990

Identifiable causes for poor outcome in surgery for cervical spondylosis. Post-operative computed myelography and MR imaging.

Outcome from surgery for cervical spondylosis is often disappointing. To identify possible causes of poor outcome 56 such patients referred for post-operative computed myelography or MRI were evaluated, 22 of which eventually had further surgery. Alternative diagnoses to cervical spondylosis were eventually established in 14.3%; 26.8% had spinal cord atrophy 15.6% of which also had myelomalacia; 28.6% had diffuse spinal canal stenosis; and in 57.1% surgery had failed to decompress the spinal canal. These findings can be partly explained by patient selection criteria; nevertheless they do serve to emphasises the point often ignored in discussions of the efficacy of surgery in cervical spondylosis, that operations significantly often fail to achieve adequate decompression. Furthermore there was no evidence in this material that osteophytes regress after spinal fusion.

Adult↗