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Biomedical subjects

M R Sage

Publications and source records attributed to M R Sage.

At least 73 records · Page 4Linked to original sources
PubMed1986

Rate of clearance of intrathecal iopamidol in the dog.

The incidence of post-myelographic side-effects has been significantly reduced since the advent of the new generation of water-soluble, non-ionic, contrast media (CM). One of these CM, iopamidol, has recently been released for clinical intrathecal use in Australia. Clinical evaluations have shown iopamidol to give excellent diagnostic results. However, many adverse side-effects have been cited in the literature. Reactions to iopamidol following myelography are thought to be due to the lack of a physiologic barrier between the extracellular fluid of the brain parenchyma and the CSF, thereby allowing CM to penetrate the brain parenchyma tissue, following subarachnoid injection. This study investigates the rate of clearance of intrathecal iopamidol from the brain in dogs by performing coronal CT scans at intervals over a 48 h, post-injection period. Analysis of similar regions of interest (ROI) for each time period indicate that iopamidol can be detected in canine brains for at least 48 h following intrathecal injection (P less than 0.05). Furthermore, the disappearance of iopamidol from the brain parenchyma is approximately logarithmic in form, with a half-life of approximately 22 h.

Animals↗
PubMed1986

Effects of intracarotid ionic and non-ionic contrast material on the blood-brain barrier in a rabbit model.

A rabbit model was used to assess the effects of intracarotid injections of ionic monomer (meglumine iothalamate), non-ionic monomer (iohexol, iopromide), and non-ionic dimer (iotrol) contrast materials on the blood-brain barrier. The degree of blood-brain barrier damage was assessed qualitatively using Evans' blue dye, and quantitatively by calculating the difference in pertechnetate uptake between injected and non-injected hemispheres. The results showed that the non-ionic dimer, iotrol, had the least effect on the blood-brain barrier, and that although iopromide and iohexol produced greater damage than iotrol, the ionic compound, meglumine iothalamate, caused the greatest disruption to the blood-brain barrier. The implications of these findings are discussed.

Animals↗
PubMed1985

Effects of intracarotid ioxaglate on the normal blood-brain barrier. A comparison of two animal models.

Using two different models, the effect on the blood-brain barrier of intracarotid injections of sodium/meglumine ioxaglate at similar iodine concentrations (280 mgI/ml) was investigated. In both models the degree of blood-brain barrier damage was assessed visually using Evans' Blue stain. Quantitative assessment of blood-brain barrier disruption was made by contrast enhancement as measured by CT of the dog brain, and by 99mTc-pertechnetate uptake by the brain in the rabbit model. No Evans' Blue staining was observed in any study using the canine/CT model. Slight staining was observed in two studies with ioxaglate using the rabbit/pertechnetate model. Statistical analysis of results from the canine/CT model did not detect any damage to the blood-brain barrier with either ioxaglate or saline control studies (P greater than 0.1). However, in the rabbit/pertechnetate model a slight increase in disruption of the blood-brain barrier was observed with ioxaglate compared with control studies, but this was only significant at the 0.1 level. The results suggest that the rabbit/pertechnetate model is a more sensitive measure of blood-brain barrier disruption than the canine/CT model. This study also demonstrates that blood-brain barrier disruption following intracarotid injection of ioxaglate is minimal.

Animals↗
PubMed1984

Computed tomography in the diagnosis of iliopsoas abscesses.

Two cases in which patients presented with lower back pain and bacteraemia, and in which the diagnosis of iliopsoas abscess was made by computed tomography, are reported. Before the introduction of computed tomography, this diagnosis was difficult to establish by means of clinical and radiological investigations. Computed tomography makes it possible to obtain a clear view of the retroperitoneum.

Abscess↗
PubMed1984

Is viscosity important in the production of blood-brain barrier disruption by intracarotid contrast media?

A canine model was used to investigate the effects of intracarotid methylglucamine iothalamate (280 mgI/ml) at different viscosities on the normal blood-brain barrier. To alter viscosity, without changing physiochemical parameters, injections were made at either 23 degrees C or 37 degrees C. The degree of blood-brain barrier damage was assessed using Evans' Blue dye as a visual marker and by contrast enhancement measured by a computed tomographic (CT) scanner. It was found that methylglucamine iothalamate caused more blood-brain barrier damage at 23 degrees C than at 37 degrees C (p less than 0.1). Control studies at each temperature using intracarotid injections of physiological saline showed no temperature effect (p greater than 0.1). The implications of these findings are discussed.

Animals↗
PubMed1984

Computed tomography in cervical disc disease when myelography is unsatisfactory.

Water-soluble contrast media have replaced myodil for cervical myelography. In the presence of significant degenerative disease, the normal cervical lordotic curve may be decreased, straightened or even reversed, making it impossible to 'pool' sufficient contrast medium in this region. In such cases, third generation computed tomography is invaluable in confirming or excluding the presence of cervical disc protrusion.

Adult↗
PubMed1984

The diagnosis and local staging of renal cancer--an appraisal.

The standard pattern of investigation for renal masses usually involves excretion urography, ultrasonography and angiography. This study was undertaken to determine whether computed tomography (CT) and fine needle aspiration cytology could provide information that might allow this pattern to be modified. Diagnostic information was obtained by needle aspiration cytology in 25 patients who were shown at operation to have a neoplasm. The diagnosis was correct in 22 cases (88%). By comparison, arteriography was accurate in 22 out of 24 (92%), and computed tomography provided the correct diagnosis in 19 out of 21 (90%). Staging was performed surgically and histologically in 21 patients, and when this was compared with the results of CT staging there was complete agreement in 13 cases (62%). A literature review revealed an average staging accuracy for CT of 81% while arteriography was accurate in only 57%. Thus CT appears to be as good as arteriography for diagnosis and potentially better for local staging. It is also less invasive, rapid and cost effective and could supersede arteriography as the primary diagnostic and staging investigation in patients with a solid renal mass.

Biopsy, Needle↗
PubMed1984

Computed tomography of paraspinal musculature in ankylosing spondylitis.

Computed tomography (CT) was used to delineate the paraspinal musculature in 14 patients with ankylosing spondylitis (AS). Abnormal atrophy of the erector spinae muscles and multifidi was demonstrated in all 8 patients with total bony ankylosis of the spine, but was not present in those with isolated syndesmophyte formation, vertebral squaring alone or sacroiliac joint ankylosis with normal spinal radiographs. There was a significant positive correlation between a CT score of paravertebral muscle wasting and clinical parameters of disease duration and restriction of spinal mobility. Wasting and asymmetry of the psoas muscles was seen in 3 patients with unilateral hip joint involvement. These findings suggest that a relationship exists between decreased or absent spinal movement and atrophy of the paraspinal musculature in AS.

Adult↗
PubMed1983

Gastric duplication in an adult.

Congenital alimentary duplications occur most commonly in relation to the ileum and are rare in the region of the stomach. A case of gastric duplication presenting in an adult and visualized on computed tomography is reported.

Adult↗