Search PubMed⌕ Search

Biomedical subjects

F R Murtagh

Publications and source records attributed to F R Murtagh.

At least 37 records · Page 2Linked to original sources
PubMed1993

Brain magnetic resonance imaging in acute optic neuritis. Experience of the Optic Neuritis Study Group.

OBJECTIVE: Changes in the brain on magnetic resonance images are common in patients with optic neuritis even when there is no other clinical evidence of multiple sclerosis. The current study was designed to determine systematically the prevalence of brain abnormalities on magnetic resonance images in the patients entered into the Optic Neuritis Treatment Trial. DESIGN: Prospective multicenter clinical trial. SETTING: Referral centers. PATIENTS AND METHODS: Brain magnetic resonance images from 418 patients with acute optic neuritis (77% women; mean age, 32.0 years) were evaluated at a central reading center with the use of a standardized classification system (ranging from 0 for normal to IV for most extensive changes). RESULTS: Of the scans, 40.9% were classified as grade 0, 10.8% as grade I, 9.1% as grade II, 6.7% as grade III, and 32.5% as grade IV. For patients with isolated (monosymptomatic) optic neuritis, 26.7% had two or more lesions. CONCLUSIONS: We found a lower prevalence of brain magnetic resonance imaging abnormalities in isolated optic neuritis than previous studies have reported. This likely is due to our study having a higher degree of standardization of patient inclusion criteria, which limited patient selection bias.

Acute Disease↗
PubMed1993

Use of a clinical MR scanner for imaging the rat brain.

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy are established techniques that enable noninvasive anatomic and functional tissue characterization in vivo. These tools have been employed to probe experimental models of neoplasia, cerebrovascular disease, brain injury, and neurotransplantation in small animals. To date, these studies have been executed primarily on research-dedicated instruments of limited availability or resolution. Using relatively straightforward software and hardware modifications of a widely used clinical MRI unit, we were able to image numerous structures within the living rat brain including the neostriatum, hippocampus, periaqueductal gray, and the ventricular system. Illustrative applications of this imaging technique in two intracerebral infusion models involving rats are presented. Such adaptation of clinical MRI scanners has the potential to significantly expand the availability of high resolution in vivo imaging of small animals for a variety of experimental protocols.

Animals↗
PubMed1992

Computer tomographically guided discography as a determinant of normal disc level before fusion.

Computer tomographically guided discography was used as a reproducible and reliable method of determining the internal architecture and integrity of intervertebral discs before spinal fusion operation. One hundred disc levels were studied in 60 prospective patients with 54 (54%) of levels proving abnormal. Twenty-nine levels (29% of total levels) demonstrated complete anular tears, and 25 (25% of total) showed incomplete radial tears of the anulus, often multiple, indicative of degenerative change. In each of these cases, one level higher had to be studied and was subsequently found to be normal and would, therefore, support a fusion.

Humans↗
PubMed1991

Magnetic resonance imaging anatomy of the cranial nerves.

Correlation of findings on neurological examination of the cranial nerves with gross anatomy, neuroanatomy, and neuropathology provides the optimal diagnostic use of magnetic resonance imaging (MRI). Illustrations of the anatomy of each of the cranial nerves, with concise labeling of relevant anatomical relationships, are compared with brief neurological summaries and MRIs of patients.

Adult↗
PubMed1991

The role and incidence of facet tropism in lumbar spine degenerative disc disease.

The correlation of posterior intervertebral (facet) joint tropism (asymmetry), degenerative facet disease, and intervertebral disc disease was reviewed in a retrospective study of magnetic resonance images of the lumbar spine from 100 patients with complaints of low back pain and sciatica. Of the 27 of 100 (27%) of patients discovered to have disc disease (either herniation of nuclear material or bulge) at the L4-5 level, an approximately equal number had facet tropism (14 of 27) as did not (13 of 27). Of the 27 of 100 (27%) patients noted to have disc disease at the L5-S1 level, slightly more (16 of 21) had facet tropism than did not (11 of 27). Of the 65 of 100 (65%) of patients who had facet degenerative disease at the L4-5 level, an approximately equal number had facet tropism (33 of 65) as did not (32 of 100). At the L5-S1 level there was slightly more of a difference, with 25 of 41 having facet degenerative joint disease and tropism and 16 of 41 without it. This study raises questions as to the significance of facet joint tropism in intervertebral disc disease and degenerative facet joint disease but did show that asymmetry of the posterior intervertebral joint is far more common than previously thought: 50% of patients were found to have asymmetric facets at the L5-S1 level and 42% at the L4-5 level.

Back Pain↗
PubMed1990

MR imaging in a patient with Leigh's disease (subacute necrotizing encephalomyelopathy).

Leigh's disease, also known as subacute necrotizing encephalomyelopathy, is a rare progressive neurological disorder of childhood that was first described by Leigh in 1951. Diagnosis of this disease can be difficult because onset is usually insidious and can present with a number of different focal findings, however diagnostic imaging has been shown to be of benefit in this regard. We present a patient with Leigh's disease in whom serial MR imaging studies helped to make the diagnosis and also demonstrated the dynamic characteristic of this disease process.

Brain↗
PubMed1989

Magnetic resonance imaging of intracranial epidermoid tumours.

Epidermoid tumours are rare lesions within the skull which are usually found in a cerebellopontine angle. In the computed tomography (CT) literature, they have been described as well-defined lesions of low density which seldom show calcification or tissue enhancement. We have recently encountered three intracranial epidermoids, which appeared to exhibit uniform findings on low field strength magnetic resonance (MR) of moderate signal intensity in the T1-weighted images and a bright signal (increased T2) in the T2-weighted sequences. It may be possible to predict accurately the presence of an epidermoid tumour when this particular configuration of findings is present.

Adult↗
PubMed1989

Fatal pontine metastasis: clinical, CT, MRI and pathological correlates.

Progressive brainstem and cerebellar signs developed in a previously healthy 70-year-old man over a course of seven days. A pontine mass characterized by CT and MRI suggested an infiltrating primary pontine glioma. Gross postmortem examination showed a medullary-pontine hemorrhage. Microscopic analysis disclosed an undifferentiated large cell carcinoma which was found to originate from the lung. Differential diagnoses in cases of suspected brainstem lesions are given, including metastatic tumors which are rare when presenting as a solitary brainstem mass. Optimal patient management should be formulated on the basis of histopathological diagnosis rather than imprecise imaging data. Exact tissue diagnosis will also avoid an extensive and expensive search for an occult systemic cancer. The roles of radiation, chemotherapy and surgery are also discussed.

Aged↗
PubMed1988

CT-guided nerve root block and ablation.

We report our experience in performing 52 CT-guided peripheral nerve root blocks and 27 CT-guided nerve root ablations. The nerve root block procedures were performed as diagnostic tests to determine the clinical significance of equivocal herniated disk or foraminal stenosis (n = 33) and before nerve root ablations (n = 19). To evaluate the clinical significance of these nerve root blocks, we performed 52 procedures at the vertebral level where a herniated disk or foraminal stenosis had been identified on CT or MR images. In 51 of 52 cases, the procedures were successful in anesthetizing the intended nerve root, which allowed us to determine whether that particular nerve root was the source of pain. By relieving or not relieving pain, the results of the diagnostic nerve root blocks helped determine whether a protrusion or foraminal stenosis was clinically significant. The nerve root ablations were done exclusively for treatment of pain in patients with malignant disease. Significant relief of pain was obtained in 17 (63%) of 27 patients. The thoracic nerve ablations were the most successful (9/10 or 90%) because the correct thoracic nerve innervation to the offending lesion could be identified. The lumbosacral nerve ablation procedures were the least successful (6/14 or 43%) because the innervation of the pelvic neoplasms was complex, arising from multiple lumbosacral nerves that often were bilateral. Equivocal foraminal stenosis and disk protrusion are common findings on CT and MR imaging, and CT-guided nerve block procedures can help determine which of these findings are clinically significant. CT-guided nerve root ablations have limited efficacy but can help control pain in patients with a malignant disease, especially when the pain is in the distribution of a thoracic nerve dermatome.

Ethanol↗
PubMed1988

Computed tomography and fluoroscopy guided anesthesia and steroid injection in facet syndrome.

One hundred patients with posterior compartment lumbar spinal axis pain syndromes and focal tenderness were injected with lidocaine and betamethasone in 194 sites. Lidocaine injection was diagnostic in 183 instances (94%) and steroid injection provided long-term relief (greater than 3 months) in 105 instances (54%). CT guidance proved helpful in directing the needle tip to the precise location for optimal delivery of medications to exact anatomical sites.

Anesthesia, Spinal↗
PubMed1987

Pulsed Doppler frequency and carotid stenosis.

Two hundred and forty-two internal carotid arteries (ICA) were evaluated by independently interpreted arteriography and pulsed Doppler spectrum analysis using ultrasonic arteriography to evaluate the ability of peak systolic frequency (PSF) to predict the degree of internal carotid stenosis. Mean PSF in the 129 (53.3%) high grade ICA stenoses of greater than 50% diameter reduction was 6.55 +/- 0.14 (SEM) khz, while mean PSF in the 113 (46.7%) low grade (less than 50% diameter reduction) stenoses was 3.38 +/- 0.12 (SEM) kHz (P less than 0.0001). Receiver-operator characteristic (ROC) analysis revealed that PSFs of 4.5 kHz (sensitivity 87%, specificity 88%) and 5.0 kHz (sensitivity 83%, specificity 93%) were best for identifying a 50% diameter stenosis. Positive predictive value of 5.0 kHz was 93% (107/115) and negative predictive value was 82.7% (105/127). Linear regression analysis of PSF in kHz versus percentage diameter reduction yielded the equation: % stenosis = 10.7 (PSF) - 4.1 (r = 0.76). A nonlinear equation was also derived: % stenosis = 61.9 - 33.5 (PSF) + 8.7 (PSF)2 - 0.5 (PSF)3 (r = 0.77). Based on this analysis peak systolic frequency criteria measured by pulsed Doppler spectrum analysis appear to be useful for distinguishing high grade from low grade stenoses. Both the linear and nonlinear equations further suggest that PSF can more precisely quantitate the degree of ICA luminal narrowing.

Carotid Artery Diseases↗
PubMed1987

Cervical rheumatoid arthritis: value of flexion and extension views in imaging.

The magnetic resonance (MR) imaging findings in the cervical spines of eight patients with long-standing polyarticular rheumatoid arthritis were reviewed. Three pathologic conditions were readily demonstrated: anterior atlantoaxial subluxation (n = 6), atlantoaxial impaction (n = 6), and subaxial subluxation (n = 6). An abnormal soft-tissue signal was noted in the preodontoid space in six patients; this signal was thought to represent the associated inflammatory mass. MR imaging was useful not only for depicting the bony abnormalities in the cervical spine that are associated with rheumatoid arthritis, but also can directly show the effect of the disease process on the spinal cord and brain stem.

Arthritis, Rheumatoid↗
PubMed1987

Childhood scoliosis: MR imaging.

The spinal cords of 28 scoliosis patients between the ages of 1 month and 17 years were examined with magnetic resonance (MR) imaging. Complete visualization was obtained in all cases. In 15 patients (53%) neuropathologic abnormalities demonstrated by MR imaging significantly affected their clinical course, including tethered cords (n = 7), syringomyelia (n = 5), Arnold-Chiari I malformation (n = 4), spinal cord tumors (n = 2), Arnold-Chiari II malformation (n = 3), and diastematomyelia (n = 1). The advantages of MR imaging in the evaluation of the scoliotic spine in children include a high sensitivity for the occult conditions associated with scoliosis, good anatomic demonstration of the cord, and absence of bone artifacts. MR imaging is recommended as a primary imaging modality in scoliosis, following conventional radiography.

Arnold-Chiari Malformation↗