Search PubMed⌕ Search

Biomedical subjects

D J Quint

Publications and source records attributed to D J Quint.

At least 37 records · Page 2Linked to original sources
PubMed1998

Spinal cord infection: myelitis and abscess formation.

PURPOSE: Our purpose was to describe the MR findings and evolution of spinal cord abscess and to define those MR features that allow differentiation of cord infection from other intramedullary abnormalities. METHODS: We retrospectively reviewed the MR studies of all patients in whom intramedullary spinal cord abscess was proved either by blood or cerebrospinal fluid culture or by serologic examination at our institution between January 1988 and January 1996. The study group included four adults and two children, 7 to 74 years old (mean age, 38 years). RESULTS: Initial MR studies showed intramedullary high signal on T2-weighted sequences with poorly defined marginal enhancement on T1-weighted images. On follow-up contrast-enhanced T1-weighted studies, the lesions had well-defined enhancing margins with central low signal intensity. After the initiation of therapy, T2 signal abnormalities decreased markedly and contrast-enhanced studies showed ring enhancement. These T1 findings resolved with treatment over serial studies in four patients. The organisms identified were Streptococcus milleria, S pyogenes, atypical mycobacteria, Mycobacterium tuberculosis, and Schistosoma mansoni (both children). CONCLUSION: A characteristic sequence of imaging findings aids in the differentiation of cord infection from other intramedullary lesions.

Abscess↗
PubMed1997

Computer-assisted measurement of lumbar spine radiographs.

RATIONALE AND OBJECTIVES: The authors evaluated a method for obtaining reproducible, reliable measurements from standard lumbar spine radiographs for determining the degree of spondylolisthesis, vertebral body height, intervertebral disk space height, disk space angle, and degree of vertebral body wedging. MATERIALS AND METHODS: Four to six easily defined points were identified on each vertebral body on anteroposterior and lateral plain radiographs of the lumbosacral spine of patients. From these points, the degree of spondylolisthesis, the vertebral body height, the intervertebral disk space height, the disk space angle, and the degree of vertebral body wedging were easily calculated by using well-known geometric relationships. This method requires the use of a personal computer and a standard spreadsheet program but does not require the use of any other specialized radiographic equipment, computer hardware, or custom software. RESULTS: Calculations of intra- and interobserver variability for the measurement of spondylolisthesis, disk space height, disk space angle, and vertebral body height measurement showed that the technique is extremely reproducible. CONCLUSION: This technique may prove useful in the prospective evaluation of potential candidates for lumbar spinal stenosis surgery.

Humans↗
PubMed1997

MRI findings in narcolepsy.

The neuropathology of narcolepsy is unknown. Recently, Plazzi et al. (1) reported magnetic resonance imaging (MRI) abnormalities in the pontine tegmentum of three patients with long-standing idiopathic narcolepsy. Considering the localization of the neuroradiological findings in the pontine reticular formation, where rapid eye movement (REM) sleep is generated, the authors suggested a causal relationship between narcolepsy and MRI abnormalities. Frey and Heiserman, however, found pontine MRI abnormalities in only two of 12 patients with narcolepsy both of whom had long-standing hypertension (2). Pullicino et al. noted similar pontine MRI abnormalities in patients with subcortical arteriosclerotic encephalopathy-like ischemic rarefaction of the pons (3). Thus, the changes noted by Plazzi et al. may have been caused by small-vessel disease rather than narcolepsy. To assess whether altered pontine MRI signals are a regular feature of idiopathic narcolepsy, we selected randomly from our database seven patients with narcolepsy with cataplexy. Of these seven, three agreed to have brain MRIs; their cases are described below. None had pontine MRI abnormalities.

Adult↗
PubMed1997

MRI of optic nerve enlargement in optic neuritis.

We report two cases of optic neuritis with optic nerve enlargement on MRI. Both had a clinical course typical for optic neuritis but also had a neuroradiologic finding most commonly seen with optic nerve glioma or meningioma, which initially led to an incorrect diagnosis. We review the six previous reported cases of optic nerve enlargement in optic neuritis. Including our cases, six of eight reported cases were in children with severe initial visual loss. Optic nerve enlargement is a rare finding in optic neuritis that might be a subtype of optic neuritis.

Child↗
PubMed1997

CT demonstration of periorbital graft-versus-host disease.

A 13-year-old boy who had undergone allogenic bone marrow transplantation for treatment of acute lymphocytic leukemia presented with bilateral periorbital rash and swelling. A CT scan showed bilateral symmetric periorbital swelling, subconjunctival fluid collections, and lacrimal gland enlargement. The patient was initially treated for presumed cellulitis. However, persistently negative regional cultures (eye, nasopharynx), a rapid response to immunosuppressive therapy after several days of nonresponse to intravenous antibiotic therapy, and ultimately, results of a skin biopsy confirmed the diagnosis of acute graft-versus-host disease.

Acute Disease↗
PubMed1997

Globe tenting as a result of head trauma.

Ocular tenting in the setting of acute trauma, inflammatory processes, or carotid cavernous fistulas is reported to be associated with a poor outcome with respect to visual acuity. Therefore, acute decompressive intervention is recommended for these patients. We report a case of acute posttraumatic ocular tenting with acute visual compromise that resolved over 4 days with conservative management and intravenous corticosteroid therapy.

Accidents, Traffic↗
PubMed1997

CT-guided brachial plexus biopsy.

We describe a technique for conducting a CT-guided biopsy of the brachial plexus region, report two illustrative cases, discuss potential complications, and conclude that, in selected cases, biopsy of lesions in the region of the brachial plexus can be performed safely with CT guidance.

Adenocarcinoma↗
PubMed1996

Magnetic resonance imaging of normal meningeal enhancement at 1.5 T.

RATIONALE AND OBJECTIVES: We examined patterns of intracranial meningeal enhancement on gadolinium chelate contrast media-enhanced 1.5-T spin-echo magnetic resonance (MR) imaging and developed criteria that might be useful for distinguishing between normal and abnormal meningeal enhancement. METHODS: The convexity, falx cerebri, tentorium cerebelli, and suprasellar cistern regions of 204 patients were prospectively evaluated for contrast enhancement with a grading system ranging from 0 (no enhancement) to 5 (diffuse, irregular, thickened enhancement). Meningeal findings were correlated with other MR abnormalities and pertinent clinical histories that have been associated previously with meningeal enhancement. RESULTS: Short-segment convexity meningeal enhancement was commonly seen and most likely represents intravascular contrast material in normal meningeal vessels. Such enhancement did not correlate with the presence of other MR abnormalities. Long-segment (> 3 cm) or diffuse convexity meningeal enhancement did correlate with other significant MR abnormalities and pertinent clinical history. Fine linear falcine and tentorial meningeal enhancement, as an isolated finding, did not correlate with other MR or clinical abnormalities. The suprasellar cistern and ventricular walls were rarely enhanced. CONCLUSION: Short-segment convexity meningeal contrast enhancement is a normal finding representing normal vascular structures. More extensive convexity meningeal enhancement is abnormal and should prompt careful examination of the remainder of an MR image as well as the patient's clinical history for an etiology of the enhancement.

Adolescent↗
PubMed1996

Neuroradiology.

Explore the source record for details and available documents.

Humans↗
PubMed1996

Recurrence of head and neck cancer after surgery or irradiation: prospective comparison of 2-deoxy-2-[F-18]fluoro-D-glucose PET and MR imaging diagnoses.

PURPOSE: To evaluate the diagnostic accuracy of positron emission tomography (PET) with administration of 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) relative to that of magnetic resonance (MR) imaging and/or computed tomography (CT) in recurrent head and neck cancers. MATERIALS AND METHODS: Twelve adult patients (mean age, 63 years) with previously treated head and neck cancers and clinical suspicion of recurrence underwent FDG PET and MR imaging and/or CT. All images were blindly and independently interpreted without histopathologic findings (obtained within 1 week of imaging). The level of confidence in image interpretation was graded by using a five-point rating system (0 = definitely no recurrence to 4 = definite recurrence). RESULTS: Recurrence was confirmed in eight patients. With a rating of 4 as a positive finding, FDG PET yielded a sensitivity and specificity of 88% (seven of eight) and 100% (four of four), respectively; MR imaging and/or CT, 25% (two of eight) and 75% (three of four), respectively. Receiver-operating characteristic analysis showed significantly better diagnostic accuracy with FDG PET than with MR imaging and/or CT (area under curve = 0.96 vs 0.55, P < .03). CONCLUSION: These data indicate that PET metabolic imaging, as compared with anatomic methods, has improved diagnostic accuracy for recurrent head and neck cancer.

Aged↗
PubMed1996

Pre- and postoperative MR imaging of craniopharyngiomas.

PURPOSE: To compare the pre- and postoperative MR appearance of craniopharyngiomas with respect to lesion size, tumour morphology and identification of surrounding normal structures. MATERIAL AND METHODS: MR images obtained prior to and following craniopharyngioma resection were evaluated retrospectively in 10 patients. Tumour signal characteristics, size and extension with particular reference to the optic chiasm, the pituitary gland, the pituitary stalk and the third ventricle were evaluated. RESULTS: Following surgery, tumour volume was reduced in all patients. In 6 patients there was further tumour volume reduction between the first and second postoperative images. Two of these patients received radiation therapy between the 2 postoperative studies, while 4 had no adjuvant treatment to the surgical intervention. There was improved visualization of the optic chiasm in 3, the pituitary stalk in one, and the third ventricle in 9 of the 10 patients. The pituitary gland was identified preoperatively only in one patient, postoperatively only in another, pre- and postoperatively in 5, and neither pre- nor postoperatively in 3 patients. In 3 patients MR imaging 0-7 days postoperatively identified tumour remnants not seen at the end of the surgical procedure. The signal intensities of solid and cystic tumour components were stable from pre- to the first postoperative MR images. Optic tract increased signal prior to surgery was gone 28 days postoperatively in one patient, but persisted on the left side for 197 days after surgery in another. CONCLUSION: Postoperative MR imaging of craniopharyngiomas demonstrated tumour volume reduction and tumour remnants not seen at surgery. Early postoperative MR imaging of craniopharyngiomas may overestimate the size of residual tumour. Improved visualization of peritumoral structures may be achieved.

Adult↗
PubMed1996

Intracranial gas: a pictorial essay.

Intracranial gas is a common finding on postcraniotomy computed tomography scans. It can also be found in a wide variety of other benign and life-threatening clinical settings. Because intracranial gas is never normal, its presence must be explained. This pictorial essay describes the imaging features of intracranial gas and demonstrates the findings for many of the causes of this condition.

Artifacts↗
PubMed1996

Unusual tumours of the skull and skull base: a pictorial essay.

Six unusual tumours of the skull and skull base are illustrated in this pictorial essay; for three of the tumours, both magnetic resonance imaging and computed tomography were performed preoperatively. These two imaging modalities can provide complementary information in the preoperative evaluation of unusual tumours of the skull and skull base.

Adenoma↗
PubMed1995

Detection of degradation of magnetic resonance (MR) images: comparison of an automated MR image-quality analysis system with trained human observers.

RATIONALE AND OBJECTIVES: The perceived need for magnetic resonance (MR) imaging quality control (QC) is occasionally minimized on the assumption that significant errors will be detected by the users. To evaluate the validity of this assumption, we compared the sensitivity of a test object and automated image analysis system for MR imaging QC with the sensitivity of trained human observers by evaluating images that were intentionally degraded. METHODS: Parameters for imaging the test object and normal human volunteers were set to values that decreased the signal-to-noise ratio (SNR), caused distortion, and increased the slice thickness and separation. RESULTS: The human observers were able to detect a 6-13% reduction in the SNR and distortions of more than 15% in human images. They were unable to identify 40% increases in the slice thickness. Automated analysis of test object images was able to detect all image degradations at the minimum levels applied. CONCLUSION: The poor sensitivity of the human observers indicated that degradation, especially spatial measurements, could be significantly in error before being detected through visual analysis of clinical images. These errors would be detected by automated analysis of the test object used. Further investigation is needed to better define the accuracy with which quantitative image-quality analysis predicts the effects of degraded image quality on the ability of human observers to detect subtle abnormalities in clinical images.

Contrast Sensitivity↗