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Biomedical subjects

A B Dublin

Publications and source records attributed to A B Dublin.

At least 19 recordsLinked to original sources

One-year follow-up evaluation of magnetic resonance imaging of the brain in dogs with pituitary-dependent hyperadrenocorticism.

OBJECTIVE: To evaluate magnetic resonance imaging (MRI) brain scans of dogs with pituitary-dependent hyperadrenocorticism (PDH) and no signs of CNS dysfunction 1 year after diagnosis and initial MRI. DESIGN: Prospective study of surviving dogs from a previous study. ANIMALS: 13 dogs underwent MRI of the brain at the time that PDH was diagnosed and prior to treatment. At that time, none of the dogs had clinical signs suggestive of an intracranial mass. Approximately 1 year after diagnosis and MRI, the brain was again evaluated by MRI. RESULTS: On the initial MRI scan, 5 of the 13 dogs had normal findings, and 8 had evidence of a mass (tumor) in the area of the pituitary gland. Of the 5 dogs that had no visible pituitary mass on the initial MRI scan, 3 had a normal MRI brain scan 1 year later. Of the 5 dogs that had no visible pituitary mass on initial MRI scan, 2 had a visible pituitary mass at 1 year. The 8 dogs that had a visible mass on the initial MRI brain scan had easily identified pituitary masses on the second MRI scan. Of these 8 dogs, 4 had no apparent change in pituitary mass size, and 4 had obvious increase in vertical height of the pituitary mass. Of the 4 dogs, 2 developed signs of neurologic dysfunction within 1 year after diagnosis of PDH, presumably attributable to that mass. Of the 13 dogs, 12 were treated with mitotane soon after completion of the initial MRI scan. Sensitivity to mitotane and initial pituitary mass size or growth were not correlated. Of the 13 dogs evaluated initially and 1 year after diagnosis, 10 had pituitary masses identified on MRI brain scans. CLINICAL IMPLICATIONS: The incidence of visible pituitary masses among dogs with PDH at the time of or within a year of diagnosis was > 75%. In 2 dogs, signs of CNS dysfunction developed within 1 year of PDH diagnosis when pituitary masses were > or = 10 mm.

Adrenocortical Hyperfunction↗

Magnetic resonance imaging of the brain in dogs with recently diagnosed but untreated pituitary-dependent hyperadrenocorticism.

Magnetic resonance imaging was used to determine the prevalence of visible pituitary masses in 21 dogs with recently diagnosed and untreated pituitary-dependent hyperadrenocorticism. All dogs had clinical signs and routine database values (CBC, serum biochemical panel, and urinalysis) consistent with a diagnosis of hyperadrenocorticism, and none had clinical signs suggestive of an intracranial mass. Each dog had plasma cortisol concentrations after adrenocorticotropic hormone administration or low-dose dexamethasone administration consistent with hyperadrenocorticism. Pituitary-dependent hyperadrenocorticism was confirmed by the finding of 2 equal-size adrenal glands on abdominal ultrasonography and by results of plasma endogenous adrenocorticotropic hormone concentration and high-dose dexamethasone suppression testing. Sagittal and transverse T1-weighted magnetic resonance images of the brain were obtained before and after IV administration of gadopentenate dimeglumine. Eleven dogs had visible masses, ranging in size from 4 to 12 mm at greatest vertical height. Mean age and body weight of dogs with a visible pituitary mass was not significantly different from dogs without a visible mass. There was no significant difference in endocrine test results when comparing dogs with a visible pituitary mass to dogs without. The prevalence of visible pituitary masses in dogs with pituitary-dependent hyperadrenocorticism was greater than suggested by the prevalence of clinical neurologic signs.

Adrenal Cortex Diseases↗

Magnetic resonance imaging for diagnosis of pituitary macrotumors in dogs.

The value of magnetic resonance imaging (MRI) for the evaluation of dogs with pituitary-dependent hyperadrenocorticism (PDH) and CNS signs was assessed. Magnetic resonance imaging of the brain was performed in 13 dogs with PDH and neurologic signs. The diagnosis of PDH was made on the basis of results of adrenocortical function tests and abdominal ultrasonography, in conjunction with appropriate history, clinical signs, and clinicopathologic alterations. Eight dogs had been treated with the adrenocorticolytic agent, mitotane, for 1 to 30 months before the development of neurologic signs. Prior to MRI, each dog had progressive neurologic signs that could not be attributed to hypocortisolism or mitotane toxicosis. The neurologic signs most frequently detected were disorientation and ataxia. Mean age of dogs at the time neurologic signs developed was 9.5 years. Sex predilection was not detected; however, most were large-breed dogs, with 11 of the 13 dogs weighing more than 20 kg. A large mass in the pituitary gland, suprasellar region, or both was easily identified on the magnetic resonance images of each dog. The masses ranged from 8 to 24 mm in size. Expansion of tumors into the suprasellar region and compression of structures adjacent to the pituitary gland were readily detected by MRI. Contrast enhancement did not improve tumor identification, but did enable better delineation between tumor and surrounding structures. After the diagnosis of a macrotumor was made by MRI, radiotherapy was initiated in 9 dogs and was successfully completed in 6. Three dogs had a relapse of neurologic signs 8, 11, and 26 months after radiotherapy was completed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Dural and carotid cavernous sinus fistulas. Diagnosis, management, and complications.

Carotid cavernous sinus fistulas (CCSFs) are a rare entity occurring as a result of head trauma and also spontaneously. The major threat from these fistulas is loss of vision. The authors reviewed 18 cases of direct and dural CCSFs seen over the last 10 years and compared our results with 553 cases treated in the literature. Seventy-one percent of our patients with direct CCSFs had successful balloon embolization. In the literature, successful closure of direct CCSFs has ranged from 58 to 100%. As experience with embolization techniques broadens, morbidity and mortality is reduced. The clinical features, diagnostic procedures, therapeutic options, and complications of treatment of CCSFs are discussed.

Adolescent↗

Rupture of inferior thyroid artery aneurysm.

We report a case in which rupture of an aneurysm of the inferior thyroid artery caused respiratory arrest. The aneurysm was embolized successfully by an angiographic technique. Published reports of rupture of thyroid artery aneurysms are reviewed.

Aged↗

Evaluation of spinal infections by plain radiographs, computed tomography, intrathecal metrizamide, and CT-guided biopsy.

16 cases of spinal infection were reviewed to evaluate the usefulness of plain radiographs, noncontrast computed tomography (CT), computed tomographic metrizamide myelography (CTMM), plain film metrizamide myelography, and CT-guided biopsy techniques. Noncontrast CT was more useful than plain films in the evaluation of disc space and bony involvement and soft tissue extension of infection into the paraspinal spaces. CTMM was needed for evaluation of epidural or subdural involvement of infection in the cervical and thoracic spine, while plain film metrizamide myelography was useful as a survey for CTMM. CT-guided biopsy was definitive in establishing the etiology of the offending organism.

Adolescent↗

Long-term delta-9-tetrahydrocannabinol treatment. Computed tomography of the brains of rhesus monkeys.

High-resolution computed tomographic (CT) scanning of the brain was performed on three groups of rhesus monkeys for the detection of ventricular or cisternal enlargement. These three groups comprised four age-matched controls that had no prior drug usage--four monkeys receiving short-term (two to ten months) orally administered delta-9-tetrahydrocannabinol (delta 9-THC [now known nonproprietarily as dronabinol] and four monkeys receiving long-term (five years) orally administered delta 9-THC. Our results show a statistically significant enlargement of the frontal horns and the bicaudate distance in the long-term group as compared with the control and less significant enlargement of these areas in the long-term group compared with the short-term group. These findings suggest atrophy of the head of the caudate nucleus and the frontal portion of the brain of rhesus monkeys receiving long-term treatment with delta 9-THC.

Administration, Oral↗

Outpatient low-dose computed tomography metrizamide myelography and evaluation of lumbar disk disease.

Outpatient low-dose computed tomography metrizamide myelography (CTMM) for the evaluation of lumbar disk disease is described in 55 patients. Ten individuals (group 1) were studied using 3.5 ml of 150 mg I/ml (525 mg I total) of metrizamide. Forty-five additional patients (group 2) were examined with 5 ml of 110 mg I/ml (550 mg I total) concentration of metrizamide. Group 2 experienced less post-procedure headache (6.6%) and nausea (2.2%) than did group 1 (30% and 10%, respectively). Group 2 demonstrated a lowered rate of headache (p less than .01) and showed a trend to less nausea (p less than .09) than a recently published study describing full-dose lumbar myelography. In addition, CTMM in group 2 produced more uniform mixing of metrizamide than in group 1. Overall, low-dose CTMM increased accuracy and reduced morbidity, patient cost, and inconvenience as compared with routine full-dose lumbar myelography.

Adult↗

The value of computed tomographic metrizamide myelography in the neuroradiological evaluation of the spine.

The diagnostic value of plain film metrizamide myelography (PFMM) was compared with computed tomographic metrizamide myelography (CTMM) in a study of 106 individuals who had undergone high-resolution computed tomographic scanning of the spine. CTMM provided more significant information than PFMM in 42 of 106 cases (40%), but showed no advantage over PFMM in 63 of 106 cases (59%). In 19 of the 42 cases (45%), PFMM was useful in directing the CT analysis to the appropriate region of pathology. In one patient, PFMM revealed a mobile herniated disc that had not been visualized with CTMM. In 30 of 106 cases in which plain CT scans of the spine were also obtained, the addition of intrathecal metrizamide demonstrated additional pathology in ten individuals. In general, CTMM was useful in the delineation of a variety of pathologic entities, especially neoplasms and congenital abnormalities. Low-dose CTMM (3 ml of a 150 ml/mg concentration) was performed as an outpatient procedure and found to be a useful adjunct to plain CT in two patients. A schema for the radiological evaluation of pathology of the spine is presented.

Adolescent↗

Residual myelographic contrast material seen on the chest radiograph.

Oily contrast material remaining after myelography may escape through the lumbar needle track and enter the dependent thoracic extradural spaces as droplets and collections in the intercostal spaces. Until these intercostal collections are absorbed, which takes place slowly over a period of one or more years, they can produce densities on the chest radiograph. The authors report 26 such cases representing three different patterns of distribution.

Absorption↗

Percutaneous transluminal carotid angioplasty in fibromuscular dysplasia. Case report.

A patient with fibromuscular dysplasia (FMD) of the internal carotid artery was treated by balloon percutaneous transluminal angioplasty (PTA). This is the sixth reported case of FMD stenotic disease which was dilated by PTA. All previous cases including the current example were treated successfully with resolution of symptoms. This procedure is associated with a relatively low morbidity and is an alternative method of treatment to operative endarterectomy for this disorder.

Adult↗

Cranial computed tomography in the diagnosis of symptomatic indirect trauma to the carotid artery.

Five patients who were involved in motor vehicle accidents sustained indirect, nonpenetrating carotid artery injuries leading to cerebral infarction. Four patients were conscious when a severe lateralized neurological deficit developed three to 12 hours after injury indicating the presence of a vascular injury and not a mass lesion. In 3 patients with occlusion of the main stem middle cerebral artery, computed tomographic (CT) scans performed between 1 and 7 hours after the onset of the ischemic signs were normal, but all scans performed after 11 or more hours revealed progressive edema in a vascular distribution leading to a midline shift. The fifth patient had a severe diffuse brain injury and no apparent clinical pattern of a posttraumatic vascular complication. Sequential changes on the CT scans similar to those of the other patients led to the proper diagnosis of vascular injury; this was later confirmed by arteriography. Indirect, nonpenetrating injury to the carotid artery should be suspected in the presence of the typical clinical pattern or when serial CT scans show the evolution of progressive edema in a distribution atypical for traumatic contusion.

Adult↗

Classic and contemporary imaging of coccidioidomycosis.

Disseminated coccidioidomycosis should be considered as a diagnostic possibility whenever a patient has visited or resides in an endemic coccidioidal area and has a history of fever, skin rash, persistent pulmonary symptoms, bone pain, headache, or confusion. Imaging of this multisystem disease, especially of the lung, bone, and central nervous system, shows various protean manifestations that can simulate many infectious entities. The radiographic, scintigraphic, computed tomographic, or sonographic findings of this disease may be helpful in diagnosis, prognosis, and treatment follow-up in patients with disseminated coccidioidomycosis.

Amphotericin B↗

Computed tomography of disseminated coccidiodomycosis.

Fifteen cases of disseminated cerebral coccidioidomycosis (DCC) were evaluated by computed tomography (CT). Of the 14 patients with abnormal CT scans, all but 2 showed definite evidence of hydrocephalus. Abnormalities of the basal cisterns were present on non-contrast scans in 8 cases (53%). Ten (67%) demonstrated abnormal contrast enhancement of basal cisterns and other cerebrospinal fluid (CSF) spaces. White-matter lesions were detected in 6 cases (40%). Hydrocephalus usually follows abnormal enhancement of basal cisterns. A consistent relationship between active disease (as diagnosed by CSF complement fixation titers) and contrast enhancement could be demonstrated only in the first weeks of the illness.

Adolescent↗