Single energy quantitative computed tomography: the effects of phantom calibration material and kVp on QCT bone densitometry.
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Bone Density↗
Biomedical subjects
J E Adams
Publications and source records attributed to J E Adams.
Elevations of CK-MB following pulmonary embolism. A manifestation of occult right ventricular infarction.
To determine the frequency and etiology of elevations of CK-MB in patients with pulmonary emboli, we studied 52 patients with well-documented emboli and the absence of known ischemic heart disease or ECG changes suggestive of acute infarction. All patients were evaluated with serial CK-MB determinations at 8-h intervals. All patients with elevations of CK-MB had noninvasive cardiac evaluations. Four (7.7 percent) of the 52 patients had a rising and falling pattern of CK-MB that satisfied enzyme criteria of acute infarction. Three of these four also manifested classic echocardiographic features of right ventricular infarction. None of the four had evidence of left ventricular regional wall motion abnormalities or dysfunction. Of the 48 patients without elevations of CK-MB, only two had segmental right ventricular dysfunction. These findings suggest that pulmonary emboli can induce right ventricular infarction in some (7.7 percent) patients even when patients with a history of coronary artery disease and/or ECG changes of infarction are excluded. Conversely, the diagnosis of pulmonary embolism should be considered in patients when right ventricular infarction is diagnosed.
Adult↗
Osteoporosis and bone mineral densitometry.
Osteoporosis is a common cause of vertebral and hip fractures and although their occurrence depends on a variety of factors, bone mineral density (BMD) is the most important determinant. Methods of measuring BMD are therefore pertinent to identify individuals with reduced bone mass and at increased risk of fracture, and current techniques provide accurate and precise BMD measurements with low radiation dose. The methods most widely used are single photon absorptiometry; dual photon absorptiometry, which has been replaced by dual energy x-ray absorptiometry; and quantitative CT. Dual energy x-ray absorptiometry permits BMD measurement in the lumbar spine, femoral neck, forearm, and whole body. Bone strength is also related to trabecular width and arrangement. The newer techniques of broadband ultrasound attenuation and MR imaging (T2*) offer potential for investigating both trabecular bone mass and structure, as does high-resolution CT. These methods provide powerful tools for the study of the skeleton in health and disease and have established roles in appropriate clinical circumstances. Although BMD measurement can provide an estimate of fracture risk, there are limitations to fracture prediction in an individual subject, but efforts are being made to improve the discriminatory and predictive aspects of BMD.
Absorptiometry, Photon↗
Severe hypercarbia resulting from inspiratory valve malfunction in two anesthetized horses.
Severe hypercarbia was documented by arterial blood gas analysis in 2 adult horses anesthetized for exploratory laparotomy. Both horses appeared to be adequately anesthetized, but continued to breathe against the ventilator. In both cases, the inspiratory valve on the anesthesia machine was found to be stuck open, permitting expired CO2 to return to the inspiratory limb of the anesthetic circuit and to be inhaled with the next breath. Correction of the malfunctioning valve alleviated the hypercarbia. Problems with the flow valves of the anesthesia machine should be suspected when anesthetized horses breathe against the ventilator and develop severe hypercarbia.
Anesthesia↗
Gastrointestinal carriage of Clostridium difficile in cats and dogs attending veterinary clinics.
Cats and dogs being treated at two veterinary clinics were investigated for gastrointestinal carriage of Clostridium difficile using selective solid and enrichment media. Thirty-two (39.5%) of 81 stool samples yielded C. difficile. There were significant differences in isolation rates between clinics, 61.0% of animals being positive at one clinic compared to 17.5% at the other (Chi-square, P less than 0.005). Of 29 animals receiving antibiotics, 15 (52.0%) harboured C. difficile while 11 (23.9%) of 46 animals not receiving antibiotics were positive (Chi-square, P less than 0.01). There was no difference in carriage rate between cats (38.1%) and dogs (40.0%). The environment at both veterinary clinics was surveyed for the presence of C. difficile. Fifteen of 20 sites at one clinic were positive compared to 6 of 14 sites at the other clinic. Both cytotoxigenic and noncytotoxigenic isolates of C. difficile were recovered from animals and environmental sites. These findings suggest that household pets may be a potentially significant reservoir of infection with C. difficile.
Animals↗
Case of the month. A dense problem.
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Adult↗
The application of clinical guidelines for skull radiography in the Accident and Emergency department: theory and practice.
Clinical guidelines for the selection of patients with head injuries for skull radiography, based on those formulated by the Royal College of Radiologists, were introduced into the Accident and Emergency department at the Manchester Royal Infirmary. Before the guidelines were implemented 94 skull X-rays were obtained per 1000 new casualty attenders. After implementation the rate of skull radiography initially fell by 40%, but thereafter slowly increased so that 12 months later it had returned to the pre-implementation level. During the first and second 6 months of the study reductions of 37% and 17%, respectively, were achieved. Although the overall annual reduction was only 27% an estimated saving of almost 10,000 pounds was made. Although clinical guidelines for skull radiography can reduce the number of skull radiographs without detriment to the care of the head-injured patient, their constant use is difficult to sustain. The application of clinical guidelines needs regular monitoring. Referring clinicians and radiologists need to be strongly motivated if such guidelines are to find a useful place in clinical management.
Adult↗
The effects of nafarelin and danazol on vertebral trabecular bone mass in patients with endometriosis.
Single and dual-energy quantitative computed tomography (QCT) were used to measure spinal trabecular bone mineral content in 24 women treated with either nafarelin (15 patients) or danazol (nine patients) for endometriosis. Significant loss of bone mineral (-9.6 g/l; -5.9% P less than 0.001) was demonstrated after 6 months' treatment with nafarelin. This loss was reversible with no significant difference in the bone mineral measurement made before treatment and that made at 6 months after treatment was stopped (difference -1.95 g/l, NS). A small but statistically significant (+2.2 g/l, P less than 0.05) increase in bone mineral was measured in the group of patients treated with danazol for 6 months. The dual-energy QCT gave similar results, indicating little change in trabecular fat content. A significant correlation was demonstrated between mean serum oestradiol levels during treatment with nafarelin and the change in bone mineral (r = 0.655, P less than 0.005).
Adult↗
A survey of U.S. Army aeromedical equipment.
Medical equipment is necessary to support patients requiring air transportation, but it may not be compatible with the aviation environment. Aircraft systems may cause errors in the functioning of medical equipment, or that equipment may interfere with the aircraft. Medical equipment has been tested, primarily for fixed wing aircraft, to military standards by the U.S. Air Force. This study reports 1986 and 1987 surveys which document the use of such equipment on U.S. Army medical evacuation aircraft and compares items in current use to the U.S. Air Force's test results. Of the 115 different nonissue items reported in use, 32 have been formally evaluated, and 9 of those were judged unacceptable for use on aircraft. Only two items reported in the survey were tested inflight in helicopters. The remaining 83 items have not been tested. Helicopters have unique requirements, and the U.S. Army has begun a program to evaluate medical equipment for helicopter use.
Aerospace Medicine↗
The petrous temporal bone and deafness in X-linked hypophosphataemic osteomalacia.
Radiological anatomy of the petrous bones and skull base has been studied in a group of 11 patients with X-linked hypophosphataemic osteomalacia and hearing loss, and comparison made with a control group of normal subjects. Patients with X-linked hypophosphataemic osteomalacia were found to have generalised osteosclerosis and thickening of the petrous bone, with some narrowing of the internal auditory meatus, particularly in its mid-portion. No evidence of platybasia nor of basilar impression was found in the hypophosphataemmic group. The aetiology of the hearing loss which occurs in patients with X-linked hypophosphataemic osteomalacia is discussed in relation to the radiological abnormalities described.
Chromosomes↗
Long-term treatment of Nelson's syndrome with sodium valproate.
Eleven patients with Nelson's syndrome were given sodium valproate (Epilim, Sanofi). Plasma ACTH and cortisol levels were measured under carefully controlled conditions which were designed to eliminate spontaneous fluctuations in ACTH. At 6 weeks all 11 patients were reassessed while taking sodium valproate 600 mg/day; there was then a small but significant (P less than 0.05) reduction in plasma ACTH concentration. Six patients continued to take sodium valproate, and were reassessed at 1 year when five were taking 1200 mg/day and one patient was taking 600 mg/day. At 1 year for these six patients there had been an increase in mean plasma ACTH which was then not significantly different from basal values. The five patients who discontinued sodium valproate were also reassessed at 1 year, when there were no significant differences compared to basal or 6-week values. During therapy with sodium valproate, there were no significant changes in the half-life of plasma cortisol, plasma sodium and potassium concentrations, or serum liver enzymes. Weight gain on sodium valproate was the main reason for patients asking to discontinue therapy. Sodium valproate is not an effective long-term therapy for reducing plasma ACTH for patients with Nelson's syndrome.
Adolescent↗
Jugular vein thrombosis associated with distant malignancy.
We describe two patients who developed internal jugular vein thrombosis associated with primary malignant disease arising outside the neck, and in one patient it was the presenting feature. Computed tomography was performed and the findings characteristic of internal jugular vein thrombosis are illustrated. We conclude that malignant disease should be considered in patients presenting with spontaneous internal jugular vein thrombosis with no other predisposing factors and that computed tomography is of value in confirming the diagnosis.
Carcinoid Tumor↗
A critical appraisal of "out-of-hours" radiography in a major teaching hospital.
The use of plain radiography performed outside normal working hours was studied at the Manchester Royal Infirmary to determine the costs of the service and where possible financial savings could be made. The annual cost of "out-of-hours" radiography was estimated to be in order of 250,000 pounds. During a selected 2-week period, 84% and 76% of all examinations performed on Accident and Emergency patients and inpatients, respectively, were found to be normal. Previous reports suggest that the number of radiographs requested in the Accident and Emergency department can be reduced without detriment to patients by the implementation of appropriate clinical guidelines. We consider that if similar guidelines were developed and applied to the use of out-of-hours radiography, substantial savings could be made. We estimate that in our hospital these savings could amount to 18% of the current expenditure on this service.
Appointments and Schedules↗
Skull radiographs after head injury.
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Craniocerebral Trauma↗
Treatment of chronic pain by deep brain stimulation: long term follow-up and review of the literature.
Since the senior author's (J.E.A.) first report in 1972 of the use of deep brain stimulation (DBS) to control chronic pain, electrodes for DBS have been implanted in 141 patients. Of reported series, this one has the largest number of patients and the longest period of follow-up. The mean age of patients in this study was 51.2 years. The mean length of follow-up was 80 months. Patients had experienced pain for a mean period of 65 months before DBS was attempted; all patients had exhausted other medical and surgical therapies. For the purposes of this study, pain states were characterized as being either nociceptive or deafferentation in nature. Nociceptive pain was treated primarily by stimulation of the periaqueductal or periventricular gray, and deafferentation pain was treated primarily by stimulation of the sensory thalamus. Eighty-four patients were treated for deafferentation pain, which included the thalamic pain syndrome (25 cases), peripheral neuropathic pain (16 cases), anesthesia dolorosa (12 cases), paraplegia pain (11 cases), postcordotomy dyesthesia (5 cases), phantom limb pain (5 cases), thoracic neuralgia (4 cases), and miscellaneous pain states (6 cases). We treated 57 patients with nociceptive pain states, 51 for low back and skeletal pain and 6 for pain from the invasion of cancer. Initial relief of pain was obtained by 83 patients (59%). After the mean follow-up period of 80 months, 42 patients (31%) continued to obtain significant pain relief with DBS. Some pain states, particularly anesthesia dolorosa and paraplegia pain, did not seem to respond to DBS. Major complications of therapy included wound infection (12%) and intracranial hemorrhage (3.5%); there was one death in the series (0.7%).(ABSTRACT TRUNCATED AT 250 WORDS)
Brain↗
Supplemental mandibular condyle.
A case of supplemental mandibular condyle is presented and possible aetiological factors are discussed. The value of computed tomography and of scintigraphy in the diagnosis of such cases is illustrated and surgical and histological details of an excised supplemental condyle are presented for the first time.
Adolescent↗
Intra-spinal new bone formation and spinal cord compression in familial hypophosphataemic vitamin D resistant osteomalacia.
Four patients with familial hypophosphataemic vitamin D resistant osteomalacia and spinal cord compression are reported. Three of these patients were treated by decompressive laminectomy and each made a good recovery. At surgery new bone formation in the ligamentum flavum and thickening of laminae were found to be responsible for the canal stenosis and cord compression. Two of these four patients, and 10 others were examined by computed tomography to determine the incidence, site and extent of any intra-spinal new bone formation. Facet joint hypertrophy and thickened laminae were observed at some level in all the patients, but much the most important cause of spinal canal stenosis was new bone formation in the ligamentum flavum, in the mid and lower thoracic spine, occurring at several, but mainly contiguous vertebral levels. Severe spinal canal stenosis was found in eight of the 12 patients scanned. No obvious relation was found between the presence of intra-spinal new bone formation and the clinical severity of the disease or the presence of extra-skeletal ossification in para-spinal and other sites. Computed tomography offers a simple, non-invasive technique for identifying those patients at risk of cord compression from new bone formation.
Female↗
Isolated adrenocorticotrophin deficiency and empty sella associated with hypothyroidism.
A case of isolated ACTH deficiency is described. The patient had an empty sella and longstanding radio-iodine induced hypothyroidism. The association between isolated ACTH deficiency, empty sella and hypothyroidism is reviewed. It has not previously been recognized that the commonest endocrine association of isolated ACTH deficiency is primary thyroid failure. ACTH secretion does not recover following thyroxine replacement treatment.
Adrenocorticotropic Hormone↗