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H Meindok

Publications and source records attributed to H Meindok.

At least 19 recordsLinked to original sources
PubMed1994

Alterations of the three-phase bone scan after sympathectomy.

OBJECTIVE: To evaluate alterations of the three-phase bone scan (TPBS) in patients with the clinical diagnosis of reflex sympathetic dystrophy (RSD) before and after surgical or chemical sympathectomy. DESIGN: The TPBS was done after i.v. administration of 99technetium dimethylphosphonate. Scans were read by one blinded and one nonblinded reviewer (as to site of symptoms and procedure), using a visual grading system devised in our institution. Since there were no statistically significant differences between the two examiners' scores for blood flow, pool, and delayed phases, all scores were averaged and used for comparison before and after sympathectomy. SUBJECTS: Ten women and four men with RSD were observed with 17 TPBSs before and 30 TPBSs after surgical (n = 6) or chemical (n = 8) sympathectomy. RESULTS: All three phases of TPBS were significantly enhanced after sympathectomy in 11 of 14 patients in a pattern indistinguishable from that very commonly reported in florid RSD. The increased uptake occurred within 24 h after the procedure, normalized as early as 3 months in some scans, and remained abnormal in some patients in the 12-month follow-up period. In total, only 33% of all sympathectomies performed led to long-term symptom relief. CONCLUSIONS: The data demonstrated that alterations in TPBS after sympathectomy are identical to those reported in early RSD and these alterations bear no relationship to the success of sympathectomy regarding pain relief. The mechanisms underlying alterations of TPBS as well as the potential mechanisms of sympathectomy failures are discussed.

Adolescent↗
PubMed1993

Diagnosis of diabetic gastroparesis on Tc-99m hepatobiliary scintigraphy.

Diabetic gastroparesis is a common problem in diabetics, especially insulin-dependent diabetics. The diagnosis usually is suggested on plain radiographs and confirmed on either upper gastrointestinal barium series or radionuclide gastric emptying studies. The clinical diagnosis is not always easy and some patients may present atypically with right upper quadrant pain simulating acute cholecystitis. In these patients, hepatobiliary scintigraphy may be the initial investigation performed and may first demonstrate unsuspected gastroparesis. Therefore, it is useful for the nuclear medicine physician to be aware of this entity to ensure early diagnosis and prompt treatment. The authors report one such case of diabetic gastroparesis that was diagnosed initially on a Tc-99m hepatobiliary scan.

Adult↗
PubMed1992

Advantages of peripheral radiogrametry over dual-photon absorptiometry of the spine in the assessment of prevalence of osteoporotic vertebral fractures in women.

Since osteoporosis develops in most postmenopausal women and is probably the most important single factor in the pathogenesis of osteoporotic fractures of the spine, hip, and wrist (and at other sites), methods suitable for mass screening should be developed. In this study of 97 women aged 24-79, measurements of the lumbar spine mineral content by dual-photon absorptiometry (DPA) were compared with the summed combined cortical thickness measurements from radiographs of the radius and metacarpal II (MR). There was good correlation between the two methods (r = 0.90). The correlation of age with MR was higher than with DPA. The correlation of years postmenopause was significant with MR but not with DPA. Taking the -2 SD level of the premenopausal means to be previously established vertebral fracture thresholds, 24% of the DPA measurements, but no MR measurements in patients with vertebral compressions, were above the fracture threshold. Since MR measurement requires taking only two small plain radiographs using ordinary x-ray equipment, it is concluded that this less expensive method is better suited to screening for osteoporotic vertebral fracture risk in postmenopausal women than DPA.

Absorptiometry, Photon↗
PubMed1992

Diagnosis of bleeding mycotic iliac aneurysm on technetium-99m renal scan.

Since abdominal aneurysms are common in the elderly, it is not unusual to see incidental aneurysms on renal scintigraphy performed for other reasons. However, the initial discovery of a bleeding aneurysm on a renal scan in a patient with salmonella septicemia who has no other obvious focus of infection should be considered suspicious for mycotic aneurysm. A prompt diagnosis is crucial to avoid catastrophic outcome associated with delayed surgical intervention.

Aged↗
PubMed1986

Radionuclide assessment of regional left ventricular function in acute myocardial infarction.

To determine changes in global and regional left ventricular function following acute myocardial function, 17 patients underwent radionuclide angiography at 3 and 10 days post infarction. Five patients had nontransmural myocardial infarction and 12 had transmural infarction (six anterior and six inferior). There were no previous infarctions in 16 (94%) patients. Regional ejection fractions were calculated by dividing the left ventricle into four quadrants using the geometric center of the left ventricle on the end-diastolic frame as a reference point. At 3 days post infarction, 8 of 17 (47%) patients had an abnormality of global left ventricular ejection fraction (LVEF), whereas 16 of 17 (94%) patients had abnormalities of one or more regional ejection fractions (p less than 0.01). Between 3 and 10 days, global LVEF did not change (51% to 49%, p = NS). However, there were significant changes in 23 of 68 (34%) regional LVEFs. These changes did not relate to type, ECG location, creatine kinase (CK) size of infarction, or initial global LVEF. These data suggest that regional LVEF is a sensitive technique for identifying segmental dysfunction associated with myocardial infarction. In addition, significant changes occur in regional LV function during acute myocardial infarction despite stable serial global LV performance.

Adult↗
PubMed1985

Quantitative radionuclide scanning in metabolic bone disease.

A simple method of quantifying skeletal uptake of 99Tcm-methylene diphosphonate, using a rectilinear scanner and a simultaneously image standard, is described. The pattern of quantified uptake in ten regions of the skeleton, the sacro-iliac joints and kidneys in 57 controls and 54 patients with various metabolic bone disease is presented. This method distinguishes patients with primary hyperparathyroidism and osteomalacia from controls with a sensitivity adequate for clinical purposes. In primary hyperparathyroidism the increased skull uptake of tracer correlated well with levels of serum alkaline phosphatase, plasma parathyroid hormone, urinary hydroxyproline excretion and the degree of intracortical resorption in the metacarpal bones. The skull uptake in oestoporosis was normal or moderately elevated and correlated well with bone mass density measurements of the radius. Patients with osteomalacia also showed the greatest increase in tracer uptake in the skull. Patients with thyrotoxicosis differed from most other patients by showing moderately increased uptake in shafts of long bones. We propose our method of quantitative bone uptake as a useful noninvasive test to detect metabolic bone disease and to monitor responses to therapy of bone disease.

Adolescent↗
PubMed1982

Spontaneous changes in thallium-201 myocardial perfusion imaging after myocardial infarction.

To examine regional myocardial perfusion after myocardial infarction, 26 patients underwent exercise electrocardiographic testing with thallium-201 myocardial perfusion imaging 3 weeks and 3 months after infarction. At 3 weeks, 9 of 26 patients (35%) had myocardial ischemia by exercise electrocardiographic testing, whereas 18 of 26 (69%) had ischemia by thallium-201 imaging. The thallium-201 scintigrams were scored by dividing each image, in 3 views, into 5 segments, using a 5-point scoring scheme. The exercise thallium-201 score was 44.3 +/- 1.2 and increased to 47.3 +/- 1.2 in the redistribution study (p less than 0.001). Three months after infarction, although there was a significantly greater rate-pressure product which would predict a larger ischemic defect and a decrease in the stress thallium-201 score, the stress score was improved (48.3 +/- 1.1, p less than 0.001). The redistribution score was similar, that is, 48.9 +/- 1.0. The improvement in thallium-201 myocardial perfusion was associated with a loss of stress-induced ischemia in 8 patients (30%). These results indicate that spontaneous improvements in thallium-201 myocardial perfusion imaging may occur after myocardial infarction.

Adult↗
PubMed1981

Treatment of renal osteodystrophy with 1,25-dihydroxycholecalciferol.

Nine patients with renal osteodystrophy were tested for 6.5 to 35 months with 1,25-dihydroxycholecalciferol (1,25-DHCC). A close biochemical follow-up was performed during the first 6 months of treatment, including biweekly determinations of serum calcium, phosphorus, magnesium, alkaline phosphatase and creatinine levels. A bone biopsy, radiologic investigations and determinations of plasma levels of immunoreactive parathyroid hormone (IPTH) and intestinal absorption of calcium 47 were performed before and after the 6 months. Although the five patients with osteitis fibrosa showed a significant improvement, the four with predominantly osteomalacic lesions showed no response to treatment. These four had a normal initial plasma iPTH level, higher serum calcium levels than the other five patients, extreme sensitivity to 1,25-DHCC, with frequent episodes of hypercalcemia, and only a slightly increased serum alkaline phosphatase level, which remained unchanged during treatment. All but one of the patients, irrespective of the histologic abnormality, showed a decrease in the uptake of radionuclide by bone after treatment. The renal function of one patient, a man with long-standing stable renal failure who had not undergone dialysis, deteriorated during treatment.

Calcitriol↗
PubMed1980

The arthropathy of maintenance intermittent peritoneal dialysis.

Among 61 patients undergoing maintenance peritoneal dialysis for an average of 20 months, 13 (21%) had a history of attacks of acute arthritis and 19 (31%) were found to have tender and often swollen joints. Deposits of calcium pyrophosphate dihydrate crystals in articular cartilage were identified in four patients and inflammation probably induced by hydroxyapatite crystals was noted in one. Periarticular calcification was observed in 12 patients and subperiosteal resorption of the phalanges in 20. The average calcium X phosphorus product was significantly higher (P < 0.025) in patients with a history of attacks of acute arthritis or with inflamed joints (58 +/- 12) than in those without (50 +/- 12). In the 19 patients whose treatment was changed to continuous ambulatory peritoneal dialysis there was a significant decrease (P < 0.025) in the calcium X phosphorus product but not in the proportion of patients with attacks of acute arthritis or with inflamed joints. The results indicate that articular complications are frequent among patients undergoing maintenance peritoneal dialysis and may be more common than with long-term hemodialysis.

Acute Disease↗
PubMed1979

Lung function in diaphragm pacing.

Electric stimulation of the diaphragm via the phrenic nerve to induce ventilation has recently been used for the long-term management of chronic ventilatory insufficiency. Since 1973 three patients with inadequate alveolar ventilation have been treated with diaphragm pacing at the Toronto Western Hospital. Two, who had quadriplegia due to lesions of the spinal cord in the upper cervical region and a severe restrictive ventilatory defect, were treated with continuous diaphragm pacing. The third patient required assisted nocturnal ventilation because of primary alveolar hypoventilation. All three patients tolerated the diaphragm pacing well, and pulmonary function tests showed satisfactory gas exchange with the patients breathing room air. This form of therapy seems to be a practical clinical method of managing chronic ventilatory failure in patients with lesions of the upper cervical cord or primary alveolar hypoventilation.

Adolescent↗
PubMed1978

Detection and pathogenesis of visceral calcification in dialysis patients and patients with malignant disease.

Scintiscanning to detect the uptake of bone-seeking radioactive isotopes by soft tissue is a promising technique for the in vivo study of visceral calcification. Visceral uptake of such radioisotopes was studied in 40 patients: 22 undergoing long-term dialysis, 9 with malignant disease and hypercalcemia and 9 with primary hyperparathyroidism and hypercalcemia.Fifteen patients, 11 undergoing dialysis and 4 with malignant disease, had radioisotope uptake in the lungs, and 5, 3 undergoing dialysis and 2 with malignant disease, had uptake in the stomach. None of the patients with primary hyperparathyroidism had visceral uptake, nor did the patients with uptake have radiologic evidence of pulmonary or gastric calcification. The dialysis patients with visceral uptake had a mean calcium x phosphate product of 84.3 +/- 23.7 (standard deviation), which was significantly greater (P < 0.001) than that of patients without such uptake (59.2 +/- 14.0). Similarly, in patients with malignant disease and visceral uptake the Ca x P product was 72.2 +/- 6.4 - significantly greater (P < 0.005) than that of patients without such uptake (49.3 +/- 6.7).These findings indicate that scintiscanning for the visceral uptake of a bone-seeking radioisotope is a simple and effective technique for the in vivo study of visceral calcification. An elevation in the Ca x P product seems to be the single most important factor in the production of visceral calcification.

Adult↗
PubMed1978

Visceral calcification and the CaXP product.

The authors studied the presence of visceral calcification as evidenced by the visceral uptake of bone-seeking radionuclides during the course of a bone scan among 22 patients with terminal renal failure maintained on dialysis, nine patients with hypercalcemia secondary to malignancy, and nine patients with primary hyperparathyroidism. Uptake by the lungs or stomach was observed in 11 renal failure patients (50%) and in four of those with malignancy and hypercalcemia (44%). None of the patients with primary hyperparathyroidism had evidence of visceral calcification. The serum CaXP product was significantly higher among those with visceral calcification than those without. The results of this study indicate that a CaXP product of 60 represents the saturation product of calcium phosphate in serum above which spontaneous precipitation of this salt may occur in such viscera as stomach and lungs.

Adult↗
PubMed1976

Liver scan in Budd-Chiari syndrome.

Seventeen liver scans were performed in seven patients with occulsion of hepatic veins: the Budd-Chiari syndrome. When some, but not all liver veins were occluded, markedly diminished uptake over the affected segments was usually seen (absence of uptake may occur in acute infarction and in chronic cases). When all major liver veins are occluded, markedly diminished uptake is seen over the peripheral parts of the right and left lobes with a triangular midline area of normal or excessive activity. The latter effect is probably caused by uptake in segments surrounding the inferior vena cava (frequently the caudate lobe) that have direct venous drainage. This liver-scan appearance is characteristic enough to warrant consideration of the Budd-Chiari syndrome as the first diagnosis. Good correlation existed between selective venography and liver-scan findings. The usefulness of liver scans in the followup after portocaval shunting is illustrated in one patient.

Adult↗
PubMed1972

Visualization of arterial and arterial graft patency by intravenous radionuclide angiography.

A method of visualizing patency of arteries and arterial grafts by means of intravenous (99m)Tc pertechnetate using a Nuclear Chicago Pho/Gamma HP camera is described. Polaroid pictures showing normal arteries in the upper and lower limbs, as well as partial and complete occlusion of arteries and the state of arterial bypass grafts in pre- and postoperative patients are compared with conventional arteriograms. The advantages and limitations of this method are discussed.

Adult↗