99Tcm-MDP blood-pool phase in the assessment of repetitive strain injury.

We reviewed three-phase bone scans of the limbs of 7 patients suffering from limb pain suggestive of occupational repetitive strain injury (RSI) and compared them with 13 patients with limb pain due to various aetiologies. Doppler ultrasound measurement of blood flow had been performed in 13 of the 20 patients. The bone scan results showed increased blood flow and pooling (second phase) in the affected limbs of patients with RSI as compared to those with algodystrophy or non-specific limb pain (sensitivity 86%, specificity 85%). Doppler ultrasound also demonstrated increased blood flow to the affected limbs (sensitivity 83%) but failed to differentiate between the different aetiologies of pain (specificity 14%). We conclude that the blood-pool phase of three-phase bone scans can play a potential role in screening RSI patients.

Uptake of technetium-99m hexamethylpropylene amine oxime labelled white cells in lymph nodes involved in non-Hodgkin's lymphoma.

Radiolabelled white cell scanning is widely used to detect the presence of infection. We present a case of non-Hodgkin s lymphoma manifesting with signs and symptoms suggestive of infection, in which a technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) white cell scan demonstrated high uptake in lymph nodes involved by lymphoma. Differential cell analysis showed preferential lymphocyte labelling. The classification and management of the disease were changed accordingly. Our findings suggest that a future role for 99mTc-HMPAO labelled white cells in the assessment of disease activity of lymphoma should be investigated.

Detection of increased blood flow to the affected arm in repetitive strain injury with radionuclide and Doppler ultrasound studies. A case report.

A case of clinically diagnosed repetitive strain injury was referred for investigation to rule out the possibility of an occult bone disease. The patient was a female keyboard operator who had pain and tenderness over the flexor muscles of the right hand and arm. The pain was severe and almost constant. The authors observed an increase in Tc-99m MDP delivery to the affected forearm during the dynamic sequence of a three-phase bone scintigram, indicating increased blood flow compared to the contralateral side. The same result was achieved using quantitative blood flow measurements with the Doppler technique and Tc-99m HMPAO perfusion imaging. These findings agree with recent studies that suggest increased total arm blood flow in repetitive strain injury and may provide an easy screening method.

Clinical significance of technetium-99m methylene diphosphonate myocardial uptake: association with carcinoma of the prostate.

Benign myocardial uptake of technetium-99m labelled phosphates, not related to cardiac or metabolic disorders, has been documented except in the case of 99mTc-methylene diphosphonate (MDP). The aim of this study was to assess the frequency of myocardial uptake and its possible association with malignant tumours in general and prostatic carcinoma in particular. We reviewed bone scintigrams performed with either 99mTc-hydroxydiphosphonate (HDP) or 99mTc-MDP over a period of more than 2 years for all patients with prostatic carcinoma and a matching group of patients suffering from other malignant and non-malignant disorders. A total of 965 scintigrams of 812 patients (males = 559, females = 253; age range 50-91 years, average age 69.2 years) were reviewed. Increased myocardial uptake was detected in 19 scintigrams (MDP = 13, HDP = 6) of 18 patients (17 males, one female). Most of the male patients with increased myocardial uptake had prostatic carcinoma (13/17) and were over 80 years of age (12/17). All patients were free of any cardiac or noncardiac disorder that might account for such uptake. When scintigraphy was repeated in the same patient, the uptake of 99mTc-HDP was more diffuse and of higher grade than that of 99mTc-MDP. "Benign" myocardial uptake of 99mTc-MDP is more common than previously thought. Although uptake of radiophosphates is attributed to asymptomatic atherosclerotic changes associated with old age, a strong association with prostatic carcinoma exists which may indicate variations in the bone: soft tissue affinity of different MDP complexes.

Reversible findings of methylene diphosphonate bone scintigraphy in Raynaud's phenomenon: case report and review of the literature.

A 53-year-old woman with carcinoma of the right breast, spinal metastases and right arm lymphoedema was referred for bone scintigraphy prior to commencement of chemotherapy. The patient arrived in the department complaining of pain in the left hand, which appeared red and slightly swollen. Bone scintigraphy revealed increased tracer uptake in the first four metacarpal and all the carpal bones of the left hand. A repeat three-phase bone scintigram, performed 1 week later when the patient was asymptomatic, showed equal blood flow to both hands with normal blood pool and uptake in bone images. The case demonstrates a state of reversibly increased bone uptake in a patient injected at the time of an episode of Raynaud's phenomenon and the possible implications for scan interpretation.

Cellular versus vascular rejection in transplant kidneys. Correlation of radionuclide and Doppler studies with histology.

The presence of two distinct subtypes of renal allograft rejection are well documented by histological studies. The differentiation between vascular rejection (VR) and cellular rejection (CR) is essential for proper management by avoiding the need for unnecessary and potentially harmful immunosuppressive treatment of VR. A histological pattern with features that are similar and confusable with some cases of rejection may be seen in cyclosporin A toxicity (CyT). To evaluate the efficiency of Guy's perfusion index (GPI) and the Doppler pulsatility index (DPI) in differentiating these two histological subtypes, a prospective study was designed in which a total of 140 radionuclide tests and 133 ultrasounds scans performed on the same day on 58 patients during the first 3 months post-transplant were analysed, and the results correlated with the histological findings of 84 renal biopsies. Results show that the GPI had a sensitivity of 86.5% and a specificity of 94% in differentiating VR and CyT from CR, while the DPI had values of 83% and 69%, respectively. Chi-squared analysis showed a higher significant association between the GPI and histology (P < 0.0001) compared to that of the DPI and histology (P < 0.005), while Youden's index (J) showed a significant difference (P < 0.05) between GPI and DPI. It is concluded that GPI is more sensitive and specific than DPI in differentiating transplants that are well perfused from those with poor perfusion (VR and CyT).

The effect of ramipril, a new angiotensin-converting enzyme inhibitor on cortical nephron flow and effective renal plasma flow in patients with essential hypertension.

A placebo-controlled study of Ramipril on total and intrarenal flow distribution was carried out in 7 patients with essential hypertension. Cortical nephron flow was measured using radiolabelled tubular secreted radiopharmaceuticals 123I orthoidohippurate or 99mTc mercaptoacetyl triglycine by the transit time distribution technique. Both systolic and diastolic blood pressure were reduced significantly by Ramipril without significant changes in an index of cardiac output or in effective renal plasma flow. Cortical nephron flow increased from 207 +/- 7 to 257 +/- 21 ml/min (mean +/- SEM) p less than 0.05 and the percentage of flow to cortical nephrons increased by 6% (p = 0.05). Ramipril corrects the reduced cortical nephron flow found in essential hypertension.

Ventilation perfusion ratios of the normal supine lung using emission tomography.

Ventilation perfusion imaging using single photon emission tomography was carried out in the supine position on four subjects, three normal volunteers and one patient, all free from evidence of respiratory disease. Ventilation imaging was by means of the steady-state inhalation of krypton 81m, perfusion imaging utilised technetium 99m labelled macroaggregates. In the three normal volunteers, perfusion studies were repeated using steady state infusion of 81Krm in solution. Ventilation perfusion ratios were calculated for the anterior, middle and posterior regions of the lung using axial slices from apex to base. The results using 99Tcm for perfusion showed a gradient of ventilation perfusion ratios from front to back of 1.27 anteriorly and 0.93 posteriorly for the right lung, 1.06 anteriorly and 0.77 posteriorly for the left lung. Using 81Krm for perfusion a small gradient of 0.94 to 0.82 was observed.