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L B Arkles

Publications and source records attributed to L B Arkles.

15 recordsLinked to original sources
PubMed1992

Efficiency of labelling of red blood cells with technetium-99m after dipyridamole infusion for thallium-201 stress testing.

Experimental studies have suggested that dipyridamole may inhibit red blood cell labelling with technetium-99m. To evaluate whether this effect is clinically relevant to the performance of radionuclide ventriculography after dipyridamole-thallium stress testing, in vitro red blood cell labelling was compared immediately before and after thallium-201 stress scintigraphy combined with either dipyridamole infusion (30 patients) or exercise stress (20 patients). Modified in vivo red blood cell labelling efficiency was assessed in a further 36 patients following dipyridamole infusion and was compared with that in 15 patients following exercise stress. The importance of a reversal of the dipyridamole effects by aminophylline was evaluated for in vitro and modified in vivo techniques. The red blood cell labelling efficiency was not significantly different in patients following dipyridamole compared with that obtained following exercise stress for both in vitro (93% +/- 4% versus 91% +/- 4%) and modified in vivo (87% +/- 19% versus 90% +/- 6%) techniques. Also, in vitro red blood cell labelling efficiency after dipyridamole was not different to that before stress testing (93% +/- 4% versus 92% +/- 4%). Reversal with aminophylline had no significant effect on the in vitro labelling efficiency with either the in vitro technique (94% +/- 3% with reversal versus 92% +/- 5% without) or the modified in vivo technique (91% +/- 4% with reversal versus 82% +/- 26% without). These results suggest that the red blood cell labelling efficiency is not compromised by the preceding dipyridamole-thallium stress testing but can be optimised by using in vitro labelling.

Aged↗
PubMed1992

Progressive soft tissue uptake of Tc-99m MDP reflecting metastatic microcalcification.

A 49-year-old woman had longstanding renal impairment. Markedly increased uptake of Tc-99m MDP in the heart, lungs, and kidneys was an incidental finding on bone scintigraphy performed to exclude metastatic bone disease. These findings persisted on repeat bone imaging 1 year later. In addition, gastric and skeletal muscle uptake was subsequently seen. Soft tissue microcalcification was confirmed by computed tomography and renal biopsy. A consideration of the differential diagnosis is presented.

Bone Neoplasms↗
PubMed1991

Congestive hepatomegaly--typical features on computed tomography, ultrasound and nuclear medicine.

The features of hepatic congestion on computed tomography, ultrasound and nuclear medicine sulphur colloid scans have been reviewed. Hepatic congestion may not be appreciated clinically, especially in the elderly, but the features described should be sufficiently characteristic to establish the diagnosis. The CT appearance may be confused with neoplastic infiltration, so that recognition of the condition may avoid further unnecessary investigations.

Aged↗
PubMed1989

Beneficial effects of low dose amiodarone in patients with congestive cardiac failure: a placebo-controlled trial.

The effects of amiodarone in a low dosage (200 mg every 8 h for 2 weeks, then 200 mg/day) was assessed in a double-blind placebo-controlled trial in 34 patients with a history of severe congestive heart failure but no sustained ventricular arrhythmia. Left ventricular ejection fraction, treadmill exercise tolerance and 48 h electrocardiographic monitoring were assessed before and repeatedly after beginning amiodarone or placebo therapy over 6 months, and side effects were monitored. In patients receiving amiodarone, the ejection fraction increased significantly from 19 +/- 7 to 29 +/- 15% at 6 months (p less than 0.01 from baseline), but not significantly in 14 placebo-treated patients (18 +/- 5 to 22 +/- 9%). Exercise tolerance increased significantly in amiodarone-treated patients (median 433 s to 907 s, p less than 0.05), but not significantly in placebo-treated patients (757 to 918 s). Nonsustained ventricular tachycardia was present in 88% of amiodarone-treated patients before, but in only 21% of patients after 6 months of treatment (p = 0.06); it was seen in 43% of placebo-treated patients at baseline and in 50% after 6 months. Fifty percent of amiodarone-treated patients had side effects (principally nausea) and the drug was withdrawn in 28% of cases; no life-threatening effects were seen. Low dose amiodarone appears to have a multifaceted potential to produce benefits in arrhythmia control, exercise tolerance and ventricular function in patients with a history of severe congestive heart failure, but better control of side effects (principally nausea) appears essential. Effects on mortality could not be determined from this study; such assessment requires a larger cohort of patients.

Aged↗
PubMed1986

A palpable spleen is not necessarily enlarged or pathological.

It is widely accepted that a palpable spleen in the adult population is always enlarged and pathological. The aim of this study was to assess the validity of this statement. As a routine, our protocol for liver-spleen studies includes liver pliability, which demonstrates the level of the hemidiaphragms at full inspiration and expiration, as well as splenic size and colloidal uptake. Sixteen hundred 99mTc sulphur colloid liver-spleen studies, which had been performed in our Department, were reviewed. In 21 patients, who had been referred with "splenomegaly for investigation", the scintigraphic splenic size was 13 cm posterior length or less. In this group, splenic palpability was confirmed by at least two clinicians. Follow-up did not reveal any evidence of splenic disease in 18 of the 21 patients. In a separate postmortem follow-up of 123 sequential liver-spleen scans, 100 patients were noted to have a scintigraphic splenic size of 13 cm posterior length or less. This was shown to be a reliable upper limit of normal because 98% of spleens in this group weighed 250 g or less and were normal at post-mortem examination. This study demonstrates that a palpable spleen is not necessarily enlarged or pathological.

Adult↗
PubMed1975

Experience in parathyroid scanning.

In our experience, the low success rate of 75Se parathyroid studies does not justify continuance of the test as a routine diagnostic procedure. The initial results using the 99mTc O4--131I subtraction technique are encouraging but further experience is required in order to ascertain whether this procedure will justify a place as a routine test in the localization of parathyroid adenoma.

Adenoma↗