A quantitative assessment of scintigraphy of the legs using 201Tl

Hamanaka, D; Odori, T; Maeda, Haruyoshi; Ishii, Yasushi; Hayakawa, Katsumi; Torizuka, K

doi:10.1007/bf00254343

Cited by 30 publications

(14 citation statements)

References 14 publications

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“…Two sequential emission scans were performed from 30 to 120 & from 120 to 210 seconds after the initial time of inhalation. The time course of radioactive concentration in the arterial blood was measured by sequential blood sampling (5,10,15,20,25,30,40,60,120,180,240, and 300 seconds after injection) from one brachial artery of the subject; each sampling procedure lasts five seconds, thus averaging the radioactive concentration during this interval. The tracer concentration in the blood samples at the time of withdrawal was evaluated by weighting and counting in a well-counter, with proper correction for radioactive decay.…”

Section: Methodsmentioning

confidence: 99%

The Quantitation of Blood Flow/Metabolism Coupling at Rest and After Exercise in Peripheral Arterial Insufficiency, Using PET and 15-0 Labeled Tracers

Depairon

Zicot

1996

Angiology

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Regional blood flow and oxygen uptake of the lower limbs were studied in 11 patients with arterial insufficiency (10 with severe unilateral, 1 with bilateral intermittent claudication). Regional muscle blood flow (F), oxygen consumption rate (R), and oxygen extraction fraction (E) were evaluated by positron emission tomography (PET) and bolus inhalation of C15O2 and 15O2 by the patient. Tomograms were recorded at the greatest diameter of legs, at rest and ten minutes after a treadmill walk test leading to the development of ischemic pain in the affected leg. In 5 patients, F and E were correlated with the results of occlusive venous strain gauge plethysmography and with the measurements of blood gases in one brachial artery and in the femoral vein of the affected limb. Blood flow values measured at rest and after exercise by PET were poorly correlated with the plethysmographic findings. This may be because PET does not interfere with flow as venous occlusion plethysmography does in low peripheral pressure conditions. The results show that F, R, and E were not significantly different in normal and pathologic legs at rest. The values of F and R were significantly higher in pathologic than in normal lower limbs, ten minutes after exercise, whereas E was not significantly altered by exercise at any side. This suggests that, during the recovery from a walk test, the delayed increase in oxygen uptake is proportional to the delayed hyperemia in the ischemic muscles ("oxygen debt") and probably not linked to a luxury perfusion.

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Section: Methodsmentioning

confidence: 99%

The Quantitation of Blood Flow/Metabolism Coupling at Rest and After Exercise in Peripheral Arterial Insufficiency, Using PET and 15-0 Labeled Tracers

Depairon

Zicot

1996

Angiology

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“…Regional 201 Tl uptake in the LL is studied after exercise (11)(12)(13)(14)(15)(16)19), as in myocardial perfusion studies. The reproducibility is high (15). Two methods are available: the first consists of scanning the whole body and comparing LL thallium activity with whole-body activity (11,12,14 -16,19).…”

Section: Ll Scanning Methods and Clinical Validationmentioning

confidence: 99%

Lower-Limb Vascularization in Diabetic Patients

et al. 2001

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OBJECTIVE -To investigate, by thallium-201 scanning, circulation in the muscles of the lower limb (LL) in diabetic patients without clinical peripheral vascular disease but with a high cardiovascular risk profile. RESEARCH DESIGN AND METHODS-A total of 80 diabetic patients (76 patients with type 2 diabetes, mean age 57.3 years, duration of diabetes 13.0 Ϯ 7.5 years) with more than one additional cardiovascular risk factor but no claudication were investigated. After stress testing, 1.5 MBq/kg thallium-201 was administered to perform myocardial single-photon emission computed tomography followed by LL scanning. Muscle blood flow was considered abnormal if the asymmetry in thallium-201 uptake between the two buttocks and/or thighs and/or calves was Ͼ10%.RESULTS -Muscle perfusion defects were found in 42% of the patients, mainly in the calves. These defects correlated with retinopathy (P ϭ 0.042) and the HbA 1c level (P ϭ 0.044). In patients with defects in the buttock and/or thigh, the prevalence of nephropathy and retinopathy was higher than in those with isolated defects in the calf (P ϭ 0.032 and 0.023, respectively).CONCLUSIONS -This study suggests that LL scanning coupled with myocardial scintigraphy is a convenient method of investigating peripheral muscle circulation. Proximal perfusion defects in patients without clinical arterial disease are associated with increased prevalence of retinopathy and nephropathy and, therefore, may be due to microvascular disease of LL muscle. Distal defects may indicate silent macrovascular disease of the LL. Diabetes Care 24:870 -874, 2001A fter 38 years of follow-up, the Framingham Heart Study showed that the risk of developing intermittent claudication was increased by associated coronary heart disease and diabetes (1). The prevalence of coronary artery disease and peripheral vascular disease (PVD) is high in the diabetic population (2,3).More than 50% of diabetic patients die from cardiovascular diseases (4), and the morbidity due to PVD is very high (5). Furthermore, claudication is, in turn, a strong predictor of subsequent cardiovascular events (6 -8).In diabetic patients with other risk factors, myocardial scintigraphy is suggestive of silent myocardial ischemia (SMI) in 20 -30% of cases (9). These patients commonly have angiographically normal coronary arteries and endothelial dysfunction, and myocardial microvascular changes are involved (10). Whole-body exercise thallium-201 ( 201 Tl) scintigraphy, performed after stress testing, permits detection of early functional abnormalities of lower-limb (LL) vascularization (11)(12)(13)(14)(15)(16)(17)(18)(19). Furthermore, this test investigates not only macrovascular but also microvascular blood flow (12,19).We performed myocardial 201 Tl scintigraphy after stress testing to detect SMI in a selected population of diabetic patients without claudication and without cardiac symptoms and signs but with a high cardiovascular risk profile. We took this opportunity to perform LL scanning. In particular, we examined the prevalen...

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“…We did not relate muscle activities to bony structures, as these parameters are appreciably influenced by the individual variability in muscle mass, which is high in our experience and inevitably widens the normal range. The measurement of stressinduced changes in muscle perfusion, as compared with rest conditions, in terms of fractional uptake relative to whole-body activity [6], might have improved the sensitivity. However, it could not have decreased the false-positive ratio, which was higher than the false-negative one.…”

Section: Discussionmentioning

confidence: 99%

Technetium-99m sestamibi scintigraphy for the assessment of lower extremity ischaemia in peripheral arterial disease

et al. 1994

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Technetium-99m sestamibi was used for functional investigation of the muscle perfusion of lower extremities in 35 patients with peripheral vascular disease. The aim was to test what useful information could be obtained by additional imaging of the legs in patients referred for risk stratification with dipyridamole myocardial scanning. Posterior images were acquired over the thighs and calves after postocclusive reactive hyperaemia and at rest. Inter- and intraextremity ratios and differences between the stress and rest data were used for the assessment of abnormal circulation. Arteriography was performed in every case, and surgical procedures or transluminal angioplasty in 31 patients. To estimate diagnostic accuracy, the results of 99mTc-sestamibi scintigraphy were compared with those of angiography and the functional consequences of revascularization procedures. The sensitivity and specificity of 99mTc-sestamibi scintigraphy were 55% and 25%, respectively, with an overall accuracy of 50%. Apparently methodological error was not responsible for these poor results. Instead, a paradoxically high uptake of the radiopharmaceutical in muscles supplied by significantly stenosed vessels was identified as the main source of both false-negative and false-positive results. The phenomenon resembles the findings of a previous study involving delayed administration of thallium-201 after exercise. In conclusion, 99mTc-sestamibi scintigraphy has not proved sufficiently reliable to help in the management strategy for patients with peripheral vascular disease.

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A quantitative assessment of scintigraphy of the legs using 201Tl

Cited by 30 publications

References 14 publications

The Quantitation of Blood Flow/Metabolism Coupling at Rest and After Exercise in Peripheral Arterial Insufficiency, Using PET and 15-0 Labeled Tracers

The Quantitation of Blood Flow/Metabolism Coupling at Rest and After Exercise in Peripheral Arterial Insufficiency, Using PET and 15-0 Labeled Tracers

Lower-Limb Vascularization in Diabetic Patients

Technetium-99m sestamibi scintigraphy for the assessment of lower extremity ischaemia in peripheral arterial disease

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