Whole-body (201)Tl scintigraphy can detect exercise lower limb perfusion abnormalities in asymptomatic diabetic patients with normal Doppler pressure indices.

Significant lower limb arterial obstruction is usually detected by Doppler ankle-brachial pressure index (ABPI) measurement. However, ABPI is non-contributory in cases of diabetic medial sclerosis or calcifications and is unsuitable for the detection of small vessel involvement. Thallium-201, a perfusion agent, is frequently used for the investigation of coronary artery disease, and whole-body (201)Tl scintigraphy (WBS) has also been reported to be useful in the assessment of peripheral artery disease (PAD). Thus, we evaluated the clinical feasibility of simultaneous myocardial and lower limb perfusion assessment. WBS was performed after treadmill exercise and myocardial scintigraphy, and again 4 h later. Calf (201)Tl fractional activities (percentage of whole-body (201)Tl uptake) were calculated. We determined a threshold value of normal post-exercise calf (201)Tl uptake (mean of the (201)Tl fractional uptakes minus 2 SD) in a control group of nine healthy volunteers. We checked its accuracy in a pilot group of 25 diabetic patients with proven PAD. This method permitted the detection of lower limb perfusion abnormalities in 38% of 47 asymptomatic diabetic patients with no evidence of PAD. In conclusion, for asymptomatic diabetic patients, whole-body (201)Tl scintigraphy after a treadmill test seems an efficient method of showing lower limb perfusion abnormalities not detected by ABPI measurement. It allows the evaluation of vascular status with no additional inconvenience for patients when performed after myocardial scintigraphy.

Prognostic value of radionuclide angiography in patients with right ventricular arrhythmias.

BACKGROUND: The prognosis of patients with right ventricular (RV) arrhythmias remains uncertain. This study prospectively evaluated the prognostic value of RV and left ventricular (LV) involvement assessed by radionuclide angiography (RNA) as predictors for sudden death. METHODS AND RESULTS: Patients (n=188) with severe arrhythmias originating from the RV were followed up for a mean of 45+/-34 months. Data on clinical presentation, resting and stress ECG, signal-averaged ECG, 24-hour Holter monitoring, and programmed stimulation were collected along with RNA. Patients were classified as group I (n=82) with normal RNA or group II (n=106) with an abnormal RV suggestive of arrhythmogenic RV cardiomyopathy, classified as diffuse or localized disease, with or without associated LV abnormalities. During follow-up, 14 patients died suddenly, all in group II. None of the clinical and electrical data were predictive of death. An abnormal RNA study was a highly predictive factor for death (P<0.005), as well as the presence of LV abnormalities (P<0.01). CONCLUSIONS: The present study confirms that arrhythmogenic RV cardiomyopathy is a severe disease with a high risk for cardiac death. Evidence of RV abnormalities in patients presenting with RV arrhythmias is highly predictive for sudden death, as is its association with LV involvement.

Somatostatin receptor scintigraphy in pituitary adenomas: a somatostatin receptor density index can predict hormonal and tumoral efficacy of octreotide in vivo.

UNLABELLED: Previous studies have failed to predict somatostatin analog response with somatostatin receptor scintigraphy in pituitary adenomas. In vitro studies have shown that the density of somatostatin receptors in pituitary tumors might be critical for octreotide response. METHODS: The density of somatostatin receptors was calculated in vivo combining the uptake index obtained from somatostatin receptor scintigraphy and the tumor volume obtained by MRI. The ratio of these two values, called density index (DI), was established in 32 of 37 consecutive patients with pituitary adenomas (11 had growth hormone-secreting adenomas, 4 thyroid-stimulating hormone-secreting and 17 nonfunctioning). It was compared with hormonal response, assessed in 15 secreting adenomas on growth hormone or thyroid stimulating hormone suppression (which was considered significant when it reached at least 50% of basal level), and with tumor shrinkage (which was considered significant when > or =20% of pretherapeutic value) in 12 secreting and 14 nonfunctioning adenomas. RESULTS: In agreement with previous reports, uptake index is not predictive of octreotide response. In contrast, DI predicts both hormonal suppression and tumor shrinkage (P = 0.009 and P = 0.0002, respectively) obtained with octreotide therapy. DI sensitivity, specificity and accuracy were 92% each, and a positive correlation was found between DI and the percentage of tumor shrinkage (r = 0.54, P = 0.004). CONCLUSION: The combination of scintigraphic and MRI data allows the computation of a DI for somatostatin receptors that points out patients who can profit from somatostatin analog treatment.

A new quantitative D-dimer assay appropriate in emergency: reliability of the assay for pulmonary embolism exclusion diagnosis.

Plasma D-dimers, degradation products of cross-linked fibrin, are elevated in several thrombotic diseases. In the last decade, their measurement has been performed with specific monoclonal antibody based ELISA assay, with a high negative predictive value of such pathologies. However these methods have a low clinical impact since they cannot be used in emergency because they are time consuming and require series. Recently, rapid tests have been proposed with similar accuracy and are feasible for use in emergency conditions. The aim of our study was to evaluate the potential value of a new quantitative rapid assay, based on agglutination of latex microparticles coated with two monoclonal antibodies specific for D-dimers (Liatest D-Di, Diagnostica Stago), in the exclusion diagnosis of pulmonary embolism (PE). Eighty-five consecutive suspected PE patients were included in the study. D-dimer determination was performed with both standard ELISA and Liatest D-Di just before pulmonary scintigraphy. Sixty-nine patients were free of PE and 16 had PE. Our results confirm the excellent sensitivity and negative predictive values of the conventional D-dimer ELISA. Using a cut-off value of 500 ng/ml, the sensitivity and the negative predictive values of Liatest D-Di were 94% and 96%, respectively. Only one case of PE had a D-dimer value at 480 ng/ml, close to the cut-off value. This study demonstrates that the Liatest D-Di assay is sensitive enough to be used as the first step in the assessment of PE. However, the best cut-off value has to be determined to get an exclusion diagnosis with certainty.

Incidence of dysthyroidism during interferon therapy in chronic hepatitis C.

Seventy-nine patients (40 males, 39 females) were enrolled in a prospective study of lymphoblastoid interferon-alpha (IFN), 3-5 MU three times weekly. They were randomly assigned to receive either 12 months of IFN therapy, or to 6 months of observation followed by 6 months of IFN therapy. The thyroid functional and immunological status was checked every other month during and after treatment. Before treatment, antithyroid antibodies were found in 6 patients (7.5%). Two were hypothyroid and were excluded from the study before starting IFN therapy. Seventy-seven patients received IFN therapy. Of these, thyroid abnormalities appeared in 6 (7.5%). Hyperthyroidism was observed in 3 patients. Two recovered within a few months, but 1 developed subsequent hypothyroidism. Hypothyroidism was observed in 2 patients. TSH blood values were persistently abnormal, but thyroid antibody levels remained increased and fluctuating. Thyroid function usually recovered within a few months; but 2 patients required hormonal therapy and 1 was treated with carbimazole. In 1 patient, a small thyroid papillary carcinoma was observed, but no evidence of relationship with the liver disease or with IFN therapy was found. In a patient with chronic hepatitis C, systematic thyroid assessment should be performed before initiating IFN therapy, including clinical examination, and measurement of TSH and anti-thyroperoxidase antibodies (TPO Ab). During treatment, a TSH assay every other month appears to be necessary and sufficient.

Radioisotope bone scanning in chronic osseous sarcoidosis.

Sarcoidosis is rarely recognized as an osseous manifestations alone. Patients with osseous involvement usually have a chronic multivisceral form of the disease. The authors report a case of osseous sarcoidosis without other visceral involvement. A bone scan was requested to evaluate the extent of the bone involvement and explore buttocks pain.

Indium-111 pentetreotide scintigraphy in malignant lymphomas.

Somatostatin receptor imaging (SRI) was carried out as part of the initial staging of 26 patients with histologically proven Hodgkin's (3) and non-Hodgkin's (23) lymphoma, and in the assessment of the first treatment's efficacy in seven of these patients. Static acquisitions over the whole body were performed 4 and 24 h after intravenous administration of 150 MBq of indium-111 pentetreotide. SRI data were compared with the results of conventional methods (clinical data, abdominal and thoracic computed tomography, bone marrow biopsy). Only 50 of the 86 (58%) confirmed extra-medullary tumour sites were detected by SRI. Twelve previously unknown localizations were visualized in seven patients. The Ann Arbor clinical stage was modified in only one of them. When tumoral tracer uptake was present, a tumour uptake index (TUI) was calculated using two regions of interest (one over the tumoral hot spot and one over the shoulder) on 24-h planar images. The patients were classified into three groups: high tumour uptake (TUI > 2.5 in all tumour sites, group A, six patients), low tumour uptake (1.5 < TUI < 2.5 in all tumour sites, group B, 18 patients), and no tumour uptake (group C, two patients). The sensitivity of SRI detection was higher in group A (90%) than in group B (52%) (P < 0.001). Six weeks after the fourth chemotherapy cycle, conventional methods and SRI were concordant in five of seven investigated cases (four complete remissions and one residual active thoracic mass showing tracer uptake), and discordant in two. SRI demonstrated residual tumoral tracer uptake in these two patients, who had previously been considered to be in complete remission. In conclusion, SRI does not seem to be reliable for the initial staging of lymphomas because of the highly variable and usually low tumoral tracer uptake. It may be more useful in the diagnosis of residual masses after treatment. However, further studies are needed to assess its specificity.