Dual-isotope subtraction SPECT-CT in parathyroid localization.

OBJECTIVE: The aim of this study was to investigate the accuracy of locating parathyroid adenomas using dual-Isotope subtraction single-photon emission computed tomography-computed tomography (SPECT-CT) in comparison with clinical follow-up and pathology findings from surgery. PATIENTS AND METHODS: A retrospective cohort study of dual-isotope subtraction SPECT-CT was carried out on 224 consecutive patients who were diagnosed with primary hyperparathyroidism. All the patients were injected with 20 MBq of iodine-123-iodide, followed 20 min later by 900 MBq of technetium-99m-sestamibi. Planar neck and chest views and SPECT-CT images were acquired 15 min after administration, followed by an additional planar image set at 2 h to view washout; all images were dual energy. In all, 115 out of 224 of the patients imaged underwent parathyroid surgery. The imaging results were compared with pathology findings when available and, in those who did not undergo surgery, and in some complex cases, with clinical measures after a 2-year clinical follow-up period. FINDINGS: Out of the 224 patients, 135 patients had complete pathology and/or clinical follow-up data and were included in the analysis. The sensitivity of the subtraction SPECT-CT findings was measured to be 95%, with a specificity of 89% for the detection and localization of parathyroid adenomas. The positive predictive value was found to be 97% and the negative predictive value was found to be 83%. The accuracy of the technique was 94% in detecting parathyroid adenoma and 92% in accurate localization. CONCLUSION: Dual-isotope subtraction SPECT-CT imaging has a very high sensitivity and specificity in detecting and locating a parathyroid adenoma, showing that it is a very reliable preoperative imaging technique in primary hyperparathyroidism.

A New Class of Safe Oligosaccharide Polymer Therapy To Modify the Mucus Barrier of Chronic Respiratory Disease.

The host- and bacteria-derived extracellular polysaccharide coating of the lung is a considerable challenge in chronic respiratory disease and is a powerful barrier to effective drug delivery. A low molecular weight 12-15-mer alginate oligosaccharide (OligoG CF-5/20), derived from plant biopolymers, was shown to modulate the polyanionic components of this coating. Molecular modeling and Fourier transform infrared spectroscopy demonstrated binding between OligoG CF-5/20 and respiratory mucins. Ex vivo studies showed binding induced alterations in mucin surface charge and porosity of the three-dimensional mucin networks in cystic fibrosis (CF) sputum. Human studies showed that OligoG CF-5/20 is safe for inhalation in CF patients with effective lung deposition and modifies the viscoelasticity of CF-sputum. OligoG CF-5/20 is the first inhaled polymer therapy, represents a novel mechanism of action and therapeutic approach for the treatment of chronic respiratory disease, and is currently in Phase IIb clinical trials for the treatment of CF.

Preliminary experience of 99mTc-Aprotinin scintigraphy in amyloidosis.

BACKGROUND AND AIM: Radio-labelled Aprotinin has been shown to bind with amyloid fibrils in vitro as well as in vivo. The aim was to test the usefulness of 99mTc-Aprotinin imaging in systemic amyloidosis. METHODS: Thirty-five cases who had 99mTc-Aprotinin scans for the assessment of systemic amyloidosis were reviewed retrospectively. Eighteen had biopsy-proven amyloidosis and 17 were controls (amyloidosis was excluded by negative biopsies and non-invasive tests). Five of 18 patients with amyloidosis had final diagnosis of cardiac amyloid. RESULTS: Physiological uptake of 99mTc-Aprotinin was noted in the urinary tract (kidneys and bladder) and in the liver of all patients and controls; and non-specific uptake of 99mTc-Aprotinin was visualised in the spleen and oro-facial structures in the majority of both groups. Myocardial 99mTc-Aprotinin uptake was noted in all five patients with final diagnosis of cardiac amyloidosis and in none of the 30 subjects who did not have cardiac amyloid. The median heart to background uptake ratio was 2.0 in cardiac amyloid patients and 1.1 in subjects without cardiac amyloid (P = 0.0004). Single Photon Emission Tomography (SPECT) studies of the thorax confirmed that the site of uptake lay within the myocardium. In the amyloidosis group, site-specific 99mTc-Aprotinin uptake was also identified in the subcutaneous tissue of the legs and in a breast nodule shown to be positive for amyloidosis on biopsy. CONCLUSIONS: 99mTc-Aprotinin imaging may be a useful non-invasive method for the assessment of the presence and extent of extra-abdominal amyloid, particularly cardiac amyloidosis. It has little role in diagnosis of amyloidosis involving the oro-facial and abdominal structures.

The Modification of Diet in Renal Disease (MDRD) equations provide valid estimations of glomerular filtration rates in patients with advanced heart failure.

BACKGROUND: Glomerular filtration rate (GFR) has major prognostic implications in heart failure. Our objective was to validate the MDRD prediction equations for GFR in patients with advanced heart failure, and to compare their predictive performance to that of the Cockcroft-Gault (CG) equation. METHODS: We analysed GFR in 45 patients referred for heart transplantation evaluation. 51Cr-EDTA-measured GFR was compared to GFR estimates obtained by MDRD1 and MDRD2 equations, CG equation using actual body weight, and ideal body weight. Regression analyses and Pearson correlations were performed, and Bland and Altman plots were drawn. ROC curves were obtained to illustrate each equation's ability to predict a GFR less than 60 ml/min/1.73 m2 (moderate renal impairment). RESULTS: Patients had a mean age of 52 years, and 69% were in NYHA class III. The mean EDTA-measured GFR was 46.9+/-17.2 ml/min/1.73 m2. The MDRD1 equation provided the best predictive model (narrowest limits of agreement; r = 0.766, p < 0.001), and the highest performance in predicting a GFR less than 60 ml/min/1.73 m2 (area under curve: 0.901). CONCLUSIONS: MDRD equations, especially MDRD1, adequately predict GFR in advanced heart failure, with higher accuracy than the CG equation. MDRD1 also has higher performance in predicting a GFR less than 60 ml/min/1.73 m2.