Clearance of technetium-99m-DTPA in pulmonary sarcoidosis

Background. The aim of this study was to explore the possible association of the lung clearance of 99mTc- DTPA scan with HRCT lung abnormalities and with the pulmonary function tests [PFTs] in patients with sarcoidosis. Methods. We studied prospectively 15 patients [5 males, 10 females] of median age 46yr [range 27-67] with histologically proved sarcoidosis. HRCT scoring included the sum of the severity and extent of lymph node enlargement and parenchymal involvement. Results. The mean DTPA clearance half-time [τ 1/2 <40 min] was found [mean [SD]] 38.3+4.5min. The lymph node enlargement was found 34% and the parenchymal involvement 12%. DTPA clearance was negatively correlated with the parenchymal involvement [r= -0.651, p=0.009]. The HRCT parenchymal abnormalities were found significantly correlated with PFTs [FVC [r= -0.65, p=0.008] and TLCO [r= -0.76, p=0.02]. Conclusions. Our data suggest a moderate association between 99mTc-DTPA scan and HRCT in pulmonary sarcoidosis. However, further studies in large scale of sarcoid patients are needed to clarify the role of this novel methodology in the evaluation and follow-up of this disorder

Clearance of technetium-99m-DTPA and HRCT findings in the evaluation of patients with Idiopathic Pulmonary Fibrosis

BACKGROUND: Clearance of inhaled technetium-labeled diethylenetriamine pentaacetate ((99m)Tc-DTPA) is a marker of epithelial damage and an index of lung epithelial permeability. The aim of this study was to investigate the role of (99m)Tc-DTPA scan in patients with Idiopathic Pulmonary Fibrosis (IPF). Our hypothesis is that the rate of pulmonary (99m)Tc-DTPA clearance could be associated with extent of High Resolution Computed Tomography (HRCT) abnormalities, cell differential of bronchoalveolar lavage fluid (BALF) and pulmonary function tests (PFTs) in patients with IPF. METHODS: We studied prospectively 18 patients (14 male, 4 female) of median age 67yr (range 55–81) with histologically proven IPF. HRCT scoring included the mean values of extent of disease. Mean values of these percentages represented the Total Interstitial Disease Score (TID). DTPA clearance was analyzed according to a dynamic study using a Venticis II radioaerosol delivery system. RESULTS: The mean (SD) TID score was 36 ± 12%, 3 patients had mild, 11 moderate and 4 severe TID. Abnormal DTPA clearance half-time (t(1/2)<40 min) was found in 17/18 (94.5%) [mean (SD) 29.1 ± 8.6 min]. TID was weakly correlated with the DTPA clearance (r = -0.47, p = 0.048) and with % eosinophils (r = 0.475, p = 0.05). No correlation was found between TID score or DTPA and PFTs in IPF patients. CONCLUSION: Our data suggest that (99m)Tc-DTPA lung scan is not well associated with HRCT abnormalities, PFTs, and BALF cellularity in patients with IPF. Further studies in large scale of patients are needed to define the role of this technique in pulmonary fibrosis

Conceptus radiation dose and risk from cardiac catheter ablation procedures

Background-The aim of the current study was to estimate the conceptus radiation dose and risk associated with fluoroscopic imaging during a catheter ablation procedure for supraventricular tachycardia performed on the expectant mother. Methods and Results-Exposure parameters and fluoroscopy times for each projection of the cardiac ablation procedure performed in 20 female patients of childbearing age were recorded. Radiation doses for a potential conceptus were estimated by using dose data obtained in anthropomorphic phantoms simulating pregnancy at the first, second, and third trimesters. Dose measurements were carried out using thermoluminescent dosimeters. For a typical examination, the average radiation dose to the conceptus was &lt; 1 mGy in all periods of gestation. Average excess fatal cancer was 14.5/10(6) unborn children irradiated during the first postconception weeks. Corresponding values for the second and third trimesters were 30 and 55.7/10(6), respectively. The risk for hereditary effects in future generations was 1.5/10(6) cases for conceptus irradiation during the first postconception weeks. Corresponding values for the second and third trimesters were 3.0 and 5.6/10(6), respectively. Formulas and dose data are presented for estimating the conceptus risk from any technique and x-ray system used for catheter ablation procedures. Conclusions-A typical catheter ablation procedure results in a very small increase in risk of harmful effects to the conceptus. However, estimation of conceptus dose from catheter ablation procedures is always needed to assess the risk to the individual developing in utero