Table of Contents
ISRN Endocrinology
Volume 2012, Article ID 126720, 9 pages
http://dx.doi.org/10.5402/2012/126720
Clinical Study

Assessment of the Effects of Low-Level Laser Therapy on the Thyroid Vascularization of Patients with Autoimmune Hypothyroidism by Color Doppler Ultrasound

1Ultrasound Unit, Department of Radiology, Clinics Hospital, University of Sao Paulo Medical School, 05403-000 São Paulo, SP, Brazil
2Laser Medical Center, Heart Institute, Clinics Hospital, University of Sao Paulo Medical School, 05403-000 São Paulo, SP, Brazil
3Thyroid Unit, Department of Endocrinology and Metabolism, Clinics Hospital, University of Sao Paulo Medical School, 05403-000 São Paulo, SP, Brazil
4Department of Nuclear Physics, Physics Institute, University of Sao Paulo, 05508-900 São Paulo, SP, Brazil

Received 11 September 2012; Accepted 2 November 2012

Academic Editors: Z. Canturk and E. Hajduch

Copyright © 2012 Danilo Bianchini Höfling et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Chronic autoimmune thyroiditis (CAT) frequently alters thyroid vascularization, likely as a result of the autoimmune process. Objective. To evaluate the effects of low-level laser therapy (LLLT) on the thyroid vascularization of patients with hypothyroidism induced by CAT using color Doppler ultrasound parameters. Methods. In this randomized clinical trial, 43 patients who underwent levothyroxine replacement for CAT-induced hypothyroidism were randomly assigned to receive either 10 sessions of LLLT (L group, ) or 10 sessions of a placebo treatment (P group, ). Color Doppler ultrasounds were performed before and 30 days after interventions. To verify the vascularity of the thyroid parenchyma, power Doppler was performed. The systolic peak velocity (SPV) and resistance index (RI) in the superior (STA) and inferior thyroid arteries (ITAs) were measured by pulsed Doppler. Results. The frequency of normal vascularization of the thyroid lobes observed in the postintervention power Doppler examination was significantly higher in the L than in the P group ( ). The pulsed Doppler examination revealed an increase in the SPV of the ITA in the L group compared with the P group ( ). No significant differences in the SPV of the STA and in the RI were found between the groups. Conclusion. These results suggest that LLLT can ameliorate thyroid parenchyma vascularization and increase the SPV of the ITA of patients with hypothyroidism caused by CAT.