RESUMO
OBJECTIVE: To assess the bedside utility of Spectral Doppler Ultrasound (SDUS) in the initial evaluation of patients presenting with thyrotoxicosis. METHODS: This is a retrospective cross-sectional study of patients diagnosed with thyrotoxicosis at an academic outpatient endocrinology clinic from August 2019 to November 2022. The thyroid arteries' peak systolic velocities (PSV) were measured bilaterally using SDUS. PSV ≥40 cm/s in at least a single thyroid artery was considered a reasonable cut-off for Graves' disease and PSV of perinodular artery ≥ 25 cm/s for toxic adenoma. RESULTS: We identified 73 patients. Mean age ± standard deviation 45.2 ± 16.4 years, 54 (74.0%) were female, 49 (67.1%) were Caucasian, 23 (31.5%) were African American, and 1 (1.4%) was Asian. The confirmed diagnoses were 48 (65.8%) Graves' disease, 13 (17.8%) thyroiditis, four (5.5%) toxic adenoma, four (5.5%) amiodarone-induced thyroiditis type 2, 1 (1.4%) toxic multinodular goiter, 1 (1.4%) had an unremarkable repeat thyroid function testing, and two (2.7%) were unconfirmed. Diagnosis based on the SDUS initial assessment was accurate in 65 (89.0%) of the patients, and it was conclusive and confirmatory during the initial encounter in 55 (75.3%) of the patients before additional testing. A thyroid scan was obtained in nine (12.3%) patients. Incorrectly diagnosed patients were observed in two patients of each of the following categories: Graves' disease, thyroiditis, toxic adenoma, and unconfirmed diagnoses. CONCLUSIONS: SDUS can be a valuable, efficient, and cost-effective bedside tool in the initial assessment of patients presenting with thyrotoxicosis.
Assuntos
Glândula Tireoide , Tireotoxicose , Humanos , Feminino , Tireotoxicose/diagnóstico por imagem , Estudos Transversais , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Adulto , Glândula Tireoide/diagnóstico por imagem , Doença de Graves/diagnóstico por imagem , Ultrassonografia Doppler , Testes ImediatosRESUMO
BACKGROUND: Amiodarone-induced thyrotoxicosis (AIT) is caused by excessive hormone synthesis and release (AIT I), a destructive thyroiditis (AIT II), or a combination of both (AIT Ind). Although no gold-standard diagnostic test is available, technetium-99m sestamibi thyroid scintigraphy (99mTc-STS) has been previously reported to be an accurate tool for differentiating subtypes with important therapeutic implications. However, the information to guide reporting of 99mTc-STS is qualitative and highly subjective. This study aims to compare the interobserver reliability of 99mTc-STS before and after the use of quantitative thyroid-to-background ratios (TBRs) displayed on a time-activity curve for differentiation of AIT subtypes. METHODS: A retrospective audit of Nuclear Medicine Departments at Royal Melbourne Hospital (Parkville, Victoria, Australia) and Cabrini Hospital (Malvern, Victoria, Australia) identified 15 consecutive 99mTc-STS studies performed for AIT. Four nuclear medicine physicians reported the studies according to previously established criteria (series 1). Quantitative TBR and estimated 'normal' range TBR were subsequently provided before the studies were reordered and reported again (series 2). Interobserver reliability was calculated using Fleiss' κ statistic for each assessment. RESULTS: The overall percentage of agreement (PoA) and κ statistics for use of conventional 99mTc-STS for diagnosis of AIT improved from 47 to 80% and from 0.30 to 0.67 following the use of quantitative TBR displayed on a time-activity curve with reference to a normal population. Interobserver reliability improved substantially under all diagnostic comparisons, particularly for differentiation of either AIT I (PoA 80% to 94%, κ: 0.48 to 0.84) or AIT Ind (PoA 47% to 82%, κ: -0.05 to 0.51) from other types of AIT. CONCLUSION: Use of quantitative TBR improves the interobserver reliability of reporting 99mTc-STS for investigation of different types of AIT. There is 'almost perfect' agreement upon differentiation of AIT I from AIT II and AIT Ind, with important implications for rationalizing the use of corticosteroid therapy. Prospective identification of AIT Ind is improved from 'poor' to a 'moderate' level of agreement to facilitate rational use of combination therapy at diagnosis.
Assuntos
Amiodarona/efeitos adversos , Tecnécio Tc 99m Sestamibi , Glândula Tireoide/diagnóstico por imagem , Tireotoxicose/induzido quimicamente , Tireotoxicose/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Cintilografia , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
OBJECTIVE: To explore the use of ultrasonography as a diagnostic alternative to the traditional "gold standard" imaging study of nuclear scintigraphy in the evaluation of thyrotoxicosis. METHODS: We review the relevant literature and share our own experience to highlight the promising role of ultrasonography in thyrotoxicosis. In addition, we present a diagnostic algorithm suggesting liberal use of ultrasonography in the evaluation of thyrotoxicosis. RESULTS: Ultrasonography has proved effective not only in the differentiation of Graves disease from other types and causes of thyrotoxicosis but also in the detection of subtle thyroid nodules. The latter role is emphasized in light of the recent observation of an increased risk of occurrence of papillary thyroid carcinoma in patients with Graves disease. CONCLUSION: Ultrasonography is a cost-effective, noninvasive, portable, and safe imaging modality in the evaluation of thyrotoxicosis, both for physiologic assessment and for detection of nonpalpable thyroid cancers that may elude identification on physical examination and nuclear imaging studies. Although thyroid scintigraphy remains a standard radiologic study, thyroid ultrasonography can be a practical alternative in many cases and the primary imaging modality in some situations such as during pregnancy and lactation and for evaluation and management of amiodarone-induced thyrotoxicosis.