3T magnetic resonance spectroscopy as a powerful diagnostic modality for assessment of thyroid nodules

ABSTRACT Objective: Magnetic resonance spectroscopy (MRS) is a powerful tool for structural studies of chemical compounds and biomolecules and also documented promising findings as a potential imaging technology in thyroid oncology. This prospective study was to ascertain the clinical significance of 3 Tesla MRS in the evaluation of patients with thyroid nodules (TNs) as an ancillary diagnostic technique for thyroid carcinoma. Materials and methods: Magnetic resonance spectroscopy at 3T at echo- times (TEs) 136 and 270 ms was carried out on 15 patients with total number of 32 TNs larger than 1 cm3, which all were surgically resected. Choline (Chol) to creatine (Cr) ratio was assessed at 136 and 270 TEs on each nodule and a receiver operating characteristic (ROC) curve was used to determine optimal cut-off point. The findings were compared with histopathology of thyroid specimens. Results: There were 23 benign and 9 malignant lesions (7 papillary and 2 follicular thyroid carcinomas). The mean values of Chol/Cr at 136 and 270 TEs was 2.28 ± 3.65 and 1.52 ± 1.67 respectively and the difference between benign and malignant nodules was only significant at 136 TEs. The study revealed that Chol/ Cr ratio cut-off point of 2.5 best correlates with histopathology results (sensitivity = 75%; specificity = 100%; PPV = 100%; NPV= 92%). Conclusion: This preliminary study showed that 3T magnetic resonance spectroscopy might be a specific modality for the evaluation of thyroid nodules in differentiation of benign from malignant thyroid tissue. However, a larger series would give much greater confidence that this state-of-the-art technology will worth pursuing in clinical practice.

Bone single photon emission computed tomography (SPECT) in a patient with Pancoast tumor: a case report / Tomografia óssea computadorizada por emissão de fóton único (SPECT) em paciente com tumor de Pancoast: um relato de caso

CONTEXT: Non-small cell lung carcinomas (NSCLCs) of the superior sulcus are considered to be the most challenging type of malignant thoracic disease. In this disease, neoplasms originating mostly from the extreme apex of the lung expand to the chest wall and thoracic inlet structures. Multiple imaging procedures have been applied to identify tumors and to stage and predict tumor resectability in surgical operations. Clinical examinations to localize pain complaints in shoulders and down the arms, and to screen for Horner's syndrome and abnormalities seen in paraclinical assessments, have been applied extensively for differential diagnosis of superior sulcus tumors. Although several types of imaging have been utilized for diagnosing and staging Pancoast tumors, there have been almost no reports on the efficiency of whole-body bone scans (WBBS) for detecting the level of abnormality in cases of superior sulcus tumors. CASE REPORT: We describe a case of Pancoast tumor in which technetium-99m methylene diphosphonate (Tc-99m MDP) bone single-photon emission-computed tomography (SPECT) was able to accurately detect multiple areas of abnormality in the vertebrae and ribs. In describing this case, we stress the clinical and diagnostic points, in the hope of stimulating a higher degree of suspicion and thereby facilitating appropriate diagnosis and treatment. From the results of this study, further clinical trials to evaluate the potential of SPECT as an efficient imaging tool for the work-up on cases of Pancoast tumor are recommended.

CONTEXTO: Carcinomas pulmonares de células não pequenas (NSCLCs) do sulco superior são considerados como o maior desafio nos tumores malignos torácicos. Nesta doença, as neoplasias se originam principalmente do ápice do pulmão e se expandem pela parede e pelas estruturas torácicas. Diversas técnicas de imagem têm sido utilizadas para identificar e estagiar os tumores, permitindo um prognóstico para a sua ressecção em procedimentos cirúrgicos. O exame clínico tem sido bastante usado para diagnóstico diferencial de tumores do sulco superior nas queixas de dores no ombro, síndrome de Horner e anormalidades observadas em exames paraclínicos. Embora diversos tipos de exames de imagem sejam utilizados para diagnóstico e estadiamento de tumores de Pancoast, praticamente não existem relatos sobre a eficácia do exame ósseo do corpo todo (WBBS) na detecção do nível de anormalidade em casos de tumores do sulco superior. RELATO DE CASO: Descrevemos um caso de tumor de Pancoast, em que foi realizada a tomografia computadorizada óssea por emissão de fóton único (SPECT) com metileno difosfonato de tecnécio-99 (Tc-99m MDP). Este exame foi capaz de detectar com acurácia as múltiplas áreas de anormalidade em vértebras e costelas. Ao descrever este caso, os autores ressaltam os pontos clínicos e diagnósticos, esperando estimular maior grau de suspeita, facilitando assim o diagnóstico e tratamento apropriados. A partir dos resultados deste trabalho, outros estudos clínicos podem avaliar o potencial do SPECT como uma ferramenta eficiente de imagem a ser recomendada na investigação de casos de tumor de Pancoast.

Role of Tc-99m RBC scintigraphy in specific diagnosis of liver hemangioma; a case report

Hemangioma is one of the most common benign tumors. "Differentiating hemangiomas from malignant tumoral lesions and metastases by a non-invasive method is so important". This case shows an asymptomatic patient with incidental finding of a large hepatic hemangioma and the role of the Tc-99m RBC SPECT study in final diagnosis and localization of the tumor.

Myocardial Tc-99m MDP uptake on the bone scintigraphy in the hemodialysis-associated amyliodosis (an incidental finding)

Amyliodosis is characterized by an abnormal extracellular deposition of amyloid in different organs, where it usually causes some type of dysfunction. From the five different types of amyloidosis, we report a case of hemodialysis-associated amyliodosis in a 56-year-old man with an incidental finding of diffuse myocardial and kidney uptake in a bone scan performed for assessing osteomyelitis , which raised the possibility of amyloidosis in this patient. The diagnosis of amyliodosis was later established by analysis of aspirated abdominal fat. We conclude that incidental findings in nuclear medicine should be valued. As in this case extraosseus accumulation of Tc-99m MDP, especially with a pattern of diffuse myocardial uptake, warrants further evaluation for a possible amyloidosis disease.