The Value of CT and MRI for Determining Thymoma in Patients With Myasthenia Gravis

Abstract

The aim of the study was to evaluate the usefulness of computed tomography (CT) and magnetic resonance imaging (MRI) for differentiating thymoma from nonthymoma abnormalities in patients with myasthenia gravis (MG). A cross-sectional study of 53 patients with MG, who had undergone surgical thymectomy, was conducted at 103 Hospital (Hanoi, Vietnam) and Cho Ray Hospital (Ho Chi Minh City, Vietnam) during August 2014 and January 2017. The CT and MRI images of patients with MG were qualitatively and quantitatively (radiodensity and chemical shift ratio [CSR]) analyzed to determine and compare their ability to distinguish thymoma from nonthymoma abnormalities. Logistic regression was used to identify the association between imaging parameters (eg, CSR) and the thymoma status. The receiver operating curve (ROC) analysis was used to determine the differentiating ability of CSR and radiodensity. As results, of the 53 patients with MG, 33 were with thymoma and 20 were with nonthymoma abnormalities. At qualitative assessment, MRI had significantly higher accuracy than did CT in differentiating thymoma from nonthymoma abnormalities (94.3% vs 83%). At quantitative assessment, both the radiodensity and CSR were significantly higher for thymoma compared with nonthymoma groups ( P < .001). The ROC analysis showed that CSR had significantly higher sensitivity (Se) and specificity (Sp) than radiodensity in discriminating between the 2 groups (CSR: Se 100%, Sp 95% vs radiodensity: Se 90.9%, Sp 70%). When combining both qualitative and quantitative parameters, MRI had even higher accuracy than did CT in thymoma diagnosis ( P = .031). In conclusion, chemical shift MRI was more accurate than CT for differentiating thymoma from nonthymoma in patients with MG.

Computed Tomography Study of the Thymus at a Tertiary Care Centre of Nepal

“…There are various modalities of the thymus imaging, among them CT and MRI are the two main modalities. 6,[13][14][15][16] CT scan has advantage of rapid scanning with short time taken to scan it so, artifact due to cardiac motion and large vessels pulsation is very low. It has very good soft tissue contrast and it can accurately depict the presence of fat and soft tissue densities.…”

“…15,16 Many studies have been conducted using multidetector CT scan. 2,4,6,14 In the present study too, authors used CT scan method.…”

Purulent pericarditis in advanced thymoma: A case report

“…Most thymoma cases are usually found through CT-scan, and this modality helps differentiate between thymoma and thymic cancer [8] . On CT-scan findings, a focal oval soft tissue mass with sharply demarcated round found in the anterior mediastinum compartment is strongly suggestive of thymoma [9] . In our cases, the CT-scan showed a heterogeneously irregular mass at the anterior mediastinum that invaded mediastinal fat and adhered to the left upper hemithorax and the adjacent vessels.…”

Đặc Điểm Lâm Sàng, Cận Lâm Sàng Của Người Bệnh Nhược Cơ Có Phẫu Thuật Tuyến Ức

“…Tỉ lệ chính xác của kết quả hình ảnh học tuyến ức phù hợp với kết quả giải phẫu bệnh có u và không có u tuyến ức của MRI lồng ngực là 95,2%, của CT Scan lồng ngực là 84,6%. Nghiên cứu nhóm tác giả Phùng Anh Tuấn (8) Sau 06 tháng, 12 tháng phẫu thuật tỉ lệ người bệnh thuyên giảm triệu chứng cao hơn so với lúc xuất viện. Không có sự khác biệt kết cục lâm sàng giữa nhóm có và không có u tuyến ức sau 06 tháng, 12 tháng phẫu thuật, tương tự với kết quả của nhóm tác giả De Roxas Ranhel (4) .…”