Abstract

THE ROLE OF STIR SEQUENCE IN MAGNETIC RESONANCE IMAGING EXAMINATION OF BONE TUMOUR

*Dr. Kaniza Kabir, Dr. Rashimul Haque, Dr. Md. Ishtiaque Mazid, Dr. Mashah Binte Amin, Dr. Samar C. Sarker and Dr. Tamanna Tabassum

Abstract

Background: Short Tau Inversion Recovery (STIR) sequences of MRI, by its marrow fat suppression provides clearer image of intramedullary tumor extension than conventional method. Therefore, the study underwent with an aim to assess the role of STIR sequence in Magnetic Resonance Imaging examination of bone tumour. Methods: This study was conducted at the Department of Radiology and Imaging in Enam Medical College Hospital with collaboration with the Department of Orthopaedics and Pathology. Patients attending the orthopedic OPD with history suggestive of primary bone lesions were included in the study. Before enrollment, informed consent was ensured. Magnetic resonance imaging (MRI) at 1.5 T with both conventional spin-echo (SE) and STIR sequences were done to reach a radiological diagnosis. A comparative analysis of the results have been performed in order to investigate the specificity, sensitivity, accuracy of STIR and conventional SE sequences in the detection of tumours, assessment of intramedullary extension and soft-tissue involvement. The intraosseous neoplastic extent has been compared with histopathology reports of biopsy specimens. In this study, total 30 cases of histologically proven bone tumour was included. Data were recorded in a preformed case record form. Data analysis was done by SPSS 23. Results: Among 30 patients, 30% had benign tumours (n=9) and 70% (n=21) malignant neoplasms. Osteosarcoma (30%) and hemangioma (13.3%) were the most frequently encountered malignant and benign tumours, respectively. Vertebral column (40%) was the most common tumour site. The lesions were mostly oval and lobulated (26.7% each) with regular margin (60%) and 66.7% had mass effect and 30% showed calcification. On MRI, lesions demonstrated hyperintense lesion in 70% cases during STIR sequence. The latter showed more sensitivity (100% vs 66.7%) and accuracy (86.7% vs 76.7%) as compared to the usual SE method in detecting benign tumours from malignant ones. Conclusion: STIR sequencing has proved to be a better diagnostic modality with greater sensitivity, accuracy but similar specificity for bone tumour classification than SE method of MRI.

Keywords: Bone tumour, Magnetic resonance imaging, Short tau inversion recovery, Short T1 inversion recovery, STIR sequence.