Is chemical shift imaging useful in differentiating Tubercular lesions from Neoplastic lesions of spine? : A controversial study.

Dr.Nilesh Gupta; Dr.Vinay Goel

Volume : VIII, Issue : IX, September - 2018

Is chemical shift imaging useful in differentiating Tubercular lesions from Neoplastic lesions of spine? : A controversial study.

Dr. Nilesh Gupta, Dr. Vinay Goel

Abstract :

AIM: Tubercularand neoplastic lesions in the bone marrow usually have similar signal intensity on conventional MR imaging sequences. Purpose of this study is whether in phase opposed phase sequence in MRI can helps to differentiate tubercular from neoplastic lesions of spine.

SUBJECTS AND METHODS: 23 consecutive patients with suspected focal lesion or incidental bonemarrow lesions underwent standard MR imaging (T1,T2,STIR) with additional in–phase and opposed–phase imaging done in sagittal planes. The images were assessed independently by two viewers who unaware of patient identities and clinical histories. An elliptical ROI measurement of signal intensity in the lesions site was made on the both in–phase and opposed phase images. From abnormal signal intensity of opposed phase to abnormal signal intensity of in–phase. Relative signal intensity ratio was calculated. Relative signal intensity ratio(SIR)= signal intensity of opposed phase image/ signal intensity of in–phase

Pathological confirmation obtained in 23patients in whom 14 cases were positive for tuberculosis and 9 were neoplastic.

RESULTS: There was nosignificant difference in the mean signal intensity ratio(SIR) for the tubercular lesions (mean, 1.15; SD, 0.15) compared with the neoplastic lesions (mean, 1.16; SD, 0.12 ).

Presence of both fat and water in normal marrow results in suppression of signal intensity on the opposedphase. The existence of normal marrow fat should result in suppression of signal intensity on the opposed–phase images. In tuberculosis, though the pathology is thought not to be affecting the normal marrow, there is no suppression of marrow in opposed phase images.

In neoplastic lesions, normal fat–containing marrow is replaced with tumour, which resulted in lack of suppression on the opposed phase images.

CONCLUSION: In–phase and opposed phase imaging of bone marrow signal intensity abnormalities is unable differentiate Tubercular lesions from neoplastic lesions. However, further studies are warranted to establish this clause.