Purpose: To evaluate the usefulness of chemical shift imaging (CSI) in differentiating benign osteoporotic and malignant vertebral marrow lesions. Material and methods:Patients undergoing spinal magnetic resonance imaging (MRI) for back pain, which showed altered marrow signal intensity on conventional MRI sequences, were included in the study. Patients with acute traumatic vertebral fractures, infective spondylodiscitis, paravertebral collections, etc. were excluded. The patients underwent CSI. In-phase and opposed-phase images were taken to calculate the signal intensity ratio (SIR) of the abnormal vertebra. The SIR of the mean signal intensity measured on opposed-phase to mean signal intensity measured on in-phase images was measured and recorded. Results:The studied population included 30 patients, in whom 58 vertebrae were accessed, which included 38 dorsal, 18 lumbar, 1 sacral, and 1 cervical. Out of 58 vertebrae, 46 (79%) were malignant and 12 (20%) were benign. The mean CSI/SIR of malignant lesions was 0.96 and the mean SIR of benign lesions was 0.76. Conclusions:Conventional MRI sequences cannot always differentiate between benign and malignant lesions. So newer sequences like CSI have been developed. CSI SIR can be used as a new tool in differentiating benign osteoporotic and malignant vertebral marrow lesions.

OBJECTIVE: To assess the utility of types of periosteal reactions on radiography in distinguishing between nonaggressive (usually benign) and aggressive (usually malignant) osseous neoplasms. MATERIALS AND METHODS: Current study is a retrospective study. Review of X-rays of 52 bone lesions were done. Type of periosteal reaction was assessed in radiograph of each bone lesion and was categorised as either non-aggressive or aggressive with further subcategorization into further types. Type of periosteal reaction (Aggressive v/s Nonaggressive) was correlated with histopathological diagnosis. RESULTS: Of 52 osseous lesions, there were 22 benign bone lesions and 30 malignant bone lesions. 17 of 22 (77%) benign osseous lesions showed Nonaggressive periosteal reaction and 1 of 22 (5%) showed aggressive periosteal reaction. 4 of 22 (18%) benign osseous lesions did not show any periosteal reaction. 28 of 30 (93%) malignant lesions showed aggressive periosteal reaction and 2 of 30 (7%) malignant osseous lesions showed nonaggressive periosteal reaction. CONCLUSIONS: Types of periosteal reactions (Aggressive and Nonaggressive) correlate with risk of malignancy. Lesions with nonaggressive type of periosteal reaction are usually benign and lesions with aggressive type of periosteal reaction are usually malignant.

OBJECTIVE:To evaluate the usefulness of diffusion-weightedMRIwith apparent diffusion co-efcients(ADC) cut-off value indifferentiatingbenignandmalignantbonelesions. MATERIALSAND METHODS: 58 patients with suspected bone tumours based on clinical examination and plain radiographs were included in the current study. They were subjected to routine MRI examination with inclusion of diffusion-weighted imaging, followed by histopathology for nal diagnosis.Allthe lesionswere assessed to see the presence of diffusion restriction if any. ADC values (mean, minimum and maximum) were obtained by two observers individually. Interobserver measurement and the ADC values in benign and malignant lesions were calculated. Receiver operating characteristic (ROC) analysis was done to determine optimal cut-off ADC values in distinguishing benign and malignant bone lesions. RESULTS: Of 58 lesions, there were 28 benign lesions and 30malignant lesions. Diffusion restriction was noted in 83.3% ofmalignant lesions whereas 57.1% of benign lesions did not show diffusion restriction. There were higher mean, minimum and maximum ADC values in benign lesions when compared with malignant lesions. With cut-off value of minimumADC as 0.92 x 10-3 mm2/sec to differentiate malignant and benign lesions, the sensitivity of 79% and specicity of 64% was obtained. CONCLUSIONS: DWIis useful in differentiating between benign and malignant lesions with diffusion restriction favoring malignancy. Higher mean, minimumandmaximumADCvalues are seen in benign lesions as compared tomalignant lesions. Even though, there isslight overlap inADCvalues of bothbenignandmalignantlesions,ADCvalueshelpintheirdifferentiation.