The Value of Chemical Shift Magnetic Resonance Imaging in Characterization of Bone Tumors
Authors: Reyad Helal Youssef Tarek , Sakr Hossam Moussa , Mohammed Hesham Salah 
Published: November 2024

Abstract

Background
The primary bone tumor incidence rate comprises at least two distinct peaks of an individual's life in the second decade and late adulthood. The dynamic of bone tissue- dependent on the tissue’s physiological and pathological condition which makes it susceptible to cellular re-arrangement, tumor cell formation, and tumor cell implantation.

Aim of the Work
to investigate the potential application of opposed phase imaging (OPI) or chemical shift imaging (CSI) in characterization and differentiation of various bone tumors to set a cut-off point using chemical shift imaging signal intensity ratio to differentiate benign from malignant bone tumors.

Patients and Methods
This study is a cross-sectional study was conducted on 35 patients who are clinically suspected to bone tumor, the period from July 2022 to July 2023 in Radio- diagnosis Department of Aim Shams University and Police Academy Hospital was undergoing MRI imaging for the identification of bone tumors.

Results
The current study findings compared the gender and age distributions among patients with benign and malignant bone lesions. Among the benign group (N = 21), 57.1% were male and 42.9% were female, while in the malignant group (N = 14), 71.4% were male and 28.6% were female. A chi-square test was conducted for gender, yielding a test statistic of 0.734 and a p-value of 0.392, indicating no statistically significant difference in gender distribution between benign and malignant lesions (p &gt; 0.05). Regarding age, the mean age in the benign group was 26.76 years with a standard deviation of 14.20 years, whereas in the malignant group, it was 42.29 years with a standard deviation of 23.6 years. The age difference between the two groups was statistically significant, as determined by an independent samples t-test (T = 2.209, p = 0.039), suggesting that patients with malignant bone lesions tended to be older compared to those with benign lesions. The current study findings compared lesion site distribution between patients with benign and malignant bone lesions. In the benign group (N = 21), the femur was the most common site (28.6%), followed by the tibia (23.8%) and radius (9.5%). No benign lesions were observed in certain sites. In the malignant group (N = 14), the vertebrae were most common (21.4%), followed by the femur and tibia (each 28.6%). A chi-square test showed no significant difference in lesion site distribution between the two groups (p = 0.234).

Conclusion
the comprehensive analysis of various parameters derived from chemical shift imaging (CSI) in the characterization of bone lesions reveals valuable insights into their diagnostic utility. The study examined demographic characteristics, lesion sites, sizes, and CSI parameters in a cohort of patients with benign and malignant bone lesions. Notably, while gender distribution and lesion sites did not significantly differ between benign and malignant groups, age and CSI parameters demonstrated notable distinctions. Malignant lesions tended to occur in older individuals and exhibited higher mean out-phase signal intensities compared to benign lesions. Importantly, the signal intensity ratio (SIR) emerged as a highly sensitive and specific parameter for distinguishing between benign and malignant lesions, with a perfect diagnostic performance at the specified cutoff value. These findings underscore the importance of incorporating CSI, particularly SIR, into routine imaging protocols for accurate characterization and differentiation of bone lesions, thereby facilitating timely diagnosis and appropriate clinical management.