ABSTRACTBackground and Aims: As modern society has advanced, the elderly population has increased; this has resulted in increasing osteoarthritis (OA) and brain injury. The T2 map technique, which verifies changes in the cartilage component due to the pressuring and relaxation of cartilage via T2 mapping, could prove useful for the early diagnosis of cartilage disease. And magnetic susceptibility artifacts are generated by metals in echo-planar diffusion weighted images (EP-DWI), and this imposes significant limitations on diagnosis. However, by comparison, magnetic susceptibility artifacts were reduced in periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DW images. For this reason, in this study we measured changes in the T2 values of cartilage among healthy people without ankle and knee arthritis and patients with ankle and knee arthritis in order to evaluate the shape of ankle and knee joint cartilage and damage to the ankle and knee joint cartilage, and also to evaluate the utility of the T2 map images. And we examined whether brain PROPELLER DWI can remove magnetic susceptibility artifacts generated by metal, rather than artifacts generated by different tissue susceptibilities. Furthermore, we compared ADC values obtained using the PROPELLER DWI and the echo planer (EP) DWI techniques in brain study.Materials and Method: First, the study intended to assess the utility of the T2 map image. The multi-echo technique was used for 20 healthy individuals who had experienced no clinically diagnosable ankle and knee arthritis in the past or in the present, and 20 patients who were found to have ankle and knee arthritis in order to obtain T2 spin echo (SE) images of knee joint cartilage. As for the multi-echo SE T2 image obtained, we used T2 map software with an Advantage Workstation to acquire color scale images of the T2 map. T2 maps were displayed by using the available software tools provided by the MR imager manufacturer, which are based on least-squares algorithms. Based on the images obtained, we measured changes in signal intensity (SI) for each area of the ankle joint cartilage. Additionally, we divided the talotibial joint into medial position, middle position, and lateral position in order to calculate the mean values of T2 in 18 spots including the anterior part, middle part, and posterior part of the cartilage of the neck bone and ankle bone. Beside, we calculate the mean values of T2 in 6 spots including the femoral part, tibial part, medial femur part, medial tibia part, lateral femur part, and lateral tibia part of the cartilage of the Knee bone. Mean T2 values were measured in the healthy group and the ankle arthritis patient group. Secondly, twenty patients that underwent brain magnetic resonance imaging (MRI) with a metal dental implant were selected. A 3.0T MR scanner was then used to obtain EP DWI, PROPELLER DWI, and corresponding apparent diffusion coefficient (ADC) maps for a b-value of 0 and 1,000 s/mm2. ADC maps were analyzed using functool? on the Advantage workstation (GE Healthcare). ADC maps functool is software that analyzes MR diffusion-weighted imaging (DWI) datasets and generates Apparent Diffusion Coefficient (ADC) maps.The frequencies of magnetic susceptibility artifacts in four parts of the brain (bilateral temporal lobes, pons, and orbit) were selected. In the ADC maps, we measured the ADC values of both sides of the temporal lobe and the pons.Result: According to the measurement first results, the mean T2 value of the ankle arthritis patient group was higher than that of the healthy group in the anterior part, middle part, and posterior part of the neck bone and ankle bone in the medial position of the talotibial joint. In the middle position of the talotibial joint, the mean T2 value of the ankle arthritis patient group was higher than that of the healthy people group in the anterior part, the middle part, and the posterior part of the neck bone and ankle bone. Also in the lateral position of the talotibial joint, the mean T2 value of the ankle arthritis patient group was also found to be higher than that of the healthy group in the anterior part, middle part, and posterior part of the neck bone and ankle bone. The mean T2 value of the knee arthritis patient group was higher than that of the healthy group in the femoral part, tibial part, medial femur part, medial tibia part, lateral femur part, and lateral tibia part of the cartilage of the knee joint. According to the study second results, the frequency of magnetic susceptibility artifacts in PROPELLER DW images was lower than it was in EP DW images. In ADC maps, the ADC values of the bilateral temporal lobes and the pons were all higher in PROPELLER ADC maps than in EP ADC maps. Our findings show that when a highfield MRI machine is used, magnetic susceptibility artifacts can distort anatomical structures and produce high-intensity signals.Conclusion: As modern society has advanced, the elderly population has increased; this has resulted in increasing OA and brain injury. The MRI scan is used to diagnose a brain injury and osteoarthritis. First, along with the morphological MR imaging technique previously used, the T2 map technique seems to help patients with cartilage problems, in particular, those with the arthritis of the knee for early diagnosis by quantitatively analyzing the structural and functional changes of the cartilage. Secondly, Our findings show that when a high-field MRI machine is used, magnetic susceptibility artifacts can distort anatomical structures and produce high-intensity signals. Furthermore, our findings suggest that in such cases PROPELLER DWI would be helpful in terms of achieving a correct diagnosis in brain injury.Key Words: Arthritis, brain injury, Ankle, Knee, T2 map images, T2 value, susceptibility artifacts, PROPELLER DWI