ABSTRACT
<p><b>OBJECTIVE</b>To investigate the PET/CT features of primary central nervous system lymphoma(PCNSL).</p><p><b>METHODS</b>A retrospective analysis of PET/CT imaging manifestations and clinical data was performed in 4 PCNSL cases which were confirmed by surgery or stereotactic pathologic biopsy.</p><p><b>RESULTS</b>The pathologic biopsy in 4 patients all showed diffuse large B cell lymphoma with a total of 8 lesions. All cases were performed withF-FDG PET/CT imaging except 1 patient simultaneously withF-FLT PET/CT imaging in the brain. Single lesion was found in 2 cases which both were located in the left frontal lobe. Multiple lesions were found in 2 cases, out of them 1 case located in the corpus callosum and the right lateral ventricle Angle, and the other 1 located in dual lateral ventricle and pineal region. InF-FDG PET/CT image, 4 patients were characterized by high metabolism, even higher than the surrounding brain tissue. The patient which underwentF-FLT PET/CT imaging was also presented with high metabolism and had better Target and non-target ratio(T/N). 3 cases with surrounded by edema and 2 cases with area of cystic necrosis.</p><p><b>CONCLUSION</b>PCNSL are characterized by high metabolism inF-FDG PET/CT images and can better contrast with the surrounding normal brain. Combined use of other tracer such asF-FLT can improve the diagnostic value of PET/CT in PCNSL.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the correlation between T2* relaxation time and the pathological changes in the knee joint of patients with osteoarthritis (OA) and analyze the changes of T2* relaxation time in early cartilage injury.</p><p><b>METHODS</b>Sixty-two patients with OA in different phases underwent magnetic resonance imaging (MRI) of the knee and the articular cartilage T2* relaxation time was recorded, with 20 young healthy volunteers as the control group.</p><p><b>RESULTS</b>Patients with mild OA showed significantly different T2* relaxation time for most of the articular cartilage from that of the healthy volunteers (P<0.05), but no such difference was found between serious OA group and the healthy volunteers. The change of T2* relaxation time of the cartilage was also associated with age, weight and body height, and the potential effects of other factors could not be excluded.</p><p><b>CONCLUSION</b>The articular cartilage shows no obvious morphological changes in early OA of the knee, a stage characterized mostly by alterations of the tissue structure and compositions. Cartilage pathologies can be the most obvious on the weight-bearing surface of the medial condyle of the femur or in the patella. T2* relaxation time measurement can be helpful in the detection of early cartilage pathologies.</p>