Preliminary Clinical Application Of Whole Body Diffusion Weighted Imaging

Partâ… :Whole Body Diffusion Weighted Imaging on Normal Bone MarrowObjective:To evaluate the correlation between quantitive parameters of bone marrow DWI and gender,age,height,weight,BMI index and serum sex hormone levels and to estabalish the normal reference range.Methods:108 healthy volunteers(53 males and 55 female,age range 20～80 years, mean age 49.454 years) were enrolled in study.The whole body DWI examination was performed on GE Signa 1.5T MR scanner using embedded body coil.The serum estradiol(E2) and corporin were measured in 60 healthy subjects within 48h of MR examination.The ADC values and SNR values of the 7^th cervical spine,8^th thoracic spine,4^th lumbar spine and bilateral ilium were measured,and the average values were used.The 108 volunteers were classified as young-aged group(age range 18～39 years),middle-aged group(age range 40～59 years) and old-aged group(age range 60～80 years),the ADC and SNR values between genders and different age groups were compared.The partial correlation analysis was performed between ADC and SNR values and gender, age,height,weight,BMI index and serum sex hormone levels.Results:ADCs and SNRs of female subjects were significantly higher than those of male(P＜0.01),and there were significant difference of ADCs and SNRs between different age groups(P＜0.01).ADCs of bone marrow showed no statistical correlation with height,weight and BMI index(P＞0.05),but had significant negative-correlation with age(r= -0.642,P＜0.01) and slightly statistical positive-correlation with serum E2 and corporin levels(r= 0.278,P =0.04;r=0.271,P=0.045).SNRs of bone marrow showed no statistical correlation with height,weight,BMI index and corporin levels(P＞0.05),but showed significant negative-correlation with age(r= -0.709,P＜0.01) and slightly statistical positive-correlation with serum E2 levels(r= 0.293,P=0.03).Serum E2 and corporin showed synergistic effect on ADCs and SNRs of bone marrow(r= 0.65,P＜0.01;r=0.573,P＜0.01).Conclusion:The ADCs and SNRs of bone marrow were influenced by gender, age and sex hormone levels,the variances of bone marrow DWI in different genders and age groups were observed.To understand the normal appearance of bone marrow DWI was valuable on confirming bone abnormality.Partâ…¡:Efficacy of Whole Body Diffusion Weighted Imaging in Detecting and Differentiating Skeletal MaligancyObjective:To evaluate the efficacy of WB-DWI in bone metastasis detection using bone scintigraphy as comparison and to differentiate spinal infection and malignancy with DWI.Methods:Forty-five patients with malignancy history(20 males and 25 females, age range 17～74 years,mean age 52.7 years) were enrolled in our study.All the patients received WB-DWI on GE Signa 3.0T MR scanner and bone scintigraphy scan within 1 week.The images were reviewed separately by two radiologists and two nuclear medicine physicians,who were blinded to the results of the other imaging modality.The sensitivity,specificity,positive predictive value(PPV) and negative predictive value(NPV) were analyzed.Twenty-three patients with veterbral metastases and fourteen patients with spinal infection received WB-DWI on GE Signa 1.5T MR scanner.The ADC values and CNR values of the 32 metastastic lesions and 19 infectious lesions were compared.Results:A total of 181 metastatic lesions in 77 regions of 35 patients were detected by WB-DWI,and 167 metastatic lesions in 76 regions of 34 patients were identified by bone scintigraphy.The patient-based sensitivity and PPV of the WB-DWI and bone scintigraphy were similar(89.5%vs.81.6%,97.1%vs. 91.2%),whereas,the patient-based specificity and NPV of WB-DWI were obviously higher than those of bone scintigraphy(85.7%vs.57.1%,60%vs. 36.4%).The region-based sensitivity and specificity of WB-DWI were slightly higher than those of bone scintigraphy(89.5%vs.88.4%,95.6%vs.87.6%).The mean ADCs and CNRs of metastasis were 0.963±0.150(×10^-3mm²/s) and 27.417±4.819,and those of infectious diseases were 1.412±0.211(×10^-3mm²/s) and 13.127±3.604 respectively.The ADCs of metastasis were significantly lower than those of infectious diseases,while CNRs of metastasis were significantly higher than those of infectious diseases(P＜0.01).Using the threshold ADC value as 1.17×10^-3mm²/s,the sensitivity,specificity,PPV,NPV and accuracy were 93.8%,84.2%,90.9%,88.9%and 90.2%respectively.Conclusion:WB-DWI revealed excellent concordance with bone scintigraphy regarding detection of bone metastasis.DWI had important value for differentiating spinal infection and malignancy.Partâ…¢:Comparison of Whole Body Diffusion Weighted Imaging and PET-CT on LymphomaObjective:To evaluate the application of WB-DWI on lymphoma using PET-CT as reference.Methods:12 patients(9 males and 3 females;age range 24～85 years,mean age 46.67 years) who suffered from initial or recurrent lymphoma were received whole body DWI-FIESTA and PET-CT examinations within 10 days and without clinical therapy between them.DWI and FIESTA images were confused as whole body DWI-FIESTA images using GVCM V3.1 software(CREALIFE Company). The images were reviewed separately by two radiologists and two nuclear medicine physicians.The tumor stagings and "affected regions" of 12 patients by two methods were compared.SUV values and ADC values of 75 regions were measured,and correlation between them was analyzed using Spearsman rank test.Results:The consistency of WB-DWI and PET-CT on tumor staging was 100%. A total of 87 "affected regions" were detected by PET-CT while 85 regions by WB-DWI,the sensitivity and specificity of WB-DWI were 97.7%and 100% respectively when using PET-CT as reference.The two modalities showed no significant difference in detecting lesions(P＞0.05).Mean SUVs of 75 regions was 5.156±4.452 and mean ADCs was 0.884±0.214(×10^-3mm²/s),there was no significant correlation between SUVs and ADCs(r= -0.120,P=0.306).Conclusion:WB-DWI had important clinical value on tumor staging and lesion detection of lymphoma.There was no significant correlation between SUVs and ADCs because of different principles of the two methods. Partâ…£:The Study of Diffusion Weighted Imaging on Evaluating Proliferation,Invasion and Prognosis of LymphomaObjective:To study the value of DWI on evaluating the proliferation,invasion and prognosis of lymphoma.Methods:30 patients(17 males and 13 females,age range 19～85 years,mean age 45.73 years) with initial or recurrent lymphoma were performed WB-DWI examination.ADC values of surgery or biopsy regions were measured. Immunohistochemistry staining of Ki-67 was carried out to indicate tumor proliferation,and was classified as low expression group(＜25%),middle expression group(25～75%) and high expression group(＞75%).ADCs of different groups were compared.Patients were divided into Hodgkin's lymphoma(HD), inert non-hodgkin's lymphoma(NHL),aggressive NHL and highly aggressive NHL according to 2000 WHO classification and ADCs of these groups were compared.Patients were classified as low risk group(0～1 scores),low-middle risk group(2 scores),middle-high risk group(3 scores) and high risk group(4～5 scores) according to international prognosis index(IPI),and the ADCs were compared between them.Results:There were significant difference between different expression groups of Ki-67(F=15.46,P＜0.01).The ADC values of high expression group were significantly lower than those of middle expression group(0.625±0.105 vs 0.828±0.164,P＜0.01),and the ADC values of middle expression group were significantly lower than those of low expression group(0.828±0.164 vs 1.019±0.149,P＜0.01).The ADC values of four groups with different aggressiveness were significantly different(F=14.81,P＜0.01),however,there was no significant difference between HD and inert NHL.There was no significant difference of ADC values between four groups with different IPI index(F=1.97,P=0.14).Conclusion:The ADC values could reflect the proliferation and invasive potention of lymphoma to some extent,but had no statistical relationship with international Prognosis index.