| Objectives:To investigate the DWI appearances of normal organ, primary malignancy and all kinds of metastases. Further, to evaluate the competence of WB-DWI in screening primary malignancy and metastases. Meanwhile, to research the contribution of DWI and ADC value on monitoring therapeutic effect of uterine cervix cancer with radiotherapy.Methods:1. 72 cases suspected or diagnosed malignancy were performed axial DWI without breath-hold at Siemens Magnetom trio# tim 3.0Tesla MR scanner. The b value was 1000s/mm2. The PET-like imaging was formed with 2D or 3D maximum intensity projection and an inverted gray scale.2. 16 cases with osteosarcoma were performed coronal or sagittal msh-EPI-DWI with b value 600s/mm2. The background signal was suppressed with SPIR. The ADC values of neoplastic solid parts, necrotic parts and neoplastic bone parts were measured respectively. Statistic analysis was performed.3. 9 cases with uterine cervix cancer were performed axial DWI without breath-hold before and after radiotherapy respectively with the same parameters. The b value was 1000s/mm2. The ADC values of tumor before and after radiotherapy were measured respectively. Statistic analysis was performed.4. 10 healthy volunteers were performed axial DWI without breath-hold. The b value was 1000s/mm2. The background signal was suppressed with SPIR and STIR respectively. The PET-like imaging was formed with maximum intensity projection and an inverted gray scale. The appearances of normal organs on SPIR-WB-DWI and STIR-WB-DWI were summarized and the SNR of some normal organs at SPIR-DWI and STIR-DWI was compared.5. 25 cases suspected whole body metastases were performed axial WB-DWI without breath-hold. The b value was 1000s/mm2. The background signal was suppressed with SPIR. The PET-like imaging was formed with maximum intensity projection and an inverted gray scale. The competence of WB-DWI in screening primary malignancy and metastasis was investigated.Results:1. 64 of 72 cases were confirmed with malignancy and other 8 cases were confirmed with benign lesions. The lesions of 59 cases with malignancy without therapy showed significant hyper-intensity and had higher CNR than T1WI and T2WI. 5 of 64 cases with malignancy were performed DWI after therapy. Mucous cyst located in region of uterine cervix of 1 uterine cervix cancer after operation showed hyper-intensity on DWI. Chronic inflammation located in region of choledochus of 1 carcinoma of gallbladder after operation showed slight hyper-intensity on DWI. Fibrous scar tissue of 2 uterine cervix cancers after radiotherapy showed iso-intensity. The uterine cervix of 1 uterine cervix after radiotherapy had atrophied and showed normal signal. 2 tubercular abscess located in lumbar vertebrae of 8 benign lesions showed hyper-intensity on DWI.1 case with adenoma located in bilateral adrenal gland showed moderate hyper-intensity on DWI. 1 hysteromyoma and 1 angioleiomyolipoma located in broad ligament of uterus showed moderate hyper-intensity on DWI. 1 hepatic hemangioma and 1 regenerated nodule of hepatic cirrhosis showed iso-intensity on DWI. 1 hepatic cyst showed hypo-intensity on DWI.2. On DWI of 16 cases with osteosarcoma, normal bone tissue and background showed significant hypo-intensity because of signal intensity suppressed. The neoplastic parts showed nonuniform signal intensity on DWI. The neoplastic solid portion revealed moderate hyper-intensity; neoplastic bones showed significant hypo-intensity, whereas necrotic or cystic tumors revealed hypo-intensity on DWI. The mean ADC value of neoplastic bone parts were significantly lower than necrotic and neoplastic solid parts, they were (0.32±0.06)×10-3mm2/s, (2.23±0.16)×10-3mm2/s, (1.34±0.12)×10-3mm2/s respectively. The distinction has noticeable statistic significance (P < 0.01).3. The lesions of 9 cases with uterine cervix cancer before radiotherapy showed significant uniform hyper-intensity. The average ADC value of 9 cases with uterine cervix cancer before radiotherapy was (0.99±0.07)×10-3mm2/s. The tumors after radiotherapy became smaller than those of before radiotherapy. The signal intensity of tumor after radiotherapy became lower and more nonuniform than before. The average ADC value of 9 cases with uterine cervix cancer after radiotherapy was (1.52±0.08)×10-3mm2/s. The distinction has statistic significance (P < 0.01).4. Some organs such as brain, salivary glands, inter-vertebral discs, spinal marrow and nerve root, spleen, kidneys, adrenal glands, prostate and testes showed moderate hyper-intensity on healthy volunteers'SPIR-DWI, while other organs and skeleton showed hypo- or iso-intensity. There had slight artifacts located in proximate part of clavicle on 3D MIP SPIR-WB-DWI, but those artifacts had hardly any influence on diagnosis. The appearance on healthy volunteers'STIR-WB-DWI was similar with SPIR-WB-DWI, but its SNR was lower than SPIR-WB-DWI. There had no artifact on 3D MIP STIR-WB-DWI. The background signal was suppressed thoroughly with STIR.5. Primary malignancy and whole body metastases including parenchymal organic, bony, lymphatic and peritoneal metastases showed significant hyper- intensity on 23 cases confirmed malignancy'SPIR-WB-DWI. SPIR-WB-DWI had higher CNR than conventional MR sequences. SPIR-WB-DWI had detected malignant lesions located in 68 organs of 23 patients. The sensitivity is 100%. The specificity is 97.15%. The false positive rate is 2.85%.Conclusions:1. Both primary malignancy and whole body metastases show significant hyper-intensity on DWI. The CNR of DWI is higher than that of T1WI and T2WI. DWI should be applied in malignancy, because it can detect more metastases than conventional MR sequences.2. The image quality is high on coronal or sagittal msh-EPI-DWI performed at 3.0Tesla MR scanner of osteosarcoma located in extremities. The ADC value can be measured precisely. DWI combined with ADC value and conventional MR sequences can evaluate the constitution of osteosarcoma and guide the biopsy.3. The lesion of uterine cervix cancer before radiotherapy show significant uniform hyper-intensity on DWI. The SI of tumor after radiotherapy is lower and more nonuniform than before. The average ADC value after radiotherapy is higher than that before radiotherapy. DWI will be an ideal tool to monitor the radiotherapeutic effect on uterine cervix cancer.4. The background signal of SPIR-WB-DWI with improved method at Siemens Magnetom trio# tim 3.0Tesla MR scanner is suppressed thoroughly on the whole. Its SNR is higher than that of STIR-WB-DWI. The anatomic structure shows clearly on SPIR-WB-DWI. SPIR-WB-DWI with improved method can be a potent tool to screen the metastases of whole body.5. Because WB-DWI can image whole body one time and have high detection competence for primary malignancy and metastases; it will be a potent tool to screen the metastases of whole body in patients with malignancy. |
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