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Magnetic resonance imaging (MRI) is a very important imaging method for diagnosis and treatment of prostate cancer (PCa) in clinical practice. As functional MRI is growing and maturing, its quantitative parameters are expected to enhance the clinical value of MRI furtherly. Intravoxel incoherent motion diffusion imaging, diffusion tensor imaging, and diffusion kurtosis imaging, which were derived from diffusion weighted imaging, have provided richer and more accurate parameters. The newly-developed magnetic resonance elastography can complement the mechanical characteristics of PCa.
Subject(s)
Humans , Male , Diffusion Magnetic Resonance Imaging , Diffusion Tensor Imaging , Magnetic Resonance Imaging , Motion , Prostatic Neoplasms/diagnostic imagingABSTRACT
Objective To comparatively analyze the application of conventional echo planar imaging-diffusion weighted imaging (EPI-DWI) and readout-segmented echo-planar diffusion imaging (RESOLVE) in the diagnosis of nasopharyngeal carcinoma.Methods A total of 35 patients with nasopharyngeal carcinoma confirmed by pathology were included in this study.All patients underwent conventional EPI-DWI and RESLOVE (b=800 s/mm2) with a 3.0 T MRI scanner.ADC values of the tumors and normal nasopharyngeal tissues were calculated.Scoring (Five-point score) for imaging quality of conventional EPI-DWI and RESLOVE was independently performed by two radiologists with 5 years experiences and the agreement evaluation was performed using Kappa analysis.The numbers of cases with effectively ADC values,the ADC values of the same tissue in different sequences and the ADC values of the tumor and the normal muscle tissue in the same sequence were compared.The data was statistically analyzed by x2 test,paired sample t test and independent sample t test.Results The agreement between two radiologists was excellent.The Kappa value of the conventional EPI-DWI was 0.91 1(P＜0.01).The Kappa value of the RESOLVE was 0.827(P＜0.01).Four points or more accounted for 97.1％ (34/35) in the RESOLVE group,while only 2.9％ (7/35) images scored four points and most of them were less than four points in the conventional EPI-DWI group.The effectively ADC values can be measured in the conventional EPI-DWI,accounting for 54.3％ (19/35) cases.The ADC values could be measured in all cases of group (100.0％,35/35).The scores of imaging quality of RESOLVE were higher than those of conventional EPI-DWI,which were significantly different (x5=19.091,P＜0.001).The ADC values of the normal nasopharyngeal tissue were (1.65 ±0.13) × 10-3,(1.96±0.14) × 10-3 mm2/s and the ADC values of the tumor were (0.87±0.09) × 10-3,(0.83±0.10)× 10-3 mm2/s in the conventional EPI-DWI and the RESOLVE,respectively.The ADC values were significantly different between the tumors and the normal nasopharyngeal tissues (t=-23.284,-31.509,P＜0.05).The ADC values of the tumors were apparently lower than the normal nasopharyngeal tissues.There were no significant difference of the ADC values between the conventional EPI-DWI and the RESOLVE measuring the same tissue (t=-0.957,-0.921,P＞0.05).Conclusion Compared with conventional EPI-DWI,RESLOVE can provide a higher quality image and may be helpful to accurate diagnosis.
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Purpose To explore the three-dimensional display and parameter features of 3.0T MR diffusion tensor imaging (DTI) in the imaging of normal female pelvic floor muscle fiber bundles, and to provide a reference standard for the application of DTI in patients with pelvic organ prolapse. Materials and Methods Fifty cases of females who had not given birth or had given birth by cesarean delivery were divided into four groups:20 to 29 years (15 cases), 30 to 39 years (15 cases), 40 to 49 years (12 cases) and 50 to 54 years (8 cases). First, the conventional sagittal, axial, coronal T2WI and axial T1WI images were acquired with a 3.0T MRI scanner;then a dynamic sagittal fiesta sequence was executed to exclude pelvic organ prolapse; at last, the transverse two-dimensional diffusion-weighted spin echo-echo planar imaging (SE-EPI) pulse sequence was executed to acquire pelvic floor DTI data, through the post-processing of the data, normal female pelvic floor muscle fiber bundle images can be obtained and apparent diffusion coefficient (ADC) value and fractional anisotropy (FA) value were calculated. Results Content three-dimensional muscle fiber bundle images and corresponding ADC and FA values of the pubic visceral muscles in pelvic wall and obturator muscles in pelvic wall were acquired in all subjects;there was no statistically significant difference (P>0.05) for the ADC and FA values between the left and right side of the pubic visceral muscles and obturator muscles within the same age group;and the difference of ADC and FA values of pubic visceral muscles and obturator muscles among different age groups were not statistically significant (P>0.05), either. Conclusion 3.0T MR DTI fiber tracking imaging can be applied for the three-dimensional observation of the complicated muscle fiber bundle structures in female pelvic floor, through the measurement of ADC and FA value changes, functional abnormity can be suggested before the anatomy structure changes of the pelvic muscles occurs, thus provides an important new approach for further study of pelvic organ prolapse.
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Introduction: For more than a decade the diffusion tensor imaging model has been widely used in order to resolve and represent the intracranial white-matter microanatomy. Howeverthere are numerous studies that have successfully demonstrated the limitations associated with DTI in trying to define crossing-fibre regions. Various models have been developed with the intention of overcoming these limitations. This is why our study focuses on the description and preliminary experience in the use of tractography based on high-angular-resolution-diffusion imaging (HARDI) using the constrained spherical deconvolution (CSD) technique. Methods: The data was acquired on a Philips Achieva 1.5T resonator using a diffusion weighted single-shot echoplanar sequence along 32 directions with a b-value of 1000s/mm2. The images were processed using FSL v5.0 and MRtrix v0.2.10 software. Results: We achieved tensor free high-angular-resolution-diffusion tractographic images that better represented the white-matter micro-architecture than those obtained from the tensor model. Additionally, it was possible to generate track-density images (TDI) with a final resolution more than 500 times that of the acquired data.
Introducción: Desde hace más de una década que el modelo de tensor de difusión ha sido ampliamente utilizado con el fin de resolver y representar la microanatomía de la sustancia blanca intra-cerebral. Sin embargo, no son pocos los estudios que han logrado demostrar las grandes desventajas que el modelo presenta al tratar de definir regiones de entrecruzamiento de fibras. Diversos modelos han sido desarrollados para ofrecer una solución consistente, capaz de representar dichas regiones con mayor grado de correlación anatómica. Es por ello que nuestro estudio se enfoca en la descripción y experiencia preliminar en el uso de tractografía basada en imágenes de difusión de alta resolución angular (HARDI) usando el modelo de deconvolución esférica restringida (CSD). Métodos: La adquisición se realizó en un resonador Philips Achieva 1.5T mediante secuencia de difusión single-shot echo-planar de 32 direcciones con un b-value de 1.000s/mm² procesamiento de las imágenes se realizó mediante software FSL v5.0 y MRtrix v0.2.10. Resultados: Se lograron tractografías libres de tensor de difusión de alta resolución angular que representan la micro-arquitectura de la sustancia blanca de mejor manera que con las generadas a partir del modelo de tensor. Adicionalmente, se logró generar imágenes de densidad tractográfica (TDI) con una resolución final de más de 500 veces a la de adquisición.
Subject(s)
Humans , Male , Female , Adult , Brain/physiology , Brain/diagnostic imaging , Magnetic Resonance Imaging/methods , Image Interpretation, Computer-Assisted/methods , Diffusion Tensor Imaging/methodsABSTRACT
Objective: To analyze the correlation of intervetebral disc degeneration with the diffusion values of lumbar vertebral discs and lumbar blood supply in patients with suspected lumbar intervertebral problems, so as to assess ADC value in diagnosis of intervertebral degeneration and the related blood supply. Methods: Sixty-five patients with suspected lumbar intervertebral problems were included in the present study; they had a mean age of (52.3±28.5) years and an age range of 16-76 years. Eleven of them had low back pain complicated with sciatica, 16 had low back pain without sciatica, 33 had sciatica without low back pain, and 5 had intermittent claudication. The disease course was 1-57 weeks, with a mean of (13.4±6.3) weeks. MR angiography and diffusion imaging were performed to evaluate the status of lumbar arteries and to obtain the ADC values of L1-4, so as to analyze the correlation of ADC values, lumbar blood supply, and intervetebral disc degeneration. Results: The ADC values of L1-4 were negatively correlated with the degeneration of lumbar discs (P<0.05). There was a relation between the artery status of L1, L2 and L3 with the degeneration of corresponding lumbar discs of L1-2, L2-3, and L 3-4, (r3 = 0.823, P = 0.016 3 ; r5 = 0.791, P = 0.019 2; r, = 0.835, P = 0.010 3). The artery status of L4 and the L4-5 discs was not significantly correlated with degeneration of corresponding lumbar discs(r3 =0.306, P = 0.209 2). Conclusion: The ADC values of lumbar intervertebral disc can reflect the degeneration of L 1-4 , and degeneration of L1-2, L2-3 is and L3-4 is correlated with the artery status of corresponding discs.