Diffusion Magnetic Resonance Imaging

In our study: statistically, the extent of agreement between dynamic contrast MRI and histopathological staging was almost perfect (κ =0.880) and highly significant (P = 0.001), which is higher compared to the study done by Gupta N. and his colleagues on 60 patients, that resulted in good agreement equals (κ =0.690) and

All MR images were evaluated in T2WI and DWI for site, size, and signal intensity of the

The doctors also advise getting brain imaging before surgery in patients receiving induction therapy for the primary tumor.

Apparent diffusion coefficient is the most widely used diffusion MRI parameter which can be easily and rapidly obtained and could be used to grade cerebral gliomas. ADC assesses water diffusivity and inversely correlated with tumor grade.

We have been given a new type of Magnetic Resonance Imaging (MRI) machine that will be available at our healthcare facility. As everyone knows an MRI machine is a non-invasive imaging technology machine that will help detect diseases in the brain, spinal cord and even soft tissues such as muscles, tendons (NIH, 2015). We need to organize a team that will oversee the education of the staff on how to use the machine. Then we need to figure out how we are going to educate the public on the machine and how it will benefit everyone. We need to have goals, timeframes as well. We also need to figure out the best forms of communication that we would use to get the information to the public as well as within our timeframe for the roll out of this new

Although conventional MRI has been used widely now to diagnose and follow up the brain tumor patients, it provides narrow information on tumor physiology, as well as the degree of contrast enhancement of glioblastoma has a relatively poor correlation with tumor grade, also its difficult to distinguish between glioma and radiation necrosis.

Furthermore, WBRT, positron-emission computed tomography (PET-CT) showed multiple suspicious lesions in both lungs as well as in spleen. In the liver solitary FDG avid lesion highly suspicious of metastatic foci was visible. Fig 2.

First, the standard DWI measurement shows the average molecule displacements among each imaging voxel without differentiating the diffusion from different tissue sub-compartment within the voxel. Furthermore, DWI cannot show enough tissue geometric information because, to avoid T2 signal overlay the DWI signal, DWI does not take advantage of T2 information during the signal acquisition. Finally, conventional DWI images are subject to significant distortion from magnetic field inhomogeneities.

Their analysis showed out of 240 cases 93.67% cases were non neoplastic 8.62% cases were neoplastic lesions and malignant lesions were

Apparent diffusion coefficient (ADC) value, which is dependent on the material being imaged, then can be determined to show the amount of water movement. Because molecules diffuse in three dimensions, diffusion weighted images can be obtained along the X, Y, and Z planes. These images then can be averaged to produce a more accurate measurement. In each of the three planes, two strong dephasing and rephasing gradient pulses are added to a standard MRI pulse sequence at varying degrees of strength. The bright areas show the volume of the brain that may be damaged. Strong magnetic field gradients are used to separate fast and slow moving water molecules. The strength and duration of these gradient pulses are much stronger than those used with standard imaging sequences. The degree of diffusion weighting depends on the region of interest as well as the time between the diffusion gradients.

Researchers reviewed a total of 285 fourth and subsequent follow-up PET/CT. All the follow-up scans were performed within about 13 years of the original scans. The number of follow-up scans per patient ranged from 4 to 28 scans. Sixty-one (71.8%) patients had 4 to 6 follow up scans. Seventeen patients (20%) had 7 to 10 follow-up scans; 9 patients (10.6%) had more than 10 follow-up scans. A total of 112 scans were performed as the seventh follow-up scan or later. Of the 285 follow-up scans, 54 (48.2%) scans were performed for routine follow-up; 24 (21.4%) scans were done for posttreatment assessment of either chemotherapy, radiation therapy, surgical resection, or radiofrequency ablation instituted for disease recurrence; 7 (6.3%) scans were performed as part of mid chemotherapy response assessment; 14 (12.5%) scans were performed as follow-up of previously PET-positive findings; 9 (8%) scans were performed as follow-up of previously PET-indeterminate findings; 2 (1.8%) scans were performed for evaluation of a paraneoplastic syndrome; and 2 (1.8%) scans were performed for evaluation of clinically identified disease

Surgery is basically done to clarify that the mass on the brain scan in indeed a tumor.

On histopathology, the tumor is characterized by numerous giant cells, which vary in size from 10 µ to 100 µ and exhibit many centrally placed uniform nuclei. The other components of the tumor are the spindle cells. These are oval, elongated and contain large nuclei with a small amount of acidophilic cytoplasm. It is believed that the spindle cells are the malignant component of the tumor rather than the giant cells. Therefore, the tumor aggressiveness depends on the spindle cells and not the giant cells [ref].

Magnetic resonance imaging has the potential of totally replacing computed tomography. If history was rewritten, and CT invented after MRI, nobody would bother to pursue CT. --Philip Drew (Mattson and Simon, 1996)

Tumors are one of the most feared diseases of our time. Many people upon hearing the word “tumor” immediately resonate to the conclusion of it being cancer, which is not necessarily true. Tumors fall into to two main types, benign and malignant. Although they are considerably different in tissue invasion, their nature that makes them distinct and symptoms, they are also quite similar in the way they recur in the same location, growth size and their health risks.