Mri tech Essay Example | Topics and Well Written Essays - 2000 words

Mri tech - Essay Example Therefore, with T1 weighted MRIs, the images will appear to be bright (high intensity). This is because the major composition of yellow marrow is fat and fat possess very short T1 relaxation phase. The red or hematopoietic marrow is framed up with 40% of water and fat and 20% protein. Water holds a longer T1 relaxation phase and therefore, the images of red marrow is low intense or dark in nature due to very low signal intensity. The diagnoses of bone marrow lesion on yellow marrow background are effective using T1 weighted MRIs but it can be difficult with the case of lesion on a red marrow. With T2 weighted images, the red marrow and yellow marrow cannot be easily distinguished. STIR is more effective than T2 weighted spin images. (Dimopoulos, Moulopoulos, 1997). The figure shows dark signals highlighted with small arrows that indicate the red marrow in the spinal region and bright signals highlighted with long arrows indicates yellow marrow around femoral epiphyses as well as apop hyses. This is an image of a normal bone marrow of a child. (Dimopoulos, Moulopoulos,1997). An abnormal situation characterized by severe pain and irritation in the knee as a result of high level of pressure offered from patella or kneecap is referred as Chondromalacia (cluett, 2010). The patella is normally covered with a smooth layer composed of cartilage. The cartilage moves effortlessly and flexibly across our knee and thus, facilitates easy bending of the knee joint. The case is different with patients affected with chondromalacia wherein the patella inclines to rub against one or another side of the joint. This results in irritation and pain in the knee. Chondromalacia patella symptoms include distributed knee pain mainly in the front and back side of knee cap. It is accompanied with worsening of pain while arising from an elongated sitting posture, climbing upstairs, wearing heels, kneeling or jumping. (Cluett, 2010) MRI appearance of chondromalacia comprises of signal hetero geneity surrounded by hyaline cartilage, predominantly with T2 weighted MR images, hyaline cartilage covered focal hyperintensity, mainly showing linear or focal abnormalities in the hyaline cartilage and asymmetrical configuration to the hyaline cartilage surface. It is required to use the modifier â€Å"severe† when variations that are greater than one cm in diameter are observed. If high density central defects are present then also the severe modifier need to be used. These defects can be distinguished from usual chondral defects by comparing the centralization of the final lesion that are widely spread and lacks surroundings (Loren, 2008) Full thickness chondral defect is appeared with high signal joint surface lesion represented in black arrow is covered by normal low intense hyaline cartilage on this spin echo T2 weighted image. (Loren, 2008) Osteochondritis dessecans is a medical condition that arises when certain amount of cartilage in a joint connected with a thin b oney layer separates from the rest of the bone. The affected person usually experience server pain, irritation and discomfort near a bone ending position. (Kennedy, no date) OCD is usually seen with larger joints such as the hips, knees and the ankles. The condition is also accompanied by severe rib pain. In association with rib pain, the uneasiness normally occurs in breastbone or in the spine where the ribs get connected. The major cause of OCD is certain type of repetitive injury or