Lymphoma And Residual Tumour


The MRI signal characteristics of untreated lymphomas are different from those of treated lymphomas. Untreated lymphomatous tissue has high signal intensity, whereas a homogeneous, hypointense pattern is characteristic of inactive residual fibrotic masses in patients receiving successful therapy for lymphoma. A heterogeneous pattern with mixed hypointensity and hyperintensity is often seen in untreated nodular sclerosing Hodgkin disease. A heterogeneous pattern with mixed areas of low and high signal intensity on T1- and T2-weighted images is seen in lesions containing mixed fat (high signal intensity) and fibrous tissue (low signal intensity). This pattern is seen after treatment of patients with sterilized tumors. (Positron emission tomography [PET] CT may play a role in assessing for residual lymphoma.) [3, 4, 10, 5, 6, 11] 

Degree of confidence

With MRI of the thorax, motion artifacts may occur. Breathing motion and pulsation of the heart and great vessels can markedly degrade image quality. Hence, in general, fast imaging sequences and artifact reduction techniques must be used for MRI of the mediastinum and chest.
MRI provides information similar to that provided by CT scanning in the evaluation of thymomas. MRI is particularly useful when an intravenous contrast agent cannot be administered for use with CT because the patient is allergic to the agent.

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