Proton spin-lattice and spin-spin relaxation times have been measured in surgically-removed normal CNS tissues and a variety of @entity5 of the brain. All measurements were made at 20 MHz and 37 degrees C. Between grey and white matter from autopsy @entity1 or @entity235 specimens significant differences in T1 or T2 were observed, with greater differences seen in T1. Such discrimination was reduced in samples obtained from live @entity1313 @entity1 due to lengthening in T1 and T2 of white matter near tumorous lesions. @entity4 white matter showed T1 and T2 values higher than those of @entity62 . Compared to normal CNS tissues, most @entity1313 examined in this study demonstrated elevated T1 and T2 values. Exceptions, however, did exist. No definitive correlation was indicated on a T1 or T2 basis which allowed a distinction to be made between benign and malignant states. Furthermore, considerable variation in relaxation times occurred from @entity5 to @entity5 of the same type, suggesting that within a @entity5 type there are important differences in physiology, biology, and/or pathologic state. Such variation caused partial overlap in relaxation times among certain @entity5 types and hence may limit the capability of magnetic resonance imaging (MR) alone for the diagnosis of specific disease. Nonetheless, this study predicts that on the basis of T1 or T2 differences most @entity1313 are readily detectable by MR via saturation recovery or inversion recovery with appropriate selections of pulse-spacing parameters. In general, @entity5 can be discriminated against white matter better than grey matter and contrast between @entity11 and grey matter is usually superior to that between @entity1653 and grey matter. This work did not consider tissue-associated proton density which should be addressed together with T1 and T2 for a complete treatment of MR contrast.

Magnetic resonance of XXXX : considerations of imaging contrast on the basis of relaxation measurements.

@entity1 :: ('9606', 'Species') :: ['human', 'patients'] @entity1313 :: ('MESH:D001932', 'Disease') :: ['brain-tumor', 'brain tumors'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'tumors'] @entity4 :: ('MESH:D004487', 'Disease') :: ['Edematous'] @entity235 :: ('9615', 'Species') :: ['canine'] @entity11 :: ('MESH:D005910', 'Disease') :: ['glioma'] @entity1653 :: ('MESH:D008579', 'Disease') :: ['meningioma'] @entity62 :: ('MESH:D056784', 'Disease') :: ['autopsy disease-free white matter']
@entity1313 :: (MESH:D001932,Disease) :: ['brain tumors']
