MRI Sequences: T1 and T2 Weighted Imaging

Introduction to MRI Sequences

The American College of Radiology recommends T1 weighted images for anatomical detail evaluation, as they provide excellent contrast between different tissues 1
T2 weighted images are useful for characterizing edema, inflammation, and lesion composition, as they show both fat and fluid as hyperintense signals 1

T1 weighted images show fat as hyperintense, cerebrospinal fluid (CSF) and edema as hypointense, making them ideal for detecting hemorrhage 1
The American College of Radiology suggests using T1 weighted images for contrast uptake evaluation, as they provide optimal contrast between enhancing and non-enhancing lesions 1

T2 weighted images show both fat and fluid as hyperintense signals, making them useful for detecting increased water content in pathological processes 1
The American Heart Association recommends using T2 based markers for specific detection of edema in myocardial inflammation 4

T1 weighted sequences are optimal for anatomical detail evaluation, hemorrhage detection, and contrast uptake assessment 1
T2 weighted sequences are ideal for characterizing edema, inflammation, and lesion composition, and are used in myocardial inflammation to detect edema 1, 4
The American College of Cardiology suggests using T2 mapping in acute myocarditis diagnosis, as it provides higher signal-to-noise ratio and better diagnostic confidence than conventional T2 weighted imaging 4, 5

T2-FLAIR and TIRM sequences should not be confused, as they have different effects on fluid and CSF 1
The "blooming effect" can make microhemorrhages appear larger on T2 or T2* sequences than they are histologically 2
It is essential to distinguish between cystic and necrotic lesions in brain metastases, as cystic metastases show thin/smooth ring enhancement, while necrotic lesions show irregularly enhancing walls 3