Resources/MRI fundamentals
T1 vs T2 weighting
The fastest tell: look at fluid. CSF is dark on T1-weighted images and bright on T2-weighted images. T1 shows anatomy; T2 shows pathology — because most pathology is wet.
Signal cheat sheet
| Tissue | T1-weighted | T2-weighted |
|---|---|---|
| CSF / fluid | Dark | Bright |
| Fat | Bright | Bright (FSE) to intermediate |
| White matter | Brighter than gray | Darker than gray |
| Gray matter | Intermediate | Brighter than white |
| Edema / most lesions | Dark-ish | Bright |
Why pathology loves T2
Inflammation, edema, many tumors and most acute processes increase local water content. Water has a long T2, so on a long-TR/long-TE image those regions light up against normal tissue. That is why the T2 series is often the first place a reader's eye goes.
Why anatomy loves T1
T1 images have high signal-to-noise from fat and myelin, crisp gray–white differentiation and short scan times — ideal for structure, and the base sequence for contrast-enhanced studies, where gadolinium shortens T1 and makes enhancing tissue bright.
Try it in ScanFlo: Scan the same brain slice T1 (TR 500 / TE 14) and T2 (TR 3000 / TE 100). Put them side by side in the viewer and find the ventricles in each before reading the labels. If you can call the weighting from the CSF alone, the lesson stuck.