Core Sequences
-Regardless of the machine, these classics keep the same meaning:
>T1 – anatomy, fat, hemorrhage age
>T2 – edema, pathology
>FLAIR – suppresses CSF, highlights periventricular lesions
>DWI / ADC – acute ischemia detection
Hemorrhage or Ca?
GRE (T2*)
-The traditional workhorse
-Picks up blood and calcium as dark “blooming” foci
SWI (Susceptibility‑Weighted Imaging)
-A more sensitive evolution of GRE
-Detects microbleeds, venous structures, and subtle susceptibility changes
Left or Right-handed systems
Left-handed→ Siemens, Canon
Calcium = dark
Blood = bright
Right-handed→ GE, Philips
Calcium = bright
Blood = dark
*If you ever forget, look for an internal reference area of known calcification
Cranial Nerves
(1) Spin Echo–based 3D
DRIVE / FRFSE / RESTORE
-Clean, stable anatomy
-Great near bone or metal
-Ideal for IACs, CN VII/VIII irritation, and anatomy-focused questions
(2) Gradient Echo–based 3D
b‑FFE / FIESTA / CISS
-Razor-sharp nerve detail
-Best for vascular loops (e.g., trigeminal neuralgia)
-Prone to banding artifacts near the skull base
*Choose based on artifact sensitivity and clinical question
Why Some Scans are Faster (but Look Worse)
-In MRI, speed comes at a price:
>Gradient sequences (2–4 min): Fast, beautiful detail, but artifact-sensitive
>Spin-echo sequences (4–8 min): Slower, but more reliable with fewer “false lesions”
Post-Contrast 3D T1
-Same concept, but ≠ name
>MPRAGE (Siemens)
>BRAVO (GE)
>3D TFE (Philips)
Summary
*GRE is an specific sequence of gradient echo