T1
T1 fat saturatedT1 POST I.V.CONTRASTT1 fat saturated post contrastT2T2 fat saturatedproton density(pdproton density(PD) fat saturatedSTIRFLAIRTrue FISPTrue FISP Fat SaturatedTrue FISP Dual ExcitationVolume Interpolated GREVolume Interpolated GRE  Post ContrastVolume Interpolated GRE fat satVolume Interpolated GRE fat sat Post ContrastSpoiled Gradient EchoSpoiled Gradient Echo Post ContrastSpoiled Gradient Echo fat satSpoiled Gradient Echo fat sat Post ContrastSingle-Shot TSE Ultrafast Gradient Echo 3DTime Of Flight (TOF)Phase Contrast (PC)3D TSE with Variable Flip AngleDiffusion-Weighted ImagingDouble Echo Steady StateMulti-Echo Data Image CombinationContrast Bolus Timing Visualization

BRAIN

The inversion recovery sequences are spin echo sequences with a 180° preparation pulse to flip the longitudinal magnetization into the opposite direction (i.e. spins are flipped to the 180° position). Transverse magnetization remains equal to zero therefore we do not receive any an MR signal. During the recovery, the negative longitudinal magnetization decays to zero and then begins to rise. Because transverse magnetization is not possible, no signal is measured. To generate an MR signal, the longitudinal magnetization is then converted to transverse magnetization through the application of a 90° pulse. The interval between the 180° pulse and the 90° stimulation pulse is known as inversion time (TI).  As the spins relax back to their equilibrium configuration the signal for each spin group will evolve from a negative signal which is zero (null point) to a positive signal. This rate is determined by the T1 of the spin group. Since at 1.5 T, T1  fat= 260 ms and for most other tissues T1 > 500 ms. There fore the null point for the fat signal will occur sooner than the other tissues. Therefore an inversion recovery sequence with a short inversion time (TI) of 130-150 is used for fat suppression.

FLAIR

MRI image appearance

The easiest way to identify STIR images is to look for fat and fluid filled space in the body (e.g. Cerebrospinal fluid in the brain ventricles and spinal canal, free fluid in the abdomen, fluid in the gall bladder and common bile duct, synovial fluid in joints, fluid in the urinary tract and urinary bladder, oedema or any other pathological fluid collection in the body). Fluids normally appear bright and fat appear very dark in a STIR image.

Tissues and their STIR appearance

Muscles: - darker than fat signal
White matter - darker than gray
Bone marrow: - dark
Moving blood- dark
Gray matter - gray
Fluids – very bright
Bone - dark
Fat – dark
Air - dark

Pathological appearance

Pathological processes normally increase the water content in tissues. Due to the added water component this results in a signal increase on STIR images. Consequently pathological processes are usually bright on STIR images.

Use

Very useful for brachial and lumbar plexus imaging
Very useful for anterior neck orbits and face imaging
Very useful for any musculoskeletal imaging
Very useful for extremity imaging
Very useful for spine imaging
Useful for abdominal imaging (respiratory gated STIR)
Useful for chest imaging  (respiratory gated STIR)

 

STIR axial sequence used in face imaging

STIR coronal sequence used in orbits imaging

STIR coronal sequence used in neck imaging

STIR sagittal sequence used in C spine imaging

STIR sagittal sequence used in b plexus imaging

STIR coronal sequence used in sternum  imaging

STIR axial sequence used in chest  imaging

STIR axial sequence used in breast imaging

STIR coronal sequence used in abdominal   imaging

STIR sagittal sequence used in L spine imaging

STIR  axial sequence used in L plexus imaging

STIR coronal sequence used in shoulder imaging

STIR coronal sequence used in elbow imaging

STIR coronal sequence used in wrist imaging

STIR coronal sequence used in hips imaging

STIR coronal sequence used in thigh imaging

STIR sagittal sequence used in knee imaging

STIR coronal sequence used in lower legs imaging

STIR sagittal sequence used in ankle imaging

STIR coronal sequence used in foot imaging

BRAIN