Usman Bashir

Jun 20, 2024 | radiopaedia.org | Usman Bashir |Lachlan McKay

Gibbs artifact, also known as truncation artifact or ringing artifact, is a type of MRI artifact. It refers to a series of lines in the MR image parallel to abrupt and intense changes in the object at this location, such as the CSF-spinal cord and the skull-brain interface. The MR image is reconstructed from k-space which is a finite sampling of the signal subjected to inverse Fourier transform in order to obtain the final image.

May 14, 2024 | radiopaedia.org | Usman Bashir |Ashesh Ishwarlal Ranchod

Radiographic evaluation of anterior cruciate ligament (ACL) reconstruction involves: femoral component a line is drawn along the posterior cortex of the femur a second line is drawn along the roof of the intercondylar notch of the femur (Blumensaat line) the point of intersection of these two lines should be at the inferior portion of the femoral component of the graft the angle measured between a line drawn along the femur diaphysis and the femoral tunnel angle must be ~39°; angles of...

May 11, 2024 | radiopaedia.org | Usman Bashir |Joachim Feger

Echo planar imaging (EPI) is an MRI acquisition methodology with an excellent temporal resolution that is required in specific clinical settings e.g. cardiac imaging. There are single-shot and multi-shot echo-planar sequences.

May 9, 2024 | radiopaedia.org | Usman Bashir |Arlene Campos

Gadolinium-based contrast media (GBCM), gadolinium-based contrast agents (GBCAs), or simply gadolinium contrast agents, are molecular complexes containing the rare earth metal gadolinium, chelated to a carrier ligand. They area type of paramagnetic contrast agent, which are the primary class of MRI contrast media. The intravenous route of administration is the most common.

Apr 20, 2024 | radiopaedia.org | Usman Bashir |Rohit Sharma

k-space is an abstract concept and refers to a data matrix containing the raw MRI data. This data is subjected to mathematical function or formula called a transform to generate the final image. A discrete Fourier or fast Fourier transform 1-3 is generally used, though other transforms such as the Hartley 4 can also work. DiscussionA single slice corresponds to a k-space plane acquired in real-time.