Learning objectives
Fetal Magnetic Resonance Imaging (MRI) is an increasingly available technique for in utero assessment of the fetus in cases where abnormality is suspected on prenatal ultrasound.
Optimal evaluation by ultrasound is limited due to unavoidable factors caused by acoustic shadowing,
oligohydromnios and position of fetus [1].
Although,
Ultrasonography (USG) is the primary modality,
its limitations include observer dependence,
dependent of fetal position and liquor,
difficult to visualize brain abnormalities due to shadowing from the skull bones and is dependent on the built of the mother...
Background
MRI has the advantage of excellent soft tissue contrast,
multiplanar imaging and a large field of view.
Knowledge about the normal fetal anatomy is essential to detect abnormalities.
Fetal age (gestational age: GA) is an important factor in the evaluation of fetal anatomy.
Prenatal counseling is extremely useful to make decisions about prenatal therapies,
postnatal therapies or termination of pregnancy.
Findings and procedure details
MRI helps in better tissue characterization with the aid of multiple parameters of the T1 and T2 weighted sequences.
There is inherent contrast between soft tissue and fluid filled structures.
Fetal as well as maternal anatomy can be accurately evaluated.
Single-shot fast spin-echo (SSFSE) T2-weighted imaging or half-Fourier single shot turbo spin-echo (HASTE) are commonly used sequences.
The spatial resolution of T1 weighted sequence improves with gestational age.
Gradient echo sequences (EPI) and true fast imaging with steady state precession (FISP) are better for detecting...
Conclusion
Prenatal MRI plays a vital role to assist the family and clinicians in determining the prognosis and guide therapy.
Fetal MRI contributes to surgical planning and postoperative evaluation.
Additionally,
it is a useful tool for research studies of both normal and abnormal fetuses including fetal development.
References
1] Saleem SN.Fetal MRI: an approach to practice: a review.J Adv Res2014;5:507–23.
2] Levine D,
Barnes P,
Sher S,
et al.
Fetal fast MR imaging: reproducibility,
technical quality,
and conspicuity of anatomy. Radiology 1998; 206:549-554
3] Coakley FV,
Glenn OA,
Qayyum A,
et al (2004) Fetal MRI: a developing technique for the developing patient.
AJR 182:243–252
5] GarelC.Imaging the fetus: when does MRI really help?.Pediatr Radiol2008;38(3suppl 3):S467–S470.
4] Pascual-Castroviejo I,
Roche MC,
Martinez Bermejo A,
Arcas J,
Garcia Garcia Blazquez M.
Primary intracranial arachnoidal cysts:...