Cine Mode MRI in Pre- & Post-Operative Evaluation of Hydrocephalus – Life beyond NPH and aqueduct stenosis

Congress:

ECR 2019

Poster Number:

C-2799

Type:

Educational Exhibit

Keywords:

CNS, MR physics, MR, Surgery, Imaging sequences, Chronic obstructive airways disease, Obstruction / Occlusion

Authors:

V. Venugopal¹, S. RAJAN², V. Mahajan³, H. Mahajan ³; ¹New Delhi, DELHI/IN, ² New Delhi/IN, ³New Delhi/IN

DOI:

10.26044/ecr2019/C-2799

DOI-Link:

https://dx.doi.org/10.26044/ecr2019/C-2799

Table 1: Conventional Imaging of Hydrocephalus and Imaging findings to differentiate ...

Fig. 1: Classification of Hydrocephalus

Fig. 5: 35 yrs Male patient with headache. Conventional imaging shows A. Axial T2W...

Fig. 4: 10 year Male. Sagittal PC cine flow images reveal normal flow anterior to the...

Fig. 10: Sagittal phase contrast CSF flow images show turbulent flow within the dilated...

Fig. 14: Classic Imaging findings in DESH variant of Normal Pressure hydrocephalus A....

Learning objectives

1. To learn the relevant pathophysiology of Hydrocephalus. 2. To learn the physics of cine mode (Phase contrast) MRI brain sequences and detail the acquisition protocols, including tips and tricks. 3.To define an approach to interpretation of the Cine Mode (Phase-Contrast) images, as an adjunct to conventional sequences in pre- and post –operative evaluation of Hydrocephalus

Background

Hydrocephalus is usually defined as ventriculomegaly with sulcal effacement and can be classified as communicating,non- communicating or Normal Pressure Hydrocephalus. Communicating Hydrocephalus is implied if the level of the obstruction is distal to the 4th ventricle while non communicating hydrocephalus is implied if the level of obstruction is cranial to the 4th ventricular outflow. Normal Pressure hydrocephalus is a special sub-class of hydrocephalus with disproportionate ventricular dilatation relative to sulcal prominence. All causes of hydrocephalus are typically treated by shunt procedures, with external shunt procedures...

Findings and procedure details

Physics & Technique CSF Flow is pulsatile & is synchronized to cardiac pulsations, with a phase difference between cardiac pulsations and CSF pulsations, resulting in caudad CSF flow during cardiac systole and cephalad CSF flow during cardiac diastole. Typical CSF flow velocities are in the range of 5 to 8 cm/s. In hyperdynamic circulations, velocities can go up to 25 cm/s. Time-resolved 2D phase contrast imaging with velocity encoding uses Phase encoding pulses in opposing directions, sensitized to a velocity (called VENC- Velocity Encoding). In...

Conclusion

Proper evaluation ofhydrocephalus on MRI needs a basic understanding of physiology of CSF flow dynamics as well the physics behind the MRI protocols. Correct imaging plan including the protocol parameters and planes of imaging isas important as the knowledge of imaging presentations to avoid misinterpretation and misdiagnosis.

Personal information

References

Black, P. M., Ojemann, R. G. & Tzouras, A. CSF shunts for dementia, incontinence, and gait disturbance. Clin Neurosurg 32, 632–651 (1985). Armonda, R. A., Citrin, C. M., Foley, K. T. & Ellenbogen, R. G. Quantitative cine-mode magnetic resonance imaging of Chiari I malformations: an analysis of cerebrospinal fluid dynamics. Neurosurgery 35, 214–223; discussion 223-224 (1994). Ellenbogen, R. G., Armonda, R. A., Shaw, D. W. & Winn, H. R. Toward a rational treatment of Chiari I malformation and syringomyelia. Neurosurg Focus 8, E6 (2000). Bargalló,...