Evaluation of hydrocephalus and other cerebrospinal fluid disorders with MRI: An update

Abstract

MRI is not only beneficial in the diagnosis of cerebrospinal fluid (CSF)-related diseases, but also aids in planning the management and post-surgery follow-up of the patients. With recent advances in MRI systems, there are many newly developed sequences and techniques that rapidly enable evaluation of CSF-related disorders with greater accuracy. For a better assessment of this group of disorders, radiologists should follow the developments closely and should be able to apply them when necessary. In this pictorial review, the role of MRI in the evaluation of hydrocephalus, CSF diversion techniques, and other CSF disorders is illustrated. Teaching Points • The 3D-SPACE seems to be most efficient technique for evaluation of hydrocephalus and ventriculostomy. • In complex cases, PC-MRI, 3D-heavily T2W, and/or CE-MRC images may prevent false results of 3D-SPACE.• MRI is beneficial in the diagnosis and management of hydrocephalus and other CSF-related diseases.

Fig. 1

Heavily T2W 3D-SPACE images of different cases. A normal midline sagittal image is shown for comparison (A). The rest of the images from two different patients with aqueductal stenosis demonstrate enlargement of the ventricles proximal to the obstruction (B, C), enlargement of the third ventricular recesses (B, C), dilated ventricular horns (D–F) and narrowed cortical sulci (MIP image, E), which are typical findings of obstructive hydrocephalus

Fig. 2

Axial FLAIR images of three different patients with hydrocephalus. In the first patient with chronic compensated hydrocephalus, lack of periventricular CSF resorption is seen (A). In the second patient, periventricular hyperintensity consistent with interstitial oedema due to acute decompansated hydrocephalus is demonstrated (arrow, B). Periventricular caps seen in middle aged adults should be differentiated from decompansated hydrocephalus (arrows, C)

Fig. 3

A 46-year-old male patient with a colloid cyst. Axial noncontrast-material enhanced CT image demonstrates hyperdense lesions located in the foramen of Monro sized 2 cm in diameter (arrow, A). The lesion is hypointense in FLAIR images, which indicates the proteinous content of the cyst (arrow, B)

Fig. 4

A 32-year-old female patient with partial aqueductal stenosis, partial empty sella and hydrocephalus. In the sagittal midline 3D-MPRAGE image no increase in third ventricle size and no aqueductal abnormalities are detected (A). However, axial and sagittal PC-MRI images (VENC value: 6 cm/s) demonstrate lack of CSF flow in the aqueduct (B, C). Sagittal 3D-SPACE image demonstrates passage of CSF from basal-prepontine cisterns into the sellar cavity through the diaphragm sella (white arrows, D). This finding explains why hydrocephalus may be associated with empty sella in most of the patients. In the midline sagittal 3D-SPACE image, a narrowed but patent aqueduct is demonstrated (black arrow, E)

Fig. 5

Reformatted coronal (A) and sagittal (B) 3D-MPRAGE images of a 50-year-old male patient with a left cerebello-pontine angle mass and hydrocephalus. Coronal image demonstrates the mass extending out of the internal acoustic canal, decompressing and displacing midbrain structures to the right (arrow, A). In sagittal images it is shown that the mass narrows the fourth ventricle and fourth ventricular outlet (B)

Fig. 6

A 19-year=old female patient with Chiari malformation. Sagittal 3D-MPRAGE (A) and heavily T2W 3D-SPACE (B) images demonstrate cerebellar tonsils extending into the foramen magnum (arrows). 3D-SPACE with variant FA mode image shows the narrow foramen of magendi and foramen magnum (arrow, C). Thinned hypointense signal in these foramina is due to decreased CSF flow (arrow, C). On coronal curved reformatted 3D-MPRAGE (D) and heavily T2W 3D-SPACE (E) images, the patency of the foramina and position of the cerebellar tonsils are better evaluated. The coronal curved reformatted images are obtained by drawing a line on sagittal images as in Fig. 6a (yellow line in A)

Fig. 7

A 62-year-old male with normal pressure hydrocephalus (NPH). Coronal TruFisp image shows enlarged Sylvian cisterns, tight medial parietal sulci and ventriculomegaly (A). Sagittal 3D-SPACE image shows hypointense hyperdynamic CSF flow in the aqueduct and fourth ventricle (B). Axial PC-MRI examination at another centre shows aqueductal ROI placement (broken arrow) for determination of CSF flow (C). Aliasing seen in the flow chart occurred because the VENC value was selected as less than what it should be (VENC: 10 cm/s) (arrow, D). On axial phase images obtained in the PC-MRI examination carried out by selecting a Venc value of 20 cm/s, ROIs on the aqueduct (long arrow) and right occipital lobe (reference ROI, short arrow) are seen (E). Maximum aquaductal CSF flow is calculated as 14.73 cm and stroke volume was calculated as 0.051 ml (F)

Fig. 8

Sagittal 3D-MPRAGE (A) and 3D-SPACE with variant FA mode (B) images of a 41-year-old male patient with aqueduct stenosis and a history of previous ETV. 3D-SPACE image demonstrates that the ETV stoma is patent and CSF flow is clearly seen (arrow, B)

Fig. 9

Reformatted 3D-SPACE images of an 11-year-old girl with aqueduct stenosis and hydrocephalus. Axial images show right temporal-parietal subdural haematoma (arrows in A and B) and iatrogenic callosal injury (asterisk in A). On reformatted sagittal 3D-SPACE images obtained at the level of the shunt catheter, as shown in Fig. 6B, the position and integrity of the catheter and shunt reservoir can be precisely evaluated (arrows in C and D). Distal end of the catheter is shown to be in the corpus callosum (arrow in D). Also, tectal glioma is well demarcated in sagittal images (asterisks in C and D)

Fig. 10

A 34-year-old male patient with intraventicular arachnoid cyst (AC) and hydrocephalus. Sagittal 3D-MPRAGE (A) and axial FLAIR (B) images show AC extending from the right lateral ventricle into the third ventricle (arrows). Sagittal heavily T2W 3D-SPACE image clearly shows the morphology of the AC and third ventricle (C). Sagittal 3D-SPACE with variant FA mode (D) and PC-MRI (E, F) images demonstrate the narrowed aqueduct and decreased aqueductal CSF flow (arrows)

Fig. 11

A 32-year-old male patient with rhinorrhoea and a history of trauma. Electrophoresis study (A) shows no beta-2-transferrin in the blood sample assigned as no. 1, whereas in the columns assigned as 2 (CSF) and 3 (nasal sample) beta-2-transferrin is demonstrated (arrows). Coronal precontrast fat-saturated T1W images cannot precisely locate the level of CSF leakage (B). After intrathecal Gd-DTPA administration, postcontrast T1W image obtained with the same parameters clearly demonstrates the leakage into the left frontal sinus (arrow, C)