Evaluation of CSF flow patterns of posterior fossa cystic malformations using CSF flow MR imaging

Abstract

Phase-contrast cine MR imaging for CSF flow evaluation may be a useful adjunct to routine MR imaging in the evaluation of the cystic malformations of the posterior fossa because it can improve the specificity in differentiating such malformations.

Congenital Abnormalities of the Posterior Fossa

“…Mega Cisterna Magna.-Mega cisterna magna is an enlarged cisterna magna (10 mm on midsagittal images) with an intact vermis, a normal fourth ventricle, and, in some patients, an enlarged posterior fossa (Fig 2c) (16,20,21). It represents a truly focal enlargement of the subarachnoid space in the inferior and posterior portions of the posterior fossa.…”

Pediatric MRI Brain: Normal or abnormal, that is the question.

“…If the cystic structure does not communicate with the 4 th ventricle, a diagnosis of mega cisterna magna should be made ( Figure 20). Mega cisterna magna is defined as an enlarged cisterna magna which measures ≥10mm on mid sagittal plane [59, 60,61]. It is postulated that mega cisterna magna is a consequent of delayed fenestration of the Blake pouch while absence of fenestration result in a Blake pouch cyst [62].…”

Cerebrospinal fluid flow imaging by using phase-contrast MR technique

“…Moreover, the discrimination between normal CSF spaces and intracranial cysts may not always be evident with anatomical imaging and this may be clarified with CSF flow studies. There are CSF flow patterns specific to each entity and PC MRI may improve the diagnostic confidence in differentiating communicating and non-communicating arachnoid cysts ( Figure 2) and posterior fossa cystic malformations (Figures 3-6) from each other [1].…”

“…CSF flow MRI can be used to discriminate between communicating hydrocephalus and non-communicating hydrocephalus, to localise the level of obstruction in obstructive hydrocephalus, to determine whether arachnoid cysts communicate with the subarachnoid space, to differentiate between arachnoid cysts and subarachnoid space, to discriminate between syringomyelia and cystic myelomalacia, and to evaluate flow patterns of posterior fossa cystic malformations. This imaging method can also provide significant information in pre-operative evaluation of Chiari 1 malformation and normal pressure hydrocephalus and post-operative follow-up of patients with neuroendoscopic third ventriculostomy (NTV) and ventriculoperitoneal (VP) shunt [1][2][3][4][5][6][7][8][9][10][11]. In this pictorial review, we emphasise phase-contrast (PC) MRI technique, CSF physiology and cerebrospinal space anatomy, congenital and acquired disorders that can alter the cerebrospinal fluid dynamics, and the use of PC MRI in the assessment of various central nervous system (CNS) abnormalities.…”

“…The aims of this pictorial review are to outline the PC MRI technique, CSF physiology and cerebrospinal space anatomy, to describe a group of congenital and acquired disorders that can alter the CSF dynamics, and to assess the use of PC MRI in the assessment of various central nervous system abnormalities. During the last two decades, flow-sensitive MRI techniques have been increasingly applied to quantitatively and qualitatively assess cerebrospinal fluid (CSF) flow dynamics [1]. CSF flow MRI can be used to discriminate between communicating hydrocephalus and non-communicating hydrocephalus, to localise the level of obstruction in obstructive hydrocephalus, to determine whether arachnoid cysts communicate with the subarachnoid space, to differentiate between arachnoid cysts and subarachnoid space, to discriminate between syringomyelia and cystic myelomalacia, and to evaluate flow patterns of posterior fossa cystic malformations.…”