Cerebrospinal Fluid Signal‐void Sign in Dogs

Abstract

The cerebrospinal fluid signal-void sign is an observable signal loss from cerebrospinal fluid (CSF), especially on T2-weighted magnetic resonance (MR) images. In people, this sign is attributed to rapid CSF flow or turbulence from arterial pulsations and occurs more frequently with reduced intracranial compliance. The purposes of this study were to describe the CSF signal-void sign, document whether a similar sign occurs in dogs and investigate associations between it and other conditions. The sample population consisted of 327 dogs admitted for neurocranium evaluation using a 0.2 T system. Review of the medical records and MR images was performed to characterize the presence and location of a CSF signal-void sign, ventricular size, syringomyelia, and other lesions. A CSF signal-void sign was detected in at least the mesencephalic aqueduct in 59/327 (18.0%) dogs, including some with no morphologic brain abnormality. The majority of these dogs (45/59% or 76%) weighed < 15 kg. In two other dogs, a CSF signal-void sign was detected only in a cervical syrinx. In dogs weighing > 15 kg, a CSF signal-void sign was seen with various conditions. In 137/327 (41.9%) dogs weighing < 15 kg, the presence of a CSF signal-void sign in the aqueduct (45 dogs) was associated with syringomyelia (P = 0.0468) and increased ventricular size (P = 0.0054): syringomyelia also was associated with increased ventricular size (P = 0.0009). In conclusion, a CSF signal-void sign was seen in dogs with various conditions. In small-breed dogs, a CSF signal-void sign in the aqueduct was associated with ventricular enlargement and syringomyelia.

Volume reduction of the jugular foramina in Cavalier King Charles Spaniels with syringomyelia

“…The venous congestion and elevated ICP have also been associated with turbulent flow and jets of CSF as well as with cerebellar herniation [37,38]. This might also play a role as a pathogenetic factor in the development of SM in CKCSs, as has been proposed previously [39]. …”

Mri Characteristics of Fourth Ventricle Arachnoid Diverticula in Five Dogs

“…Syringohydromyelia was defined as dilation of the central canal . A signal void sign was defined as loss of signal, mainly in T2‐weighed pictures, at the emergence of the mesencephalic aqueduct . MRI findings were also subjectively characterized as mild, moderate, or severe.…”

Radiographic markers of clinical outcomes after endoscopic third ventriculostomy with choroid plexus cauterization: cerebrospinal fluid turbulence and choroid plexus visualization

“…7,10 Prior studies have reported higher incidence of CSF flow void signs and signal heterogeneity in patients with ventriculomegaly as compared to individuals with normal sized ventricles. 9,10 In this study, radiographic evidence of CSF turbulence appeared in 55% of patients following ETV/CPC failure as compared to 18% of patients following successful endoscopic treatment, reaching statistical significance ( p = 0.02; Table 2).…”

“…9,10 Signal loss due to elevated CSF flow velocity or turbulence has been observed clinically and reported in both humans and dogs. 7,8 For instance, Sherman and Citrin reported the frequent occurrence of CSF flow-voids or signal dropout within the cerebal aqueduct of Sylvius and 4 th ventricle among MRI studies of adult patients without intra-ventricular abnormalities. 8 The cerebral aqueduct represents a common location for CSF flow voids due to increased velocity of flow from a larger volume (third ventricle) through a region with comparatively smaller cross-sectional area (cerebral aqueduct).…”

“…In simplistic terms, turbulence involves multiple randomly oriented velocity vectors of CSF flow with different signal phases, resulting in a heterogenous pattern of signal loss. 7,9,10 Consequently, turbulent non-laminar flow produces CSF flow voids and signal heterogeneity. 4,9 …”