flow void

flow void

1. in MRI, absence of signal from blood whose activated protons leave a bodily area before the magnetization is measured.
See also: signal void.
2. In MRI, any loss of signal caused by combined turbulence and intravoxel dephasing.
References in periodicals archive ?
On dynamic post contrast study (in flexion), we found interiorly shifted dura mater (in 2 cases), prominent epidural flow void (in 2 cases), enhancing epidural mass in lower cervical region (in 3 cases) and congested posterior internal vertebral venous plexus (in 1 case).
As previously reported, Craig-Hallum analyst Matt Hewitt downgraded Lannett to Hold from Buy, stating that the ending of the company's "fruitful long-time partnership" with Jerome Stephens Pharmaceuticals is a "significant disappointment" that creates a noticeable cash flow void and creates a risk that the company's debt gets refinanced at higher interest rates.
Hemangioma or cavernoma often cause confusion in diagnosis especially in early stages, which unlike AVM are well-demarcated and do not have arteriovenous shunts.11 AVMs show flow void signs on MRI due to the rapid flow in the lesions.8 The diagnosis of AVM in the present case was made by contrast enhanced CT and MRI brain and the feeding vessels viz., superficial temporal artery, internal maxillary and middle meningeal arteries were demonstrated by MRI neck angiography.
The axial T1 fat-saturated images showed an absence of the flow void of the foraminal segment of the right vertebral artery.
In the axial (C) and coronal (D) T2W images, the arrows point to the flow void of the vessel.
MRI of the head showed acute and subacute strokes in the brain (Figures 1(c) and 1(d)) and a flow void in the left hemisphere (Figure 1(d)).
A suspicious large flow void within the region of the cavernous segment of the left ICA was confirmed to reflect a probable pseudoaneurysm on postgadolinium imaging and subsequent CT and catheter angiography (Figure 2), which revealed additional dysplastic irregular lobular projections arising from the pseudoaneurysm sac.
Surprisingly, worm-like appearance of flow void signal intensity markedly noted at C1-2 level of the dural sac and extending into C7 level.
Analysis of endoscopic third ventriculostomy patency by MRI: value of different pulse sequences, the sequence parameters, and the imaging planes for investigation of flow void. Childs Nerv Syst.
(1) Efforts to visualise the patency of a third ventriculostomy begin with the detection of a flow void in the floor of the third ventricle on T2-weighted MR images and later confirmation with the use of cine 2-dimensional (2D) phase-contrast (PC) MR images.
Greenberg, microbleeds should be black on [T*.sub.2] -weighted MRI; blooming on [T.sub.2] weighted MRI; devoid of signal hyperintensity on [T.sub.1]-or [T.sub.2]-weighted sequences; round or ovoid rather than linear; at least half surrounded by brain parenchyma; and be distinct from other potential mimics such as iron /calcium deposits, bone, or flow void; and should have a clinical history that excludes traumatic brain injury (Lancet Neurol.
Other tests, such as radionuclide cisternography or magnetic resonance imaging CSF flow void, have predictive values too low or have too few studies to be recommended.