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 ?
Coronal MRI shows a focal mass like area exhibiting characteristics of a flow void in the upper and central interpolar left kidney (Figure 4).
On imaging with contrast enhanced CT scan of paranasal sinuses, it is seen as soft tissue enhancing mass with or without associated bony destruction and on MRI these lesions have intermediate signal on T1 weighted and heterogeneous signal with areas of flow void on T2 weighted sequences showing intense enhancement post gadolinium.
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.
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.
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.
It may show the absence of flow void in the normal venous channels.
In a normal MR image, the principle of flow void usually is demonstrated.
T2-weighted images show high-signal change involving the white matter with absent flow void in the related cortical vein or dural venous sinus.
Central bronchogenic cyst shows high signal T2 without any contact with pericardium, pericardial cyst shows high signal T2 when it is not in contact with pericardium, Cardiac tumours typically shows signal flow void and epicardial lipomas shows typically high T1 and T2 signal intensity.
6) On MRI, the varix appears as a dilated, serpiginous flow void in the epidural space.
A flow void originating from the right PICA was present on midline sagittal T1-weighted images (Figure 2).