CT Perfusion in Lacunar Stroke: A Systematic Review

Abstract

Background. The main theory underlying the use of perfusion imaging in acute ischemic stroke is the presence of a hypoperfused volume of the brain downstream of an occluded artery. Indeed, the main purpose of perfusion imaging is to select patients for endovascular treatment. Computed Tomography Perfusion (CTP) is the more used technique because of its wide availability but lacunar infarcts are theoretically outside the purpose of CTP, and limited data are available about CTP performance in acute stroke patients with lacunar stroke. Methods. We performed a systematic review searching in PubMed and EMBASE for CTP and lacunar stroke with a final selection of 14 papers, which were examined for data extraction and, in particular, CTP technical issues and sensitivity, specificity, PPV, and NPV values. Results. A global cohort of 583 patients with lacunar stroke was identified, with a mean age ranging from 59.8 to 72 years and a female percentage ranging from 32 to 53.1%.CTP was performed with different technologies (16 to 320 rows), different post-processing software, and different maps. Sensitivity ranges from 0 to 62.5%, and specificity from 20 to 100%. Conclusions. CTP does not allow to reasonable exclude lacunar infarct if no perfusion deficit is found, but the pathophysiology of lacunar infarct is more complex than previously thought.

Computed tomography perfusion imaging-guided intravenous thrombolysis in acute minor ischemic stroke

“…Although in the present study, we could not detect a significant association of cardioembolic stroke with CTP mismatch, there was a trend toward higher prevalence of cardioembolic stroke in patients with vs. without CTP mismatch. In addition, data concerning the detection of lacunar stroke in CTP are inconsistent, with up to 50% of false negative results reported in CTP studies ( 31 ). Previous evidence indicates a sensitivity of 0 to 62.5% and specificity of 20% to 100% for the detection of lacunar stroke in CTP ( 31 ).…”

“…In addition, data concerning the detection of lacunar stroke in CTP are inconsistent, with up to 50% of false negative results reported in CTP studies ( 31 ). Previous evidence indicates a sensitivity of 0 to 62.5% and specificity of 20% to 100% for the detection of lacunar stroke in CTP ( 31 ). In addition to technical parameters that may attenuate the reliability of CTP for lacunar stroke detection ( 31 ), heterogeneous pathophysiological mechanisms of subcortical infarcts may also account for the limited prognostic utility of CTP in this patient population ( 32 ).…”

Perfusion Status in Lacunar Stroke: A Pathophysiological Issue

“…CT perfusion is more easily accessible than MRI in several settings, but lacunar stroke accounts for most of the 50% rate of false negatives [ 115 , 116 ]. A recent systematic review on the topic of CTP in acute lacunar stroke [ 117 ] showed several sources of heterogeneity in the global performance of this technique. In particular, there are issues related to the technique (scanner features and technological era, rows number, perfusion protocol, vertical coverage, postprocessing software versus visual assessment of the maps) but also issues related to the disease and the patient (size and location of lacunar infarcts, even excluding infratentorial stroke; administration of IVT; etc.).…”

“…Conversely, in the late window, the lack of identification of a perfusion deficit usually does not allow for the performance of IVT. As detailed in the systematic review on CTP in lacunar stroke patients [ 117 ] and in the present review, the pathophysiology of RSSI and technical issues of available techniques may affect the possibility to image the perfusion status of these patients and the best treatment has not been defined. After the acute phase, another matter is the etiology of RSSI, because pure SVD mechanisms are the main causes, but—particularly in larger lesions, where a putative involvement of more than one penetrating artery can be supposed—atherothrombosis of the parent vessel and, less frequently, embolic causes also have to be considered and investigated.…”