Aneurysm - CT
Aneurysm - CT
Search Pattern Assist ?Exam
Purpose
2. Detect combinations of SAH and local parenchymal hematoma to suggest sentinel aneurysm hemorrhage.
3. Detection of saccular ("true") aneurysms and recognize their complexities (daughter aneurysm, incorporation of parent artery, local dissection, wide neck relative to fundal width, associated underlying anomalies like fenestrations).
4. Detection inflammatory, mycotic, idiopathic giant aneurysm, giant thrombosed aneurysms.
5. Detection of multiple aneurysms and which is the likely bleeding site.
6. Detection of atherosclerotic sacculo-fusiform aneurysms.
7. Detection of exaggerated arteriosclerotic dolichoectasia.
8. Detection of acute hydrocephalus includes: rapidly progressive ventricular enlargement, plus features of raised CSF pressure: transependymal fluid accumulation, effacement of sulci and cisterns, optic hydrops and eventually downward incisural and tonsillar herniation. The hydrocephalus can be related to either an internal or an external CSF resorption block. Ventriculomegaly (in general) grading scale is 1 (NL for age) to 4 (gross vent enlargement)/4. In other words, Grade 1.1/4 is the very first detection of lateral ventricular enlargement. Grade 4/4 is massive ventriculomegaly with virtually no remaining brain. Everything else is in between. Ex vacuo ventriculomegaly is not under pressure and can be any grade. In acute hydrocephalus ventriculomegaly can only reach 2/4 before fatal brain herniation occurs. Therefore, the ventriculomegaly in hydrocephalus can only go from 1.1/4 to 2/4. In between are 10% interval, i.e. 1.1/4 1.2/4, 1.3/4 and so on up to 2/4. Concurrently, there will be other features of rising CSF pressure: transependymal fluid accumulation, tight ependymal margins, papiiledema, exaggerated CSF pulsations, and finally brain herniation at grade 2/4. In terms hydrocephalus acuity rating Grade 1.1 to grade 1.3/4 represent early or mild hydrocephalus; grades 1.4-to 1.6 are moderate hydrocephalus, grade 1.7 to 1.8 are serious hydrocephalus and grades 1.8 to 2 represent critical (impending herniation) hydrocephalus. If ventriculomegaly reaches exceeds grade 2/4 then the hydrocephalus is more likely subacute or chronic compensated hydrocephalus (which has slowly progressing ventricular enlargement) or may have stabilized (arrested hydrocephalus). Ex vacuo (brain loss) conditions can be any grade but lacks any of the features of raised intracranial pressure; ex vacuo ventricular enlargement should NOT be described as hydrocephalus.
9. Format for saccular aneurysm dictation: There is evidence of a [location] saccular aneurysm; the aneurysm points [direction]. The apex to base distance measures (?) mm’s. The cross-sectional fundal width measures (?) mm’s, consistent with a [small (<7 mm), large (8-15 mms), giant (>15 mms)] aneurysm. The cross-sectional neck width measures (?) mm’s. The aspect ratio (i.e. fundal width/neck width) is [< 1.6 or >1.6] [this indicates whether the neck is too wide to hold the coils].The aneurysm dome (height) to neck ratio is > or < 1.6 [this ratio indicates whether the aneurysm fundus is wide enough for the coils to fold appropriately to stay in place] . The two aspect ratios are such that balloon or stent assisted coiling ( is or is not likely) to be required during coiling. [Note-include if relevant: Elongated aneurysm (i.e. dome to neck ratios >> 2.0) have a higher risk of rupture. Saccular aneurysm complexities: There is [no] calcification in the aneurysm wall or neck wall. There is [no] evidence of a daughter aneurysm arising off the fundus. The aneurysm neck [does or does not] incorporate part of the parent (?) artery. There is [no] evidence of co morbid fenestration of other anomaly in the region of the aneurysm. There is [no] evidence of proximal [?minimal, moderate, advanced] vasospasm. There is [no] evidence of significant distal vasospasm; [if positive there is (persistent flow, limited Q but with retrograde collateral, collapse of distal Q without appreciable collateral]. There is [no] thrombus within the aneurysm. CT [does or does not ] demonstrate Fisher grade III (focal hyperdense clot) adjacent to the aneurysm.
Findings
Initial CT findings
There is evidence of acute subarachnoid blood in a location consistent with possible aneurysm hemorrhage. [Yes/No]
There is evidence of concurrent intra ventricular bleeding. [Yes/No]
There is evidence of concurrent parenchymal and SAH suggesting sentinel aneurysm bleed. [Yes/No]
There is evidence of either non localizing diffuse SAH or only trace amount of blood in occipital horns, posterior intrasylvian sulci, or the interpeduncular fossa. [Yes/No]
There is evidence of intercurrent hydrocephalus related to the SAH. [Yes/No]
There is evidence of SAH in relationship to cortical veins or dural sinuses consistent with venous thrombosis. [Yes/No]
There is evidence of SAH near falx (possibly post traumatic in origin). [Yes/No]
There is evidence of vertex sulcal blood (possibly reversible vasoconstrictive vasc disorders or vasculitis or coagulopathy source). [Yes/No]
There is evidence of concurrent focal blood and cytogenic edema consistent with a intercurrent hemorrhagic stroke source. [Yes/No]
There is evidence of thrombosed pial artery/vein simulating acute SAH. [Yes/No]
There is evidence of thrombosed vascular malformation simulating acute CNS bleed. [Yes/No]
There is evidence of pial calcification simulating SAH. [Yes/No]
There is evidence of hemorrhagic met or other tumor as the source for SAH. [Yes/No]
There is evidence of multicentric bleeding sites consistent with coagulopathy as cause for bleeding. [Yes/No]
There is evidence of mass effected (and possible herniation) produced by hemorrhage, tissue edema, or hydrocephalus. [Yes/No]
There is evidence of a giant aneurysm or sacculo-fusiform atherosclerotic aneurysm or arteriosclerotic dolichoectasia possibly with calcification in its wall. [Yes/No]
Other abnormalities [Yes/No]
