Interobserver reliability of computed tomography angiography in the assessment of ruptured intracranial aneurysm and impact on patient management

Table 2 Inter-observer agreement of computed tomography and computed tomography angiography features of aneurysm

Signs		Reader 1	Reader 2	K	95% CI	P value	Agreement, %
NCCT findings
SAH Fisher scale		3.47 ± 0.6	3.33 ± 0.4	0.84	0.78-0.85	< 0.001	89.50
Hydrocephalus (HCP)	Negative (N)	93	95	0.91	0.85-0.97	< 0.001	95.90
	Positive (p)	53	51
Intraparenchymal hematoma (IPH)	Negative (N)	105	105	1	1.0-1.0	< 0.001	100.00
	Positive (p)	41	41
Aneurysm features
Number	Total	166	169	0.95	0.89-1.0	< 0.001	98.80
	Single	126	127
	Multiple	40	42
Size	Small	55	57	0.89	0.83-0.96	< 0.001	94.70
	Medium	101	102
	Large	5	5
	Giant	5	5
Site	Anterior	156	157	0.94	0.83-1.0	< 0.001	99.40
	Posterior	10	12
Shape	Saccular	160	162	0.92	0.76-1.0	< 0.001	99.40
	Fusiform	4	4
	Serpentine	2	2
	Blister	0	1
Margin	Sharp	71	75	0.95	0.90-0.99	< 0.001	97.60
	Lobulated	95	94
Thrombus		6	9	0.82	0.65-0.99	< 0.001	97.60
Calcification		9	9	1	1.0-1.0	< 0.001	100.00
Branch incorporation		50	55	0.9	0.83-0.97	< 0.001	95.90
Orientation				0.95	0.91-0.97	< 0.001	96.50
Perianeurysmal findings
Vasospasm		21	25	0.9	0.81-0.99	< 0.001	97.60
Perianeurysmal cyst		1	1	1	1.0-1.0	< 0.001	100.0
Other vascular lesions		2	4	0.82	0.59-1.0	< 0.001	98.80
Bony relations		23	26	0.88	0.78-0.98	< 0.001	97.00
Bone fracture		1	1
Vascular variant		84	88	0.89	0.83-0.96	< 0.001	94.90
Overall agreement				0.95	0.94-0.96	< 0.001	97.80

NCCT: Non-contrast computed tomography; SAH: Subarachnoid hemorrhage; IPH: Intraparenchymal hematoma.