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

Table 1 Imaging features considered in the management of ruptured intracranial aneurysms

	Endovascular therapy	Surgical management
Non-contrast computed tomography	Absence of parenchymal hematoma	Presence of intra-parenchymal hematoma
Aneurysm characters	Posterior circulation aneurysms	Middle cerebral and pericallosal arteries aneurysm
	Small aneurysm neck < 4 mm	Aneurysm diameter > 15 mm Wide neck aneurysm > 4 mm
	Aneurysm diameter < 15 mm	Abnormal configuration
	Unilobar configuration	Aneurysmal sac incorporating arterial branches
	Multiple aneurysms	Presence of intraluminal thrombus
	Calcification located at the aneurysm neck
Perianeurysmal findings	Presence of vasospasm	Vascular variants interfere with endovascular 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.

Table 3 Inter-observer agreement of computed tomography angiography locations of aneurysm

Parent artery	Reader 1	Reader 2
ACOM	73	73
ACA	5	6
RT ICA	20	20
LT ICA	16	16
RT MCA	21	22
LT MCA	20	20
Basilar	8	9
LT PCA	1	1
RT Vertebral	1	1
LT SCA	0	1
K	95%CI	P value
0.97	0.87-1.0	< 0.001
Arterial segment	Reader 1	Reader 2
ACOM- Lt ACA complex	36	36
ACOM- Rt ACA complex	34	34
ACOM proper	3	3
A1	1	1
RT A2	1	1
LT A2	0	1
Azygous A2	2	2
A3	1	1
RT MCA bifurcation	14	14
LT MCA bifurcation	15	15
RT M1	4	4
LT M1	3	3
RT M2	3	3
LT M2	2	2
M4	0	1
RT PCOM	12	12
LT PCOM	9	9
RT ICA Terminus	4	4
LT ICA Terminus	2	2
RT Cavernous ICA	4	4
LT Cavernous ICA	5	5
Basilar tip	4	4
Mid Basilar	2	3
Basilar Perforators	2	2
Rt V4	1	1
LT SCA	0	1
Lt P1	1	1
K	95%CI	P value
0.97	0.87-1.0	< 0.001

ACA: Anterior cerebral artery; RT: Right; ICA: Internal carotid artery; LT: Left; MCA: Middle cerebral artery; PCA: Posterior cerebral artery; SCA: Superior cerebellar artery; PCOM: Posterior communicating artery.

Table 4 Inter-observer agreement of computed tomography angiography measurements of aneurysm

	Size		Dome		Neck		Dome/neck ratio
	Reader 1	Reader 2	Reader 1	Reader 2	Reader 1	Reader 2	Reader 1	Reader 2
Mean	7.4	7.4	3.7	3.6	2.7	2.7	1.3	1.3
Median	6	6	3	3	2.3	2.3	1.2	1.2
SD	5.44	5.47	3.2	3.1	2.1	2.1	0.8	0.8
Minimum	1.8	1.8	1	1	1	1	0.2	0.2
Maximum	40	42	22	22	20	20	4.7	5.6
ICC	0.97		0.97		0.96		0.98
95%CI	(0.96-0.98)		(0.96-0.97)		(0.95-0.97)		(0.97-0.98)

ICC: Interclass correlation.