Assessment of Explicitly Stated Interval Change on Noncontrast Head CT Radiology Reports

Article Figures & Data

Table 1:

Categorization of radiology report findings

Finding	Elaboration
Hemorrhage	Intraparenchymal, intraventricular, subdural, subarachnoid, extra-axial hemorrhages/suspicious collections
Infarct/ischemia	Transcortical, ischemia, encephalomalacia
Intracranial mass	Known and unknown diagnosis; including intraparenchymal, sellar, pineal, and so forth
Mass effect	Herniation, midline shift, diffuse edema, sulcal effacement, ventricular effacement
Microvascular	Chronic ischemic microvascular white matter changes, lacunar infarctions
Pneumocephalus	Intraparenchymal, extra-axial, intraventricular
Postprocedural	Craniotomy, craniectomy, ventricular catheters/drains, drains, cataract surgery, lines
Sinus	Acute or chronic paranasal or mastoid disease
Soft-tissue/osseous	Any abnormalities pertaining to these structures
	Exception: postsurgical or related to the sinuses
Ventricular caliber	Hydrocephalus, ex vacuo dilation, ventriculomegaly, prominent
	Exception: effacement caused by mass effect
Volume loss	Cortical atrophy/volume loss, both diffuse and focal
	Exception: ventriculomegaly likely secondary to volume loss
Other	Malformations, abnormal calcification, dural thickening, artifacts, and so forth

Table 2:

Analysis of IC for all findings (n = 979)

	Total (%) (No.)	IC Stated (%) (No.)	χ² Likelihood Ratio	χ² Likelihood Ratio P Value
All findings	100% (979)	67.3% (659)
Interval <31 days	57.5% (563)	74.1% (417)	27.3	<.001^{^a}
Remote finding	42.1% (412)	52.2% (215)	73.9	<.001^{^a}
Generalized statement	14.1% (138)	100% (138)	120.0	<.001^{^a}

Table 3:

Subgroup analysis of IC for finding categorization

Finding	Total (%) (No.)	Interval Change (%) (No.)	χ² Likelihood Ratio	χ² Likelihood Ratio P Value	IC in the Impression (%) (No.)	χ² Likelihood Ratio	χ² Likelihood Ratio P Value
Total	100% (979)	67.3% (659)			42.6% (417)
Hemorrhage	13.0% (127)	95.3% (121)	67.5	<.001^{^a}	67.7% (86)	37.5	<.001^{^a}
Infarct/ischemia	7.0% (69)	76.8% (53)	3.2	.07	42.0% (29)	0.01	.9
Intracranial mass	1.4% (14)	92.9% (13)	5.4	.02^{^a}	57.1% (8)	1.2	.3
Mass effect	9.7% (95)	82.1% (78)	11.5	.001^{^a}	54.7% (52)	6.3	.01^{^a}
Microvascular	16.6% (163)	50.9% (83)	22.8	<.001^{^a}	33.7% (55)	6.4	.01^{^a}
Pneumocephalus	2.9% (28)	71.4% (20)	0.2	.6	46.4% (13)	.2	.7
Postprocedural	14.8% (145)	69.7% (101)	0.4	.5	41.4% (60)	0.1	.7
Sinus	5.8% (57)	43.9% (25)	14.1	<.001^{^a}	26.3% (15)	6.9	.009^{^a}
Soft-tissue/osseous	4.5% (44)	36.4% (16)	18.5	<.001^{^a}	11.4% (5)	21.5	<.001^{^a}
Ventricular caliber	11.6% (114)	72.8% (83)	1.8	.2	50.9% (58)	3.6	.06
Volume loss	8.7% (85)	47.1% (40)	16.3	<.001^{^a}	24.7% (21)	12.9	<.001^{^a}
Other	3.9% (38)	68.4% (26)	0.02	.9	39.5% (15)	0.2	.7