Application value analysis of magnetic resonance imaging and computed tomography in the diagnosis of intracranial infection after craniocerebral surgery

Table 1 True positive, false positive, true negative, false negative results

Examination method	True positive (n)	False positive (n)	True negative (n)	False negative (n)
CT	19	7	35	21
MRI	37	2	40	3

CT: Computed tomography; MRI: Magnetic resonance imaging.

Table 2 Comparison of diagnostic sensitivity, specificity, positive predictive value and negative predictive value between magnetic resonance imaging and computed tomography examinations

Examination method	Sensitivity(%)	Specificity (%)	Positive predictive value (%)	Negative predictive value (%)
CT	47.50 (19/40)	83.33 (35/42)	73.08 (19/26)	62.50 (39/56)
MRI	92.50 (37/40)	95.24 (40/42)	94.87 (37/39)	93.02 (40/43)
χ2	48.214	7.414	17.642	26.931
P value	0.001	0.006	0.001	0.001

CT: Computed tomography; MRI: Magnetic resonance imaging.

Table 3 Comparison of coincidence rates among different types of infection and different types of examinations, n (%)

Examination methods	Number of gold standard positive cases	Staphylococcus aureus infection	Staphylococcus epidermidis infection	Staphylococcus hemolyticus infection	Other
CT	40	10 (25.00)	4 (10.00)	4 (10.00)	1 (2.50)
MRI	40	19 (47.50)	8 (20.00)	9 (22.50)	5 (12.50)
χ2	-	10.953	3.922	5.741	7.207
P value	-	0.001	0.048	0.017	0.007

CT: Computed tomography; MRI: Magnetic resonance imaging.

Table 4 Comparison of overall diagnostic coincidence rates between magnetic resonance imaging and computed tomography examinations, n (%)

Examination method	Total number of cases	Missed diagnosis/ misdiagnosis	Diagnostic coincidence rate
CT	82	28 (34.15)	54 (65.85)
MRI	82	5 (6.10)	77 (93.90)
χ2	-	24.473
P value	-	0.001

CT: Computed tomography; MRI: Magnetic resonance imaging.