Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

Table 1 Summarizing table of number of patient correctly staged with multiplanar reconstruction and axial computed tomography images in comparison of magnetic resonance imaging

Image analysis	TN1	FN2	TP3	FP4	TOT5
CT-axial	30	10	41	10	91
CT-MPR	35	6	45	5	91
MRI	40		51		91

¹TN: True negative. Number of patients in which the MRF was correctly considered not involved with axial and MPR imaging according to MRI;

²FN: False negative. Number of patients in which the MRF was wrongly not considered involved with axial and MPR imaging, but it was with MRI;

³TP: True positive. Number of patients in which the MRF was correctly considered involved with axial and MPR imaging according to MRI;

⁴FP: False positive. Number of patients in which the MRF was wrongly considered involved with axial and MPR imaging, but it wasn’t with MRI;

⁵TOT: Total of patients. CT: Computed tomography; MPR: Multiplanar reconstruction; MRI: Magnetic resonance imaging.

Table 2 Summarizing table of sensitivity, specificity, positive predictive value, negative predicting value and accuracy of axial and multiplanar reconstruction computed tomography images in correctly identify the involvement of the mesorectal fascia in comparison of magnetic resonance imaging

Axial CT images
Sensitivity	Specificity	PPV	NPV	Accuracy
80.40%	75%	80.4%	75%	78%
MPR CT images
Sensitivity	Specificity	PPV	NPV	Accuracy
88%	87.5%	90%	85.36%	88%

CT: Computed tomography; PPV: Positive predictive value; NPV: Negative predicting value; MRF: Mesorectal fascia; MRI: Magnetic resonance imaging.

Table 3 Summarizing table of McNemar test calculation to determine the statistical significant of sensitivity and specificity between axial and multiplanar reconstruction computed tomography images in comparison to magnetic resonance imaging

	Axial- subjects	Axial+ subjects	Total of subjects with MRI+
Sensitivity1 (P = 0.22)
MPR- subjects	5	1	6
MPR+ subjects	5	40	45
Total subjects of MRI+	10	41	51n
	AXIAL- subjects	AXIAL+ subjects	Total of subjects with MRI-
Specificity2 (P = 0.13)
MPR- subjects	29	6	35
MPR+ subject	1	4	5
Total of subjects with MRI-	30	10	40n

McNemar test: 2 × 2 contingency table, which tabulates the outcomes of the two tests (axia CT and MPR images) on a sample of n subjects (respectively 51 who were positive with MRI and 40 who were negative).

¹P = 0.22, two tails, not statistically significant;

²P = 0.13, two tails, not statistically significant. CT: Computed tomography; MRI: Magnetic resonance imaging.

Table 4 Summarizing table of McNemar test calculation to determine the statistical significant of accuracy between axial and multiplanar reconstruction computed tomography images in comparison to magnetic resonance imaging

	Uncorrect subjects staged with AX/MPR CT images	Correct subjects staged with AX/MPR CT images	Total of correct subjects staged with MRI
Accuracy1 (P = 0.02)
Uncorrect subjects staged with MPR/AX	9	2	11
Correct subjects staged with MPR/AX	11	69	80
Total of correct subjects staged with MRI	20	71	91

McNemar test: 2 × 2 contingency table, which tabulates the outcomes of the two tests (axial CT and MPR images) on a sample of n subjects (91 correct staged with MRI).

¹P = 0.02, two tails, statistically significant. MPR: Multiplanar reconstruction; MRI: Magnetic resonance imaging; CT: Computed tomography.