Contrast-enhanced ultrasonography in peripheral lung consolidations: What’s its actual role?

Table 1 Contrast-enhanced ultrasonography parameters

	TE		EE		PE	TW		EW
Enhancement present	Early (0-1 s with respect to normal lung)	Late (≥ 2 s later than normal lung)	Marked	Moderate	Homogeneous	-	-	-	-	-
Enhancement absent	Stop assessing CEUS parameters					-	-	-	-	-
Wash-out						Early ( < 60 s)	Late (≥ 60 s)	Marked	Mild	Absent

TE: Time to enhancement; EE: Extent of enhancement; PE: Pattern of enhancement; TW: Time to wash-out; EW: Extent of wash-out; CEUS: Contrast-enhanced ultrasonography.

Table 2 Final diagnoses

Non-neoplastic lesions	n	Neoplastic lesions				Lost at follow-up (n)
		Primary tumors	n	Metastatic tumors (origin)	n
Slow resolution pneumonia	19	Adenocarcinoma	18	Colon	5	5
BOOP	5	Squamous carcinoma	5	Stomach	2
Abscess	4	Small-cell lung cancer	3	Testis (seminoma)	2
Pulmonary infarction	3	Indifferentiate carcinoma	6	Liver (HCC)	1
Organized pleural effusion	4	Sarcomatoid carcinoma	2	Breast	1
Post-surgical fibrosis	4	Mesothelioma	2	Indeterminate	2
Obstruction atelectasys	2	Schwannoma	2
Fibrotic plaque of the pleura	1	Plasmacytoma	1
		Lymphoma	1
			40		13
Total	42	53				5

BOOP: Bronchiolitis obliterans organizing pneumonia; HCC: Hepatocellular carcinoma.

Table 3 Enhancement and wash-out findings in non-neoplastic and neoplastic lesions n (%)

	Enhancement								Wash-out
	Early	Delayed	Absent	Marked	Moderate	Homogeneous	Inhomogeneous	Marked	Mild	Absent	Early	Late
Non-neoplastic lesions	28/42	2/42	12/42	25/30	5/30	18/30	12/30	0/30	11/30	19/30	0/30	11/30
	(66.7)	(4.8)	(28.6)	(83.3)	(16.7)	(60)	(40)	(0)	(36.7)	(63.3)	(0)	(36.7)
Neoplastic lesions	3/53	50/53	0/53	29/53	24/53	6/53	47/53	16/53	36/53	1/53	26/53	26/53
	(5.7)	(94.3)	(0)	(54.7)	(4.3)	(11.3)	(88.7)	(30.2)	(67.9)	(1.9)	(49)	(49)

Table 4 Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio of enhnacement and wash-out parameters

		Sensitivity	Specificity	PPV	NPV	PLR	NLR
		95%CI	95%CI	95%CI	95%CI	95%CI	95%CI
	Present	100	28.6	63.9	100	1.4	0
		100-100	14.9-42.2	53.5-74.2	100-100	1.21-1.59	--
	Early	5.7	6.7	9.7	3.8	0.06	14.15
		-0.719	-17.9	-20.8	-10.5	-2.24	12.8-15.5
	Delayed	94.3	95.2	96.2	93	19.81	0.06
Enhancement		88.1-100.6	88.8-101.7	90.9-101	85.4-100.6	18.4-21.2	-2.2
	Marked	54.7	16.7	53.7	17.2	0.66	2.72
		41.3-68.1	3.3-30	40.4-67	3.5-31	0.36-0.95	1.86-3.57
	Moderate	45.3	83.3	82.8	46.3	2.72	0.66
		31.9-58.7	70-96.7	69-96.5	33-59.6	1.86-3.57	0.36-0.95
	Homogeneous	11.3	40	25	20.3	0.19	2.22
		2.8-19.9	22.5-57.5	7.7-42.3	10.1-30.6	-1.62	1.77-2.67
	Inhomogeneous	88.7	60	79.7	75	2.22	0.19
		80.1-97.2	42.5-77.5	69.4-89.9	57.7-92.3	1.77-2.67	-1.62
	Marked	30.8	100	100	23.4	--	0.69
		18.2-43.3	100-100	100-100	11.3-35.5		0.5-0.87
Wash-out	Mild	69.2	0	76.6	0	0.69	--
		56.7-81.8		64.5-88.7		0.5-0.87
	Absent	98.1	63.3	82.5	95	2.68	0.03
		94.5-101.8	46.1-80.6	73.2-91.9	85-104.6	2.2-3.15	-3.92
	Early	50	100	100	29.7	--	0.5
		36.4-63.6	100-100	100-100	15-44.5		0.23-0.77
	Late	50	0	70.3	0	0.5	--
		36.4-63.6		55.5-85		0.23-0.8

PPV: Positive predictive value; NPV: Negative predictive value; PLR: Positive likelihood ratio; NLR: Negative likelihood ratio.

Table 5 Arbitrary score based on the ratio between the positive predictive value calculated for each contrast-enhanced ultrasonography parameter

		PPV	Score
Enhancement	Absent	63.9	0
	Early	9.7	1
	Delayed	96.2	9.9
	Marked	53.7	1
	Moderate	82.8	1.5
	Homogeneous	25	1
	Inhomogeneous	79.7	3.2
Wash-out	Marked	100	1.3
	Mild	76.7	1
	Absent	69.3	0
	Early	100	1.4
	Late	70.3	1

Absent enhancement or wash-out = 0; lower positive predictive value (PPV) = 1.