Table 2.

Comparison of imaging characteristics of MSPL and BSPL in the training set

Imaging characteristics	MSPL (n = 95)	BSPL (n = 60)	p value
Baseline ultrasound
Nodule size (cm)	3.7 ± 1.5	3.1 ± 1.6	.02
Location			.52
Head	64 (67.4)	45 (75)
Body or tail	31 (32.6)	15 (25)
Echo			.71
Hypo-/iso-	94 (98.9)	58 (96.7)
Hyper	1 (1.1)	2 (3.3)
MPD dilation (≥ 4 mm)	47 (49.5)	7 (11.7)	< .001
CBD dilation (≥ 10 mm)	21 (22.1)	2 (3.3)	.003
Ill-defined lesion border	89 (93.7)	20 (33.3)	< .001
Irregular lesion shape	89 (93.7)	22 (36.7)	< .001
Adjacent vessel involvement	17 (17.9)	2 (3.3)	.01
Necrotic contents	11 (11.6)	7 (11.7)	.80
Calcification	2 (2.1)	3 (5)	.59
CEUS manifestations
Arterial phase			< .001
Hyperenhancement	16 (16.8)	34 (56.7)
Isoenhancement	7 (7.4)	14 (23.3)
Hypoenhancement	72 (75.8)	10 (16.7)
No enhancement	0 (0)	2 (3.3)
Venous phase			< .001
Hyperenhancement	2 (2.1)	15 (25)
Isoenhancement	2 (2.1)	21 (35)
Hypoenhancement	91 (95.8)	22 (36.7)
No enhancement	0 (0)	2 (2.1)
CEUS enhancement pattern†			< .001
Pattern A	4 (4.2)	38 (63.3)
Pattern B	72 (75.8)	10 (16.7)
Pattern C	19 (20)	12 (20)

Except for nodule size, data are pancreatic nodules and data in parentheses are percentages. Qualitative data are presented as numbers and percentage, quantitative data as mean ± standard deviation. MSPL malignant solid pancreatic lesion, BSPL benign solid pancreatic lesion, MPD main pancreatic duct, CBD common bile duct, CEUS contrast-enhanced ultrasound, AP arterial phase, VP venous phase

†Five CEUS enhancement modes of solid pancreatic lesions were summarised as three patterns: pattern A: hyperenhancement in both the AP and VP, hyper- or isoenhancement in the AP followed by isoenhancement in the VP, or no enhancement through either phase; pattern B: hypoenhancement in both the AP and VP; and pattern C: iso- or hyperenhancement in the AP followed by hypoenhancement in the VP