Comparative Diagnostic Evaluation with Contrast-Enhanced Ultrasound, Computed Tomography and Magnetic Resonance Imaging in Patients with Pancreatic Cystic Neoplasms

Figures & data

Table 1 Characteristics of the Enrolled Study Population

Characteristics	No. of Patients (%, n=90)
Median age, years (range; standard deviation)	42.6 (18–71; 13.3)
Sex, no. (%)
Male	24 (26.7)
Female	66 (73.3)
Symptoms, no. (%)
Abdominal pain	10 (11.1)
Abdominal distention	12 (13.3)
Negative symptom	68 (75.6)
Location of cyst, on CEUS, no. (%)
Head	35 (38.9)
Body/tail	52(57.8)
Unspecified	3 (3.3)
Examination, no. (%)
CEUS	90 (100)
MRI	85 (94.4)
CT	69 (76.7)
Cyst size, cm (range; standard deviation)
On CEUS (n=90)	4.6 (1.6–13; 2.5)
On MRI (n=85)	4.1 (1.2–13.5; 2.9)
On CT (n=69)	4.9 (2.3–10.7; 2.1)

Abbreviations: CEUS, contrast-enhanced ultrasound; MRI, magnetic resonance imaging; CT, computed tomography.

Table 2 Sensitivity and Accuracy of CEUS, MRI and CT to Diagnose the PCNs

Variable	Sensitivity for Discriminating PCNs from PCLs (%)	Accuracy for Differentiating the Specific Type of PCN (%)
Examination
CEUS	88.9 (80/90)	64.4 (58/90)
MRI	91.8 (78/85)	70.6 (60/85)
CT	84.1 (58/69)	53.6 (37/69)
P-value
CEUS vs MRI	0.614	0.791
CEUS vs CT	0.479	0.017
MRI vs CT	0.207	0.03

Abbreviations: CEUS, contrast-enhanced ultrasound; MRI, magnetic resonance imaging; CT, computed tomography; PCL, pancreatic cystic lesions; PCN, pancreatic cystic neoplasms.

Figure 1 Diagnosis of pancreatic cystic neoplasms by pathology and different modalities.

Abbreviations: PCL, pancreatic cystic lesion; PCN, pancreatic cystic neoplasm; CEUS, contrast-enhanced ultrasound; CT, computed tomography; MRI, magnetic resonance imaging; SCA, serous cystadenoma; MCA, mucinous cystadenoma; IPMN, intraductal papillary mucinous neoplasm; SPN, solid pseudopapillary neoplasm; NEN, neuroendocrine neoplasm; Ca, cystadenocarcinomas.

Table 3 Comparison of Diagnostic Accuracy of Different Cysts Size and Detection Rates of Nodule, Septa, Duct Dilatation in Pancreatic Cystic Neoplasms by CEUS, MRI and CT

Parameters	Accuracy (%)	P-value
Cysts <3 cm
n = 15		1.000
CEUS	40.0 (6/15)
CT	33.3 (5/15)
n = 22		0.039
CEUS	36.4 (8/22)
MRI	68.2 (15/22)
Cysts ≥3 cm
n = 54		0.041
CEUS	77.8 (42/54)
CT	59.3 (32/54)
n = 63		0.774
CEUS	74.6 (47/63)
MRI	71.4 (45/63)
Septa
n = 69		0.003
CEUS	53.6 (37/69)
CT	29.0 (20/69)
n = 85		0.443
CEUS	54.1(46/85)
MRI	48.2 (41/85)
Nodule
n = 69		0.018
CEUS	24.6 (17/69)
CT	8.7 (6/69)
n = 85		0.033
CEUS	31.8 (27/85)
MRI	17.6 (15/85)
Duct dilatation
n = 69		0.625
CEUS	14.5 (10/69)
CT	11.6 (8/69)
n = 85		1.000
CEUS	14.1 (12/85)
MRI	15.3 (13/85)

Abbreviations: CEUS, contrast-enhanced ultrasound; MRI, magnetic resonance imaging; CT, computed tomography.

Table 4 Characteristics of Serous Cystadenomas and Mucinous Cystadenomas Observed by Contrast-Enhanced Ultrasonography

Parameters	SCAs (%, n=36)	MCAs (%, n=29)	P-value
Location			0.252
Head-unicate	15 (41.7)	11 (37.9)
Body-tail	21 (58.3)	18 (62.1)
Shape
Regular	14 (38.9)	19 (65.5)	0.033
Irregular	22 (61.1)	10 (34.5)
Number of septa
0–2	14 (38.9)	20 (69.0)	0.016
≥2	22 (61.1)	9 (31.0)

Abbreviations: SCA, serous cystadenoma; MCA, mucinous cystadenoma.

Figure 2 A serous cystadenoma diagnosed via pathology in a 42-year-old woman without symptoms. (A) A US image shows an anechoic-hypoechoic lesion with an irregular shape 3.8 cm in diameter in the pancreatic tail. (B) CEUS image clearly depicts the lobulated shape with a thin septum (red arrow) and a small daughter cyst (yellow arrow). (C) Plain CT scan revealed a watery density mass with an unclear internal structure. (D) Contrast-enhanced CT demonstrates lobulated morphology and septum (red arrow). (E) T2-weighted MRI shows a thin intralesional septum (red arrow). (F) Enhanced MRI reveals the septum (red arrow).

Figure 3 A mucinous cystadenocarcinoma diagnosed via pathology in a 48-year-old woman without symptoms. (A) A US image shows a cystic lesion with a hypoechoic attachment (white arrow) 2.5 cm in diameter in the pancreatic head. (B) A CEUS image clearly displays the round margin and a nodule in the cyst (white arrow) with enhancement. (C) T2-weighted MRI confirms presence of lesion and shows a nodule (white arrow) and thin intralesional septa (red arrow). (D) Enhanced MRI reveals the nodule (white arrow). (E) Photograph of pathologic specimen through HE staining reveals a nodule (red circle), cyst wall (yellow arrow), and pancreas parenchyma (green arrow). (F) Malignant tumor cells as shown under high power microscope.