Evolution of incidental branch-duct intraductal papillary mucinous neoplasms of the pancreas: A study with magnetic resonance imaging cholangiopancreatography

Table 1 Acquisition parameters of the magnetic resonance cholangiography sequences acquired in the study

	1.5T (1)		1.5T (2)		3.0T
	2D	3D	2D	3D	2D	3D
Sequence	HASTE	TSE	HASTE	TSE	SS-FSE	FSE
Type of acquisition	Breath hold	Navigator gated	Breath hold	Navigator gated	Breath hold	Respiratory triggered
TR (ms)	4000	2500	4500	2500	9449	1661.5
TE (ms)	735	685	725	700	740	401.2
FOV (mm × mm)	300 × 300	380 × 380	250 × 250	380 × 380	300 × 300	300 × 300
Matrix (pixel × pixel)	307 × 384	357 × 384	269 × 384	353 × 384	256 × 320	200 × 200
Number of slices	1 × 8	72	1 × 8	72	1 x 6	107
Slice thickness (mm)	40-50	1	50	1	40-50	0.75
Number of excitations	1	2	1	1.5	1	1
Acquisition time	4.5 s × 8	3 min 4 s (nominal)	4.5 s × 8	5 min 1 s (nominal)	9.3 s × 6	4 min 54 s (nominal)

Table 2 Overall view of imaging evolution of incidental branch-duct intraductal papillary mucinous neoplasms cysts

Pattern of imaging evolution over the follow-up	Number of patients involved, n (95%CI)	Total number of cysts involved/per-patient mean number of cysts involved	Mean time of first change/mean time of last change1 (mo)	Median time of first change/median time of last change1 (mo), n (95%CI)	Mean size on baseline MRCP/Mean size at the end of the follow-up (mm)
Increase in size occurring in ≥ 1 examination	14/72	17/1.2	34.2 ± 27.2/38.6 ± 29.6	23.5 (5-79)/25.5 (5-92)	8.4 ± 5.7/13.5 ± 6.9
	19.4% (11.4-30.8)
Increase in size in ≥ 1 examination followed or alternating with a decrease in size and/or number in ≥ 1 examination	5/72	8/1.6	21.0 ± 7.4/53.6 ± 23.0	21 (12-32)/48 (23-85)	8.4 ± 3.2/13.6 ± 6.1
	6.9% (2.6-16.1)
Decrease in size occurring in ≥ 1 examination	4/72	6/1.5	15.5 ± 16.8/17.7 ± 16.9	9 (4-40)/13.5 /(4-40)	14.7 ± 7.6/10.5 ± 9.1
	5.6% (1.8-14.3)
Disappearance	2/72	2/1.0	20.0 ± 11.3/20.0 ± 11.3	20 (12-28)/20 (12-28)	10.0/0
	1.4% (0.1-8.5)
Other2	1/72	6/6.0	5/89	5/89	5.0/7.0
	1.4% (0.1-8.5)
Any type of evolution with development of alert findings	6/72	8/1.3	34.5 ± 19.9/42.1 ± 19.4	34 (15-63)/45.5 (13-71)	11.3 ± 6.4/15.8 ± 6.1
	8.3% (3.4-17.9)
Total	32/72	47/1.4	28.1 ± 22.1/39.4 ± 26.9	22.5 (4-79)/32 (4-92)	9.7 ± 5.7/12.5 ± 7.3
	44.4% (32.9-56.6)

¹In the case of more than one change in cysts aspects during the follow-up;

²See the text for details.

Table 3 Overall view of alert findings occurrence in branch-duct intraductal papillary mucinous neoplasms cysts

Patient/sex/age on baseline MRCP	Type and timing of alert finding occurrence	Type and timing of associated imaging evolution	Final diagnosis	Standard of reference	Notes
1/female/58 yr	Non-enhancing small filling defect at 48 mo in an 8 mm cyst, increased from previous control	The same cyst showed initial increase in size (from 5 mm to 8 mm) at 12 mo, followed by decrease (from 8 mm to 5 mm) at 18 mo	Mucin plug; no dysplasia or invasive cancer	EUS with FNA: mucin plug, negative cytology	-
2/male/59 yr	Thickened/nodular septa at 15 mo	Minimal increase of two cysts at 6 mo	No dysplasia or invasive cancer	EUS: negative examination	No further evolution over the whole follow-up (24 mo). Patient died for alcoholic liver cirrhosis
3/female/68 yr	Non-enhancing filling defect at 43 mo	Disappearance of a 9 mm cyst at 33 mo	Mucin plug; no dysplasia or invasive cancer	EUS with FNA: negative cytology	-
4/female/55 yr	Thickened/nodular septa at 63 and then 71 mo	Increase in size of the same cyst from 10 mm to 15 mm at 9 mo	Low-grade dysplasia bd-IPMN	EUS with FNA: low grade dysplasia bd-IPMN, negative CEA and CA 19.9	Non further evolution over the whole follow-up (99 mo)
5/female/60 yr	Dilation of the main pancreatic duct (head, caliber 9 mm) and mural filling defects in the larger cyst (15 mm) at 25 mo	No other evolution observed	Evolution from bd-IPMN to mixed-type IPMN	EUS with FNA (repeated 3 times): negative cytology, elevated CEA, CA 19.9 and amylase. No vascularization of filling defects on Color Doppler exam	Liver-transplanted patient (alcoholic cirrhosis) in whom pancreatic surgery was unfeasible. No further evolution over the whole follow up period (92 mo)
6/female/72 yr	Increase in size of one cyst from 20 mm to 30 mm at 13 mo	Increase in size of the same cyst from 16 mm to 20 mm at 9 mo	No dysplasia or invasive cancer	Histological examination after surgical resection of the cyst	Occurrence of the alert finding preceded by negative EUS
					No further evolution over the subsequent follow-up (39 mo)

bd-IPMN: Branch-duct intraductal papillary mucinous neoplasms.

Table 4 Results of the Cox proportional hazard analysis

Clinical or imaging feature	Imaging evolution			Alert findings
	HR	P value	95%CI	HR	P value	95%CI
Sex	0.78	0.569	0.33-1.81	0.60	0.644	0.69-5.19
Age	0.98	0.488	0.95-1.02	1.00	0.967	0.92-1.08
Previous cholecistectomy	0.89	0.794	0.40-2.00	-1
Diabetes mellitus (type 2)	0.92	0.873	0.34-2.44	2.39	0.316	0.43-13.14
Autoimmune systemic disease	0.58	0.218	0.25-1.36	0.51	0.543	0.59-4.39
Alcoholic liver cirrhosis	1.88	0.143	0.80-4.40	2.49	0.295	0.45-13.75
History of extrapancreatic neoplasia	1.79	0.109	0.87-3.68	0.70	0.694	0.12-3.93
Cysts size > 10 mm on baseline MRCP	2.13	0.055	0.98-4.64	4.02	0.205	0.46-34.70
Number of cysts on baseline MRCP	1.42	0.590	0.70-1.96	1.26	0.680	0.40-3.95

¹No patients showing the outcome. MRCP: Magnetic resonance cholangiopancreatography.