Are pancreatic IPMN volumes measured on MRI images more reproducible than diameters? An assessment in a large single-institution cohort

Abstract

• MRI measurements by different radiologists can be used for IPMN follow-up. • Both diameter and volume measurements demonstrate excellent interobserver and intraobserver reproducibility. • Manual axial measurements show the highest interobserver reproducibility in determining size. • Axial and coronal volume measurements show similar limits of agreement. • Manual axial measurements show the lowest variability in agreement range.

Branch-duct intraductal papillary mucinous neoplasm (IPMN): Are cyst volumetry and other novel imaging features able to improve malignancy prediction compared to well-established resection criteria?

“…Moreover, the IPMN's segmentation process was performed manually, based on a "by-pen" tracing method on paper that eventually was scanned and digitalized, rendering this method not feasible for routine clinical practice. Our semi-automatic segmentation method is more practical, although not correlated to the grade of dysplasia, and volumetry may potentially be performed with any segmentation tool available in any PACS system in a non-time-consuming fashion as proposed by Pandey P. et al [12]. Furthermore, semi-automatic volumetric segmentation has the important advantage of being independent of the axis manually chosen by the radiologist and has very high intra-and interobserver reproducibility even in smaller lesions [12,17].…”

“…Our semi-automatic segmentation method is more practical, although not correlated to the grade of dysplasia, and volumetry may potentially be performed with any segmentation tool available in any PACS system in a non-time-consuming fashion as proposed by Pandey P. et al [12]. Furthermore, semi-automatic volumetric segmentation has the important advantage of being independent of the axis manually chosen by the radiologist and has very high intra-and interobserver reproducibility even in smaller lesions [12,17]. Thus, it may potentially overcome the issue of nonstandardized manual measurements of cystic diameters, which are affected by intra-and inter-observer variability [17].…”

“…A few studies investigated the role of cystic volume in the morphologic assessment of PCNs [10][11][12]. Since IPMNs are not perfect spheres, the largest diameter might not correctly represent the entire inner surface of the IPMN [11], whose epithelium is affected by varying grade of dysplasia up to invasive carcinoma.…”

Diagnostic accuracy of MRI with MRCP and B-Mode-sonography with elastography of the pancreas in patients with cystic fibrosis: a point-to-point comparison

“…Current studies by Pandey et al and [12] Jeon et al [14] showed reproducible size measurements of pancreas in MRI, however, not in CF patients but in patients with intraductal papillary mucinous neoplasm (IPMN), non hypervascular pancreatic neuroendocrine tumor (PNET) and pancreatic ductal adenocarcinoma (PDAC).…”

“…A 6C1 HD transducer at 1.5 to 6.0 MHz was used for the B-Mode ultrasound and elastography. Diagnosis of pancreatic lipomatosis was made when the pancreas was significantly more echogenic than the adjacent liver parenchyma [12]. The pancreas was measured standardized at the head, body, and tail in concordance to current literature [10, 13].…”