RPS 101 - What's going on in the pancreas?

Author Block: E. G. S. Brandt¹, C. F. Müller¹, A. M. Ewald¹, Y. Wirenfeldt Nielsen¹, H. S. S. Thomsen¹, B. Ibragimov², M. Andersen¹; ¹Herlev/DK, ²Copenhagen N/DK
Purpose: The aim of this study is to investigate the image quality of pancreatic late arterial (LA) and portovenous phase (PV) pancreatic images from Photon-Counting CT (PCCT) scanners in comparison to conventional CT (EID-CT).
Methods or Background: We retrospectively identified 35 patients without suspicion of pancreatic pathology scanned on both EID-CT and PCCT in the period from October 2021 until December 2023. IV contrast was given according to patient weight and both a late arterial phase (LA) and a portovenous phase (PV) was performed. Image quality was rated on a 5-point Likert-scale (from 1=nondiagnostic to 5=optimal). Eleven different pancreatic parameters were scored by four radiology consultants. One reader made quantitative measurements of density and noise.
All data analysis was performed with RStudio, version 2022.07.1. Continuous parameters were compared with a paired t-test and mean image quality ratings with a Wilcoxon signed rank test.
Results or Findings: Image quality was rated significantly higher on PCCT for the pancreatic parenchyma in the LA (3.87 vs 2.77, p<.001), the pancreatic parenchyma in the PV (3.31 vs 2.53, p<.001), pancreatic ducts (2.88 vs 2.62, p<.001), SMA (4.10 vs 2.74, p<.001), celiac axis (4.04 vs 2.70, p<.001) and portal vein (3.29 vs 2.52, p<.001).
Noise levels were significantly lower with PCCT with a mean reduction of 5.8 HU across all parameters. DLP was significantly reduced with a 31.8% reduction (p< 0.01) for the LA and 21.5% (p< 0.01) for the PV.
Conclusion: Image quality was significantly improved for all evaluated pancreatic and peripancreatic structures with PCCT. Additionally, image noise and radiation dose were significantly reduced. The improved image quality with PCCT could potentially lead to improvements in the currently difficult evaluation of pancreatic diseases.
Limitations: No limitations were identified.
Funding for this study: Innovation Fund Denmark, Grant No. 1044-00015B.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the national ethics committee with the number: nvk2215338.

Author Block: A. Licha, C. Touloupas, A. Delpla, A. Pouvelle, M. Zins; Paris/FR
Purpose: Assess inter-observer agreement of pancreatic ductal adenocarcinoma (PDAC) tumor size measurement on CT and MRI, before and after neoadjuvant therapy (NAT)
Methods or Background: We reviewed all patients with a histological diagnosis of PDAC at Paris Saint-Joseph Hospital, between 2010 and 2022, and who underwent CT and MRI, both before and after NAT. Three independent radiologists anonymously evaluated the large axial tumor axis on 2 CT acquisitions and 6 MRI sequences. Inter-observer agreement was assessed by intra-class correlation coefficients (ICCs) and by LOAM graphs (Bland & Altmann extension for multiple observers).
Results or Findings: The final population consisted of 50 patients. On CT exams, inter-observer agreement was excellent before NAT (ICC of 0.83 [0.73;0.90] at arterial phase and 0.84 [0.74;0.90] at portal-venous phase) and decreased but remained good after NAT (ICC of 0.66 [0.52;0.78] at arterial phase and 0.65 [0.51;0.77] at portal-venous phase). On MRI exams, inter-observer agreement was moderate to good before NAT (best sequence being T1 at arterial phase with ICC of 0.67 [0.53;0.79]) and decreased becoming moderate for all sequences after NAT (best sequence being T1 at late phase with ICC of 0.55 [0.37;0.71]).
Conclusion: Inter-observer agreement of PDAC great axe measurement is better on CT than on MRI, and decreases between pre-NAT and post-NAT imaging, both on CT and MRI
These results encourage to keep on performing technically perfect CT scans, without questioning the need for pre-operative hepato-pancreatic MRI in non-metastatic patients.
Limitations: This is a monocentric retrospective study.
Funding for this study: - Inter-observer agreement of tumor size measurement is higher on CT than on MRI, both before and after NAT.

- Inter-observer agreement of tumor size measurement decreases following NAT, both on CT and MRI.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by our organization's Medical Research Ethics Group.

Author Block: B. Zhao, S. Ju; Nanjing/CN
Purpose: To construct an imaging ITH (IITH) through radiomics methodology to effectively reflect the ITH of PDAC and explore its prognostic value.
Methods or Background: This study enrolled 961 patients with pathologically confirmed PDAC who had undergone preoperative contrast-enhanced computed tomography (CT) in two cohorts. Firstly, Tumor regions of interest were automatically segmented in both arterial and venous phase images. Radiomics features from these 2 phasea images were extracted based on PyRadiomics. Highly variable radiomic features with median absolute deviation > 1, were selected to assess the ITH. Similarity Network Fusion (SNF) was employed to identify distinct imaging heterogeneity phenotypes in the discovery cohort (Cohort 1), and the identical criteria were applied to Cohort 2. Kaplan-Meier analysis was utilized to investigate the association between the identified imaging phenotypes and overall survival (OS).
Results or Findings: A total of 961 patients (mean age, 63.1 years ± 9.2 standard deviation; 460 men) from 2 cohorts were enrolled. And 3378 radiomics features were extracted for each patient. In the discovery cohort (Cohort 1, n = 637), 241 highly variable heterogeneity-related features were selected to identify IITH, and 283 patients were classified into a high-IITH subgroup. Patients with high-IITH in the discovery cohort presented significantly poorer OS compared to those with low IITH (median time, 20.6 vs. 37.1 months, P < 0.001). The identical criteria were applied to the validation cohort (Cohort 2, n = 324). Kaplan-Meier analysis also confirmed that patients with high-IITH (n =149) had shorter OS (median time, 16.4 vs. 26.3 months, P < 0.001).
Conclusion: We established a noninvasive radiomics method to evaluate the ITH of PDAC. Furthermore, we demonstrated the prognostic power of IITH.
Limitations: This study requires further multi-omics validation in the future.
Funding for this study: NSFC, No. 82330060, 92059202, 823B2040, 61821002 and 82372024)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: IEC for Clinical Research ofZhongda Hospital, Affliated to Southeast University

Author Block: B. Zhao, S. Ju; Nanjing/CN
Purpose: To develop a radiomics model to predict lymph node metastasis (LNM) in patients with pancreatic ductal adenocarcinoma (PDAC) and assess its value for clinical management.
Methods or Background: Patients with pathologically confirmed PDAC were retrospectively enrolled from four centers and divided into a training (n = 192), validation (n = 82), testing (n = 100), and clinical utilization cohort (n = 163).A radiomics model was constructed based on the arterial phase of computed tomography (CT) for predicting LNM. The areas under the curve (AUCs) were used to compare the performance between the radiomics model and other models. Subsequently, Kaplan-Meier analysis was used to validate the model’s value for prognosis and therapy decisions.
Results or Findings: A total of 437 patients (mean age, 63.1 years ± 9.2 standard deviation; 253 men) were included. The radiomics model demonstrated AUCs of 0.84, 0.82, and 0.78 in the training, validation, and testing cohorts, respectively, superior to other models (all P < 0.05). Besides, LNM predicted by the radiomics model was strongly associated with overall survival (OS) (P < 0.001). Kaplan-Meier analysis also demonstrated that patients with a high risk of LNM had a worse prognosis (all P < 0.05). Furthermore, patients who were dissected with ≥ 15 LNs had a longer OS than those with fewer LNs dissected in the high-risk subgroup predicted by the radiomics model in the clinical utilization cohort (P = 0.002).
Conclusion: The radiomics model demonstrated impressive performance in predicting LNM and prognosis, indicating its potential for. therapy decisions.
Limitations: The model we developed should be validated in a prospective study.
Funding for this study: NSFC, No.
82330060, 92359304, 92059202, 823B2040, 61821002 and 82372024
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: IEC for Clinical Research ofZhongda Hospital, Affliated to Southeast University

Author Block: D. Palumbo,A. Campisi, V. Andreasi, F. Prato, S. Partelli, D. Tamburrino, M. Falconi, F. De Cobelli; Milan/IT
Purpose: Postoperative pancreatic fistula (POPF) and postpancreatectomy hemorrhage (PPH) are major complications following pancreatoduodenectomy (PD). Despite their clinical importance, no tool currently exists to predict their occurrence or severity. This study aims to identify radiological characteristics that can aid in the early prediction and stratification of POPF and PPH.
Methods or Background: We retrospectively reviewed 399 patients who underwent PD at San Raffaele Hospital between January 2015 and December 2021. Patients included had at least one contrast-enhanced computed tomography (CE-CT) scan within 14 days post-surgery. Several radiological features were systematically assessed, including pancreaticojejunostomy (PJ) dehiscence, PJ defects, fluid collections, perianastomotic air bubbles, and pancreatic remnant density.
Results or Findings: Clinically relevant POPF occurred in 230 patients (57.9%), with 185 classified as grade B and 45 as grade C. PPH occurred in 61 patients (15.3%). PJ dehiscence was significantly associated with clinically relevant POPF (31% vs. 22%, p = 0.035), and PJ defects were more extensive in patients with severe POPF (median 7 mm vs. 5 mm, p = 0.001). Fluid collections, particularly above the PJ site, were also linked to the development of severe POPF (p < 0.001). Additional markers, such as stump pancreatitis, perianastomotic air bubbles, and lower pancreatic remnant density, were significantly more frequent in severe POPF cases.
Conclusion: These findings support the use of postoperative CT scans to prospectively identify patients at risk of developing severe POPF and PPH, allowing for better clinical management.
Limitations: Retrospective study design.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics committee approval number: 28/INT/2015

Author Block: Y. Shu, Y. Dai, J. Wei, Q. Xu; Nanjing/CN
Purpose: We aimed to explore the correlation between celiac axis stenosis and complications after pancreatoduodenectomy.
Methods or Background: Patients who underwent pancreatoduodenectomy in our hospital pancreas center from January 2021 to December 2023 were retrospectively collected. The stenosis rate of celiac axis was measured on pre-operation arterial phase imaging of routine enhanced CT, and graded the severity of celiac trunk stenosis: no stenosis (< 30%), mild stenosis (30%-50%), and significant stenosis (≥50%). The incidence of postoperative complications was evaluated, and both univariate and multivariate logistic regression analysis were conducted.
Results or Findings: A total of 774 patients were included in the study, 205 (26.5%) had celiac axis stenosis: 144 (18.6%) with mild stenosis, and 61 (7.9%) with significant stenosis. Celiac axis stenosis was associated with pancreatic fistula (p<0.001), postoperative bleeding (p=0.033), and postoperative biliary leakage (p= 0.006). In multivariate logistic regression analysis, mild stenosis of the celiac axis was an independent risk factor for postoperative pancreatic fistula (OR 2.81, 95%CI 1.82-4.33, p<0.001), and significant stenosis of the celiac axis was an independent risk factor for postoperative biliary leakage (OR 4.91, 95%CI 1.27-19.04 , p=0.021).
Conclusion: Celiac axis stenosis was associated with the risk of complications after pancreatoduodenectomy. Surgeons may need to pay attention to the condition of celiac axis stenosis before pancreatoduodenectomy.
Limitations: Retrospective study. Single center.
Funding for this study: There was no funding for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: None

Author Block: I. Dudás, B. Lovász, M. Benke, Á. Szücs, P. N. Kaposi-Novák, A. Szijártó, P. Maurovich-Horvat, B. K. Budai; Budapest/HU
Purpose: Differentiation between pancreatic cystic lesions is a challenging task for clinicians. Spectral imaging via photon-counting detector CT (PCD-CT) scanners allows the reconstruction of virtual monoenergetic images (VMI) enabling the measurement of Hounsfield unit (HU) densities at different keV and the generation of spectral absorption curves. Our study aimed to investigate whether mucinous and non-mucinous pancreatic cystic lesions (PCL) have different spectral absorption curves that could help the differential diagnostics.
Methods or Background: Our study included 74 patients with PCLs, 53 patients with mucinous cystic neoplasms and 21 with non-mucinous cystic pancreatic lesions diagnosed based on current practice guidelines. The spectral absorption curves were generated from the pancreatic-phase scans. The average densities were measured on the 70keV (HU70keV) and 40keV (HU40keV) virtual monoenergetic images (VMIs), by placing 3-3 circular regions of interest in PCL’s cystic component parts and the density differences were calculated (HUdiff(40keV-70keV)). Kruskal-Wallis test with post-hoc Dunn’s test was used for comparing the groups. The discrimination performance was assessed by receiver operating characteristic (ROC) curve analysis. The intraobserver reproducibility and interobserver reproducibility were evaluated by the intraclass correlation coefficient (ICC).
Results or Findings: On 70keV VMIs, no significant differences were found between the average densities of mucinous and non-mucinous PCLs cystic components, however, a significant difference was found in HUdiff(40keV-70keV) values (p<0.0001). The diagnostic performance of HUdiff(40keV-70keV) in differentiating between mucinous vs. non-mucinous PCLs had AUCs of 0.92 and 0.92 on the training and test datasets, respectively, with a good interobserver (ICC=0.82) and excellent intraobserver reproducibility (ICC=0.94).
Conclusion: Spectral absorption curve assessment of cystic components could be a useful additional measurement to facilitate the non-invasive differential diagnosis between mucinous and non-mucinous pancreatic cystic lesions.
Limitations: This was a single-center study with a retrospective study design.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The presented study was approved by the institutional ethics committee of our University (SE RKEB 256/2023).

Author Block: R. Z. Borbély¹, B. Teutsch¹, V. Vass¹, K. Márta¹, B. Erőss¹, A. Vincze², A. Szentesi¹, P. Hegyi¹, N. Faluhelyi²; ¹Budapest/HU, ²Pécs/HU
Purpose: Accurately predicting the severity of acute pancreatitis (AP) remains a significant clinical challenge. CT scans, traditionally used for diagnosis, also provide valuable insights into body composition. However, the prognostic utility of CT-derived body composition metrics has been inconsistently reported. This study aimed to evaluate whether key CT body composition metrics can effectively predict the severity of AP.
Methods or Background: A post-hoc analysis was conducted on a multicenter study involving 437 AP patients who underwent CT scans within the first 24 hours of hospital admission. Measurements of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle area (SMA) were obtained at the third lumbar vertebra level. These areas were normalized for patient height to calculate the Visceral Adipose Tissue Index (VATI), Subcutaneous Adipose Tissue Index (SATI), and Skeletal Muscle Index (SMI). Muscle radiodensity in Hounsfield Units (HU) was assessed to determine fatty infiltration. The fat-to-muscle volume ratio was also calculated. These metrics were analyzed as potential predictors of severe AP using receiver operating characteristic (ROC) curves and area under the curve (AUC) values. Severity was determined using the Modified CT Severity Index (mCTSI). Statistical analyses were performed using IBM SPSS Statistics.
Results or Findings: The fat-to-muscle ratio demonstrated the highest predictive accuracy for severe AP (AUC = 0.68), followed by VATI (AUC = 0.65). Other indices did not show significant predictive potential (AUC < 0.6).
Conclusion: CT-derived body composition metrics, particularly the fat-to-muscle ratio and VATI, are valuable predictors of severe acute pancreatitis. Incorporating body composition analysis into routine CT evaluations may enhance prognostic assessments for AP patients.
Limitations: As a post-hoc analysis of retrospective data, the study may be subject to selection bias, potentially limiting the generalizability of the findings.
Funding for this study: Funding for Ruben Zsolt Borbély was supported by the EKÖP-2024-239 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research Development and Innovation Fund.
Funding for Brigitta Teutsch was provided by the ÚNKP-22-3 New National Excellence Program of the Ministry for Innovation and Technology from the source of the National Research, Development and Innovation Fund (to BT - ÚNKP-22-3-IPTE-1693).
Center costs were covered by the University of Pécs, the Momentum Grant of the Hungarian Academy of Sciences (LP2014-10/2014), and grants from the National Research, Development, and Innovation Office (GINOP-2.3.2-15-2016-00015, KH-125678).
The funders had no influence on the study design, data collection, analysis, or manuscript preparation.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This post-hoc analysis is based on a study that received ethical approval from the Scientific and Research Ethics Committee of the Medical Research Council (ISRCTN63827758, decision 55961-2/2016/EKU).

Author Block: A. Pata, F. Rizzetto, C. B. Monti, A. Vanzulli; Milan/IT
Purpose: To evaluate whether incidentally detected pancreatic calcifications on computed tomography (CT) serve as a reliable biomarker for chronic pancreatitis as defined by clinical criteria.
Methods or Background: We retrospectively reviewed CT scans from adult patients between 2014 and 2024, identifying cases where "pancreatic calcifications" were mentioned in the radiology report. Patients with known history of pancreatitis or pancreatic surgery were excluded. For each patient, we recorded pancreatic size, calcification characteristics (number, size, and location), and other features of chronic pancreatitis, such as duct dilatation or intraductal calculi. Clinical data, including pain, abdominal symptoms, and risk factors for chronic pancreatitis, were also collected.
Results or Findings: A total of 137 patients with incidental pancreatic calcifications were identified. A small subset had coarse calcifications (n=9, 7%), while the majority had both coarse and punctiform calcifications (n=102, 74%), with calcification numbers ranging from 7 to 50 in over half of the cases. In 121 patients (88%), at least two pancreatic segments were involved, most frequently the head (n=125, 91%) and the body (n=112, 81%). When coarse calcifications were present alongside duct dilation, the duct caliber was significantly larger (6.7 mm vs 4.1 mm; p=0.026), while the tail was slightly smaller (17 mm vs 19 mm, p=0.018), with no significant differences in the size of the head or body (p>0.198). Among patients with available clinical information (n=38), only 3 (11%) reported symptoms such as abdominal pain, diarrhea, or bloating, and none (0%) reported weight loss. Elevated alcohol consumption or smoking history was not associated with calcification type or location (p>0.186), pancreatic size, or duct dilation (p>0.317).
Conclusion: Incidentally detected pancreatic calcifications are not a reliable biomarker for screening for chronic pancreatitis.
Limitations: The main study limitation is its retrospective design.
Funding for this study: No fundings were received for this study
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional Review Board approved the retrospective data collection in anonymous form

Author Block: L. Ge, Y. Li, Y. Gao, X. Zhang, X. Yu; Xi An/CN
Purpose: To investigate pancreas characterizing for type 2 diabetes mellitus (T2DM) using unenhanced dual-layer Spectral CT.
Methods or Background: This retrospective study included patients who underwent abdominal unenhanced dual-layer spectral CT between March 2023 and April 2024. The patients were divided into T2DM group and control group. Nine regions of interest (ROIs) were drawn（three for head, three for body and three for tail). Mean attenuation on conventional 120-kVp CT images (CTconv), effective atomic number maps (Z-eff), iodine density maps (ID), virtual non-contrasted（VNC), and mean attenuation on virtual monoenergetic images (VMIs) at 40-200keV were measured. The Mann -Whitney U test was used to compare the differences between the two groups. The receiver operating curve (ROC) was used to evaluate the diagnostic efficacy of the above parameters.
Results or Findings: A total of 84 patients, including 44 T2DM patients and 40 controls, were evaluated. There was a statistically significant difference in the CTconv (46.7 ± 5.9 HU vs. 50.7 ± 4.5 HU, p < 0.01) ,Z-eff (7.43 ± 0.05 vs. 7.46 ± 0.03, p < 0.01), ID (103.9 ± 0.6 vs. 104.3 ± 0.4, p < 0.01), VNC (39.2 ± 5.5 HU vs. 42.3 ± 4.2 HU, p < 0.01) and VMIs (62.1 ± 9.7 HU vs. 68.6 ± 6.2 HU at 40 keV, p < 0.001) between the T2DM group and the control group. The AUCs of the CTconv, Z-eff, ID, VNC and 40 keV were 0.722,0.671,0.695, 0.691 and 0.734. Histogram analysis found that the 10th percentile value of the above parameters had higher diagnostic efficiency (0.757,0.736,0.702,0.734 and 0.805). The AUC of VMIs increased with decreasing monoenergeic levels.
Conclusion: The 10th percentile value of 40 keV was the best indicator for distinguishing T2DM patients from the controls.
Limitations: Not applicable
Funding for this study: Not applicable
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: A. Lupi, P. Dardeshi, I. Toniolo, G. Beggiato, M. Pizzi, D. Negro, E. Quaia, A. Pepe; Padua/IT
Purpose: Quantitative abdominal imaging is increasingly emerging in the radiology arena, drawing inspiration from cardiac mapping, which is significantly changing patient management. In fact, cardiac mapping sequences offer the possibility of obtaining abdominal mapping values, although with long acquisition times, due to the cardiac trigger.
The aim of our study is to evaluate the differences between abdominal mapping values obtained with and without cardiac trigger.
Methods or Background: Ten patients who were candidates for the abdominal mapping study as part of a research protocol were included. MOLLI and T2p-SSFP sequences were acquired for T1 and T2 mapping, respectively, with (T) and without (NT) cardiac trigger and with simulated trigger (ST, HR 60 bpm).
T1/T2 mapping values were extracted using manually traced regions of interest (ROIs) at the hepatic, pancreatic and renal cortical levels, using the cvi42 software. The results obtained were compared using paired t-tests.
Results or Findings: Liver T1/T2 mapping showed statistically significant differences between NT and ST sequences (p=0.003 and 0.004, respectively), and T2 mapping values turned out to be significantly different between NT and T acquisition also (p<0.001).
Pancreas T1mapping values were different between NT vs T (p=0.016) and ST (p=0.037), while T2mapping values were different between NT and ST only (p=0.029).
No differences between T and ST sequences were found in liver and pancreas T1/T2 mapping (p>0.05).
Renal T1/T2 mapping did not show significant differences among the three acquisition strategies.
Conclusion: Our results show that cardiac trigger should not be avoided in liver and pancreas mapping with MOLLI and T2p-SSFP sequences, but in order to reduce acquisition time, a simulator could be used. Further analysis on larger sample and with standard ROIs are needed to confirm these data.
Limitations: Sample size
Funding for this study: n/a
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Azienda Ospedale Università Padova