T₁ mapping for diagnosis of mild chronic pancreatitis

Abstract

Purpose To determine if the T1 relaxation time of the pancreas can detect parenchymal changes in mild chronic pancreatitis (CP). Materials and Methods This Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study analyzed 98 patients with suspected mild CP. Patients were grouped as normal (n = 53) or mild CP (n = 45) based on history, presenting symptomatology, and concordant findings on both the secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) and endoscopic retrograde cholangiopancreatography (ERCP). T1 maps were obtained in all patients using the same 3D gradient echo technique on the same 3T scanner. T1 relaxation times, fat signal fraction (FSF), and anterior–posterior (AP) diameter were correlated with the clinical diagnosis of CP. Results There was a significant difference (P < 0.0001) in the T1 relaxation times between the control (mean = 797 msec, 95% confidence interval [CI]: 730, 865) and mild CP group (mean = 1099 msec, 95% CI: 1032, 1166). A T1 relaxation time threshold value of 900 msec was 80% sensitive (95% CI: 65, 90) and 69% specific (95% CI: 56, 82) for the diagnosis of mild CP (area under the curve [AUC]: 0.81). Multiple regression analysis showed that T1 relaxation time was the only statistically significant variable correlating with the diagnosis of CP (P < 0.0001). T1 relaxation times showed a weak positive correlation with the pancreatic FSF (ρ = 0.33, P = 0.01) in the control group, but not in the mild CP group. Conclusion The T1 relaxation time of the pancreatic parenchyma was significantly increased in patients with mild CP. Therefore, T1 mapping might be used as a practical quantitative imaging technique for the evaluation of suspected mild CP.

Correlation of quantitative pancreatic T1 value and HbA1c value in subjects with normal and impaired glucose tolerance

“…On the contrary, the quantitative T 1 value of the tissue is in theory an absolute value and is not affected by other factors. In recent years, T 1 mapping pulse sequences have been used for the cardiovascular system, liver, and pancreas . We hypothesized that the pancreatic T 1 value reflects differences in pancreatic fibrosis and HbA1c values.…”

“…In recent years, T 1 mapping pulse sequences have been used for the cardiovascular system, 7 liver, 8,9 and pancreas. 10 We hypothesized that the pancreatic T 1 value reflects differences in pancreatic fibrosis and HbA1c values. Thus, the purpose of this study was to evaluate the use of pancreatic T 1 value for the assessment of subjects with normal and IGT.…”

Nonalcoholic Fatty Pancreas Disease

“…Qualitative fat assessment is also feasible with CSI. Proton density fat fraction (PDFF) mapping: PDFF mapping addresses limitations of multipoint Dixon quantification, many of which are specifically relevant to pancreatic imaging. T1 weighting is altered in chronic pancreatic inflammation and can amplify the relative fat signal …”

Obesity, metabolic disease and the pancreas—Quantitative imaging of pancreatic fat

“…64 Proton density fat fraction mapping PDFF mapping addresses limitations of multipoint Dixon quantification, many of which are specifically relevant to pancreatic imaging ( Figure 5). T 1 weighting is altered in chronic pancreatic inflammation 65 and can amplify the relative fat signal. By ensuring the acquisition flip angle is as small as possible, errors introduced by T 1 signal bias can be reduced.…”