JOG Technique Versus Nonspiral Axial Scan in Pancreatic Perfusion Computed Tomography Imaging and Their Preliminary Application

Pancreatic CT perfusion: quantitative meta-analysis of disease discrimination, protocol development, and effect of CT parameters

BACKGROUND

This study provides a quantitative meta-analysis of pancreatic CT perfusion studies, investigating choice of study parameters, ability for quantitative discrimination of pancreatic diseases, and influence of acquisition and reconstruction parameters on reported results.

METHODS

Based on a PubMed search with key terms 'pancreas' or 'pancreatic,' 'dynamic' or 'perfusion,' and 'computed tomography' or 'CT,' 491 articles published between 1982 and 2020 were screened for inclusion in the study. Inclusion criteria were: reported original data, human subjects, five or more datasets, measurements of pancreas or pancreatic pathologies, and reported quantitative perfusion parameters. Study parameters and reported quantitative measurements were extracted, and heterogeneity of study parameters and trends over time are analyzed. Pooled data were tested with weighted ANOVA and ANCOVA models for differences in perfusion results between normal pancreas, pancreatitis, PDAC (pancreatic ductal adenocarcinoma), and non-PDAC (e.g., neuroendocrine tumors, insulinomas) and based on study parameters.

RESULTS

Reported acquisition parameters were heterogeneous, except for contrast agent amount and injection rate. Tube potential and slice thickness decreased, whereas tube current time product and scan coverage increased over time. Blood flow and blood volume showed significant differences between pathologies (both p < 0.001), unlike permeability (p = 0.11). Study parameters showed a significant effect on reported quantitative measurements (p < 0.05).

CONCLUSIONS

Significant differences in perfusion measurements between pathologies could be shown for pooled data despite observed heterogeneity in study parameters. Statistical analysis indicates most influential parameters for future optimization and standardization of acquisition protocols.

CRITICAL RELEVANCE STATEMENT

Quantitative CT perfusion enables differentiation of pancreatic pathologies despite the heterogeneity of study parameters in current clinical practice.

An application study of low-dose computed tomography perfusion imaging (LDCTPI) in breast cancer and breast fibroadenoma

PURPOSE

To explore the characteristics of breast cancer and breast fibroadenoma using low-dose computed tomography perfusion imaging (LDCTPI) including specific perfusion parameter values, and seek the potential clinical applications in cancer prognosis assessment.

MATERIALS AND METHODS

Fifty patients including 30 diagnosed with breast cancer and 20 with breast fibroadenoma, as well as 15 control subjects with normal breasts were studied prospectively using LDCTPI examinations. The acquired volumetric imaging data were used for calculation, mapping and analysis by using a body tumor perfusion protocol in the CT perfusion software to measure 4 parameters: blood flow (BF), blood volume (BV), mean transit time (MTT), and the permeability surface (PS) area product. Statistical data analysis was then performed to distinguish the difference of the 4 parameter values among normal control, breast cancer and breast fibroadenoma cases.

RESULTS

The mean perfusion values of 15 normal controls were as follows: BF, 20.03±4.08 mL/100 g/min; BV, 4.53±0.95 mL/100 g; MTT, 5.90±0.82 s; and PS, 9.25±1.18 mL/100 g/min. The mean perfusion values of 30 cancer patients were as follows: BF, 56.67±6.59 mL/100 g/min; BV, 5.82±0.68 mL/100 g; MTT, 6.01±0.82 s; and PS, 24.95±5.05 mL/100 g/min. The mean perfusion values of 20 patients with breast fibroadenoma were as follows: BF, 46.24±6.65 mL/100 g/min; BV, 5.07±0.73 mL/100 g; MTT, 7.51±0.62 s; and PS, 16.73±6.48 mL/100 g/min. Comparing the 3 groups, differences were all statistically significant for BF, BV, MTT and PS values (p < 0.05, respectively); The BF, BV, PS values were highest in group of cancer patients, while the MTT value was highest in group of patients diagnosed with breast fibroadenoma.

CONCLUSION

Breast CT perfusion imaging is a promising functional imaging technology in breast cancer diagnosis, which can provide valuable quantitative imaging markers to assist evaluation of breast tumors.