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Solid pseudopapillary tumors (SPTs), predominantly affecting young women, are rare pancreatic tumors. It is reported that imaging features of SPT are solid and cystic components, and there is intratumoral hemorrhage and calcification. However, findings of positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) with pathologic correlation have not been fully evaluated. We present a case of SPT that mimicked malignancy on FDG-PET.

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Objectives: To measure phosphorus metabolites in human parotid glands by 31 P-MRS using three-dimensional chemical-shift imaging (3D-CSI), and ascertain whether this method can capture changes in adenosine triphosphate (ATP) and phosphocreatine (PCr) levels due to saliva secretion. Study Design: The parotid glands of 20 volunteers were assessed by 31 P-MRS using 3D-CSI on 3T MRI. After obtaining a first (baseline) measurement, the participants took vitamin-C tablets and measurements were obtained twice more, in a continuous manner. The peak area ratios of PCr and β-ATP were evaluated. Results: A high proportion of PCr (0.26 ± 0.08) and ATP (α: 0.16 ± 0.06; β: 0.27 ± 0.06; γ: 0.21 ± 0.03) was noted at baseline. A significant decrease in β-ATP was observed between baseline ("pre"; 0.27 ± 0.06) and the first scan after vitamin-C stimulation ("post-1"; 0.19 ± 0.07, p < 0.05). There was a near-significant decrease in PCr between pre (0.26 ± 0.08) and post-1 (0.23 ± 0.06, p = 0.074). Conclusions: 31 P-MRS with 3D-CSI can assess the major phosphorus metabolites in human parotid glands and capture changes in their levels due to saliva secretion. This technique is simple, non-invasive, and provides new information regarding saliva secretion.

We investigated the associations of time-dependent DWI, non-Gaussian DWI and CEST parameters with histological biomarkers in a breast cancer xenograft model. 22 xenograft mice (7 MCF-7 and 15 MDA-MB-231) were scanned at 2 diffusion times (Td= 2.5/ 5 ms) with 11 b values (0–600 s/mm2), and 9/ 27.6 ms with 17 b values (0–3000 s/mm2). The apparent diffusion coefficient, ADC0 − 600, shifted ADC, sADC200 − 1500 and the ADC change with Td, as well as IVIM and non-Gaussian diffusion parameters were estimated. CEST images were acquired and the amide proton transfer signal intensity (APT SI) were measured. The sADC200 − 1500 change and combined ADC change (ADC0 − 600, 2.5 ms with sADC200 − 1500, 27.6 ms) was significantly larger for MCF-7 group, and the combined ADC change was positively correlated with Ki67max and APT SI. ADC0 decreased significantly in MDA-MB-231 group and K increased significantly with Td in MCF-7 group. APT SI and cellular area had a moderately strong positive correlation in MDA-MB-231 and MCF-7 tumors combined, and there was a positive correlation in MDA-MB-231 tumors. There was a significant negative correlation between APT SI and the Ki-67-positive ratio in MDA-MB-231 tumors and when combined with MCF-7 tumors. The associations of combined ADC change and API SI with Ki-67 parameters indicate that the Td-dependent DW and CEST parameters are useful to predict the histological markers of breast cancers.