The radiologist has a critical role in recognizing and reporting excipient lung disease because the referring clinician may be unaware of the patient's i.v. drug abuse.

Purpose To determine whether apparent diffusion coefficient (ADC) measures of breast lesions at 3 tesla (T) are affected by gadolinium administration. Materials and Methods The study included 19 patients who underwent 3T MRI. Diffusion-weighted imaging (DWI) was acquired with b=0, 100, and 800 s/mm2 before and after a dynamic contrast-enhanced (DCE) sequence. ADC values were measured for each lesion and normal fibroglandular tissue. Pre and post-contrast ADC measures were compared by Wilcoxon signed-rank test, and differences between groups were compared by Mann-Whitney U test; p<0.05 was considered statistically significant. Results There was no significant difference in pre and post-contrast ADC measured at b=0,100,800 s/mm2 for malignancies (median change: −0.4%,−0.01×10−3 mm2/s, p=0.40), but there was a slight increase in post-contrast ADC in normal tissue (+1.6%,+0.04×10−3 mm2/s, p=0.0006). Findings were similar for both lesions (−0.4%,−0.01×10−3 mm2/s, p=0.54) and normal tissue (+1.5%,+0.03×10−3 mm2/s, p=0.002) with ADC measured at b=0,800 and also at b=100,800 s/mm2 (lesions: +0.9%,+0.01×10−3 mm2/s, p=0.71; normal tissue: +1.8%,+0.03×10−3 mm2/s, p=0.005). For lesions, results were not affected by lesion size, type (mass vs. non-mass enhancement), mean initial enhancement, late enhancement, or delayed enhancement rate on DCE-MRI (p>0.05 for all). Normal tissue showed some trends with greater progressive enhancement rates and higher late enhancement levels correlating with greater increase in post-contrast ADC (p=0.09 for both). Conclusions Our results show that breast lesion ADC measures using our approach were not significantly altered following DCE-MRI at 3T, suggesting DWI and DCE-MRI can be performed in any order without affecting diagnostic criteria. However, influences of contrast on ADC measures in normal breast tissue were observed and require further investigation.

3 Technical Efficacy Stage 3 J. Magn. Reson. Imaging 2017.

Worldwide, 500,000 cases of head and neck cancer (HNC) are reported each year and the primary treatment for HNC is radiotherapy. Although the goal of radiotherapy is to target the tumor, secondary exposure occurs in surrounding normal tissues, such as the salivary glands. As a result, despite successful treatment of the cancer, patients are left with long-term side effects due to direct damage to the salivary glands. The effect is chronic and currently there is no treatment. Stem cells are an attractive therapeutic option for treatment of radiation-induced glandular dysfunction because of the potential to regenerate damaged cell populations and restore salivary gland function. However, limited knowledge about the endogenous stem cell population post irradiation hinders the development for stem cell-based therapies. In this study, an ex vivo sphere formation cell culture system was utilized to assess the self-renewal capacity of cells derived from parotid salivary glands at a chronic time point following radiation. Salivary glands from irradiated mice generate significantly fewer salispheres, but can be stimulated with fetal bovine serum (FBS) to generate an equivalent number of salispheres as unirradiated salivary glands. Interestingly, the number and size of salispheres formed is dependent on the concentration of FBS supplemented into the media. Salispheres derived from irradiated glands and cultured in FBS media were found to contain cells that proliferate and express progenitor and acinar cell markers such as Keratin 5, Keratin 14, Aquaporin 5, and NKCC1. Utilization of insulin-like growth factor (IGF1) injections following radiation treatment restores salivary gland function and improves salisphere generation. These findings indicate that stimulation of these cellular populations may provide a promising avenue for the development of cell-based therapies for radiation-induced salivary gland damage.

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