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Intrapulmonary arteriovenous anastomoses (IPAVs) are large diameter connections that allow blood to bypass the lung capillaries and may provide a route for right-to-left embolus transmission. These anastomoses are recruited by exercise and catecholamines and hypoxia. Yet, whether IPAVs are recruited via direct, oxygen sensitive regulatory mechanisms or indirect effects secondary to redistribution pulmonary blood flow is unknown. Here, we hypothesized that the addition of exercise to hypoxic gas breathing, which increases cardiac output, would augment IPAVs recruitment in healthy humans. To test this hypothesis, we measured the transpulmonary passage of 99mTc-macroaggregated albumin particles (99mTc-MAA) in seven healthy volunteers, at rest and with exercise at 85% of volitional max, with normoxic (FIO2 = 0.21) and hypoxic (FIO2 = 0.10) gas breathing. We found increased 99mTc-MAA passage in both exercise conditions and resting hypoxia. However, contrary to our hypothesis, we found the greatest 99mTc-MAA passage with resting hypoxia. As an additional, secondary endpoint, we also noted that the transpulmonary passage of 99mTc-MAA was well-correlated with the alveolar-arterial oxygen difference (A-aDO2) during exercise. While increased cardiac output has been proposed as an important modulator of IPAVs recruitment, we provide evidence that the modulation of blood flow through these pathways is more complex and that increasing cardiac output does not necessarily increase IPAVs recruitment. As we discuss, our data suggest that the resistance downstream of IPAVs is an important determinant of their perfusion. [ABSTRACT FROM AUTHOR]

Abstract: To develop a protocol for prevention of hepatitis B virus (HBV) transmission in Wisconsin prisons, we interviewed 619 male prisoners at incarceration to obtain information on hepatitis B risk factors. We defined previous infections by the presence of hepatitis B surface antigen (HBsAg), antibody 10 hepatitis B surface antigen (anti-HBs), or antibody to hepatitis B core antigen (anti-HBc). Logistic regression was used to develop a model of relative risk (RR) of HBV infection. Use of illicit intravenous (IV)drugs was the most important risk factor because of a high prevalence of IV drug use and an RR which ranged from 2.93-7.47. Other important risk factors were: prior hepatitis or jaundice IRR = 6.28), race (RR = 2.54 for Blacks, RR = 3.28 for Latinos), transfusion (RR = 3.00). and age. Previous imprisonment was not an independent risk factor for HBV, hence selective serologic screening and vaccination of prisoners are justified rather than mass screening and vaccination Based upon prevalence of hepatitis B markers in subgroups, it is necessary to screen prisoners with prior hepatitis or jaundice, prior transfusion, and users of IV drugs. The identification of HBsAg carriers by such screening could prevent infection of "household" contacts. Users of IV drugs who are susceptible to HBV infection should be vaccinated. The remaining prisoners constitute a low-risk group for HBV infection and do nut require serologic screening or vaccination. (Am J Public Health 1985:75:1182-1185.) [ABSTRACT FROM AUTHOR]

Purpose: To compare the measurement of glucose uptake in primary invasive breast cancer using simultaneous, time-of-flight breast PET/MRI with prone time-of-flight PET/CT., Materials and Methods: In this prospective study, women with biopsy-proven invasive breast cancer undergoing preoperative breast MRI from 2016 to 2018 were eligible. Participants who had fasted underwent prone PET/CT of the breasts approximately 60 minutes after injection of 370 MBq (10 mCi) fluorine 18 fluorodeoxyglucose ( 18 F-FDG) followed by prone PET/MRI using standard clinical breast MRI sequences performed simultaneously with PET acquisition. Volumes of interest were drawn for tumors and contralateral normal breast fibroglandular tissue to calculate standardized uptake values (SUVs). Spearman correlation, Wilcoxon signed ranked test, Mann-Whitney test, and Bland-Altman analyses were performed., Results: Twenty-three women (mean age, 50 years; range, 33-70 years) were included. Correlation between tumor uptake values measured with PET/MRI and PET/CT was strong ( r s = 0.95-0.98). No difference existed between modalities for tumor maximum SUV (SUV max ) normalized to normal breast tissue SUV mean (normSUV max ) ( P = .58). The least amount of measurement bias was observed with normSUV max , +3.86% (95% limits of agreement: -28.92, +36.64)., Conclusion: These results demonstrate measurement agreement between PET/CT, the current reference standard for tumor glucose uptake quantification, and simultaneous time-of-flight breast 18 F-FDG PET/MRI. Keywords: Breast, Comparative Studies, PET/CT, PET/MR Supplemental material is available for this article. © RSNA, 2021See also the commentary by Mankoff and Surti in this issue., Competing Interests: Disclosures of Conflicts of Interest: A.M.F. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: author paid for virtual lecture (8/21/20) by Wisconsin Association of Hematology and Oncology and Wisconsin Oncology Network Virtual Annual Conference; author receives royalties from Elsevier for book chapters (Diagnostic Imaging: Breast). Other relationships: The Department of Radiology at the University of Wisconsin School of Medicine and Public Health receives research support from GE Healthcare. M.K. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The UW Department of Radiology received research support from GE Healthcare. L.H.B. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The UW Department of Radiology received research support from GE Healthcare. K.S. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The UW Department of Radiology received research support from GE Healthcare. J.M.J. disclosed no relevant relationships. J.K. disclosed no relevant relationships. S.B.P. disclosed no relevant relationships. T.J.B. disclosed no relevant relationships. S.A.H. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The University of Wisconsin - Madison, Department of Radiology receives research support from GE Healthcare. None of this support was specifically designated to this project or its authors. A.B.M. Activities related to the present article: institution received NIH/NIBIB grant EB026708. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The UW Department of Radiology received research support from GE Healthcare. R.M.S. Activities related to the present article: institution received NIH/NIBIB grant EB026708. Activities not related to the present article: disclosed no relevant relationships. Other relationships: The UW Department of Radiology received research support from GE Healthcare., (2021 by the Radiological Society of North America, Inc.)

Purpose: To automatically detect lymph nodes involved in lymphoma on fluorine 18 ( 18 F) fluorodeoxyglucose (FDG) PET/CT images using convolutional neural networks (CNNs)., Materials and Methods: In this retrospective study, baseline disease of 90 patients with lymphoma was segmented on 18 F-FDG PET/CT images (acquired between 2005 and 2011) by a nuclear medicine physician. An ensemble of three-dimensional patch-based, multiresolution pathway CNNs was trained using fivefold cross-validation. Performance was assessed using the true-positive rate (TPR) and number of false-positive (FP) findings. CNN performance was compared with agreement between physicians by comparing the annotations of a second nuclear medicine physician to the first reader in 20 of the patients. Patient TPR was compared using Wilcoxon signed rank tests., Results: Across all 90 patients, a range of 0-61 nodes per patient was detected. At an average of four FP findings per patient, the method achieved a TPR of 85% (923 of 1087 nodes). Performance varied widely across patients (TPR range, 33%-100%; FP range, 0-21 findings). In the 20 patients labeled by both physicians, a range of 1-49 nodes per patient was detected and labeled. The second reader identified 96% (210 of 219) of nodes with an additional 3.7 per patient compared with the first reader. In the same 20 patients, the CNN achieved a 90% (197 of 219) TPR at 3.7 FP findings per patient., Conclusion: An ensemble of three-dimensional CNNs detected lymph nodes at a performance nearly comparable to differences between two physicians' annotations. This preliminary study is a first step toward automated PET/CT assessment for lymphoma.© RSNA, 2020., Competing Interests: Disclosures of Conflicts of Interest: A.J.W. Activities related to the present article: disclosed money paid to institution for research support by GE Healthcare. Activities not related to the present article: disclosed no relevant relationships. Other relationships: disclosed no relevant relationships. M.W.K. disclosed no relevant relationships. S.B.P. disclosed no relevant relationships. M.H. disclosed no relevant relationships. R.J. Activities related to the present article: disclosed grant money paid to institution by the National Cancer Institute, in part supported by the UW Carbone Cancer Center. Activities not related to the present article: disclosed no relevant relationships. Other relationships: disclosed patent issued by WARF and patent pending with AIQ Solutions. L.K. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed money paid for consultancy by Roche, Genentech. Other relationships: disclosed no relevant relationships. T.J.B. Activities related to the present article: disclosed no relevant relationships. Activities not related to the present article: disclosed no relevant relationships. Other relationships: institution receives research support from GE Healthcare., (2020 by the Radiological Society of North America, Inc.)

Intrapulmonary arteriovenous anastomoses (IPAVs) are large diameter connections that allow blood to bypass the lung capillaries and may provide a route for right-to-left embolus transmission. These anastomoses are recruited by exercise and catecholamines and hypoxia. Yet, whether IPAVs are recruited via direct, oxygen sensitive regulatory mechanisms or indirect effects secondary to redistribution pulmonary blood flow is unknown. Here, we hypothesized that the addition of exercise to hypoxic gas breathing, which increases cardiac output, would augment IPAVs recruitment in healthy humans. To test this hypothesis, we measured the transpulmonary passage of 99mTc-macroaggregated albumin particles (99mTc-MAA) in seven healthy volunteers, at rest and with exercise at 85% of volitional max, with normoxic (FIO2 = 0.21) and hypoxic (FIO2 = 0.10) gas breathing. We found increased 99mTc-MAA passage in both exercise conditions and resting hypoxia. However, contrary to our hypothesis, we found the greatest 99mTc-MAA passage with resting hypoxia. As an additional, secondary endpoint, we also noted that the transpulmonary passage of 99mTc-MAA was well-correlated with the alveolar-arterial oxygen difference (A-aDO2) during exercise. While increased cardiac output has been proposed as an important modulator of IPAVs recruitment, we provide evidence that the modulation of blood flow through these pathways is more complex and that increasing cardiac output does not necessarily increase IPAVs recruitment. As we discuss, our data suggest that the resistance downstream of IPAVs is an important determinant of their perfusion.

Unlabelled: The goal of this study was to evaluate the effect on the average standardized uptake value (avgSUV) and maximum standardized uptake value (maxSUV) of changing the number of iterations in the reconstruction process on studies acquired with PET/CT., Methods: Data from 50 human tumors were acquired on a PET/CT scanner, using the CT portion for attenuation correction. Reconstruction was performed using the 2-dimensional reconstruction method of ordered-subsets expectation maximization (OSEM) with 28 subsets and with 1, 2, 3, 4, 5, 10, 20, and 40 iterations. The standardized uptake value (SUV) of the studies was analyzed by positioning a region of interest tightly around the tumor and reproducing the same area on all same-study iterations for SUV measurements., Results: The differences in mean avgSUV and mean maxSUV were statistically different across different iteration groups. SUV data demonstrated that the avgSUV measurements have the most significant differences between 1 versus 2 iterations and 2 versus 3 iterations. The P values for these comparisons were less then 0.001. For maxSUV, all differences had P values less than 0.001. There also was a systematic increase in the SUVs as the number of iterations increased. The avgSUV increased at early iterations (less than 5), with just 50%-60% increasing after 5 iterations. However, maxSUV increased systematically at early iterations, and this trend continued as the number of iterations increased., Conclusion: The OSEM algorithm converges sooner for avgSUV than for maxSUV. The likely reason is that avgSUV depends on low-frequency features that are recovered with fewer iterations. The differences in maxSUV were likely due to noise, which increased with the number of iterative updates, and to increased resolution and recovery of high-frequency features (i.e., tumor heterogeneity) with a larger number of iterations. Factors that determine the quantitative accuracy of iterative reconstruction may have played an additional role. Given the continued change in maxSUV with iterations, great care must be taken in selecting the number of iterative updates when using it to assess tumors and their response to chemotherapy and radiation therapy. Because 2-5 iterations with 8-28 subsets are being used in clinical settings, these data are pertinent when comparing the SUVs of a tumor before and after therapy.