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The prognosis of cervical cancer is linked to lymph node involvement, and this is predicted clinically and pathologically by the stage of the disease, as well as the volume and grade of the tumor. Staging of cervical cancer based on International Federation of Gynecology and Obstetrics (FIGO) staging uses physical examination, cystoscopy, proctoscopy, intravenous urography, and barium enema. It does not include CT or MRI. Evaluation of the parametrium is limited in FIGO staging, and lymph node metastasis, an important prognostic factor, is not included in FIGO staging. The most important role for imaging is to distinguish stages Ia, Ib, and IIa disease treated with surgery from advanced disease treated with radiation therapy with or without chemotherapy. This article reviews the current role of imaging in pretreatment planning of invasive cervical cancer. The ACR Appropriateness Criteria((R)) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. [ABSTRACT FROM AUTHOR]

99m Tc-Technegas was recently approved by the U.S. Food and Drug Administration as a radiopharmaceutical for ventilation scintigraphy. However, there are currently no data comparing the quantification of relative lung ventilation with 99m Tc-Technegas with that performed using the standard approach with inhaled 133 Xe. Methods: We performed a secondary analysis of data from prospectively recruited participants in a phase 3 trial undergoing evaluation for lung transplantation who received both 133 Xe and 99m Tc-Technegas ventilation imaging. The 133 Xe and 99m Tc-Technegas images were analyzed asynchronously using semiautomatic segmentation to extract the relative lung ventilation percentages. The anterior and posterior 99m Tc-Technegas images were analyzed to derive 3 sets of relative ventilation percentages (posterior, anterior, and geometric mean data) and compared with the values from posterior 133 Xe images. We evaluated for correlation and agreement between the relative lung ventilation percentages obtained using these 2 radiopharmaceuticals. Results: In a cohort of 74 participants, we found a strong positive correlation in the relative lung ventilation quantified using 133 Xe with that using 99m Tc-Technegas. A high level of agreement was demonstrated on the Bland-Altman plot comparing the 2 imaging modalities. Seventy-two of 74 participants (97.3%) had their relative ventilation percentage measurements within ±15% for 133 Xe and 99m Tc-Technegas. The differences in relative ventilation measurements were within the 95% CI limits of the mean for 70 of 74 participants (94.6%) and within a narrower ±10% threshold for 68 of 74 participants (91.9%), again reflecting the comparability of the 2 techniques. The strongest correlation coefficient ( r = 0.79) was observed between the relative ventilation percentages obtained from 133 Xe and posterior 99m Tc-Technegas images. The geometric mean method had a slightly lower but still comparable correlation ( r = 0.77), and as expected, the correlation with the anterior 99m Tc-Technegas images was worst ( r = 0.70). Conclusion: We showed a strong positive correlation and high agreement between the relative lung ventilation percentages obtained using 133 Xe and 99m Tc-Technegas. These data provide important clinical evidence supporting the use of 99m Tc-Technegas for quantification of relative lung ventilation., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Lung scintigraphy, or ventilation-perfusion (V/Q) scan, is one of the commonly performed studies in nuclear medicine. Owing to variability in clinical applications and different departmental workflows, many trainees are not comfortable interpreting the results of this study. This article provides a simplified overview of V/Q imaging, including a review of its technique, interpretation methods, and established and emerging clinical applications. The authors review the role of V/Q imaging in evaluation of acute and chronic pulmonary embolism, including the role of SPECT/CT and comparing V/Q scan with CT angiography. In addition, a variety of other applications of pulmonary scintigraphy are discussed, including congenital heart disease, pretreatment planning for lung cancer and emphysema, posttransplant imaging for bronchiolitis obliterans, and less common vascular and nonvascular pathologic conditions that may be detected with V/Q scan. This article will help radiologists and residents interpret the results of V/Q scans and understand the various potential clinical applications of this study. Online supplemental material is available for this article. © RSNA, 2021.

Background Comprehensive assessments of the frequency and associated doses from radiologic and nuclear medicine procedures are rarely conducted. The use of these procedures and the population-based radiation dose increased remarkably from 1980 to 2006. Purpose To determine the change in per capita radiation exposure in the United States from 2006 to 2016. Materials and Methods The U.S. National Council on Radiation Protection and Measurements conducted a retrospective assessment for 2016 and compared the results to previously published data for the year 2006. Effective dose values for procedures were obtained from the literature, and frequency data were obtained from commercial, governmental, and professional society data. Results In the United States in 2006, an estimated 377 million diagnostic and interventional radiologic examinations were performed. This value remained essentially the same for 2016 even though the U.S. population had increased by about 24 million people. The number of CT scans performed increased from 67 million to 84 million, but the number of other procedures (eg, diagnostic fluoroscopy) and nuclear medicine procedures decreased from 17 million to 13.5 million. The number of dental radiographic and dental CT examinations performed was estimated to be about 320 million in 2016. Using the tissue-weighting factors from Publication 60 of the International Commission on Radiological Protection, the U.S. annual individual (per capita) effective dose from diagnostic and interventional medical procedures was estimated to have been 2.9 mSv in 2006 and 2.3 mSv in 2016, with the collective doses being 885 000 and 755 000 person-sievert, respectively. Conclusion The trend from 1980 to 2006 of increasing dose from medical radiation has reversed. Estimated 2016 total collective effective dose and radiation dose per capita dose are lower than in 2006. © RSNA, 2020 See also the editorial by Einstein in this issue.

Endometrial cancer is the most common gynecologic and the fourth most common malignancy in women in the United States. Cross-sectional imaging plays a vital role in pretreatment assessment of endometrial cancers and should be viewed as a complementary tool for surgical evaluation and planning of these patients. Although transvaginal US remains the preferred examination for the screening purposes, MRI has emerged as the modality of choice for the staging of endometrial cancer and imaging assessment of recurrence or treatment response. A combination of dynamic contrast-enhanced and diffusion weighted MRI provides the highest accuracy for the staging. Both CT and MRI perform equivalently for assessing nodal involvement or distant metastasis. PET-CT is more appropriate for assessing lymphadenopathy in high-grade FDG-avid tumors or for clinically suspected recurrence after treatment. An appropriate use and guidelines of imaging techniques in diagnosis, staging, and detection of endometrial cancer and treatment of recurrent disease are reviewed.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Imaging is used to detect and characterize adnexal masses and to stage ovarian cancer both before and after initial treatment, although the role for imaging in screening for ovarian cancer has not been established. CT and MRI have been used to determine the resectability of tumors, the candidacy of patients for effective cytoreductive surgery, the need for postoperative chemotherapy if debulking is suboptimal, and the need for referral to a gynecologic oncologist. Radiographic studies such as contrast enema and urography have been replaced by CT and other cross-sectional imaging for staging ovarian cancer. Contrast-enhanced CT is the procedure of choice for preoperative staging of ovarian cancer. MRI without and with contrast may be useful after equivocal CT, but is usually not the best initial procedure for ovarian cancer staging. Fluorine-18-2-fluoro-2-deoxy-D-glucose-PET/CT may not be needed preoperatively, but its use is appropriate for detecting and defining post-treatment recurrence. Ultrasound is useful for evaluating adnexal disease, but has limited utility for staging ovarian cancer. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment., (Copyright © 2013 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Adnexal masses are a common problem clinically and imaging-wise, and transvaginal US (TVUS) is the first-line imaging modality for assessing them in the vast majority of patients. The findings of US, however, should be correlated with the history and laboratory tests, as well as any patient symptoms. Simple cysts are uniformly benign, and most warrant no further interrogation or treatment. Complex cysts carry more significant implications, and usually engender serial ultrasound(s), with a minority of cases warranting a pelvic MRI.Morphological analysis of adnexal masses with gray-scale US can help narrow the differential diagnosis. Spectral Doppler analysis has not proven useful in most well-performed studies. However, the use of color Doppler sonography adds significant contributions to differentiating between benign and malignant masses and is recommended in all cases of complex masses. Malignant masses generally demonstrate neovascularity, with abnormal branching vessel morphology. Optimal sonographic evaluation is achieved by using a combination of gray-scale morphologic assessment and color or power Doppler imaging to detect flow within any solid areas.The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Endovascular mapping and conjoint (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) hepatic perfusion imaging provide essential information before liver radioembolization with (90)Y-loaded microspheres in patients with primary and secondary hepatic malignancies. The aims of this integrated procedure are to determine whether there is a risk for excessive shunting of (90)Y-microspheres to the lungs; to detect extrahepatic perfusion emerging from the injected vascular territory, which might lead to nontargeted radioembolization; to reveal incomplete coverage of the liver parenchyma involved by the tumor, which may be related to anatomic or acquired variants of the arterial vasculature; and to aid in calculation of the (90)Y-microsphere dose to be delivered to the liver. This pictorial essay presents an integrated comprehensive review of the anatomic, angiographic, and nuclear imaging aspects of planned liver radioembolization. The relevant anatomy of the liver, including the standard and the variant arterial vasculature, will be shown using digital subtraction angiography, SPECT/CT, contrast-enhanced CT, and anatomic illustrations. Technical details that will optimize the imaging protocols and important imaging findings will be discussed. From the angio suite to the γ-camera-the goal of this review is to help the reader better understand how the technical details of the angiographic procedure are reflected in the imaging findings of the (99m)Tc-MAA hepatic perfusion study. In addition, the reader should learn to better recognize the pertinent findings and their clinical implications. This knowledge will enable the reader to provide a more useful interpretation of this complex multidisciplinary procedure.

Background: Pulmonary embolism (PE) is a leading cause of maternal mortality in the developed world. Along with appropriate prophylaxis and therapy, prevention of death from PE in pregnancy requires a high index of clinical suspicion followed by a timely and accurate diagnostic approach., Methods: To provide guidance on this important health issue, a multidisciplinary panel of major medical stakeholders was convened to develop evidence-based guidelines for evaluation of suspected pulmonary embolism in pregnancy using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system. In formulation of the recommended diagnostic algorithm, the important outcomes were defined to be diagnostic accuracy and diagnostic yield; the panel placed a high value on minimizing cumulative radiation dose when determining the recommended sequence of tests., Results: Overall, the quality of the underlying evidence for all recommendations was rated as very low or low with some of the evidence considered for recommendations extrapolated from studies of the general population. Despite the low quality evidence, strong recommendations were made for three specific scenarios: performance of chest radiography (CXR) as the first radiation-associated procedure; use of lung scintigraphy as the preferred test in the setting of a normal CXR; and performance of computed-tomographic pulmonary angiography (CTPA) rather than digital subtraction angiography (DSA) in a pregnant woman with a nondiagnostic ventilation-perfusion (V/Q) result., Discussion: The recommendations presented in this guideline are based upon the currently available evidence; availability of new clinical research data and development and dissemination of new technologies will necessitate a revision and update., (© RSNA, 2011)

Background: Pulmonary embolism (PE) is a leading cause of maternal mortality in the developed world. Along with appropriate prophylaxis and therapy, prevention of death from PE in pregnancy requires a high index of clinical suspicion followed by a timely and accurate diagnostic approach., Methods: To provide guidance on this important health issue, a multidisciplinary panel of major medical stakeholders was convened to develop evidence-based guidelines for evaluation of suspected pulmonary embolism in pregnancy using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system. In formulation of the recommended diagnostic algorithm, the important outcomes were defined to be diagnostic accuracy and diagnostic yield; the panel placed a high value on minimizing cumulative radiation dose when determining the recommended sequence of tests., Results: Overall, the quality of the underlying evidence for all recommendations was rated as very low or low, with some of the evidence considered for recommendations extrapolated from studies of the general population. Despite the low-quality evidence, strong recommendations were made for three specific scenarios: performance of chest radiography (CXR) as the first radiation-associated procedure; use of lung scintigraphy as the preferred test in the setting of a normal CXR; and performance of computed-tomographic pulmonary angiography (CTPA) rather than digital subtraction angiography (DSA) in a pregnant woman with a nondiagnostic ventilation-perfusion (V/Q) result., Discussion: The recommendations presented in this guideline are based upon the currently available evidence; availability of new clinical research data and development and dissemination of new technologies will necessitate a revision and update.

Endometrial cancer is one of the common malignancies in the female genital tract. Imaging in pretreatment evaluation may play an important role in an assessment of morphological prognostic factors including tumor size, depth of myometrial invasion, endocervical extent, and lymph node status. Imaging is also useful in posttreatment evaluation of patients with clinically suspected recurrence. Various modalities including MRI, CT ultrasound and FDG PET-CT-CT have been used for evaluation of the endometrial cancer in both before and after treatment settings. Literature on the indications and usefulness of these imaging studies for endometrial cancer is reviewed.

A comprehensive review of the effects of exposure to low levels of ionizing radiation, BEIR VII-Phase 2: Health Risks From Exposure to Low Levels of Ionizing Radiation, was published in 2006. The BEIR (Biological Effects of Ionizing Radiation) reports are a series of publications by the National Academy of Sciences. The last BEIR report on the effects of low level radiation, BEIR V, was published in 1990. To update the risk estimates for exposure to low levels of ionizing radiation, the BEIR committee reviewed recent epidemiologic studies of the atomic bomb survivors, as well as recent studies of populations exposed to radiation from diagnostic and therapeutic medical studies, from occupational exposures and from exposure due to releases of radioactive materials into the environment. Additional increasingly sophisticated epidemiologic studies continue to be published. BEIR VII reconfirmed that the linear no threshold model is the most practical model to estimate radiation risks, especially for radiation protection purposes. The updated risk estimates have not changed significantly from the BEIR V estimates, but the confidence intervals have narrowed as the result of the availability of additional data. The effects of low doses of radiation should be of particular interest to medical professionals because radiation exposure from diagnostic medical studies is, by far, the largest source of radiation exposure from human activity. One recommendation of the BEIR VII report is to perform epidemiologic studies of patients, especially children, who have been exposed to radiation as part of their care. A large, sophisticated epidemiologic study will likely be able to detect an increase in cancer risk. The purpose of this article is to highlight the contents of this important publication with particular emphasis on what is new.

Rapid advances in imaging technology are a challenge for health care professionals, who must determine how best to use these technologies to optimize patient care and outcomes. Hybrid imaging instrumentation, combining 2 or more new or existing technologies, each with its own separate history of clinical evolution, such as PET and CT, may be especially challenging. CT and PET provide complementary anatomic information and molecular information, respectively, with PET giving specificity to anatomic findings and CT offering precise localization of metabolic activity. Historically, the acquisition and interpretation of the 2 image sets have been performed separately and very often at different times and locales. Recently, integrated PET/CT systems have become available; these systems provide PET and CT images that are acquired nearly simultaneously and are capable of producing superimposed, coregistered images, greatly facilitating interpretation. As the implementation of this integrated technology has become more widespread in the setting of oncologic imaging, questions and concerns regarding equipment specifications, image acquisition protocols, supervision, interpretation, professional qualifications, and safety have arisen. This article summarizes the discussions and observations surrounding these issues by a collaborative working group consisting of representatives from the American College of Radiology, the Society of Nuclear Medicine, and the Society of Computed Body Tomography and Magnetic Resonance.

We evaluated whole body and regional (subcutaneous abdominal adipose tissue and forearm) norepinephrine (NE) kinetics in seven lean (body mass index 21.3 +/- 0.5 kg/m2) and six upper body obese (body mass index 36.4 +/- 0.4 kg/m2) women who were matched on fat-free mass. NE kinetics were determined by infusing [3H]NE and obtaining blood samples from a radial artery, a deep forearm vein draining mostly skeletal muscle, and an abdominal vein draining subcutaneous abdominal fat. Mean systemic NE spillover tended to be higher in obese (2.82 +/- 0.49 nmol/min) than in lean (2.53 +/- 0.40 nmol/min) subjects, but the differences were not statistically significant. Adipose tissue and forearm NE spillover rates into plasma were greater in lean (0.91 +/- 0.08 pmol. 100 g tissue-1. min-1 and 1.01 +/- 0.09 pmol. 100 ml tissue-1. min-1, respectively) than in obese (0.26 +/- 0.05 pmol. 100 g tissue-1. min-1 and 0.58 +/- 0.11 pmol. 100 ml tissue-1. min-1, respectively) subjects (P < 0.01). These results demonstrate that adipose tissue is an active site for NE metabolism in humans. Adipose tissue NE spillover is considerably lower in obese than in lean women, which may contribute to the lower rate of lipolysis per kilogram of fat mass observed in obesity.

Purpose: To determine the safety and diagnostic accuracy of a provocative protocol with heparin and urokinase to induce bleeding and determine the source in patients with chronic gastrointestinal hemorrhage., Materials and Methods: Nine patients had gastrointestinal bleeding from an indeterminate source and had negative results from esophagogastroduodenoscopy, colonoscopy, small-bowel examination, and angiography. Ten provocative bleeding studies were performed prospectively. Patients had no clinical evidence of bleeding within 2 days before the study. Intravenous administration of heparin and urokinase was performed systemically during a 4-hour period while scintigraphy was performed continuously. Mesenteric angiography was performed immediately in patients in whom substantial gastrointestinal bleeding was detected at scintigraphy., Results: The provocative protocol was successful in inducing scintigraphically detectable hemorrhage in four (40%) studies within 4 hours. In two of these four studies, the source of hemorrhage was determined and treated with embolization or surgery. Three (30%) studies demonstrated scintigraphic evidence of hemorrhage only at delayed imaging (8-24 hours after initiation of the study). The remaining three (30%) studies did not show active bleeding. No complications occurred, including hemodynamic instability or uncontrollable decreases in hematocrit., Conclusion: Since this protocol with heparin and urokinase enabled determination of the bleeding source in only two of 10 studies, protocol modifications are necessary before this intervention is used widely.