Brain volume, energy balance, and cardiovascular health in two nonindustrial South American populations.

Little is known about brain aging or dementia in nonindustrialized environments that are similar to how humans lived throughout evolutionary history. This paper examines brain volume (BV) in middle and old age among two indigenous South American populations, the Tsimane and Moseten, whose lifestyles and environments diverge from those in high-income nations. With a sample of 1,165 individuals aged 40 to 94, we analyze population differences in cross-sectional rates of decline in BV with age. We also assess the relationships of BV with energy biomarkers and arterial disease and compare them against findings in industrialized contexts. The analyses test three hypotheses derived from an evolutionary model of brain health, which we call the embarrassment of riches (EOR). The model hypothesizes that food energy was positively associated with late life BV in the physically active, food-limited past, but excess body mass and adiposity are now associated with reduced BV in industrialized societies in middle and older ages. We find that the relationship of BV with both non-HDL cholesterol and body mass index is curvilinear, positive from the lowest values to 1.4 to 1.6 SDs above the mean, and negative from that value to the highest values. The more acculturated Moseten exhibit a steeper decrease in BV with age than Tsimane, but still shallower than US and European populations. Lastly, aortic arteriosclerosis is associated with lower BV. Complemented by findings from the United States and Europe, our results are consistent with the EOR model, with implications for interventions to improve brain health.

Preservation of the heart in ancient Egyptian mummies: A computed tomography investigation with focus on the myocardium.

The ancient Egyptians considered the heart to be the most important organ. The belief that the heart remained in the body is widespread in the archeological and paleopathological literature. The purpose of this study was to perform an overview of the preserved intrathoracic structures and thoracic and abdominal cavity filling, and to determine the prevalence and computed tomography (CT) characteristics of the myocardium in the preserved hearts of ancient Egyptian mummies. Whole-body CT examinations of 45 ancient Egyptian mummies (23 mummies from the Ägyptisches Museum und Papyrussammlung, Berlin, Germany, and 22 mummies from the Museo Egizio, Turin, Italy) were systematically assessed for preserved intrathoracic soft tissues including various anatomical components of the heart (pericardium, interventricular septum, four chambers, myocardium, valves). Additionally, evidence of evisceration and cavity filling was documented. In cases with identifiable myocardium, quantitative (measurements of thickness and density) and qualitative (description of the structure) assessment of the myocardial tissue was carried out. Heart structure was identified in 28 mummies (62%). In 33 mummies, CT findings demonstrated evisceration, with subsequent cavity filling in all but one case. Preserved myocardium was identified in nine mummies (five male, four female) as a mostly homogeneous, shrunken structure. The posterior wall of the myocardium had a mean maximum thickness of 3.6 mm (range 1.4-6.6 mm) and a mean minimum thickness of 1.0 mm (range 0.5-1.7 mm). The mean Hounsfield units (HU) of the myocardium at the posterior wall was 61 (range, 185-305). There was a strong correlation between the HU of the posterior wall of the myocardium and the mean HU of the muscles at the dorsal humerus (R = 0.77; p = 0.02). In two cases, there were postmortem changes in the myocardium, most probably due to insect infestation. To our knowledge, this is the first study to investigate the myocardium systematically on CT scans of ancient Egyptian mummies. Strong correlations between the densities of the myocardium and skeletal muscle indicated similar postmortem changes of the respective musculature during the mummification process within individual mummies. The distinct postmortem shrinking of the myocardium and the collapse of the left ventriclular cavity in several cases did not allow for paleopathological diagnoses such as myocardial scarring.

Prevalence of dementia and mild cognitive impairment in indigenous Bolivian forager-horticulturalists.

INTRODUCTION: We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle. METHODS: Participants from population-based samples ≥ 60 years of age (n = 623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans. RESULTS: Tsimane exhibited five cases of dementia (among n = 435; crude prevalence = 1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n = 169; crude prevalence = 0.6%, 95% CI: 0.0, 3.2), all age ≥ 80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten. Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms, and vascular calcification in the basal ganglia. DISCUSSION: The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer's disease (AD) dementia phenotype.

Coronary atherosclerosis in indigenous South American Tsimane: a cross-sectional cohort study.

BACKGROUND: Conventional coronary artery disease risk factors might potentially explain at least 90% of the attributable risk of coronary artery disease. To better understand the association between the pre-industrial lifestyle and low prevalence of coronary artery disease risk factors, we examined the Tsimane, a Bolivian population living a subsistence lifestyle of hunting, gathering, fishing, and farming with few cardiovascular risk factors, but high infectious inflammatory burden. METHODS: We did a cross-sectional cohort study including all individuals who self-identified as Tsimane and who were aged 40 years or older. Coronary atherosclerosis was assessed by coronary artery calcium (CAC) scoring done with non-contrast CT in Tsimane adults. We assessed the difference between the Tsimane and 6814 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). CAC scores higher than 100 were considered representative of significant atherosclerotic disease. Tsimane blood lipid and inflammatory biomarkers were obtained at the time of scanning, and in some patients, longitudinally. FINDINGS: Between July 2, 2014, and Sept 10, 2015, 705 individuals, who had data available for analysis, were included in this study. 596 (85%) of 705 Tsimane had no CAC, 89 (13%) had CAC scores of 1-100, and 20 (3%) had CAC scores higher than 100. For individuals older than age 75 years, 31 (65%) Tsimane presented with a CAC score of 0, and only four (8%) had CAC scores of 100 or more, a five-fold lower prevalence than industrialised populations (p≤0·0001 for all age categories of MESA). Mean LDL and HDL cholesterol concentrations were 2·35 mmol/L (91 mg/dL) and 1·0 mmol/L (39·5 mg/dL), respectively; obesity, hypertension, high blood sugar, and regular cigarette smoking were rare. High-sensitivity C-reactive protein was elevated beyond the clinical cutoff of 3·0 mg/dL in 360 (51%) Tsimane participants. INTERPRETATION: Despite a high infectious inflammatory burden, the Tsimane, a forager-horticulturalist population of the Bolivian Amazon with few coronary artery disease risk factors, have the lowest reported levels of coronary artery disease of any population recorded to date. These findings suggest that coronary atherosclerosis can be avoided in most people by achieving a lifetime with very low LDL, low blood pressure, low glucose, normal body-mass index, no smoking, and plenty of physical activity. The relative contributions of each are still to be determined. FUNDING: National Institute on Aging, National Institutes of Health; St Luke's Hospital of Kansas City; and Paleocardiology Foundation.

Is coronary calcium scoring too late? Total body arterial calcium burden in patients without known CAD and normal MPI.

BACKGROUND: Patients with normal myocardial perfusion imaging (MPI) have a good prognosis. However, pre-clinical coronary and extracoronary atherosclerosis may exist in the absence of myocardial ischemia. METHODS: 154 Egyptian patients (mean age 53 years) underwent whole-body non-contrast CT following normal MPI. RESULTS: Atherosclerosis in the form of calcification was observed in ≥1 vascular bed in 115 of 154 (75%) patients. This included the iliofemoral (62%), abdominal aorta (53%), thoracic aorta (47%), coronary (47%), and carotid (25%) vascular beds. Mean total body calcium score was 3172 ± 530 AU. Extracoronary atherosclerosis in patients with a zero coronary artery calcium (CAC) score was common, occurring in the above-listed beds 42%, 36%, 29%, and 7% of the time, respectively. CAC was rarely present without iliofemoral or abdominal aortic calcification. CONCLUSION: Quantitative assessment of calcification in different vascular beds demonstrates that extracoronary atherosclerosis is common in patients who have normal MPI. Atherosclerotic calcifications are most common in the iliofemoral arteries and abdominal aorta, which typically predate coronary calcifications. An imaging strategy to detect extracoronary atherosclerosis could lead to greater understanding of the natural history of atherosclerosis in its long pre-clinical phase and possibly to earlier preventive strategies.

Paleoimaging of a modern mummy from Lithuania (circa 19th-20th century).

An anthropogenic human mummy curated in the Museum of the History of Medicine, Vilnius University, was recently examined by means of computed tomography. Although the mummy lacked data regarding its specific context and historical information on its identity and chronology, the investigation focused on the embalming method adopted to preserve it. Some pathological alterations were also recorded. This research appears to suggest that this body was prepared for educational and/or scientific purposes rather than funerary purposes. Hence, the case could be categorized as a "medical mummy" prepared between the mid-19th and the mid-20th centuries.

Atherosclerosis across 4000 years of human history: the Horus study of four ancient populations.

BACKGROUND: Atherosclerosis is thought to be a disease of modern human beings and related to contemporary lifestyles. However, its prevalence before the modern era is unknown. We aimed to evaluate preindustrial populations for atherosclerosis. METHODS: We obtained whole body CT scans of 137 mummies from four different geographical regions or populations spanning more than 4000 years. Individuals from ancient Egypt, ancient Peru, the Ancestral Puebloans of southwest America, and the Unangan of the Aleutian Islands were imaged. Atherosclerosis was regarded as definite if a calcified plaque was seen in the wall of an artery and probable if calcifications were seen along the expected course of an artery. FINDINGS: Probable or definite atherosclerosis was noted in 47 (34%) of 137 mummies and in all four geographical populations: 29 (38%) of 76 ancient Egyptians, 13 (25%) of 51 ancient Peruvians, two (40%) of five Ancestral Puebloans, and three (60%) of five Unangan hunter gatherers (p=NS). Atherosclerosis was present in the aorta in 28 (20%) mummies, iliac or femoral arteries in 25 (18%), popliteal or tibial arteries in 25 (18%), carotid arteries in 17 (12%), and coronary arteries in six (4%). Of the five vascular beds examined, atherosclerosis was present in one to two beds in 34 (25%) mummies, in three to four beds in 11 (8%), and in all five vascular beds in two (1%). Age at time of death was positively correlated with atherosclerosis (mean age at death was 43 [SD 10] years for mummies with atherosclerosis vs 32 [15] years for those without; p<0·0001) and with the number of arterial beds involved (mean age was 32 [SD 15] years for mummies with no atherosclerosis, 42 [10] years for those with atherosclerosis in one or two beds, and 44 [8] years for those with atherosclerosis in three to five beds; p<0·0001). INTERPRETATION: Atherosclerosis was common in four preindustrial populations including preagricultural hunter-gatherers. Although commonly assumed to be a modern disease, the presence of atherosclerosis in premodern human beings raises the possibility of a more basic predisposition to the disease. FUNDING: National Endowment for the Humanities, Paleocardiology Foundation, The National Bank of Egypt, Siemens, and St Luke's Hospital Foundation of Kansas City.

Increases in regional brain volume across two native South American male populations.

Industrialized environments, despite benefits such as higher levels of formal education and lower rates of infections, can also have pernicious impacts upon brain atrophy. Partly for this reason, comparing age-related brain volume trajectories between industrialized and non-industrialized populations can help to suggest lifestyle correlates of brain health. The Tsimane, indigenous to the Bolivian Amazon, derive their subsistence from foraging and horticulture and are physically active. The Moseten, a mixed-ethnicity farming population, are physically active but less than the Tsimane. Within both populations (N = 1024; age range = 46-83), we calculated regional brain volumes from computed tomography and compared their cross-sectional trends with age to those of UK Biobank (UKBB) participants (N = 19,973; same age range). Surprisingly among Tsimane and Moseten (T/M) males, some parietal and occipital structures mediating visuospatial abilities exhibit small but significant increases in regional volume with age. UKBB males exhibit a steeper negative trend of regional volume with age in frontal and temporal structures compared to T/M males. However, T/M females exhibit significantly steeper rates of brain volume decrease with age compared to UKBB females, particularly for some cerebro-cortical structures (e.g., left subparietal cortex). Across the three populations, observed trends exhibit no interhemispheric asymmetry. In conclusion, the age-related rate of regional brain volume change may differ by lifestyle and sex. The lack of brain volume reduction with age is not known to exist in other human population, highlighting the putative role of lifestyle in constraining regional brain atrophy and promoting elements of non-industrialized lifestyle like higher physical activity.

Do computed tomography findings agree with traditional osteological examination? The case of porous cranial lesions.

OBJECTIVE: The current study evaluates the feasibility of using clinical cranial computed tomography (CT) scans for assessing the presence and morphology of porous cranial lesions (cribra orbitalia, porotic hyperostosis). METHODS: Observers (n = 4) conducted three independent evaluations of porous cranial lesions based on photographs, 2-D CT, and 3-D CT scans of archaeological crania. Evaluations of the crania from each viewing scenario were compared to findings from direct macroscopic observation. MATERIALS: Twenty-two complete adult crania from the Peruvian sites of Pachacamac and Chicama. RESULTS: We found that lesion visibility differed by location: vault lesions with porosity larger than the resolution of the CT scan were identifiable across all viewing scenarios, but orbital lesions were identifiable only when extensive porosity was accompanied by widening of the inter-trabecular spaces. Lesions in stages of advanced remodeling were not visible on CT. CONCLUSIONS: Paleopathological criteria applied to head CTs from clinical cases of suspected cranial fracture can reliably identify moderate to severe porous cranial lesions in living individuals. SIGNIFICANCE: This validation study opens the door to broader study of porous cranial lesions in living individuals that can address open questions about the causes and consequences of these commonly reported skeletal indicators of stress. LIMITATIONS: Performance of all viewing scenarios was evaluated relative to assessment data from direct observation of skeletal remains, but direct observation is itself subject to error. SUGGESTIONS FOR FURTHER RESEARCH: The increasing resolution of routine CTs makes it increasingly possible to explore skeletal lesions in clinical contexts.

Correlation of atherosclerosis and osteoarthritis in ancient Egypt: A standardized evaluation of 45 whole-body CT examinations.

OBJECTIVE: To correlate atherosclerosis (Ath) and osteoarthritis (OA) in mummies from ancient Egypt. MATERIALS: Whole-body CT examinations of 23 mummies from the Ägyptisches Museum und Papyrussammlung, Berlin, Germany, and 22 mummies from the Museo Egizio, Turin, Italy. METHODS: Ath was assessed in five anatomical regions by means of preserved arterial calcifications. OA was assessed using the Kellgren and Lawrence (1957) classification. RESULTS: Statistical analysis revealed no correlation between Ath and total OA. A significant association was found for Ath and the upper limb group for OA grade >1 and for Ath and the lower limb group, consisting mainly of the hip and knee, for OA grade >2 OA. CONCLUSIONS: The association of Ath and advanced OA of the hip and knee is comparable in prevalence to those reported in recent clinical studies, despite the low life expectancy and the different environment and lifestyle of the ancient Egyptians. SIGNIFICANCE: This is the first study to correlate findings of Ath and OA in ancient Egypt statistically. The diseases of Ath and OA are common ailments with enormous and increasing impacts on public health. LIMITATIONS: The large number of cardiovascular diseases was indicated only by arterial calcifications that resisted the post-mortem changes of the mummification process. Also, the assessed OA was on radiological OA. SUGGESTIONS FOR FURTHER RESEARCH: Genomic studies of ancient Egyptian mummies may reveal genetic risk factors for Ath and OA that could be shared in ancient and modern populations.

High prevalence of sternal foramina in indigenous Bolivians compared to Midwest Americans and indigenous North Americans (sternal foramina in indigenous Bolivians).

The sternal foramen, usually an asymptomatic osteological defect, can lead to catastrophic consequences if not recognized prior to certain medical procedures. This study reports the prevalence of a sternal foramen in two South Amerindian populations compared with other published populations. We evaluated the presence of sternal foramina using thoracic computed tomography scans of 1334 (48% female) participants from two indigenous populations of Bolivia (n = 900 Tsimane, 434 Moseten). The prevalence of sternal foramina was compared to two U.S. populations of similar sex/age distribution (n = 572 Midwest Americans, 131 self-identified Native North Americans) via similar CT scans. A sternal foramen was significantly more common in the two Bolivian populations (prevalence ranging from 12.8 to 13.4%), compared to 4.4-5.1% in the two U.S. groups, consistent with prior estimates in studies from industrialized populations. Males had higher frequency of a sternal foramen compared to females in each of the four groups (OR = 1.904, 95% CI: 1.418-2.568, p < 0.001). Age was not associated with sternal foramen presence. These data show both a higher rate of sternal foramina in the South Amerindian populations versus comparator populations in North America and the highest rate of any studied living population. Although it is not possible to determine from our data the relative contribution of genetics versus early life or environmental causes to the higher rates of sternal foramen, we note that small prior studies have likewise demonstrated a higher prevalence in lower income countries. Further determination of the contributing factors warrants greater investigation and research.

The Indigenous South American Tsimane Exhibit Relatively Modest Decrease in Brain Volume With Age Despite High Systemic Inflammation.

Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. Despite a high infectious disease burden, Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population and present few cardiovascular disease (CVD) risk factors despite a high burden of infections and therefore inflammation. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane and (b) compares this association to that of 3 industrialized populations in the United States and Europe. This cohort-based panel study enrolled 746 participants aged 40-94 (396 males), from whom computed tomography (CT) head scans were acquired. BV and intracranial volume (ICV) were calculated from automatic head CT segmentations. The linear regression coefficient estimate ß^T of the Tsimane (T), describing the relationship between age (predictor) and BV (response, as a percentage of ICV), was calculated for the pooled sample (including both sexes) and for each sex. ß^T was compared to the corresponding regression coefficient estimate ß^R of samples from the industrialized reference (R) countries. For all comparisons, the null hypothesis ß T = ß R was rejected both for the combined samples of males and females, as well as separately for each sex. Our results indicate that the Tsimane exhibit a significantly slower decrease in BV with age than populations in the United States and Europe. Such reduced rates of BV decrease, together with a subsistence lifestyle and low CVD risk, may protect brain health despite considerable chronic inflammation related to infectious burden.

Decorated bodies for eternal life: A multidisciplinary study of late Roman Period stucco-shrouded portrait mummies from Saqqara (Egypt).

This study focuses on the multidisciplinary investigation of three stucco-shrouded mummies with mummy portrait from Egypt dating from the late 3rd to the middle of the 4th century AD, corresponding to the late Roman Period. These three mummies were excavated in the early 17th and late 19th centuries in the Saqqara necropolis near the ancient Egyptian capital of Memphis. Two of them experienced an interesting collection history, when they became part of the collection of the Elector of Saxony and King of Poland August II in Dresden, Germany, in 1728. The investigation includes information about the mummies' discovery, collection history and shroud decoration obtained through Egyptological expertise. In addition, information on the state of preservation, technique of artificial mummification, age at death, sex, body height and health of the deceased was achieved through computed tomography (CT) analysis. Research yielded an adult male, a middle-aged female and a young female. Due to the rather poorly preserved bodies of the male and middle-aged female, a specific technique of artificial mummification could not be ascertained. Brain and several internal organs of the well-preserved young female were identified. Wooden boards, beads of necklaces, a hairpin, and metal dense items, such as lead seals, nails and two coins or medallions were discovered. Paleopathological findings included carious lesions, Schmorl's nodes, evidence of arthritis and a vertebral hemangioma. The study revealed insights on the decoration and burial preparation of individuals of upper socioeconomic status living in the late Roman Period, as well as comprehensive bioanthropological information of the deceased.

Use of Computed Tomography scanning in a 'virtual' bioarchaeology of care analysis of a Central Coast Peruvian mummy bundle.

BACKGROUND: CT scanning was utilized to investigate an intact mummy bundle within the bioarchaeology of care framework. The project sought to ascertain whether a 'virtual' analysis was feasible, thereby avoiding physical disturbance to bundle structure and contents. METHODS: The bundle selected for this study contained an adult male (FA 54), Ichma culture, Peru, displaying evidence for two pathologies: chronic osteomyelitis of the right tibia, and cranial trauma. CT images provided the basis for bioarchaeology of care analysis, which followed Index of Care protocols. RESULTS: CT images enabled description and diagnosis of FA 54, and revealed human neonate remains and material artifacts within the bundle. Probable disease impacts were identified, and likely forms of care provided were inferred. CT scanning was of limited value in identifying characteristics of textile wrapping (a clue to cultural identity) and in resolving questions regarding funerary treatment (primary vs. secondary burial), and this constrained consideration of wider social implications of caregiving. CONCLUSION: 'Virtual' examination of FA 54 achieved an advanced stage of bioarchaeology of care analysis, but building on this would require physical examination of bundle elements. Further investigation of CT imaging potential for bioarchaeology of care research in mummy studies is recommended.

Radiological and archaeological investigation of a mummy from Roman Egypt curated in the National Museum of Lithuania.

Among the collections belonging to the National Museum of Lithuania at Vilnius, resides an ancient Egyptian coffin containing a mummified human body. The coffin and its occupant are believed to have belonged to the King of Poland and to have been located in his palace at Warsaw. At the turn of the last century, Egyptologists dated the coffin to the end of the 21st dynasty (1070 BC-945 BC), and described the item as coming from Thebes, belonging to Hori, priest of Amun-Ra. However, no investigation was ever carried out on the human body associated with the coffin. Within the framework of the Lithuanian Mummy Project, the preserved human remains underwent computed tomographic investigation in order to reconstruct the biological profile of the subject and to determine the embalming method employed. This led to the identification of a young adult male. Additionally, the mummy shroud was stylistically assessed in order to determine the mummy's chronology in Egyptian history. Interestingly, the body could be ascribed to the Roman period of Egypt (30 BC-395 AD) due to analogies with the burial shrouds of the Soter group. This indicates a reuse of the coffin at some point in history.

Forensic Analysis Reveals Acute Decompensation of Chronic Heart Failure in a 3500-Year-Old Egyptian Dignitary.

Naturally preserved and embalmed bodies from archeological contexts represent a powerful source of information for forensic investigators. They allow one to ascertain pathology, cause of death, to enhance diagnostic methodology, and to improve the analysis of altered remains. We investigated the complete head and lung remnants of a 3,500-year-old Egyptian dignitary by radiological, microscopic, and genetic approaches. The individual, a middle-aged male, suffered from severe periodontitis, mild atherosclerosis, and experienced cardiogenic pulmonary insufficiency with recurrent mini-bleeds and pulmonary edema. Histology and ancient DNA analyses excluded the presence of Mycobacterium tuberculosis or of any other pathogenic species. Based on our collection of evidence, we propose that acute decompensation complicating chronic cardiac insufficiency was the likely cause of death. The underlying causes for this failure remain unknown although chronic hypertension appears to be the most likely candidate. Our finding represents the earliest reported case of chronic heart failure in ancient mummies.

ACR Appropriateness Criteria Palpable Breast Masses.

A palpable breast mass is one of the most common presenting features of breast carcinoma. However, the clinical features are frequently nonspecific. Imaging performed before biopsy is helpful in characterizing the nature of the mass. For women with clinically detected breast masses, the vast majority will require evaluation with ultrasound. Diagnostic mammography is the initial imaging modality of choice for women aged ≥ 40 years; ultrasound is typically necessary unless a definitively benign mass is identified as the etiology of the clinical finding. For evaluating women aged <30 years and women who are pregnant or lactating, ultrasound is used for initial evaluation. For women aged 30 to 39 years, either ultrasound or diagnostic mammography may be used for initial evaluation. MRI is rarely indicated to evaluate a clinically detected finding. Biopsy is indicated for masses with suspicious features. Short-term follow-up is a reasonable alternative to biopsy for solid masses with probably benign features suggesting fibroadenoma. Correlation between imaging and the clinical finding is essential. 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 in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria Breast Cancer Screening.

Mammography is the recommended method for breast cancer screening of women in the general population. However, mammography alone does not perform as well as mammography plus supplemental screening in high-risk women. Therefore, supplemental screening with MRI or ultrasound is recommended in selected high-risk populations. Screening breast MRI is recommended in women at high risk for breast cancer on the basis of family history or genetic predisposition. Ultrasound is an option for those high-risk women who cannot undergo MRI. Recent literature also supports the use of breast MRI in some women of intermediate risk, and ultrasound may be an option for intermediate-risk women with dense breasts. There is insufficient evidence to support the use of other imaging modalities, such as thermography, breast-specific gamma imaging, positron emission mammography, and optical imaging, for breast cancer screening. 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 includes 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.