Breast cancer screening recommendations are based on risk factors. For average-risk women, screening mammography and/or digital breast tomosynthesis is recommended beginning at age 40. Ultrasound (US) may be useful as an adjunct to mammography for incremental cancer detection in women with dense breasts, but the balance between increased cancer detection and the increased risk of a false-positive examination should be considered in the decision. For intermediate-risk women, US or MRI may be indicated as an adjunct to mammography depending upon specific risk factors. For women at high risk due to prior mantle radiation between the ages of 10 to 30, mammography is recommended starting 8 years after radiation therapy but not before age 25. For women with a genetic predisposition, annual screening mammography is recommended beginning 10 years earlier than the affected relative at the time of diagnosis but not before age 30. Annual screening MRI is recommended in high-risk women as an adjunct to mammography. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.
Teriparatide, the active fragment of human parathyroid hormone (hPTH 1-34), is an anabolic agent for the treatment of osteoporosis. Important questions remain regarding management strategy beyond the recommended 18- to 24-month course of teriparatide treatment. We followed 21 men for up to 2 years after discontinuing teriparatide. Twelve men (57%) chose treatment with bisphosphonate immediately after teriparatide withdrawal, while 9 (43%) opted for no pharmacologic agent. At the end of 1 year lumbar spine bone density increased an additional 5.1+/-1.0% in the bisphosphonate group, while it declined by 3.7+/-1.7% in those on no medication (P<0.002). In six men who delayed initiation of bisphosphonate until 1 year after teriparatide withdrawal, their subsequent gains in the second year, 2.6+/-1.7%, still placed them below the peak gains they achieved on teriparatide. In contrast, the 12 men who began bisphosphonates immediately and continued treatment for the entire 2-year post-PTH period had continued gains at the lumbar spine, 8.9+/-1.5% above their post-PTH values (P=0.002). For the 4-year period, including 2 years of teriparatide and 2 years of bisphosphonate, the total gains at the lumbar spine were 23.6+/-2.9%. Men, who received bisphosphonate in only the 2nd year post-teriparatide, had cumulative gains of 11.1+/-3.4%. Three men who did not receive any bisphosphonate at any time during the post-PTH period had cumulative gains of only 5.5+/-3.7%. These findings suggest that the use of bisphosphonates following teriparatide is an important component of any strategy utilizing this anabolic drug for osteoporosis in men. The immediate use of bisphosphonates after teriparatide withdrawal may help to optimize gains in bone density at the lumbar spine.
The accuracy and precision of an automated graph-cuts (GC) segmentation technique for dynamic contrast-enhanced (DCE) 3D MR renography (MRR) was analyzed using 18 simulated and 22 clinical datasets. For clinical data, the error was 7.2 ؎ 6.1 cm 3 for the cortex and 6.5 ؎ 4.6 cm 3 for the medulla. The precision of segmentation was 7.1 ؎ 4.2 cm 3 for the cortex and 7.2 ؎ 2.4 cm 3 for the medulla. Compartmental modeling of kidney function in 22 kidneys yielded a renal plasma flow (RPF) error of 7.5% ؎ 4.5% and single-kidney GFR error of 13.5% ؎ 8.8%. The precision was 9.7% ؎ 6.4% for RPF and 14.8% ؎ 11.9% for GFR. It took 21 min to segment one kidney using GC, compared to 2.5 hr for manual segmentation. One technique to determine renal function consists of the intravenous injection of radioactive tracer followed by assessment of its plasma clearance 2-4 hr later. This technique is time-consuming, requires multiple blood samples, and measures only the global glomerular filtration rate (GFR)-a disadvantage when asymmetric or unilateral renal disease is present. The gold standard technique for assessing single-kidney GFR is inulin clearance, but this method is too invasive and complex for routine clinical application. As an alternative, dynamic gamma camera imaging with 99m Tc-DTPA has been shown to provide single-kidney GFR by analysis of the renal radioactivity. By combining measures of renal physiology with depiction of anatomical detail, dynamic contrast-enhanced (DCE) 3D MR renography (MRR) has the potential to improve upon nuclear medicine techniques and also provide useful functional information to supplement anatomic renal MRI examinations (1). Good spatial, temporal, and contrast resolution is achievable with current contrast-enhanced dynamic protocols, whereby serial 3D MR images of the kidneys are generated following an injection of contrast material. Gadolinium (Gd) chelates, such as gadopentetate dimeglumine (Gd-DTPA), are suitable MR contrast agents because they are freely filtered at the glomerulus without tubular secretion or resorption.Several approaches have been proposed to analyze renography data, including the upslope method (2), deconvolution (3,4), the Rutland-Patlak method (5,6), and renal kinetic modeling (7-10). The key prerequisite is the ability to segment dynamic MR images into functional regions (i.e., the cortical and medullary compartments). Fitting concentration-time activity (CTA) curves to kinetic models yields perfusion and filtration rates per unit volume of tissue. These kinetic rates multiplied by the cortical and medullary volumes (determined from segmented images) give the renal plasma flow (RPF) and GFR for the entire kidney.Accurate segmentation of contrast-enhanced MRR data remains a difficult task. Dynamic 3D MR images of the abdomen suffer from partial-volume and respiratory-motion artifacts and have a relatively low signal-to-noise ratio (SNR). Other sources of error include signal nonuniformity and wraparound artifacts. The presence of cysts and renal masses, and reduced...
The incidence of ductal carcinoma in situ (DCIS) has increased over the past few decades and now accounts for over 20% of newly diagnosed cases of breast cancer. Although the detection of DCIS has increased with the advent of widespread mammography screening, it is essential to have a more accurate assessment of the extent of DCIS for successful breast conservation therapy. Recent studies evaluating the detection of DCIS with magnetic resonance (MR) imaging have used high spatial resolution techniques and have increasingly been performed to screen a high-risk population as well as to evaluate the extent of disease. This work has shown that MR imaging is the most sensitive modality currently available for identifying DCIS and is more accurate than mammography in evaluating the extent of DCIS. MR imaging is particularly sensitive for identifying high-grade and intermediate-grade DCIS. DCIS may have variable morphologic features on MR images, with non-mass enhancement morphology being the most common manifestation. Less commonly, DCIS may also manifest as a mass on MR images, in which case it is most likely to be irregular. The kinetics of DCIS are also variable, with fast uptake and a plateau curve reported as the most common kinetic pattern. Additional MR imaging tools such as diffusion-weighted imaging and quantitative kinetic analysis combined with the benefit of high field strength, such as 3 T, may increase the sensitivity and specificity of breast MR imaging in the detection of DCIS.
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