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Brachytherapy (BT), the use of a locally placed or implanted radioactive source for treatment of an adjacent tumor, is an important component in the treatment of patients with both early- and advanced-stage cervical cancer and is increasingly part of the standard treatment protocol. When it is feasible, many radiation oncologists choose to include a magnetic resonance (MR) imaging examination for planning BT treatment (ie, an MR imaging examination after placement of the applicator but before radiation dosing). MR imaging provides excellent soft-tissue contrast and allows radiation oncologists to individualize the radiation dose to the target volume and minimize the dose to adjacent organs that are at risk for radiation damage. However, traditionally, the radiology department has not performed imaging studies for planning, and the requirements are different compared with those of standard diagnostic imaging. In addition, many applicators are available for use in BT treatment of cervical cancer, and each must considered separately to determine MR safety and to define the best imaging parameters. Starting and supporting a robust gynecologic BT program includes implementing imaging protocols that are helpful to both radiation oncologists and diagnostic radiologists. By becoming more familiar with this treatment modality and the logistics of imaging patients undergoing BT, radiologists can provide imaging support for colleagues in the radiation oncology department and better care for patients. © RSNA, 2018.

Purpose: To assess the ability of a T2-prepared steady-state free precession blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging sequence to depict changes in myocardial perfusion during stress testing in a dog stenosis model., Materials and Methods: Study was approved by the institutional Animal Care and Use Committee. A hydraulic occluder was placed in the left circumflex coronary artery (LCX) in 10 dogs. Adenosine was administered intravenously to increase coronary blood flow, and stenosis was achieved in the LCX with the occluder. A T2-prepared two-dimensional steady-state free precession sequence was used for BOLD imaging at a spatial resolution of 1.5 x 1.2 x 5.0 mm3, and first-pass perfusion images were acquired for visual comparison. Microspheres were injected to provide regional perfusion information. Mixed-effect regression analysis was performed to assess normalized MR signal intensity ratios and microsphere-measured perfusion differences. For the same data, 95% prediction intervals were calculated to determine the smallest perfusion change detectable. Means +/- standard deviations were calculated for myocardial regional comparison data. A two-tailed Student t test was used to determine if significant differences (P < .01) existed between different myocardial regions., Results: Under maximal adenosine stress, MR clearly depicted stenotic regions and showed regional signal differences between the left anterior descending coronary artery (LAD)-fed myocardium and the stenosed LCX-fed myocardium. Visual comparisons with first-pass images were also excellent. Regional MR signal intensity differences between LAD and LCX-fed myocardium (1.24 +/- 0.08) were significantly different (P < .01) from differences between LAD and septal-fed myocardium (1.02 +/- 0.07), which was in agreement with microsphere-measured flow differences (LAD/LCX, 3.38 +/- 0.83; LAD/septal, 1.26 +/- 0.49). The linear mixed-effect regression model showed good correlation (R = 0.79) between MR differences and microsphere-measured flow differences., Conclusion: On T2-prepared steady-state free precession BOLD MR images in dogs, signal intensity differences were linearly related to flow differences in myocardium, with a high degree of correlation., Supplemental Material: radiology.rsnajnls.org/cgi/content/full/236/2/503/DC1

In 15 healthy volunteers undergoing coronary magnetic resonance (MR) angiography, the breath-hold duration with and without preoxygenation was measured. The effect of preoxygenation on coronary artery imaging was also evaluated. A three-dimensional magnetization-prepared true fast imaging with steady-state precession sequence was employed for coronary MR angiography. All subjects showed an increase in comfortable breath-hold duration with preoxygenation. This extra imaging time allowed coronary artery imaging with increased spatial resolution.

A volume-targeted contrast agent-enhanced breath-hold coronary magnetic resonance angiographic technique was optimized and evaluated in 16 volunteers. Substantial increases in coronary signal-to-noise ratio, contrast-to-noise ratio, lengths of depiction, and vessel sharpness were observed on enhanced images. The imaging approach with two 20-mL injections of contrast agent covers the left and right coronary arteries in two breath holds and is a promising method for coronary imaging.