Nonenhanced MR Angiography
Nonenhanced MR angiogram of the hands and forearms in a healthy volunteer with 3D electrocardiography-gated
partial-Fourier fast spin echo. Additional flow spoiling was used to achieve sensitivity to slower flowing arteries in the hand. Image courtesy of Jian Xu, Siemens Medical Solutions and New York University Medical Center.
(Radiology 2008;248:20–43) © RSNA, 2008. All rights reserved. Printed with permission. |
A combination of recent technical advances and concerns about the safety of gadolinium-based contrast agents has spurred a resurgence of interest in MR angiographic methods that do not require exogenous contrast material.
In an article in the July issue of Radiology (RSNA.org/radiology), Mitsue Miyazaki, Ph.D., and Vivian S. Lee, M.D., Ph.D., review established nonenhanced MR methods and discuss new strategies. Focusing on arteriographic applications, they detail:
• Basic considerations in vascular imaging
• Time-of-flight and phase-contrast MR angiographic te chniques
• Electrocardiographically gated partial-Fourier fast spin echo sequence
• Balanced steady-state free precession with and without arterial spin labeling
Dr. Miyazaki, of Toshiba Medical Systems Corporation, and Dr. Lee, of New York University Medical Center, also recommend strategies for specific angiographic applications and discuss emerging developments.
"It is also important to note that nonenhanced MR angiography can play a useful role as a supplement to gadolinium-enhanced MR angiography, particularly when the contrast-enhanced methods fail or have serious artifacts," the authors write.
To access this Radiology article now, click here
Role of Static and Dynamic MR Imaging in Surgical Pelvic Floor Dysfunction
Imaging plays a major role in the clinical management of pelvic floor dysfunction.
In an article in the July-August issue of RadioGraphics (RSNA.org/radiographics), Lousine Boyadzhyan, M.D., Steven S. Raman, M.D., and Shlomo Raz, M.D., describe current concepts in surgical pelvic floor dysfunction, including pelvic organ prolapse and pelvic floor relaxation, and illustrate how MR imaging assists urogynecologists in localizing and grading pelvic floor dysfunction for surgical triage and planning.
The authors, of the University of California, Los Angeles, specifically address:
• Surgically relevant anatomy of the pelvic floor
• MR imaging techniques and findings
• The H line, M line, organ prolapse (HMO) system of interpreting and grading pelvic floor disorders with MR imaging
"MR imaging is an important diagnostic resource in triaging patients [with pelvic floor dysfunction] to surgery and in helping surgeons plan specific repairs," the authors state. "It provides clinicians with an objective assessment of the problem in a single examination. In addition, MR imaging has tremendous potential to be used as a research tool in trying to understand the pathophysiology of these complex disorders. It is hoped that better insight into the mechanisms of this disease will lead to more efficient treatment planning."
To access this RadioGraphics article now, click here.
This article meets the criteria for 1.0 AMA PRA Category 1 Credit™. CME is available online only.
1. Midsagittal T2-weighted single-shot fast SE relaxed image, obtained in a female patient who had undergone hysterectomy, shows anatomic landmarks used in the H line, M line, organ prolapse (HMO) classification system.
Point landmarks are A (the inferior margin of the symphysis pubis), B (the posterior aspect of the puborectalis muscle sling), and C (the junction between the first and second coccygeal elements). Reference lines are the pubococcygeal line (PCL), which is drawn from A to C and is a fixed anatomic reference line; H (the puborectal line), which represents the anteroposterior hiatal dimension and is drawn from A to B; and M, which is the shortest distance between B and the PCL and is a measure of pelvic floor descent.
2. Two components of pelvic floor relaxation.
(a) Midsagittal T2-weighted single-shot fast spin echo (SE) image, obtained in a female patient in a relaxed position, shows the two vectors of pelvic floor relaxation or prolapse: widening and descent. On radiologic images, these vectors are defined as an enlarging H and an enlarging M, respectively. H is the anteroposterior dimension of the levator hiatus, whereas M represents the descent of the levator from the PCL.
(b) Diagram shows changes associated with pelvic floor descent. Diagrams show a normal (c) and a pathologically widened (d) pelvic hiatus.
(RadioGraphics 2008;28:949–967) © RSNA, 2008. All rights reserved. Printed with permission.
Quality- and Informatics-Focused RadioGraphics Articles Available Ahead of Print
Starting with the September-October issue of RadioGraphics, articles designated for the Quality Initiatives and Informatics sections will be posted online as soon as two months before the print edition mails.
The articles will be available in the new Published Ahead of Print section of RSNA.org/radiographics. Articles on informatics and quality topics will be expedited through the publication process so that they appear online in a timely manner and will also still be included in the print issue.
"I am very pleased with the new Published Ahead of Print section," said William W. Olmsted, M.D., RadioGraphics editor. "The Quality Initiatives and Informatics sections frequently feature time-sensitive and breaking issues. The ability to publish electronically ahead of print allows our readers to learn the latest material in these important areas in a very timely way."
An editorial from Dr. Olmsted addressing the new online publishing and other developments for RSNA's education journal appears in the July-August issue.
Talk to Other Radiology Readers via Online Boards
Select articles in each month's issue of Radiology now have an associated online discussion board to facilitate dialogue among readers. Look for articles with this line near the title: "Discuss this article online at RSNA.org/radiology/discuss."
Discussion boards are open to all Radiology readers. Registration is required, however RSNA membership or a Radiology subscription is not. Discussions will be monitored but not moderated, although all participants are expected to adhere to the rules of conduct as presented in the registration agreement.
"The discussion boards provide the opportunity for our readers to share their views on major issues facing our field," said Radiology Editor Herbert Y. Kressel, M.D. "The boards are a vehicle for rapid interactive communication and feedback that has not previously been available. I hope our readers will register and actively participate."
For help with posting to the discussion boards, click on the FAQ link near the top of any page. Other inquiries can be directed to John Humpal, M.A., Radiology managing editor, at jhumpal@rsna.org.
