RSNA News - May 2005

A press release has been sent to the medical news media for the following scientific article appearing in the MONTH YEAR issue of Radiology (rsna.org/radiologyjnl):

Pulsed-HIFU Facilitated Local Gene Delivery with Systemically Injected Naked DNA in a Mouse Squamous Cell Carcinoma Model: Initial Experience

Pulsed-high intensity focused ultrasound (HIFU) can enhance the local delivery and expression of systemically injected naked DNA in mouse tumors.

Kristin Dittmar, M.D., and colleagues from the Warren Grant Magnuson Clinical Center at the National Institutes of Health in Bethesda, Md., studied three mice with squamous cell carcinoma.

Immediately following the HIFU exposures, a cytomegalovirus-green fluorescent protein (CMV-GFP) reporter gene construct was injected intravenously via the tail vein.

The researchers found that green fluorescent protein expression was observed in all sections of tumors that received pulsed-HIFU exposures, but not in control tumors.

“Although direct evidence is not presently available on how enhanced transfection may occur as a result of applying pulsed-HIFU exposures, the feasibility of this process occurring cannot be discounted out of hand,” the researchers write. “Plans to increase the study’s scope are already under way to further evaluate this procedure using different genes and tumor types, as well as optimizing the pulsed-HIFU exposures for gene delivery.”

(Radiology 2005;235:541-546)

Representative histologic sections from, A, control tumor and, B, tumor treated with pulsed high-intensity focused ultrasound, viewed at fluorescence microscopy. Expression of GFP reporter gene (green) is visible in tumor that underwent ultrasound exposure but not in control. DAPI staining (blue) indicates nuclei of tumor cells. Bar = 50 µm. (Original magnification, x100.) © 2005 RSNA. All rights reserved. Printed with permission.

Bowel Viability Assessment by Color Doppler Sonography in Necrotizing Enterocolitis

Color Doppler sonography (CDS) is more accurate than abdominal radiography (AR) in depicting bowel necrosis in infants with necrotizing enterocolitis (NEC). NEC is an inflammatory gastrointestinal disease of unknown etiology that primarily affects preterm infants and carries a high mortality rate.

Ricardo Faingold, M.D., and colleagues from the Hospital for Sick Children and University of Toronto in Canada prospectively studied 60 neonates—30 with clinically proven or suspected NEC, and 30 with no clinical evidence of intestinal or cardiovascular disease.

The researchers found that CDS findings were more accurate than clinical and AR findings in predicting necrosis in neonates with NEC and have the potential to alter clinical staging and management.

The researchers write: “The findings suggest that CDS should be part of the standard evaluation in NEC, particularly in patients not responding to standard medical management. Future studies with larger groups of patients are necessary to further evaluate this technique in order to determine reproducibility and interoperator variability.”

(Radiology 2005;235:587-594)

Current Realities of Delivering Mammography in the Community: Do Challenges with Staffing and Scheduling Exist?

A new study finds three key problems facing community-based mammography facilities—a shortage of radiologists and certified mammography technologists; a wait time of at least two weeks for a screening mammogram; and a possible trend toward increasing waiting times for screening and diagnostic mammograms at sites with larger volumes.

Carl D’Orsi, M.D., from Emory University in Atlanta and colleagues surveyed 53 facilities in Washington, New Hampshire and Colorado. Forty-five (85 percent) returned the survey.

The findings included a shortage of radiologists in 44 percent of mammography facilities overall, with more non-profit facilities (60 percent) than for-profit facilities (28 percent) reporting a shortage. Twenty percent of facilities reported a shortage of Mammography Quality Standards Act (MQSA) qualified technologists.

“While demand and patient expectations for mammography are increasing, the availability of radiologists and certified mammography technologists is decreasing,” the researchers write. “To ensure the continuation of quality mammography for women in the United States, in addition to recruiting and maintaining qualified technologists, mammography reimbursement, tort reform, and other disincentives for mammography practice must be addressed so facilities providing these services in the community can remain clinically and financially viable.”

(Radiology 2005;235:391-395)

Graph of responses by mammography facilities to, "We are currently experiencing a shortage of radiologists" (n = 45). Almost 50% of facilities are experiencing shortages for mammography image interpretation. © 2005 RSNA. All rights reserved. Printed with permission.

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