RSNA News - August 2005

A press release has been sent to the medical news media for the following scientific article appearing in the August 2005 issue of Radiology (rsna.org/radiologyjnl):

 

Incidentally Discovered Extracolonic Abnormalities at CT Colonography in a Male Population

CT colonography (CTC) can identify clinically important extracolonic findings at very little additional cost.

Judy Yee, M.D., and colleagues from the Veterans Affairs Medical Center and University of California School of Medicine in San Francisco prospectively evaluated the prevalence of incidental extracolonic findings at CTC in 500 high-risk and average-risk men.

Of the 500 patients in the study, 315 (63 percent) had extracolonic findings. Among that subset, 45 patients (14 percent) had clinically important extracolonic findings, the majority of which were validated on follow-up imaging. The cost of additional imaging prompted by extracolonic findings on CTC was low, averaging an additional $28.12 per patient screened.

“Given the relatively small additional cost of $28.12 per patient and that a substantial portion of the total cost was directed toward diagnosing lesions that were truly important, the work-up of abnormal extracolonic findings appears to be economically feasible,” the authors wrote.

Flow chart categorizes extracolonic findings in the study population. *This patient, who had metastatic colon cancer, refused treatment of the extracolonic finding of renal cell carcinoma.
© 2005 RSNA. All rights reserved. Printed with permission.

Adding in Vivo Quantitative ¹H MR Spectroscopy to Improve Diagnostic Accuracy of Breast MR Imaging: Preliminary Results of Observer Performance Study at 4.0 Tesla

The addition of quantitative hydrogen ¹H MR spectroscopy to the breast MR imaging examination may help to improve the radiologist’s ability to distinguish benign from malignant breast lesions.

Sina Meisamy, M.D., and colleagues from the Center for Magnetic Resonance Research Medical School in Minneapolis reviewed the results of 55 breast MR imaging cases evaluated by four radiologists.

Of the 55 lesions evaluated, 35 were invasive carcinomas and 20 were benign. The addition of 1H MR spectroscopy resulted in higher sensitivity, specificity, accuracy and interobserver agreement for all four radiologists. More specifically, two of the four radiologists achieved a significant improvement in sensitivity and all four radiologists achieved a significant improvement in accuracy.

“With the addition of 1H MR spectroscopy, it may be possible to reduce the number of missed cancers and benign lesion biopsies and to improve the accuracy of surgical staging. The promising findings in this study were observed in a moderately small group of patients; thus, an observer performance study involving a larger patient series is needed,” the researchers wrote.

Breast MR imaging case in which 1H MR spectroscopic findings led to altered treatment recommendations.

 

(a) Sagittal high-spatial-resolution 3D fat-suppressed fast low-angle shot MR images of the breast (13.5/4.1) obtained before (left) and seven minutes after (middle) gadopentetate dimeglumine injection and with subtraction (right) show an 8.3-cm³ lesion. The box surrounding the lesion depicts the MR spectroscopic voxel.

(b) Time-signal intensity (SI) curve measured from the lesion depicted in a. All four readers described this curve as showing slow enhancement during the initial phase followed by an enhancement plateau or persistent enhancement during the delayed phase. After evaluating the morphologic features and time-signal intensity curve of the lesion, three of the four readers did not recommend biopsy; rather, they recommended a six-month follow-up examination. The fourth reader recommended biopsy.

(c) ¹H MR spectra measured from the lesion. The spectral peaks of mobile lipid, water, and total choline-containing compounds (tCho) are labeled. The lines above and below the (tCho) peak represent the fitted tCho peak and the residual of the fit, respectively. The mean tCho concentration measured from this lesion was 1.78 mmol/kg ± 0.56. When the tCho measurement was presented to the readers in the second interpretation, three of the four readers changed their decision and recommended biopsy; the fourth reader kept the recommendation of biopsy. This patient received a diagnosis of invasive ductal carcinoma.

(Radiology 2005;236:465-479) © 2005 RSNA. All rights reserved. Printed with permission.

Media Coverage of Radiology

In June, 47 media outlets carried news stories generated from articles appearing in Radiology. These stories reached an estimated 103 million people.

Defensive medicine and mammography ( Radiology 2005;236:37-46) garnered the most attention with 18 media placements, including Investor’s Business Daily and United Press International. Diagnostic imaging’s role in healthcare costs (Radiology 2005;235:934-939) was covered by Physician’s Weekly. Ivanhoe Broadcast News distributed a wire story on fMRI for presurgical evaluation of patients with seizure disorder (Radiology 2005;236:247-253).

RSNA press releases are available at www.rsna.org/media.