2. THIS MONTH IN RADIOLOGY ■ CONTINUED
Isoattenuating Pancreatic Adenoarcinoma May Have Better Outcomes than Other
Pancreatic Cancers
Pancreatic adenocarcinoma with visually isoattenuating features at dynamic contrast-en-
hanced CT represents a small but meaningful subset of pancreatic cancers, with different
pathologic features and a better survival rate. In 644 patients, Kim and colleagues identified
35 isoattenuating cancers that demonstrated lower tumor cellularity, more frequent intra-
tumoral acinar tissue and islet cells, and less prominent tumor necrosis and that had better
patient survival after curative-intent surgery. MR and PET/CT were moderately sensitive for
detecting these adenocarcinomas and could be suitable as subsequent examinations when the
patients are suspected of having adenocarcinomas at CT, the researchers noted. ❚ Page 87
Calcium Score May Predict Subclinical Coronary Artery Disease
Patients with subclinical atherosclerosis as demonstrated by higher coronary artery
calcium may be more likely to have future regional wall motion abnormalities and re-
duced systolic and diastolic function. In a cohort of 386 patients—part of the larger
South Bay Heart Watch clinical study—who underwent functional analysis with MR im-
aging and calcium scoring with CT, Colletti and colleagues found that higher coronary
artery calcium score was associated with a slightly lower left ventricular ejection frac-
tion and increased likelihood of regional wall motion abnormalities. The researchers con-
cluded that calcium score may be a marker of previous and possible subclinical coro-
nary artery disease that is not predicted by specific recorded coronary events. ❚ Page 64
Apparent Diffusion Coefficient May Be Used to Predict Chemotherapy Response in
Patients with Invasive Breast Cancer
Patients with breast cancer who have a low pretreatment apparent diffusion coef-
ficient (ADC) at diffusion-weighted MR imaging tended to respond better to che-
motherapy. In a study of 53 women with 53 invasive breast cancers, Park and col-
leagues found that pretreatment ADCs were significantly lower in responders than in
nonresponders. The researchers concluded that diffusion-weighted MR imaging may
help to individualize treatment and prevent ineffective chemotherapy. ❚ Page 56
Computer-aided Detection Associated with Considerable Increase in Mammography
Interpretation Time
Computer-aided detection (CAD) may increase the time radiologists spend on interpret-
ing screening mammograms, while having less determinable effects on radiologists’ ef-
ficiency. In a study of radiologists who interpreted 267 mammograms without and then
with CAD, Tchou and colleagues found that radiologists spent 19% more time inter-
preting screening mammograms with CAD than without. Recall rate increased by 11%,
while radiologists reported increased confidence in 14% of cases and decreased confi-
dence in 8% of cases. The reported increase in interpretation time is an important con-
sideration when evaluating the efficiency of CAD, the researchers concluded. ❚ Page 40
Radiation Risk from Breast-specific Gamma Imaging and Positron Emission
Mammography Comparable to 40 Years of Mammography Screening
A single breast-specific gamma imaging (BSGI) or positron emission mammogra-
phy (PEM) examination is associated with a fatal radiation-induced cancer risk higher
than or comparable to that of annual screening mammography in women aged 40–80
years. Hendrick compared lifetime attributable risks of the imaging modalities us-
ing data from recent peer-reviewed literature and age-dependent risks in the Na-
tional Academy of Sciences’ BEIR VII report. When referring patients for new im-
aging techniques such as BSGI or PEM, physicians should consider the risks and
benefits and communicate them fully to patients, Hendrick concluded. ❚ Page 246
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radiology.rsna.org Radiology: Volume 257: Number 1—October 2010
