|Breast Imaging at ARRS 2001
May 29, 2001
There was high interest in breast imaging at the American Roentgen Ray
Society Meeting. Research papers and categorical courses generally focused
on outcome and management after percutaneous core needle biopsy, breast
MRI, malpractice issues, and computer-aided diagnosis. During the categorical
courses, many questions arose from participants in general radiology practices
about the application of new technologies, specifically MRI and computer-aided
detection. In particular, more and more practices are using contrast-enhanced
breast MRI for cancer detection, but are running into problems regarding
small lesions that are not completely characterized. One of the solutions
proposed involved using ultrasound, targeted to the MRI-detected lesion,
to further localize the abnormality.
The Scientific Session on breast ultrasound included papers 15-22. Research
concentrated on the use of harmonic imaging and SonoCT compound imaging,
a technique which obtains multiple coplanar, tomographic ultrasound images.
These multiple images are then combined into a single compound image.
Both techniques are used to reduce acoustic artifacts and noise. Paper
16 showed that SonoCT compound imaging improved evaluation of solid
breast nodule margins. These investigators found, however, that the use
of SonoCT compound imaging did not preserve posterior acoustic artifacts
(which can be helpful in diagnosis) leading to a recommendation that solid
breast nodules be assessed by a combination of both conventional and compound
imaging. In other abstracts (Paper
18) harmonic imaging was thought to improve evaluation of both breast
cysts and breast nodules.
Regarding ultrasound-guided biopsy using directional vacuum-assisted
needles, two abstracts (Papers 19 & 20) showed that the technique
is useful in removing small breast lesions. These researchers reported
complete removal in 55% of cases (Paper
19, n=61) and 89% of cases (Paper
20, n=60). However, the latter group showed an immediate complication
rate of 10% with four "cutaneous holes" and two cases of arterial
bleeding. In the same study, an additional five patients had pain (relieved
by Tylenol) and another two patients had subsequent hematoma. This study
shows that the complication rate with the vacuum-assisted devices under
ultrasound guidance is higher than with the automated devices.
Scientific Session 17, on stereotactic-guided biopsies (papers 131-140),
concentrated on follow-up and patient management after core biopsy. Papers
re-emphasized the need for excisional biopsy after the finding of atypical
ductal hyperplasia on core biopsy histology. An interesting spin on core
histology was the finding of positive cytokeratin 903 (CK903) in benign
lesions (Paper 135). When CK903 was found in patients with atypical ductal
hyperplasia, a subsequent excisional biopsy showed only benign lesions.
In contrast, malignant lesions showed a loss of CK903 staining on their
histology. This study identifies a potential role of CK903 expression
in benign biopsies that may obviate the need for excisional biopsy in
patients with atypical ductal hyperplasia. The authors stressed, however,
that these preliminary results would have to be confirmed in subsequent
Another interesting study (Paper
138) showed that the presence of mucin in large-core needle biopsies
does not always represent mucinous carcinoma. The authors presented 20
patients showing mucin on large-core needle biopsies (17 clusters of calcifications,
three masses). Large-core needle biopsies with extravasated mucin were
cancerous on surgical incisional biopsy only when atypia was found
in the original large-core needle biopsy histology. In the absence of
atypia, there was less chance for mucinous carcinoma or other types of
malignancy at incisional biopsy.
Scientific Session 24 on outcomes research and breast MRI (papers 190-197)
showed improved mammographic interpretations of calcifications after training
in BIRADS (Paper
192) with increased accuracy in recommendations for biopsy. An interesting
paper, evaluating outcomes after biopsies positive for LCIS (Paper
195), showed that 10% of women in the study (5 of 48) developed breast
cancer over a mean length of observation of 62 months. Three patients
(6%) had ipsilateral DCIS and two patients developed contralateral cancer
(one invasive ductal cancer, one DCIS). The DCIS was found by mammography
and the invasive cancer was detected by physical examination. This shows
that early breast cancer can be detected by mammography and physical examination
during surveillance after a diagnosis of LCIS. An MRI paper (Paper
197) showed that dynamic MRI was able to detect breast cancer in women
with silicon breast implants. Another MRI talk (Paper
196) showed the use of contrast enhanced MR at 0.5 Tesla produced
a sensitivity and specificity for malignancy of 95%, and a specificity
for benign lesions of 80%.
Scientific Session 29 concentrated on computer digital mammography and
ultrasound and radiological imaging of the breast and breast specimens.
Two evaluations of digital mammography (Papers 230
out a decrease in examination time for the digital imaging because no
film processor was used. Full field digital mammography acquisition time
was 7.3 minutes +/- 17.2 minutes; shorter than for film screen mammography
at 12.6 minutes ( film screen acquisition times included mammogram acquisition
time of 7.4 minutes and processing of 3.2 minutes). Recall rates for the
analog and the digital examinations were 6.7 and 5.7%, respectively, over
the 1,000 cases.
The ARRS meeting showed that patient management after core biopsy is
still a challenging dilemma when treating women with atypical ductal hyperplasia
and LCIS. Some researchers are looking to tissue markers to help with
management decisions. Also, despite the advent of CAD as a "helper"
to the radiologist in abnormality detection, radiologists still have fears
about potential malpractice issues. The balance between these fears and
the benefit of computerized technology will most likely be the subject
of discussion and research for many years to come.