Mammographically guided fine-needle aspiration biopsy of nonpalpable breast lesions. Can it replace open biopsy?

The authors report the accuracy of mammographically guided fine-needle aspiration (FNA) for the diagnosis of nonpalpable breast lesions in a series of 71 patients. Each mammographically guided FNA was immediately followed by hookwire localization and open biopsy. Seven malignancies were identified cytologically, but three cancers were not detected in aspirates judged to be sufficient for diagnosis. In addition, 19 aspirates were reported to be insufficient, and 4 of these were obtained from lesions histologically proven to be adenocarcinoma. Although no false-positive diagnoses were encountered, the technique demonstrated a sensitivity of 78% and a diagnostic accuracy of 94% for adequate specimens. In this study, mammographically guided FNA was insufficiently sensitive to replace open biopsy for the diagnosis of nonpalpable breast lesions.     

Meniscal injuries: detection using MR imaging

Both retrospective and blinded analyses of thin-section, high-resolution magnetic resonance (MR) images of the knee joint, produced using a solenoid surface coil, indicate that MR imaging is an effective technique for evaluating meniscal injuries. Images of 49 patients were evaluated, and the results were correlated with those of subsequent arthroscopy. A grading scale was developed to rate the index of suspicion of a meniscal tear based on the MR images. Overall, approximately 80% of menisci rated grade 4 (definite tear) or 3 (probable tear) were found to have corresponding tears at arthroscopy. In many other patients with a grade 4 or 3 meniscus in whom a corresponding tear was not found arthroscopically, meniscal tears at other sites or other abnormalities were correctly diagnosed using MR. A majority of the false-positive MR images involved the posterior horns of the menisci, the sites of most false-negative arthroscopic diagnoses. The predictive value of a negative MR image was almost 100%. Even in patients with moderate-to-large effusions, the menisci were accurately evaluated. The results imply that MR imaging is useful in the preoperative evaluation of suspected meniscal tears.     

Present status of residency training in mammography

We conducted a telephone interview of all 207 accredited diagnostic radiology residency training programs listed in the American Medical Association's Directory of Graduate Medical Education Programs. Resident training in mammography was offered in 206 programs, and 35% of the programs had initiated this training within the past 3 years. Residents had an assigned block of time to do mammography in 84% of the programs. Of the 206 programs, 40% had rotations devoted exclusively to mammography, with 82% of the exclusive rotations lasting from 4 to 8 weeks. Residents were performing localization procedures in 91% of the programs and dictating cases in 81%. A distinction was made between screening and diagnostic examinations by 35% of the training institutions, at least in terms of the fee for the examination. Radiologists who devoted at least half of their practice to mammography taught in 52% of the programs. The American College of Radiology has granted accreditation in mammography to 29% of the programs. Although almost all accredited residency training programs offer training in mammography, there are some deficiencies in this training. More residents need to gain the experience of dictating mammography reports and need to learn about the distinctions between screening and diagnostic mammography. Despite the anticipated deluge of screening examinations in the next decade, there were only 17 fellowships that included at least 6 months of mammography identified in 15 (7%) of the institutions; only 11 of these were full-time 1-year breast imaging fellowships.     

Solenoid surface coils in magnetic resonance imaging

A nonplanar solenoidal surface radiofrequency coil is used as a receiver with a conventional transmitter coil in a magnetic resonance imaging system. The improved signal-to-noise ratio, compared with that of conventional fixed saddle or solenoid receiver coils, permits higher resolution imaging and thinner image sections. In addition, the problem of signal dropoff that occurs in deep structures with planar and other noncircumferential surface coils is eliminated. Solenoid surface coils are particularly useful in imaging deep structures in anatomic regions that do not fit standard head and body coils, such as the neck, knees, and other smaller body parts.     

MR imaging of the normal shoulder: anatomic correlation

The complex anatomy and the requirement to image in the peripheral magnetic field have made the shoulder difficult to examine with MR. However, the use of high-resolution scanning techniques and specialized surface coils has improved the quality of MR images obtained. Seventy-five scans of the shoulders of normal volunteers were correlated with multiplanar cryomicrosections of six cadaver shoulders to study the MR appearance of normal structures. MR was shown to provide excellent depiction of shoulder anatomy.     

Combined DCE‐MRI and single‐voxel 2D MRS for differentiation between benign and malignant breast lesions

Dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and proton (1H) magnetic resonance spectroscopy (MRS) provide structural and biochemical information, including vascular volume, vascular permeability and tissue metabolism. In this study, we performed analysis of the enhancement characteristic from DCE‐MRI and the biochemical information provided by two‐dimensional (2D) Localized Correlated Spectroscopy (L‐COSY) MRS to determine the sensitivity and specificity of using DCE‐MRI alone compared to the combination with 2D MRS. The metabolite ratios from the 2D MRS spectra were analyzed using multivariate statistical analyses to determine a method capable of automatic separation of the patient cohort into malignant and benign lesions. A total of 24 lesions were studied with 21 diagnosed accurately using the enhancement characteristics alone resulting in sensitivity and specificity of 100% and 73%, respectively. Analysis of the 2D MRS data demonstrated a significant difference (p < 0.05) in 12 of 18 metabolite ratios analyzed for malignant compared to benign lesions. Previous research focused on utilizing the choline signal to noise ratio (SNR) as a marker for malignancy has been verified using 2D MRS in this study. Using Fisher's linear discriminant test using water (WAT)/olefinic fat diagonal (UFD), choline (CHO)/fat (FAT), CHO/UFD, and FAT/methyl fat (FMETD) as predictors the sensitivity and specificity increased to 92% and 100%, respectively. Using the Classification and Regression Tree (CART) statistical analysis the resulting sensitivity and specificity were 100% and 91%, respectively, with the most accurate predictor for differentiating malignant and benign determined to be FAT/FMETD. The cases within the study that presented a indeterminate diagnosis using DCE‐MRI alone were able to be accurately diagnosed when the metabolic information from 2D MRS was incorporated. The results suggest improved breast cancer detection through the combination of morphological and enhancement information from DCE‐MRI and metabolic information from 2D MRS. Copyright © 2010 John Wiley & Sons, Ltd.