Volume-localized two-dimensional correlated magnetic resonance spectroscopy of human breast cancer.

A localized 2D correlation spectroscopic sequence (L-COSY) was implemented and applied in human breast cancer in vivo to evaluate the water to fat (both saturated and unsaturated) ratios and also to identify choline. Being in agreement with the conventional 1D magnetic resonance spectroscopy (MRS) results, elevated water to lipids ratios were found in breast cancers and choline was observed only in a few cancer patients.

Multifeature analysis of Gd-enhanced MR images of breast lesions.

The objective of this study was to determine whether linear discriminant analysis of different independent features of MR images of breast lesions can increase the sensitivity and specificity of this technique. For MR images of 23 benign and 20 malignant breast lesions, three independent classes of features, including characteristics of Gd-DTPA-uptake curve, boundary, and texture were evaluated. The three classes included five, four and eight features each, respectively. Discriminant analysis was applied both within and across the three classes, to find the best combination of features yielding the highest classification accuracy. The highest specificity and sensitivity of the different classes considered independently were as follows: Gd-uptake curves, 83% and 70%; boundary features, 86% and 70%; and texture, 70% and 75%, respectively. A combination of one feature each from the first two classes and age yielded a specificity of 79% and sensitivity of 90%, whereas highest figures of 93% and 95%, respectively, were obtained when a total of 10 features were combined across different classes. Statistical analysis of different independent classes of features in MR images of breast lesions can improve the classification accuracy of this technique significantly.

Breast calcification and mass detection with mammographic anode-filter combinations of molybdenum, tungsten, and rhodium.

PURPOSE: To determine whether contrast loss on mammograms obtained with tungsten (W)-molybdenum (Mo), rhodium (Rh)-Rh, and W-Rh anode-filter units affects calcification and mass detection relative to that on mammograms obtained with Mo-Mo anode-filter units. MATERIALS AND METHODS: Three unfixed cadaveric breasts of 4.0-, 5.5-, or 7.0-cm thickness were imaged with three mammographic units with Mo-Mo, W-Mo, Rh-Rh, and W-Rh anode-filter combinations. Calcification clusters (<300 microm in diameter) and masses (0.5-1.2 cm) placed on the cadaveric breasts simulated abnormal mammograms. Thirty-five images without and 57 images with added calcifications and masses were acquired with a 180-speed screen-film system and interpreted by four mammographic specialists. With a 150-speed screen-film system, 10 normal images and 30 abnormal images with added calcifications were obtained with Mo-Mo and Rh-Rh equipment and read by three of the four radiologists. RESULTS: For the 180-speed system, there were statistically significant differences (P < .05) in detection of calcifications on Mo-Mo images compared with W-Mo, Rh-Rh, and W-Rh images. These differences disappeared with the 150-speed system. For mass detection with the 180-speed system, W-Rh was significantly better than Mo-Mo (P = .02). CONCLUSION: Dose savings and increased penetration with Rh-Rh and W-Rh anode-filter combinations may decrease calcification detection if fast screen-film systems are used, but mass detection may be improved.

Effects of ambient light and view box luminance on the detection of calcifications in mammography.

OBJECTIVE: Viewing conditions can affect diagnostic performance differently depending on background optical densities. We quantified detection accuracy when viewing calcifications in glandular tissue under recommended viewing conditions versus accuracy with lower view box luminance and higher ambient lighting. MATERIALS AND METHODS: A phantom with adipose, 50% adipose and 50% glandular, and glandular-simulating material was imaged, and images were interpreted by five medical imaging physicists using two lighting conditions: the recommended one, high view box luminance (4365 nits) with low ambient light (25 lx), and a suboptimal one, low view box luminance (1763 nits) with moderate ambient lighting (290 lx). Then, a dense (Breast Imaging Reporting and Data System breast composition pattern type 4) unfixed cadaveric breast with numerous native calcifications was imaged 28 times. Nineteen of the films had added clusters of simulated calcifications. Three radiology fellows, each with 11 months of training in mammography, identified the added calcification clusters in the images under the two lighting conditions. Changes in phantom analysis and accuracy of the clinical diagnosis were compared for each lighting condition. RESULTS: On mammograms of the phantom, both speck and fibril identification were degraded by an average of 1.4 objects for the adipose-simulating section (with its darker optical density). For medium optical densities, found in the section with the simulation of 50% glandular and 50% adipose tissue, suboptimal lighting conditions had little or no effect on speck and fibril identification. For sections of the phantom that simulated glandular tissue, an average of 0.6 specks or fibers were not seen when lighting was suboptimal. With the dense cadaveric breast, the fraction of added calcification clusters detected by the three observers improved by an average of 17% when low luminance viewers and high ambient light were replaced with recommended viewing conditions; individual scores of the observers improved significantly: p values ranged from .02 to .05. CONCLUSION: Luminance of the view box and ambient lighting significantly affect detection of calcifications in dense breasts when images are interpreted by radiologists with about 1 year of training in mammography. Detection of calcifications in phantoms is primarily degraded for adipose tissue with its darker optical density. However, when lighting conditions are suboptimal, some observers also have trouble detecting calcifications in glandular tissue with its low optical density.

Mobile mammography: results of a national survey.

PURPOSE: to learn about mobile mammography in the United States. MATERIALS AND METHODS: A survey of 82 questions was designed, pilot tested, and sent to mobile mammography facilities. The questions addressed many aspects of mobile programs, including administrative, financial, equipment, personnel, film processing, quality assurance, and communication of results. RESULTS: Of the 367 facilities that were mailed surveys, 159 facilities completed the survey, and 30 (19%) of those had discontinued their mobile programs. Seventy-six of 158 (48%) mobile facilities had performed mobile mammography for 1-5 years, and 69 of 158 (44%) had performed mobile mammography for more than 5 years. Seventy-two of 156 (46%) facilities were hospital-owned, and 25 of 156 (16%) were radiologist-owned. One hundred seven of 159 (67%) mobile facilities performed screening only. One hundred fourteen of 152 (75%) facilities charged +80.00 or less for screening. Mobile facilities averaged 20 examinations per day and served diverse populations. Sixty-seven of 159 (42%) facilities accepted self-referred women. Thirty-one percent of the facilities performed on-board processing. Only 71 of 149 (47%) facilities were financially profitable or breaking even, but 112 of 154 (73%) facilities would undertake a mobile project again. CONCLUSION: Mobile programs provide an opportunity to increase access to screening mammography, but they face many obstacles.

Mammographically guided fine-needle aspiration cytology of the breast: reducing the rate of insufficient specimens.

OBJECTIVE: The purpose of our study was to reduce the rate of insufficient specimens from fine-needle aspiration cytology (FNAC) of impalpable mammographically detected breast lesions. SUBJECTS AND METHODS: Our previous rate of insufficient specimens for FNAC was 27%. We implemented the following strategies to reduce this rate and improve accuracy: retraining of radiologists in FNAC procedures, more vigorous sampling, on-site evaluation of specimens by cytopathologist or cytotechnologist, exclusive use of stereotaxic guidance, stereotaxic equipment calibration program, and verification of initial needle placement. RESULTS: Of 77 patients with impalpable abnormalities who underwent FNAC with the new protocol, six (8%) had insufficient specimens for cytologic diagnosis: Four were incorrectly judged to contain sufficient material at the time of FNAC, one refused to complete the FNAC, and one had a vasovagal reaction. Of the six cases with insufficient specimens, four were benign at biopsy, one was malignant, and one was determined to be benign on the basis of mammographic stability. CONCLUSION: Modification of techniques and implementation of a quality assurance program can significantly improve the insufficient specimen rate for FNAC. Correlation of mammographic and cytologic findings also improves the management of these cases.

Residual silicone detection using MRI following previous breast implant removal: case reports.

The current controversy surrounding the safety of silicone gel breast implants has resulted in an increasing number being removed. Although previous reports have suggested that remnants of the implant capsule are reabsorbed after explantation surgery, the persistence of the capsule in fact may be associated with implant fragments and silicone gel leakage. In this study we have used magnetic resonance imaging (MRI) to identify residual silicone gel and silicone granulomas following the removal of silicone gel breast implants. Four representative clinical case reports are presented. These patients, who had residual silicone present in their bodies, presented to us with breast pain, palpable masses, or abnormal calcific mass densities apparent on a mammogram. High-resolution MRI images were found to be helpful in identifying local and remote collections of silicone gel, silicone granulomas, and residual capsules that were incompletely removed from previous explantation surgery. MRI breast images demonstrated high resolution and provided the accurate anatomical locations of residual silicone gel and silicone granulomas in all the regions of breast parenchyma, chest wall muscles, and axillae. Patients with persistent local symptoms following explantation surgery may benefit from an evaluation of the breast using MRI.

Evaluation of autogenous tissue breast reconstruction using MRI.

Recent controversy encountered with silicone breast implants has increased the use of autogenous tissue for breast reconstruction following mastectomy. Surveillance of patients who have undergone autogenous tissue reconstruction is important in the evaluation of recurrent or new cancer. Magnetic resonance imaging (MRI) has proven to be a useful technique in the delineation of soft tissues and provides excellent resolution. Recently, MRI has been reported to be a valuable diagnostic imaging modality for the evaluation of augmented breast implant patients with regard to implant rupture detection, silicone granuloma identification, and silicone gel migration delineation. In this study, various autologous tissue donor sites currently available for breast reconstruction were imaged by MRI. The following donor flaps were included: fleur-de-lis, TRAM, gluteal, and tensor fasciae latae. A total of 10 clinical cases were investigated. The anatomic basis of each flap type is illustrated, and various tissue components of flap tissue (skin, fat, and muscle) are demonstrated on MRI scan. Anatomic knowledge of autogenous tissue types and MRI appearance of the flap-breast-chest-wall interface are critical in the surveillance and follow-up of breast cancer patients.

Silicone implant rupture diagnosis using computed tomography: a case report and experience with 22 surgically removed implants.

Silicone elastomer shell rupture is a complication of silicone implants. To date, the rate of implant rupture has not been well documented. Magnetic resonance imaging and sonography are noninvasive breast implant imaging modalities that have been shown to be useful in evaluating the integrity of implants. We present a case of rupture detection using a follow-up computed tomographic (CT) scan of a breast cancer patient, which prompted us to use CT scans to evaluate explants of patients undergoing implant removal surgery. The purpose of the investigation was to evaluate the effectiveness of CT scan in detecting rupture. CT scan was performed on 22 explants with intact capsules, for which 17 ruptures were confirmed: 16 true-positive ruptures, 5 true-negative ruptures, O false-positive ruptures, and 1 false-negative rupture were identified. CT scan was shown to be highly sensitive and specific in rupture detection, comparable to magnetic resonance imaging. Although CT scans are consistently reliable, patients are exposed to ionizing radiation; therefore, it is not recommended for patients with augmentation mammoplasty. This study characterizes the appearance of implant rupture on CT scan, which may be useful in evaluating breast cancer patients reconstructed with silicone implants.

Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

Mammograms obtained with rhodium vs molybdenum anodes: contrast and dose differences.

OBJECTIVE: A mammography unit with both a molybdenum anode and a rhodium anode, filtered with molybdenum and rhodium, respectively, was evaluated to determine which types of women would benefit from the dose savings of the rhodium combination despite some loss of contrast. SUBJECTS AND MATERIALS: In 100 women, the molybdenum anode and molybdenum filtration (Mo/Mo) were used to obtain mammograms of the right breast, and the rhodium anode and rhodium filtration (Rh/Rh) were used for mammograms of the left breast. All mammograms were obtained at 26 kVp. All milliampere-second values used to radiograph the breasts of these women were recorded. Mammograms of 54 women (30 with previous mammograms available), representing the four types of breasts as defined by the American College of Radiology, were interpreted by three radiologists. Each mammogram was assigned a grade for breast type, preference (Rh/Rh, Mo/Mo, or previous mammograms), contrast, and sharpness. RESULTS: Overall, mammograms obtained by using the Mo/Mo combination were preferred. However, for images of types 3 and 4 breasts, Rh/Rh was preferred twice as often as it had been for mammograms of types 1 and 2 breasts. The mean glandular dose for all breast types when the Rh/Rh combination was used was 42% of the dose used for the Mo/Mo combination. For a 6-cm-thick dense breast, the Rh/Rh combination required 40% of the dose required for the Mo/Mo combination. CONCLUSION: Mammograms obtained with the Rh/Rh combination carried an overall decrease in contrast and mean glandular dose. However, for young women and some women with large dense breasts, the Rh/Rh mammograms were equivalent to or better than the mammograms obtained with the Mo/Mo combination. Effective use of Rh/Rh units requires careful selection of women based on age or the amount of glandular tissue seen on previous mammograms.

Linguine sign at MR imaging: does it represent the collapsed silicone implant shell?

One intact and one ruptured single-lumen implant were surgically placed in a rabbit. Magnetic resonance (MR) imaging was performed before and after surgical removal, and the ruptured implant was imaged after removal of the implant shell. Multiple curvilinear hypointense lines (linguine sign) were present in the MR images of the ruptured implant and of the implant shell alone immersed in saline solution but not in the image of the free silicone. The collapsed implant shell in a ruptured silicone implant does cause the linguine sign.

Mammography quality assurance from A to Z.

Quality assurance (QA) refers to all planned, systematic activities that instill confidence that quality mammography is being performed. Quality control (QC) refers only to the technical aspects of the examination. Standardized labeling of mammograms and the format for mammographic reports are important parts of a QA program; recommendations for both have been published by the American College of Radiology. Minimum staff for a mammography service consists of a scheduler, technologist(s), medical physicist, and radiologist. The scheduler asks the patient questions to ensure that the appropriate examination is performed, gives the patient instructions, and asks the patient to complete a history questionnaire including a release form to obtain earlier mammograms. One certified, licensed technologist is designated to perform QC, which includes maintaining darkroom, screen, and view box cleanliness; reviewing processor performance, checked with sensitometer, densitometer, and phantom images; repeat analysis; analysis of fixative retained in film, darkroom fog, screen-film contact, and adequacy of compression; and visual inspection of equipment. A certified medical physicist performs equipment acceptance testing and annual QC visits thereafter. The radiologist oversees all aspects of the QA program, including selecting and regularly observing the technologists, selecting and meeting with the physicist, communicating results, ensuring patient follow-up, and assessing patient outcome data. The radiologist is ultimately responsible for image quality and the standard of patient care.

Silicone breast implant rupture: comparison between three-point Dixon and fast spin-echo MR imaging.

OBJECTIVE: This study was designed to compare the three-point Dixon technique with our present MR protocol incorporating T2-weighted fast spin echo and fast spin echo with water suppression to detect ruptured silicone breast implants. SUBJECTS AND METHODS: Eighty-two symptomatic women with silicone breast implants were examined with both the three-point Dixon technique and fast spin-echo MR sequences. Of these patients, 41 had surgery to remove their implants. Four radiologists reviewed the images from only those patients who had surgery and graded each for rupture by using a scale of 1-5. Receiver-operating-characteristic analysis was performed. RESULTS: Of 81 implants removed, 18 were ruptured. Silicone implant ruptures were identified more frequently on the fast spin-echo sequence than on the three-point Dixon sequence, with areas under the ROC curves of .95 and .84, respectively. Although the difference was not statistically significant, the sensitivity for detecting silicone implant rupture was 89% for the fast spin-echo sequence and 61% for the three-point Dixon sequence. The specificity was 97% for both sequences. CONCLUSION: Silicone implant ruptures were detected more frequently with fast spin-echo MR sequences than with the three-point Dixon technique, although the difference was not significant. The greater spatial resolution used for the fast spin-echo sequence partially accounts for the difference in detection of implant ruptures in this study.

Silicone breast implant ruptures in an animal model: comparison of mammography, MR imaging, US, and CT.

PURPOSE: To determine the most accurate imaging modality for detection of silicone implant ruptures. MATERIALS AND METHODS: Forty single-lumen silicone implants were surgically placed in 20 rabbits. Each rabbit received one intact and one ruptured implant and was examined with mammography, magnetic resonance (MR) imaging, ultrasound (US), and computed tomography (CT). Five radiologists reviewed all images in a random fashion and graded each for rupture. The radiologist who performed US also graded her impression during examination with US. Receiver operating characteristic (ROC) analysis was performed. RESULTS: MR imaging and CT were the most accurate modalities in detection of implant ruptures, with areas under the ROC curves (Az) of .95 and .91. Mammography and US were statistically significantly inferior, with Az of .77 for each (P < .05). CONCLUSION: MR imaging and CT are statistically more accurate than US and mammography for detection of intracapsular silicone implant ruptures when only the images are reviewed.

Silicone breast implants: US evaluation.

PURPOSE: To determine the value of breast ultrasonography (US) in the assessment of silicone breast implants for rupture. MATERIALS AND METHODS: Seventy-four women with local or systemic symptoms related to silicone implants underwent breast US. Of these, 28 underwent surgical removal of the implants. RESULTS: Of 57 implants removed, 37 were intact. The most reliable sign of an intact implant was an anechoic interior, although reverberation artifact and radical folds could be seen. Of 20 ruptured implants, 16 were intracapsular and four were extracapsular ruptures. The most reliable US sign of rupture was echogenic, horizontal ("stepladder") lines (14 of 20 ruptures). Two of the four extracapsular ruptures were accurately identified as echogenic nodules outside the implant; two were false-negative findings. Three intracapsular ruptures identified at US were false-positive; six were false-negative. Overall sensitivity for rupture was 70%, specificity was 92%, positive predictive value was 82%, and negative predictive value was 85%. CONCLUSION: Breast US is capable of depicting intracapsular and extracapsular rupture of breast implants.

MR imaging of the breast in patients with silicone-gel implants: spectrum of findings.

Because of recent concerns about the potential dangers of rupture and leakage of silicone-gel implants, radiologists are often requested to evaluate the integrity of normal breast implants. Clinical studies suggest that MR imaging can accurately depict implant rupture. The purpose of this pictorial essay is to illustrate the spectrum of MR appearances of breasts in patients with silicone-gel implants. Types of prostheses range from the more common single-lumen silicone-gel implants to the rare foam-filled implants. Recognition of the variable appearance of intact implants is emphasized in order to distinguish these from intracapsular or extracapsular ruptures. Finally, we briefly review various investigational MR sequences designed to improve the evaluation of the integrity of silicone-gel implants and the localization of free silicone. This article is based on our experience in performing MR imaging in more than 350 patients with breast implants. In more than 50% of these patients, the MR imaging findings have been correlated with surgical and pathologic findings.

Definitive diagnosis of breast implant rupture using magnetic resonance imaging.

Breast implant rupture is an important complication of augmented and reconstructed breasts. Although several techniques such as mammography, xeromammography, ultrasound, thermography, and computed tomographic (CT) scanning have been proven to be useful to detect implant rupture, they have several disadvantages and lack specificity. In the current study, we have established magnetic resonance imaging (MRI) as a definitive, reliable, and reproducible technique to diagnose both intracapsular and extracapsular ruptures. The study was conducted in 100 symptomatic patients. Our imaging parameters were able to identify ruptures in implants with silicone shells. All the ruptures showed the presence of wavy lines, free-floating silicone shell within the gel ("free-floating loose-thread sign" or "linguine sign"). We had a 3.75 percent incidence of false-positive and false-negative results. The sensitivity for detection of silicone implant rupture was 76 percent, with a specificity of 97 percent. In addition, we also were able to identify the artifacts that may interfere with the definitive diagnosis of implant rupture.

Mammographic positioning: evaluation from the view box.

To evaluate the quality of breast positioning for mediolateral oblique (MLO) and craniocaudal (CC) views, a prospective study of 1,000 consecutive bilateral screening mammographic examinations was performed. Six criteria were tested, including depth of tissue seen, inferior extent of the pectoral muscle relative to the posterior nipple line, presence of fibroglandular tissue at the posterior edge of the film, and whether the nipple was in profile. Pectoral muscle was depicted to within 1 cm of the nipple line or below it on 1,612 of the 2,000 MLO mammograms (81%); all fibroglandular tissue was depicted on 1,532 MLO mammograms (77%). The depth of tissue depicted on the CC mammogram was within 1 cm greater or less than the depth on the MLO mammogram on 1,586 CC mammograms (79%); the pectoral muscle was seen on 646 CC mammograms (32%). The nipple was in profile in 1,769 MLO mammograms (88%) and 1,783 CC mammograms (89%) but not in profile in either view in 83 cases (4%). Overall improvement was seen in 400 of 587 examinations (68%) when new mammograms were compared with previous mammograms. These criteria can be used to evaluate positioning performance and for quality control.