Diagnostic usefulness of water-to-fat ratio and choline concentration in malignant and benign breast lesions and normal breast parenchyma: an in vivo (1) H MRS study.

PURPOSE: To compare total choline concentrations ([Cho]) and water-to-fat (W/F) ratios of subtypes of malignant lesions, benign lesions, and normal breast parenchyma and determine their usefulness in breast cancer diagnosis. Reference standard was histology. MATERIALS AND METHODS: In this HIPPA compliant study, proton MRS was performed on 93 patients with suspicious lesions (>1 cm) who underwent MRI-guided interventional procedures, and on 27 prospectively accrued women enrolled for screening MRI. (W/F) and [Cho] values were calculated using MRS data. RESULTS: Among 88 MRS-evaluable histologically-confirmed lesions, 40 invasive ductal carcinoma (IDC); 10 invasive lobular carcinoma (ILC); 4 ductal carcinoma in situ (DCIS); 3 invasive mammary carcinoma (IMC); 31 benign. No significant difference observed in (W/F) between benign lesions and normal breast tissue. The area under curve (AUC) of receiver operating characteristic (ROC) curves for discriminating the malignant group from the benign group were 0.97, 0.72, and 0.99 using [Cho], (W/F) and their combination as biomarkers, respectively. (W/F) performs significantly (P < 0.0001;AUC = 0.96) better than [Cho] (AUC = 0.52) in differentiating IDC and ILC lesions. CONCLUSION: Although [Cho] and (W/F) are good biomarkers for differentiating malignancy, [Cho] is a better marker. Combining both can further improve diagnostic accuracy. IDC and ILC lesions have similar [Cho] levels but are discriminated using (W/F) values.

Imaging histologic discordance at MRI-guided 9-gauge vacuum-assisted breast biopsy.

OBJECTIVE: The purpose of this study was to determine the frequency of discordance at MRI-guided vacuum-assisted biopsy and to assess the cancer rate in discordant lesions. MATERIALS AND METHODS: With institutional review board approval, retrospective review was performed of a database of 342 lesions that had MRI-guided vacuum-assisted biopsy during a 39-month period. Biopsy samples were obtained in a 1.5-T magnet using a 9-gauge MRI-compatible vacuum-assisted biopsy device. Medical and pathology records were reviewed to determine the number of discordant lesions and surgical outcome. Statistical analysis was performed. RESULTS: Among 342 lesions that had MRI-guided vacuum-assisted biopsy, results were discordant in 24 (7% [95% CI, 3-14%]) lesions. The discordance rate was significantly (p < 0.001) higher among MRI target lesions that were possibly missed rather than sampled. A trend was seen (p < 0.06) toward a higher discordance rate in MRI lesions that were sampled rather than excised at MRI-guided vacuum-assisted biopsy. Subsequent surgery in 20 discordant lesions yielded cancer in six (30% [12-54%]), including ductal carcinoma in situ (DCIS) in two and invasive carcinoma in four (three ductal and one lobular, all with DCIS). The cancer rate among discordant lesions was significantly higher in postmenopausal women than in premenopausal women (p <0.05). CONCLUSION: Imaging-histologic discordance was found in 7% of lesions that had MRI-guided vacuum-assisted biopsy. Among discordant lesions, surgical excision revealed cancer in 30%. Imaging-histologic correlation is essential after MRI-guided vacuum-assisted biopsy to avoid delay in the diagnosis of breast cancer.

Enhancing nonmass lesions in the breast: evaluation with proton (1H) MR spectroscopy.

PURPOSE: To prospectively evaluate the sensitivity and specificity of proton (hydrogen 1 [1H]) magnetic resonance (MR) spectroscopy for diagnosing malignant enhancing nonmass lesions identified at breast MR imaging, with histologic examination as the reference standard. MATERIALS AND METHODS: In this HIPAA-compliant, institutional review board-approved study, in which all participants gave written informed consent, proton (1H) MR spectroscopy of the breast was performed in suspicious or biopsy-proved malignant lesions that were 1 cm or larger at MR imaging. Single-voxel proton (1H) MR spectroscopic data were collected. MR spectroscopic findings were defined as positive if the signal-to-noise ratio of the choline resonance peak was 2 or greater and as negative in all other cases. MR spectroscopic results were then compared with histologic findings, and statistical analysis was performed. RESULTS: In 32 women (median age, 48.5 years [range, 20-63 years]) with enhancing nonmass lesions, the median lesion size at MR imaging was 2.8 cm (range, 1.2-9.0 cm). At histologic analysis, 12 (37%) of 32 lesions were malignant and 20 (63%) were benign. Positive choline findings were present in 15 of 32 lesions, including all 12 (100%) cancers and three (15%) of 20 benign lesions, giving proton (1H) MR spectroscopy a sensitivity of 100% (95% confidence interval [CI]: 74%, 100%) and a specificity of 85% (95% CI: 62%, 97%) for detection of enhancing nonmass lesions. For 25 lesions with unknown histologic features, proton (1H) MR spectroscopy would have significantly (P<.01) increased the positive predictive value of biopsy from 20% to 63%. If biopsy had been performed for only those lesions with positive choline findings at proton (1H) MR spectroscopy, biopsy might have been avoided for 17 (68%) of 25 lesions, and no cancers would have been missed. CONCLUSION: Proton (1H) MR spectroscopy had 100% sensitivity and 85% specificity for the detection of malignancy in enhancing nonmass lesions.

Underestimation of atypical ductal hyperplasia at MRI-guided 9-gauge vacuum-assisted breast biopsy.

OBJECTIVE: The purposes of this study were to determine the frequency of diagnosis of atypical ductal hyperplasia (ADH) at MRI-guided 9-gauge vacuum-assisted breast biopsy and to assess the rate of underestimation of ADH at subsequent surgical excision. MATERIALS AND METHODS: We conducted a retrospective review of medical records of 237 lesions consecutively detected with MRI and then subjected to MRI-guided 9-gauge vacuum-assisted breast biopsy during a 33-month period. Underestimated ADH was defined as a lesion yielding ADH at vacuum-assisted biopsy and cancer at surgery. Scientific tables were used to calculate 95% CI. RESULTS: Histologic analysis of MRI-guided vacuum-assisted breast biopsy specimens yielded ADH without cancer in 15 (6%) of 237 lesions. Among 15 patients in whom vacuum-assisted breast biopsy yielded ADH, the median age was 52 years (range, 46-68 years). The median number of specimens obtained was nine (range, 8-18 lesions). Median MRI lesion diameter was 1.3 cm (range, 0.7-7.0 cm). Among 15 MRI lesions, 10 (67%) were nonmasslike enhancement and five (33%) were masses. Surgical excision was performed on 13 lesions. Surgical histologic findings were malignancy in five (38%) of the cases, all ductal carcinoma in situ; high-risk lesion in six (46%) of the cases, including ADH without other high-risk lesions (n = 2), ADH and lobular carcinoma in situ (LCIS) (n = 1), ADH, LCIS, and papilloma (n =1), ADH and papilloma (n = 1), and LCIS (n = 1); and benign in two (15%) of the cases. These data indicated an ADH underestimation rate of 38% (95% CI, 14-68%). CONCLUSION: ADH without cancer was encountered in 6% of MRI-guided 9-gauge vacuum-assisted breast biopsies. ADH at MRI-guided vacuum-assisted breast biopsy is an indication for surgical excision because of the high (38%) frequency of underestimation of these lesions.

Imaging breast cancer.

Imaging has a significant role in diagnosing, treating, and monitoring breast cancer. Advances in this field are having a great impact in the clinical management of this disease. Breast cancer has now become an "outpatient cancer". This article describes the role and advances of imaging in breast cancer.

Proton (1H) MR spectroscopy of the breast.

Proton (hydrogen 1) [1H]) magnetic resonance (MR) spectroscopy provides biochemical information about the tissue under investigation. Its diagnostic value in cancer is typically based on the detection of elevated levels of choline compounds, choline being a marker of active tumor. The two main potential clinical applications of 1H MR spectroscopy are (a) as an adjunct to breast MR imaging to improve specificity in differentiating benign from malignant lesions, and (b) for monitoring or even predicting response to treatment in patients undergoing neoadjuvant chemotherapy. Preliminary data are promising, with study results suggesting that 1H MR spectroscopy may decrease the number of benign biopsies recommended on the basis of MR imaging findings and may help predict response as early as 24 hours after the first dose of neoadjuvant chemotherapy. Although several limitations currently exist that make the technique premature for clinical use, further evaluation with larger, preferably multicenter trials is certainly warranted.

Is surgical excision warranted after benign, concordant diagnosis of papilloma at percutaneous breast biopsy?

OBJECTIVE: The study objective was to determine the cancer frequency in lesions yielding a benign, concordant diagnosis of papilloma at percutaneous breast biopsy. MATERIALS AND METHODS: Retrospective review was performed of 3,864 lesions that had percutaneous imaging-guided biopsy. In 50 lesions (1.3%), percutaneous biopsy yielded a benign, concordant diagnosis of papilloma. Surgical pathology (n = 25) or minimum 2 years' mammographic follow-up (n = 10) was available for 35 lesions that had biopsy with 11-gauge vacuum-assisted (n = 20) or 14-gauge automated (n = 15) needles. Medical records, imaging studies, and histologic results were reviewed. RESULTS: Cancer was found in five (14%) of the 35 lesions yielding a benign, concordant diagnosis of papilloma at percutaneous biopsy. Cancer histology was ductal carcinoma in situ in four (80%) and node-negative invasive cancer in one. Four (80%) of five cancers were identified due to interval change at follow-up (median, 22 months; range, 7-25 months). In six (17%) of 35 lesions, surgery revealed high-risk lesions including atypical ductal hyperplasia (n = 3), radial scar (n = 2), and lobular carcinoma in situ (n = 1). There was a significantly (p = 0.02) higher frequency of cancer or high-risk lesion in women with multiple versus solitary papillomas and a trend (p = 0.09) toward a higher cancer rate in women with versus without a family history of breast cancer. Breast cancer history, menopausal status, mammographic pattern, biopsy method, and removal of imaging target had no significant impact on cancer rate. CONCLUSION: In our study of percutaneously diagnosed papillomas, surgery revealed cancer in 14% and high-risk lesions in 17%. Lesions yielding a benign, concordant diagnosis of papilloma at percutaneous biopsy may warrant surgical excision.

Proton MR spectroscopy with choline peak as malignancy marker improves positive predictive value for breast cancer diagnosis: preliminary study.

PURPOSE: To prospectively evaluate the diagnostic performance of magnetic resonance (MR) spectroscopy in patients with suspicious lesions or biopsy-proved cancers at MR imaging by using histologic findings as the reference standard. MATERIALS AND METHODS: After institutional review board approval and informed consent were obtained for this HIPAA-compliant study, breast MR spectroscopy was performed in patients with suspicious or biopsy-proved malignant lesions measuring 1 cm or larger at MR imaging. Single-voxel MR spectroscopy data were collected from a single rectangular volume of interest that encompassed the lesion. MR spectroscopy findings were defined as positive if the signal-to-noise ratio of the choline resonance peak was greater than or equal to 2 and as negative in all other cases. MR spectroscopy findings were then compared with histologic findings. RESULTS: A total of 56 patients (age range, 20-77 years) with 57 lesions were imaged. The median lesion size at MR imaging was 2.3 cm (range, 1-15 cm). Histologically, 31 (54%) of 57 lesions were malignant, and 26 (46%) were benign. A choline peak was present in 34 of 57 lesions (including all cancers) and in three of 26 benign lesions, giving MR spectroscopy a sensitivity of 100% and a specificity of 88%. In 40 lesions of unknown histologic type, the use of MR spectroscopy as an adjunct to MR imaging would have significantly (P<.01) increased the positive predictive value of biopsy from 35% to 82%. If biopsy had been performed only on those lesions with a choline peak at MR spectroscopy, biopsy may have been spared in 23 (58%) of 40 lesions, and none of the cancers would have been missed. CONCLUSION: Proton MR spectroscopy was successfully incorporated into breast MR imaging studies for lesions measuring 1 cm or larger. This technique may be useful in reducing the number of lesions detected at MR imaging that require biopsy.

Nonpalpable mammographically occult invasive breast cancers detected by MRI.

OBJECTIVE: The purpose of this study was to determine the MRI findings and histology of clinically and mammographically occult invasive breast cancers detected by MRI. MATERIALS AND METHODS: A retrospective review was undertaken of 1,336 breast MRI examinations performed during a 2-year period. Among these, 68 nonpalpable mammographically occult invasive cancers were identified in 57 women with a median age of 50 years (range, 30-72 years). MRI findings were classified according to the breast MRI lexicon. Medical records were reviewed to determine the histology. RESULTS: Indications for performing MRI were extent of disease assessment in 72% (41/57), high-risk screening in 25% (14/57), and problem solving in 3% (2/57). MRI lesion types in these 68 invasive cancers were nonmass in 57% (39/68) and mass in 43% (29/68). Kinetics were plateau in 59% (40/68), washout in 38% (26/68), and persistent in 3% (2/68). Histology was invasive ductal cancer in 65% (44/68), mixed invasive ductal and lobular cancer in 19% (13/68), and invasive lobular cancer in 16% (11/68). The cancer stage was I in 61% (34/56), II in 32% (18/56), and more advanced in 7% (4/56). Sixty-three percent (43/68) of lesions were minimal cancers, defined as invasive cancers measuring under 1 cm. CONCLUSION: In this study of mammographically and clinically occult cancers detected by MRI, 57% (39/68) of invasive breast cancers were evident as nonmass enhancement, and 63% were minimal breast cancers.

Advances in breast imaging: magnetic resonance imaging.

Magnetic resonance imaging (MRI) of the breast is rapidly becoming incorporated into clinical practice. Indications for breast MRI include staging of known breast cancer, monitoring response to chemotherapy, assessing recurrence, problem solving, and high-risk screening. Magnetic resonance spectroscopy is a promising technique that may decrease the number of benign biopsies generated by breast MRI in the clinical setting.