Practice guideline for the performance of breast ultrasound elastography

Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented.

Inflammatory Pseudotumor of the Breast: a Case Report with Imaging Findings

Inflammatory pseudotumor, also known as inflammatory myofibroblastic tumor and plasma cell granuloma, is an uncommon low-grade lesion composed of spindle cells admixed with mature plasma cells and other inflammatory cells, such as histiocytes, lymphocytes, and eosinophils. Here, we describe the mammographic and ultrasonographic findings of a case of an inflammatory pseudotumor of the breast in a 60-year-old woman. With the suspicion of malignancy, core needle biopsy and surgical excision confirmed the mass as being an inflammatory pseudotumor of the breast.

Correlation between High Resolution Dynamic MR Features and Prognostic Factors in Breast Cancer

OBJECTIVE: To correlate high resolution dynamic MR features with prognostic factors in breast cancer. MATERIALS AND METHODS: One hundred and ninety-four women with invasive ductal carcinomas underwent dynamic MR imaging using T1-weighted three-dimensional fast low-angle shot (3D-FLASH) sequence within two weeks prior to surgery. Morphological and kinetic MR features were determined based on the breast imaging and reporting data system (BI-RADS) MR imaging lexicon. Histological specimens were analyzed for tumor size, axillary lymph node status, histological grade, expression of estrogen receptor (ER), expression of progesterone receptor (PR), and expression of p53, c-erbB-2, and Ki-67. Correlations between the MR features and prognostic factors were determined using the Pearson chi-square test, linear-by-linear association, and logistic regression analysis. RESULTS: By multivariate analysis, a spiculated margin was a significant, independent predictor of a lower histological grade (p < 0.001), and lower expression of Ki-67 (p = 0.007). Rim enhancement was significant, independent predictor of a higher histological grade (p < 0.001), negative expression of ER (p = 0.001), negative expression of PR (p < 0.001) and a larger tumor size (p = 0.006). A washout curve may predict a higher level of Ki-67 (p = 0.05). Most of the parameters of the initial enhancement phase cannot predict the status of the prognostic factors. Only the enhancement ratio may predict a larger tumor size (p = 0.05). CONCLUSION: Of the BI-RADS-MR features, a spiculated margin may predict favorable prognosis, whereas rim enhancement or washout may predict unfavorable prognosis of breast cancer.

Imaging and the Clinical-Pathologic Features of Invasive Micropapillary Carcinoma of the Breast

PURPOSE: The purpose of this study was to describe the mammographic and sonographic appearances and the clinical-pathologic features of invasive micropapillary carcinoma. MATERIALS AND METHODS: Between December 1999 and March 2005, among the 3,109 patients who underwent operation for breast cancer, 25 patients proved to have invasive micropaillary carcinoma. Among the 25 patients, we included 22 patients (mean age: 48, range: 26-77 years) who had undergone preoperative mammography and ultrasound. The mammographic and sonographic findings of the lesions were analyzed retrospectively. The pathologic findings were analyzed via the clinical records and pathology reports. RESULTS: Patients manifested with a palpable mass (77%, 17/22), bloody nipple discharge (14%, 3/22) or incidental lesion on the screening mammography (9%, 2/22). On mammography, a mass with an irregular (86%, 12/14) shape and an indistinct (43%, 6/14) or spiculated (43%, 6/14) margin was the most common findings on mammography. On sonography, a hypoechoic (91%, 20/22) mass with irregular shape (73%, 16/22) and an indistinct (32%, 7/22) or microlobulated (32%, 7/22) margin was the most common finding. Pathologically, axillary lymph node metastasis was present in 73% (16/22) of the patients. CONCLUSION: Invasive micropapillary carcinoma appeared an irregular shaped mass with an indistinct margin mass or microcalcifications on mammography and/or sonography. The tumors were frequently associated with axillary lymph node metastasis.

Reproducibility of Computer-Aided Detection Marks in Digital Mammography

OBJECTIVE: To evaluate the performance and reproducibility of a computer-aided detection (CAD) system in mediolateral oblique (MLO) digital mammograms taken serially, without release of breast compression. MATERIALS AND METHODS: A CAD system was applied preoperatively to the full-field digital mammograms of two MLO views taken without release of breast compression in 82 patients (age range: 33-83 years; mean age: 49 years) with previously diagnosed breast cancers. The total number of visible lesion components in 82 patients was 101: 66 masses and 35 microcalcifications. We analyzed the sensitivity and reproducibility of the CAD marks. RESULTS: he sensitivity of the CAD system for first MLO views was 71% (47/66) for masses and 80% (28/35) for microcalcifications. The sensitivity of the CAD system for second MLO views was 68% (45/66) for masses and 17% (6/35) for microcalcifications. In 84 ipsilateral serial MLO image sets (two patients had bilateral cancers), identical images, regardless of the existence of CAD marks, were obtained for 35% (29/84) and identical images with CAD marks were obtained for 29% (23/78). Identical images, regardless of the existence of CAD marks, for contralateral MLO images were 65% (52/80) and identical images with CAD marks were obtained for 28% (11/39). The reproducibility of CAD marks for the true positive masses in serial MLO views was 84% (42/50) and that for the true positive microcalcifications was 0% (0/34). CONCLUSION: The CAD system in digital mammograms showed a high sensitivity for detecting masses and microcalcifications. However, reproducibility of microcalcification marks was very low in MLO views taken serially without release of breast compression. Minute positional change and patient movement can alter the images and result in a significant effect on the algorithm utilized by the CAD for detecting microcalcifications.

Killian-Jamieson Diverticula Mimicking Thyroid Nodule on Ultrasound: Radiographic Findings in Two Patients

Killian-Jamieson diverticula are lateral diverticula in the cervical esophagus. Because of their location, they have been found incidentally during ultrasound (US) and they've sometimes been mistakenly identified for thyroid nodules. We describe here the US findings, the fine needle aspiration (FNA) procedure and the esophagography of a Killian-Jamieson diverticulum in a 70-year-old man. This diverticulum was considered to be a calcified thyroid nodule until we performed FNA. We will discuss the sonographic findings that are helpful for differentiating Killian-Jamieson diverticula from thyroid nodules. In addition, we describe the US findings of a small Killian-Jamieson diverticulum in a 34-year-old woman.

Comparison of 1.5T and 3T 1H MR Spectroscopy for Human Brain Tumors

OBJECTIVE: We wanted to estimate the practical improvements of 3T proton MR spectroscopy (1H MRS) as compared with 1.5T 1H MRS for the evaluation of human brain tumors. MATERIALS AND METHODS: Single voxel 1H MRS was performed at both 1.5T and 3T in 13 patients suffering with brain tumors. Using the same data acquisition parameters at both field strengths, the 1H MRS spectra were obtained with a short echo time (TE) (35 msec) and an intermediate TE (144 msec) with the voxel size ranging from 2.0 cm3 to 8.7 cm3. The signal to noise ratios (SNRs) of the metabolites (myoinositol (MI), choline compounds (Cho), creatine /phosphocreatine (Cr), N-acetyl-aspartate (NAA), lipid and lactate (LL)) and the metabolite ratios of MI/Cr, Cho/Cr, Cho/NAA and LL/Cr were compared at both TEs between the two field strengths in each brain tumor. The degrees of spectral resolution between the Cho and Cr peaks were qualitatively compared between the two field strengths in each brain tumor. RESULTS: The SNRs of the metabolites at 3T demonstrated 49-73% increase at a short TE (p 0.05) compared with those of 1.5T. The SNR of inverted lactate at an intermediate TE decreased down to 49% with poorer inversion at 3T (p < 0.05). There was no significant difference in the metabolite ratios between the two field strengths. The degrees of the spectral resolution at 3T were slightly superior to those of 1.5T at a short TE. CONCLUSION: As compared with 1.5T, 3T 1H MRS demonstrated 49-73% SNR increase in the cerebral metabolites and slightly superior spectral resolution only at a short TE, but little at an intermediate TE, in the brain tumors. There was no significant difference in the metabolite ratios between the two field strengths.

Metanephric Adenoma of the Kidney in an Infant: A Case Report

Metanephric adenoma is a rare tumor of the kidney that has been reported mostly in adults. Despite its rarity, metanephric adenoma should be included in any differential diagnosis of solid renal masses in children, especially because of its benign nature and benign clinical course allowing for nephron sparing surgery. We report a case of metanephric adenoma, presented as a solid renal mass in a 14-month-old boy, and discuss the histologic basis of the imaging features of this entity.

Sonographically Guided Core Biopsy of the Breast: Comparison of 14-Gauge Automated Gun and 11-Gauge Directional Vacuum-Assisted Biopsy Methods

OBJECTIVE: To compare the outcomes of 14-gauge automated biopsy and 11-gauge vacuum-assisted biopsy for the sonographically guided core biopsies of breast lesions. MATERIALS AND METHODS: We retrospectively reviewed all sonographically guided core biopsies performed from January 2002 to February 2004. The sonographically guided core biopsies were performed with using a 14-gauge automated gun on 562 breast lesions or with using an 11-gauge vacuum-assisted device on 417 lesions. The histologic findings were compared with the surgical, imaging and follow-up findings. The histologic underestimation rate, the repeat biopsy rate and the false negative rates were compared between the two groups. RESULTS: A repeat biopsy was performed on 49 benign lesions because of the core biopsy results of the high-risk lesions (n = 24), the imaging-histologic discordance (n = 5), and the imaging findings showing disease progression (n = 20). The total underestimation rates, according to the biopsy device, were 55% (12/22) for the 14-gauge automated gun biopsies and 36% (8/22) for the 11-gauge vacuum-assisted device (p = 0.226). The atypical ductal hyperplasia (ADH) underestimation (i.e., atypical ductal hyperplasia at core biopsy and carcinoma at surgery) was 58% (7/12) for the 14-gauge automated gun biopsies and 20% (1/5) for the 11-gauge vacuum-assisted biopsies. The ductal carcinoma in situ (DCIS) underestimation rate (i.e., ductal carcinoma in situ upon core biopsy and invasive carcinoma found at surgery) was 50% (5/10) for the 14-gauge automated gun biopsies and 41% (7/17) for the 11-gauge vacuum-assisted biopsies. The repeat biopsy rates were 6% (33/562) for the 14-gauge automated gun biopsies and 3.5% (16/417) for the 11-gauge vacuum-assisted biopsies. Only 5 (0.5%) of the 979 core biopsies were believed to have missed the malignant lesions. The false-negative rate was 3% (4 of 128 cancers) for the 14-gauge automated gun biopsies and 1% (1 of 69 cancers) for the 11-gauge vacuum-assisted biopsies. CONCLUSION: The outcomes of the sonographically guided core biopsies performed with the 11-gauge vacuum-assisted device were better than those outcomes of the biopsies performed with the 14-gauge automated gun in terms of underestimation, rebiopsy and the false negative rate, although these differences were not statistically significant.

Breast MR Imaging: Correlation of High Resolution Dynamic MR Findings with Prognostic Factors

PURPOSE: We wanted to correlate the kinetic and morphologic MR findings of invasive breast cancer with the classical and molecular prognostic factors. MATERIALS AND METHODS: Eighty-seven patients with invasive ductal carcinoma NOS underwent dynamic MR imaging at 1.5 T, and with using the T1-weighted 3D FLASH technique. The morphologic findings (shape, margin, internal enhancement of the mass or the enhancement distribution and the internal enhancement of any non-mass lesion) and the kinetic findings (the initial phase and the delayed phase of the time-signal Intensity curve) were interpreted using a ACR BI-RADS(R)174;-MRI lexicon. We correlate MR findings with histopathologic prognostic factors (tumor size, lymph node status and tumor grade) and the immunohistochemically detected biomarkers (ER, PR, p53, c-erbB-2, EGFR and Ki-67). Univariate and multivariate statistical analyses were then performed. RESULTS: Among the MR findings, a spiculated margin, rim enhancement and washout were significantly correlated with the prognostic factors. A spiculated margin was independently associated with the established predictors of a good prognosis (a lower histologic and nuclear grade, positive ER and PR) and rim enhancement was associated with a poor prognosis (a higher histologic and nuclear grade, negative ER and PR). Wash out was a independent predictor of Ki-67 activity. CONCLUSION: Some of the findings of high resolution dynamic MR imaging were associated with the prognostic factors, and these findings may predict the prognosis of breast cancer.

Reproducibility of Computer-Aided Detection System in Digital Mammograms

PURPOSE: To evaluate the reproducibility of the computer-aided detection (CAD) system for digital mammograms. MATERIALS AND METHODS: We applied the CAD system (ImageChecker M1000-DM, version 3.1; R2 Technology) to full field digital mammograms. These mammograms were taken twice at an interval of 10-45 days (mean: 25 days) for 34 preoperative patients (breast cancer n=27, benign disease n=7, age range: 20-66 years, mean age: 47.9 years). On the mammograms, lesions were visible in 19 patients and these were depicted as 15 masses and 12 calcification clusters. We analyzed the sensitivity, the false positive rate (FPR) and the reproducibility of the CAD marks. RESULTS: The broader sensitivities of the CAD system were 80% (12 of 15), 67% (10 of 15) for masses and those for calcification clusters were 100% (12 of 12). The strict sensitivities were 50% (15 of 30) and 50% (15 of 30) for masses and 92% (22 of 24) and 79% (19 of 24) for the clusters. The FPR for the masses was 0.21-0.22/image, the FPR for the clusters was 0.03-0.04/image and the total FPR was 0.24-0.26/image. Among 132 mammography images, the identical images regardless of the existence of CAD marks were 59% (78 of 132), and the identical images with CAD marks were 22% (15 of 69). The reproducibility of the CAD marks for the true positive mass was 67% (12 of 18) and 71% (17 of 24) for the true positive cluster. The reproducibility of CAD marks for the false positive mass was 8% (4 of 53), and the reproducibility of CAD marks for the false positive clusters was 14% (1 of 7). The reproducibility of the total mass marks was 23% (16 of 71), and the reproducibility of the total cluster marks was 58% (18 of 31). CONCLUSION: CAD system showed higher sensitivity and reproducibility of CAD marks for the calcification clusters which are related to breast cancer. Yet the overall reproducibility of CAD marks was low; therefore, the CAD system must be applied considering this limitation.

Ultrasound Assessment of Invasive Breast Cancer: Correlation with Histologic Grade

PURPOSE: To correlate the final assessment of ultrasound and histologic grade in patients with invasive breast cancer. MATERIALS AND METHODS: The study consisted of one hundred eighty-six women with breast masses that were evaluated by ultrasound and subsequently found to have invasive ductal carcinoma not previously diagnosed. Two radiologists prospectively analyzed the results of the ultrasounds and issued an American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) assessment category which indicates the probability of malignancy. The histologic grade of the 186 invasive ductal carcinomas were separated as follows, low grade in 22 lesions (9%), intermediate grade in 91 lesions (50%), and high grade in 73 lesions (41%). RESULTS: In the 186 invasive ductal carcinomas not previously diagnosed, a circumscribed margin was seen in 4% (three of 73) of high-grade tumors compared to none in intermediate-grade and low-grade tumors. A spiculated margin was seen in 59% (13 of 22) of low-grade tumors compared, to 20% (18 of 91) in intermediate-grade and 7% (five of 73) in high-grade tumors. Posterior acoustic enhancement was seen in 33% (24 of 73) of high-grade tumors compared, to 20% (18 of 91) in intermediate-grade and none in low-grade tumors. Posterior acoustic shadowing was seen in 59% (13 of 22) of low-grade tumors compared, to 34% (31 of 91) in intermediate-grade and 15% (11 of 73) in high-grade tumors. The final BI-RADS assessment of the 186 cases separated as follows, three lesions (2%) were category 3 probably benign, 115 lesions (62%) were category 4 suspicious, and 68 lesions (37%) were category 5 highly suggestive of malignancy. The three cases misclassified as probably benign were high-grade tumors. CONCLUSION: Breast cancer showing a spiculated margin and posterior acoustic shadowing on ultrasound were mainly low-grade tumors whereas breast cancer showing benign features were high-grade tumors.

Various Tumors in the 4th Ventricle in Adults: MRI Findings

Primary fourth ventricular neoplasms are common in children but rare in adults, and the disease categories encountered differ according to the patient's age. This study reviewed the records of patients aged 16 years or over, who underwent magnetic resonance (MR) imaging and were found to have fourth ventricular lesions. Most patients then underwent surgical resection, leading to specific pathologic diagnosis. The various fourth ventricular tumors encountered were ependymoma (n=8), subependymoma (n=1), choroid plexus papilloma (n=3), astrocytoma (n=3), medulloblastoma (n=1), lymphoma (n=2), epidermoid cyst (n=2), meningioma (n=1), melanoma (n=1), cavernous hemangioma (n=1) and metastasis (n=1). We describe the various tumors located mainly in the fourth ventricle and review their clinical presentation and the radiological findings, the majority of which were nonspecific. In some cases, however, specific signal intensity or the growth pattern of the tumors was useful for differential diagnosis.