Ki Keun Oh

Clinical application of the BI-RADS final assessment to breast sonography in conjunction with mammography.

OBJECTIVE The objective of our study was to report the results of classification of sonographic findings according to BI-RADS and to calculate the positive predictive value (PPV) for each BI-RADS assessment category. SUBJECTS AND METHODS We prospectively classified 4,668 breast sonograms according to BI-RADS final assessment category. Suspicious sonographic findings were divided into major and minor suspicious findings. Category 1 was normal and category 2 was a benign finding such as cyst or nodule with uniform and intense hyperechogenicity. A nodule neither category 2 nor category 4 or 5 was defined as category 3. A nodule with one or more suspicious findings, not category 5, was defined as category 4. A nodule with two or more major suspicious findings was defined as category 5. RESULTS Of the 4,668 cases, 321 cases failed to undergo follow-up of at least 1 year. The PPV was 0.1% in category 1 (3/2,191), 0% in category 2 (0/773), 0.8% in category 3 (6/737), 31.1% in category 4 (161/519), and 96.9% in category 5 (123/127). In palpable lesions (n = 751), the PPV was 2.2% in category 1 (2/93), 0.9% in category 3 (2/217), 54% in category 4 (107/198), and 98% in category 5 (98/100). In nonpalpable lesions (n = 3,596), the PPV was 0.05% in category 1 (1/2,098), 0.8% in category 3 (4/520), 16.8% in category 4 (54/321), and 92.6% in category 5 (25/27). CONCLUSION As with mammography, placing sonographic lesions into BI-RADS categories is useful for predicting the presence of malignancy.

Pregnancy- and Lactation-Associated Breast Cancer Mammographic and Sonographic Findings

Objective. To evaluate the mammographic and sonographic findings of pregnancy‐associated breast cancer. Methods. A total of 22 consecutive patients with breast cancer pathologically diagnosed during pregnancy (n = 10) or lactation (n = 12) were included in this study. The ages of the patients ranged from 26 to 49 years. Both mammography and sonography were performed on 12 patients; sonography only was performed on 7 patients; and mammography only was performed on 3 patients. Mammographic and sonographic findings were evaluated retrospectively. Results. Mammography revealed positive findings in 13 (86.7%) of 15 patients, even though all 15 patients had dense breasts. Mammographic findings included masses (n = 5), masses with calcifications (n = 2), calcifications with axillary lymphadenopathy (n = 2), a mass with axillary lymphadenopathy (n = 1), calcifications alone (n = 1), asymmetric density alone (n = 1), and diffuse skin and trabecular thickening alone (n = 1). Sonographic findings were positive and showed masses for all 19 patients (100%). The common sonographic findings of masses were irregular shapes (n = 15), irregular margins (n = 16), parallel orientation (n = 11), complex echo patterns (n = 14, including marked cystic [anechoic] components [n = 4]), and posterior acoustic enhancement (n = 12). Surrounding tissue effects could be seen in 5 patients, including ductal changes (n = 2), Cooper ligament thickening (n = 1), edema (n = 3), and skin thickening (n = 3). Calcifications within or outside a mass (n = 7) and axillary lymphadenopathy (n = 8) were also detected. Conclusions. Although a mass could not be discernible by mammography because of increased radiodensity during pregnancy or lactation, calcification, asymmetric density, axillary lymphadenopathy, and skin and trabecular thickening were helpful for diagnosis of pregnancy‐associated breast cancer. Sonographic findings of a solid mass with posterior acoustic enhancement and a marked cystic component were somewhat different from the appearance of breast cancer in nonpregnant women, possibly because of the physiologic changes of pregnancy and lactation.

Sonographically Guided 14-Gauge Core Needle Biopsy of Breast Masses: A Review of 2,420 Cases with Long-Term Follow-Up

OBJECTIVE The objective of our study was to determine the diagnostic accuracy of sonographically guided core needle biopsy for breast masses by evaluating the outcomes of benign biopsies that had at least a 2-year follow-up. MATERIALS AND METHODS In this retrospective study, we included a total of 2,420 lesions from 2,198 women who had undergone sonographically guided 14-gauge core needle biopsy. For evaluating the diagnostic accuracy of this procedure, the pathologic results were reviewed and correlated with rebiopsy or long-term imaging follow-up. Agreement rate, high-risk underestimate rate, ductal carcinoma in situ (DCIS) underestimate rate, and false-negative rate were assessed. The false-negative diagnoses of core needle biopsy were reviewed in detail. RESULTS The pathologic results for the core needle biopsies were malignant in 52%, high-risk in 4%, and benign in 44%. The agreement rate was 96% (2,328 of 2,420). The underestimate rate was 29% (36 of 126) for DCIS and 27% (25 of 93) for high-risk (52% for 27 atypical ductal hyperplasia (ADH), 17% for 66 non-ADH). Of 1,071 benign lesions, malignancy was found at rebiopsy in 31 lesions (25 immediate and six delayed false-negative diagnoses), and the false-negative rate was 2.4% (31 of 1,312). The frequency of malignancy in lesions that had rebiopsy because of suspicious imaging findings (19.1%, 26 of 136) was significantly higher than that because of suspicious physical findings or request by patient or physician (0.9%, five of 584). CONCLUSION Sonographically guided 14-gauge core needle biopsy is an accurate method for evaluating breast masses. Imaging-pathologic correlation and follow-up of benign biopsy are essential for a successful breast biopsy program.

Extrathyroid Extension of Well-Differentiated Papillary Thyroid Microcarcinoma on US

BACKGROUND Extrathyroidal extension is an important factor to determine the extent of thyroid surgery. The aim of the present study was to evaluate the usefulness of high-resolution ultrasound (US) for predicting the extrathyroidal extension of papillary thyroid microcarcinoma (PTMC). METHODS This study included a total of 221 PTMCs in 181 patients. PTMC was defined as thyroid papillary carcinoma equal or less than 1 cm in size. The US findings, such as contact and disruption of thyroid capsule, were evaluated to predict the extrathyroidal extension of thyroid carcinoma. We calculated the diagnostic accuracy and odds ratio for each US finding. RESULTS Of the 221 PTMCs, extrathyroidal extension was present in 89 (40.3%) based on pathologic results. The mean size was not significantly different between PTMCs with and without extrathyroidal extension (p = 0.527). When the degree of contact was high, extrathyroidal extension of the thyroid cancer was high (p < 0.0001). Considering the odds ratio, Az value, and positive predictive value of each US finding, more than 25% contact with the adjacent capsule is the most accurate measurement for predicting extrathyroidal extension. CONCLUSIONS This study suggests that the presence and degree of contact between a PTMC and the adjacent capsule as found on preoperative US can provide an useful predictive information about an extrathyroidal extension.

Radiologic and Clinical Features of Idiopathic Granulomatous Lobular Mastitis Mimicking Advanced Breast Cancer

Idiopathic granulomatous lobular mastitis (IGLM), also known as idiopathic granulomatous mastitis, is a rare chronic inflammatory lesion of the breast that can clinically and radiographically mimic breast carcinoma. The aim of this study was to describe the radiological imaging and clinical features of IGLM in order to better differentiate this disorder from breast cancer. We performed a retrospective analysis of the clinical and radiographic features of 11 women with a total of 12 IGLM lesions. The ages of these women ranged between 29 and 42 years, with a mean age of 34.8 years. Ten patients were examined by both mammography and sonography and one by sonography alone. The sites that were the most frequently involved were the peripheral (6/12), diffuse, (3/12), and subareolar (3/12) regions of the breast. The patient mammograms showed irregular ill-defined masses (7/11), diffuse increased densities (3/11), and one oval obscured mass. In addition, patient sonograms showed irregular tubular lesions (7/12) or lobulated masses with minimal parenchymal distortion (2/12), parenchymal distortion without definite mass lesions (2/12), and one oval mass. Subcutaneous fat obliteration (12/12) and skin thickening (11/12) were also observed in these patients. Contrary to previous reports, skin changes and subareolar involvement were not rare occurrences in IGLM. In conclusion, the sonographic features of IGLM show irregular or tubular hypoechoic masses with minimal parenchymal distortion. Both clinical information and the description of radiographic features of IGLM may aid in the differentiation between IGLM and breast cancer, however histological confirmation is still required for the proper diagnosis and treatment of the disorder.

Septic Arthritis Versus Transient Synovitis of the Hip: Gadolinium-Enhanced MRI Finding of Decreased Perfusion at the Femoral Epiphysis

OBJECTIVE The purpose of this study was to identify differences in the MRI findings of septic arthritis and transient synovitis in patients with nontraumatic acute hip pain and hip effusion. MATERIALS AND METHODS The MRI findings in nine patients with septic arthritis and 11 with transient synovitis were reviewed retrospectively. This study was approved by our institutional review board. The diagnoses were based on findings at physical examination, laboratory studies, and joint aspiration and bacteriologic study. The MRI findings were analyzed with emphasis on the grade of joint effusion, alterations in signal intensity in the soft tissues and bone marrow, and the presence of decreased perfusion at the femoral head. RESULTS Low signal intensity on fat-suppressed gadolinium-enhanced T1-weighted coronal MRI suggesting decreased perfusion at the femoral head of the affected hip joint was seen in eight of nine patients with septic arthritis and in two of 11 patients with transient synovitis. Statistically reliable differences (p = 0.005) were found between the two groups. Alterations in signal intensity in the bone marrow were seen in three patients with septic arthritis but in none of the patients with transient synovitis. Decreased perfusion on fat-suppressed gadolinium-enhanced coronal T1-weighted MRI was seen in the six patients with septic arthritis who did not have alterations in signal intensity involving the bone marrow. CONCLUSION Decreased perfusion at the femoral epiphysis on fat-suppressed gadolinium-enhanced coronal T1-weighted MRI is useful for differentiating septic arthritis from transient synovitis.

Thyroid Incidentalomas Identified by 18F-FDG PET: Sonographic Correlation

OBJECTIVE The purpose of this study was to evaluate the risk of malignancy of thyroid incidentalomas detected on (18)F-FDG PET and the diagnostic accuracy of sonography for differentiating benign from malignant focal thyroid incidentalomas that were detected on FDG PET. MATERIALS AND METHODS Retrospective review was performed of a database of 87 focal thyroid lesions seen on FDG PET and sonography. Forty-two focal lesions were malignant. We compared the accuracy of the maximum standard uptake value (SUV) to differentiate benign from malignant thyroid lesions. We classified the thyroid nodules as probably benign or suspicious for malignancy by the sonographic features. Statistical analyses compared two subgroups by sonographic classifications between benign and malignant thyroid lesions. RESULTS The maximum SUV of the malignant nodules was not significantly higher than that of benign lesions. Thirty-seven (75.5%) of 49 lesions with suspicious sonographic findings revealed malignancy on cytopathology, compared with five (13.2%) of 38 lesions that showed probably benign sonographic findings. These differences were statistically significant using a kappa test (kappa = 0.675, p = 0.001) and logistic regression (odds ratio = 26.2, p = 0.001). CONCLUSION The probability (48.3%) of malignancy of focal thyroid incidentalomas seen on FDG PET is high. The maximum SUV of thyroid cancer is not significantly higher than that of benign lesions. The probability (13.2%) of malignancy is much lower when the sonographic findings appear benign, as compared with a significantly higher probability (75.5%) of malignancy when the sonographic findings are suspicious for malignancy.

Ultrasonographic Characteristics of Subacute Granulomatous Thyroiditis

Objective We wanted to describe the characteristic ultrasonography (US) features and clinical findings for making the diagnosis of subacute granulomatous thyroiditis. Materials and Methods A total of 31 lesions from 27 patients were confirmed as subacute granulomatous thyroiditis by US-guided fine needle aspiration biopsy. We analyzed the ultrasonographic findings such as the lesions size, margin and shape, the discrepancy between length and breadth and the vascularity. The clinical findings such as acute neck pain or fever were reviewed. The follow-up clinical and ultrasonographic data were reviewed for 15 patients. Results The thyroid gland was found to be enlarged in five patients, it was normal size in 20 patients and it was smaller in two patients. All the lesions had focally ill-defined hypoechogenicity. Hypervascularity was not noted in any of the lesions. Painful neck swelling was present in 18 patients. An accompanying fever was documented in nine of the 18 patients. Twelve patients showed disappearance (n = 3) or a decreased size (n = 9) of their lesions on follow-up US. Conclusion The presence of ill-defined hypoechoic thyroid lesions without a discrete round or oval shape is characteristic for subacute granulomatous thyroiditis, and particularly when this is associated with painful neck swelling and/or fever.

The Role of Ultrasound in Thyroid Nodules with a Cytology Reading of Suspicious for Papillary Thyroid Carcinoma

BACKGROUND Irrespective of ultrasound (US) features, surgery is usually recommended for patients who have a fine-needle aspiration biopsy (FNAB) read as suspicious for papillary carcinoma (PTC). The aim of the present study was to evaluate the role of US in the management of thyroid nodules with a FNAB reading suspicious for PTC. METHODS Between August 2002 and May 2006, 303 patients who had thyroid nodules with a FNAB reading suspicious for PTC underwent surgery. The sonographic findings in the patients were classified as suspicious for malignancy or probably benign based on the US reading. The US readings and final pathological diagnoses of thyroid nodules were analyzed in these patients. RESULTS The malignancy rate was 84.2% in patients with a FNAB specimen suspicious for PTC. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the US were 96.4%, 74.5%, 92.7%, 94.9%, and 80.9%, respectively, in nodules read as suspicious for PTC on FNAB. Whereas 243 (96.4%) lesions were found to be malignant at surgery, in the 252 lesions that had ultrasound findings suspicious for malignancy, only 13 (25.5%) lesions were malignant out of the 51 that had US readings of probably benign (p < 0.05). CONCLUSIONS The probability of malignancy is much lower in thyroid nodules with benign US findings even if the FNAB is read as suspicious for PTC. Therefore, US may be useful in planning the extent of surgery in patients with a FNAB reading of suspicious for PTC. As thyroid malignancy occurs in approximately 26% of patients with cytology readings suspicious for PTC and benign-appearing US, the US reading alone is not sufficient to determine the need for surgery. The US and FNAB are complementary to each other and should be useful when providing informed consent before thyroid surgery.

Microwave detection of metastasized breast cancer cells in the lymph node; potential application for sentinel lymphadenectomy.

Metastasis is the leading cause of death in breast cancer patients and an appropriate detection of metastasis can provide better prognosis and quality treatments. Microwaves can reveal the unique electromagnetic properties of materials, and this study aims to unleash the electromagnetic properties of breast cancer cells, especially, metastasized cancer cells in the lymph nodes, using broad-band microwaves in attempts to detect metastases. To distinguish the cancer-specific patterns of cancer tissues, three primary microwave parameters were assessed, i.e., permittivity in mid-band frequency (3–5 GHz), conductivity in high-band frequencies (25–30 GHz) and slope changes of permittivity at high-band frequencies (15–30 GHz). An additional parameter, Cancer Metastasis Index (CMI), was developed to effectively represent all parameters. Broadband microwave scanning can reveal cancer specific electromagnetic behaviors in all three parameters, and these were reliably reflected by CMI. CMI effectively magnified the difference of the electromagnetic properties between normal nodal tissues and cancer tissues. immunohistochemistries were performed to verify the origin of electromagnetic changes represented by CMI values.