Cancer Yield of Incidental Breast Lesions Detected on Chest Computed Tomography.

OBJECTIVE: This study aimed to determine the cancer yield for abnormal breast findings initially identified on chest computed tomography (CT). MATERIALS AND METHODS: This institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study retrospectively reviewed reports of 41,217 consecutive chest CT examinations done from January 1, 2006, to December 31, 2011, to identify those with breast findings noted in the impression of the report. Examinations done for staging of newly diagnosed breast cancer were excluded. The electronic medical record was searched for any subsequent breast imaging and any corresponding pathology results. Cancer yield was calculated. RESULTS: A total of 258 chest CT examinations with abnormal breast findings were identified in 218 unique patients. Average patient age was 65.6 years (range, 30-100 years). There were 207 women and 11 men. Of these, 75 patients had follow-up breast imaging in our system. One hundred forty-three patients did not have follow-up in our system and were excluded for purposes of cancer detection rate calculation. Thirteen of 75 patients were found to have lesions that were malignant: infiltrating ductal carcinoma (8), invasive lobular carcinoma (2), lymphoma (2), and intracystic papillary cancer with atypical features (1). Four of 75 patients underwent further workup and were found to have lesions that were benign: fibroadenoma (3) and benign fibrocystic change (1). The remainder of the 58 of 75 patients had dedicated breast imaging that was classified as either Breast Imaging Reporting and Data System score 1 or 2, and no further workup was performed. Cancer yield from CT findings was 17.3%. CONCLUSIONS: Abnormal CT findings in the breast warrant additional evaluation with dedicated breast imaging to evaluate for a possible underlying malignancy. Cancer yield from CT findings in this study was 17.3%.

Strengths and Weaknesses of Synthetic Mammography in Screening.

Synthetic mammography (SM) consists of two-dimensional images reconstructed from digital breast tomosynthesis (DBT) data. Unlike standard full-field digital mammography (FFDM), SM does not require additional radiation exposure. SM is being introduced in breast imaging centers because early clinical data demonstrate that synthetic images are comparable to FFDM in cancer detection, positive predictive values, and recall rates. SM has completely replaced FFDM in some practices. Thus, an understanding of SM and its strengths and weaknesses compared with those of FFDM is essential. The artifacts of SM include blurring subcutaneous tissue, loss of resolution in the axilla on mediolateral oblique views, pseudocalcifications, and decreased resolution near foreign bodies (eg, biopsy markers). SM's strengths include a reduced radiation dose, shorter acquisition time compared with a combined FFDM/DBT screening examination (with potentially less motion artifact), and increased conspicuity of calcifications, spiculated margins, and architectural distortion. The weaknesses of SM include the potential for false positives due to pseudocalcifications and the difficulty in assessing for motion artifact. This article reviews SM and its role in screening and presents clinical cases to highlight SM's strengths, weaknesses, and artifacts. ©RSNA, 2017.

Intra-operative microwave ablation of liver malignancies with tumour permittivity feedback control: a prospective ablate and resect study.

BACKGROUND: Tumour permittivity feedback control is a novel method for microwave ablation (MWA) that theoretically allows for larger, more predictable ablations. This prospective case series evaluates the feasibility and efficacy of MWA of liver malignancies using a device with tumour permittivity feedback control. METHODS: Ten consecutive patients initially determined to be candidates for surgical resection of a liver malignancy underwent intra-operative MWA with tumour permittivity feedback control followed by a surgical resection. A 14-gauge Medwaves microwave antenna was used to deliver a single treatment according to the manufacturer's recommendations. Tumours were assessed grossly as well as by haematoxylin and eosin (H&E) and tetrazolium chloride staining. The primary end point was per cent tumour necrosis. RESULTS: The median maximum ablation diameter measured was 4.1 cm (range 3.0-6.8). The median ablation volume was 8.7 cm(3) (range 4.84-17.55). Six of the 10 tumours demonstrated a pathological complete response (CR). Six of seven tumours ≤ 3 cm demonstrated a pathological CR. Zero of the three tumours ≥ 3 cm had a pathological CR, but all had ≥ 50% tumour necrosis. All patients survived and there were no ablation-related morbidities. DISCUSSION: MWA of liver tumours with tumour permittivity feedback control is feasible and appears effective for the treatment of small (< 3 cm) liver tumours.

Conspicuity of Screen-Detected Malignancies on Full Field Digital Mammography vs. Synthetic Mammography.

RATIONALE AND OBJECTIVES: To evaluate conspicuity of screen-detected cancers on two-dimensional synthetic mammography (SM) reconstructed from digital breast tomosynthesis (DBT) compared to two-dimensional full field digital mammography (FFDM). MATERIALS AND METHODS: IRB-approved retrospective review of consecutive screen-detected cancers from October 1, 2015 to June 30, 2017 was performed. All examinations were reviewed by three radiologists in consensus (n = 224); a score of 1-3 was given to each screen-detected cancer on SM vs. FFDM [1 = FFDM more conspicuous than SM, 2 = FFDM equivalent to SM, and 3 = SM more conspicuous than FFDM]. Findings considered only visible on tomosynthesis (n = 40), without medical history (n = 2), and with skin thickening only (n = 1) were excluded, leaving 181 cases as the study population. The longitudinal medical record was reviewed to determine patient demographics and outcomes of imaging surveillance and biopsy. RESULTS: Mammographic features on SM (n = 181) were calcifications (n = 68, 37.8%), masses (n = 51, 27.8%), asymmetries (n = 50, 27.6% [11 focal asymmetries]), and distortion (n = 12, 6.8%). The majority (76%, 137/181) of findings were equal or more conspicuous on SM vs. FFDM. However, calcifications and distortion greater than 2 cm were more conspicuous on SM and asymmetries were less conspicuous on SM vs. FFDM, controlling for menopausal status, family or personal history of breast cancer, BRCA status, and breast density. CONCLUSION: Although the majority of screen-detected cancers are equal to more conspicuous on SM when compared to FFDM, calcifications and asymmetries <2cm were less conspicuous on SM than FFDM. When SM + DBT is used as an alternative to FFDM + DBT in breast cancer screening, caution should be taken when assessing one-view asymmetries and findings <2cm on SM.

Cystic mediastinal masses and the role of MRI.

While some cystic masses can be definitively diagnosed on CT, others remain indeterminate. Because of its intrinsic superior soft tissue resolution, MR is an important tool in the evaluation of select mediastinal masses that are incompletely characterized on CT. This review describes how non-vascular MR provides greater diagnostic precision in the evaluation of indeterminate cystic mediastinal masses on CT. It also emphasizes key MR pulse sequences for optimal evaluation of problematic mediastinal masses.

Programmable shunts and headphones: Are they safe together?

OBJECT: Programmable shunts have a valuable role in the treatment of patients with hydrocephalus, but because a magnet is used to change valve settings, interactions with external magnets may reprogram these shunts. Previous studies have demonstrated the ability of magnetic toys and iPads to erroneously reprogram shunts. Headphones are even more ubiquitous, and they contain an electromagnet for sound projection that sits on the head very close to the shunt valve. This study is the first to look at the magnetic field emissions of headphones and their effect on reprogrammable shunt valves to ascertain whether headphones are safe for patients with these shunts to wear. METHODS: In this in vitro study of the magnetic properties of headphones and their interactions with 3 different programmable shunts, the authors evaluated Apple earbuds, Beats by Dr. Dre, and Bose QuietComfort Acoustic Noise Cancelling headphones. Each headphone was tested for electromagnetic field emissions using a direct current gaussmeter. The following valves were evaluated: Codman Hakim programmable valve, Medtronic Strata II valve, and Aesculap proGAV. Each valve was tested at distances of 0 to 50 mm (in 5-mm increments) from each headphone. The exposure time at each distance was 1 minute, and 3 trials were performed to confirm results at each valve setting and distance. RESULTS: All 3 headphones generated magnetic fields greater than the respective shunt manufacturer's recommended strength of exposure, but these fields did not persist beyond 5 mm. By 2 cm, the fields levels were below 20 G, well below the Medtronic recommendation of 90 G and the Codman recommendation of 80 G. Because the mechanism for the proGAV is different, there is no recommended gauss level. There was no change in gauss-level emissions by the headphones with changes in frequency and amplitude. Both the Strata and Codman-Hakim valves were reprogrammed by direct contact (distance 0 mm) with the Bose headphones. When a rotation component was added, all 3 headphones reprogrammed the Strata and Codman-Hakim valves at 0 mm. At all distances above 0 mm, the headphones did not affect the shunts. The proGAV valve was not affected by headphones at any distance. CONCLUSIONS: Although all the headphones studied generated significant gauss fields at distances less than 5 mm, the programmable valve settings only changed at a distance of 0 mm (i.e., with direct contact). Given the subcutaneous location of the valve, the authors conclude that is highly unlikely that commercially available or customary headphones can contribute to the reprogramming of shunts.