Faculty Bibliography

Apparent gadolinium-based contrast enhancement was seen on precontrast-enhanced images on two breast magnetic resonance imaging (MRI) for a patient done 1 week apart. This was caused by ferumoxytol, which is used to treat some anemias. Such nongadolinium-based therapeutics exhibiting unintended MRI contrast-like properties preclude assessment of enhancement kinetics in breast MRI significantly limiting diagnostic interpretation. This case prompted a group discussion and subsequent modification to the patient breast MRI safety screening questionnaire at our institution.

Objective/UNASSIGNED:The purpose of this study is to evaluate diffusion weighted magnetic rsonance imaging (MRI) acquisitions in delineating posterior extent of breast tumors and in predicting chest wall invasion prior to treatment. To our knowledge, there has not been any literature specifically evaluating the utility of diffusion-weighted acquisitions in chest wall invasion of breast tumors. Materials and Methods/UNASSIGNED:A retrospective review of our breast imaging database for keywords "chest wall invasion" and "breast MRI" was performed over the last 14 years. Diffusion sequences, T1 sequences (pre and post contrast), and T2 sequences were evaluated. Apparent diffusion coefficient (ADC) values in tumor and chest wall were assessed. Imaging findings were correlated with surgical pathology. Results/UNASSIGNED:in the chest wall. Sensitivity, specificity, positive predictive value and negative predictive value were 100%, 36%, 63%, and 100% for chest wall enhancement respectively and 69%, 36%, 61%, and 80% for chest wall diffusion-weighted imaging restriction respectively. Conclusion/UNASSIGNED:Diffusion weighted sequences can be helpful in characterizing chest wall invasion of breast tumors.

BACKGROUND:Medical silicone is widely used as implants and free injections but the spectrum of complications related to migration or embolization of silicone remains unclear. METHODS:We retrospectively reviewed 79 patients with silicone migration as confirmed on pathology between January 1, 2001 and December 31, 2016. The presenting clinical and imaging features, diagnostic testing, treatment, and outcome were assessed. RESULTS:Nearly all were women and 43% had a history of breast cancer. Sixty-three cases (80%) consisted of localized silicone granulomas, including one patient who developed severe hypercalcemia related to the granulomatous reaction. Remaining 16 cases (20%) involved migration of silicone to regional lymph nodes or distant tissue and included one case of chronic silicone pneumonitis. These complications were detected many years (median, 22 years; range, 1 to 40 years) after initial silicone placement. Only MRI, dual energy CT (DECT) and ultrasonography demonstrated specificity for detection of silicone in lymph nodes and soft tissues. Other modalities including PET, single energy CT, and mammography detected only nonspecific abnormalities. Excisional biopsy of symptomatic lymphadenopathy or masses usually led to resolution of symptoms. The patient with silicone pneumonitis improved with corticosteroid therapy. CONCLUSIONS:Chronic complications related to silicone extravasation and migration can present with local or distant manifestations, typically encountered many years after the original silicone placement. MRI, DECT and ultrasonography are helpful for non-invasive diagnosis.

In patients with silicone breast implants, implant rupture can occur, which can be intra- or extracapsular. Following implant rupture, silicone can travel through the lymphatic system into regional and distant lymph nodes. The purpose of this pictorial essay is to present findings of silicone implant rupture with intramammary and systemic silicone deposition as seen on dual energy CT, ultrasound, mammogram, PET/CT and MRI. We include imaging findings of silicone deposition in the breast in cases of intra- and extracapsular rupture. We also present silicone deposition in mediastinal, axillary, and internal mammary lymph nodes, as well as in the liver and spleen. To our knowledge, deposition of silicone in the liver and spleen has not been previously demonstrated on cross-sectional imaging. While all imaging modalities were able to detect silicone in the spleen, ultrasound appeared to be more sensitive than dual energy CT or MRI for detection of silicone deposition in the liver.

PURPOSE/OBJECTIVE:To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response. METHODS:Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features. RESULTS:Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN. CONCLUSIONS:The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.

Preoperative localization of breast malignancies using traditional ultrasound and digital techniques can be challenging, particularly after neoadjuvant chemotherapy when the target is not conspicuous. The purpose of this paper is to pictorially present nontraditional techniques that have been helpful in preoperative localization before surgery. We will discuss techniques for breast lesion localization using computed tomography (CT) and magnetic resonance imaging (MRI) as well as axillary lymph node localization using tomosynthesis, CT, and MRI.

OBJECTIVE:The purpose of this paper is to report on a case of a successful dorsal root entry zone procedure done for the treatment of postherpetic neuralgia and to provide unique MRI documentation outlining the precise location of the surgical lesion. CLINICAL PRESENTATION/METHODS:A 79-year-old female presented with postherpetic neuralgia in the left V1 distribution following a herpes zoster infection in that area 7 weeks earlier. She described the pain as constant, burning, aching, and throbbing, rating it as a 10 on a scale from 1 to 10. Prior to surgery, the patient was on large doses of narcotics, which were causing her to be severely somnolent. INTERVENTION OR TECHNIQUE: A dorsal root entry zone electrode with 2 mm of exposed tip was sequentially inserted into the dorsal root entry zone where 30-second, 80-degree lesions were made. The lesions were superficially continuous over the entire dorsal root entry zone from the upper cervical region to the obex. The postherpetic pain completely resolved immediately after surgery and the patient continued to have total pain relief 1 year later. An MRI performed 2 weeks after surgery clearly showed the location of the lesions. CONCLUSION/CONCLUSIONS:This unique clinical radiographic correlation shows that a nucleus caudalis dorsal root entry zone lesion, performed according to the described procedure, will be largely confined to the nucleus caudalis.