Breast MRI in patients with implantable loop recorder: initial experience.

OBJECTIVES: To investigate the feasibility of breast MRI exams and guided biopsies in patients with an implantable loop recorder (ILR) as well as the impact ILRs may have on image interpretation. MATERIALS AND METHODS: This retrospective study examined breast MRIs of patients with ILR, from April 2008 to September 2022. Radiological reports and electronic medical records were reviewed for demographic characteristics, safety concerns, and imaging findings. MR images were analyzed and compared statistically for artifact quantification on the various pulse sequences. RESULTS: Overall, 40/82,778 (0.049%) MRIs during the study period included ILR. All MRIs were completed without early termination. No patient-related or device-related adverse events occurred. ILRs were most commonly located in the left lower-inner quadrant (64.6%). The main artifact was a signal intensity (SI) void in a dipole formation in the ILR bed with or without areas of peripheral high SI. Artifacts appeared greatest in the cranio-caudal axis (p < 0.001), followed by the anterior-posterior axis (p < 0.001), and then the right-left axis. High peripheral rim-like SI artifacts appeared on the post-contrast and subtracted T1-weighted images, mimicking suspicious enhancement. Artifacts were most prominent on diffusion-weighted (p < 0.001), followed by T2-weighted and T1-weighted images. In eight patients, suspicious findings were found on MRI, resulting in four additional malignant lesions. Of six patients with left breast cancer, the tumor was completely visible in five cases and partially obscured in one. CONCLUSION: Breast MRI is feasible and safe among patients with ILR and may provide a significant diagnostic value, albeit with localized, characteristic artifacts. CLINICAL RELEVANCE STATEMENT: Indicated breast MRI exams and guided biopsies can be safely performed in patients with implantable loop recorder. Nevertheless, radiologists should be aware of associated limitations including limited assessment of the inner left breast and pseudo-enhancement artifacts. KEY POINTS: • Breast MRI in patients with an implantable loop recorder is an infrequent, feasible, and safe procedure. • Despite limited breast visualization of the implantable loop recorder bed and characteristic artifacts, MRI depicted additional lesions in 8/40 (20%) of cases, half of which were malignant. • Breast MRI in patients with an implantable loop recorder should be performed when indicated, taking into consideration typical associated artifacts.

From bedside to portable and wearable: development of a conformable ultrasound patch for deep breast tissue imaging.

A breakthrough study from Du et al. has developed a wearable, ultrasound imaging patch for standardized and reproducible breast tissue imaging. The technology utilizes a honeycomb patch design to facilitate guided movement of the ultrasound array, enabling comprehensive, multiangle breast imaging. The system was validated in vitro and in vivo with a single human subject and has the potential for early-stage breast cancer detection. This study addressed the current limitations of wearable ultrasound technologies, including imaging over large, curvilinear organs and integration of superior piezoelectric materials for high-performance ultrasound arrays. The transition of ultrasound from the bedside to portable and wearable devices will pave the way for integration with big data collection, such as artificial intelligence (AI)-based diagnosis and personalized ultrasonographic profile generation, for rapid and objective measurements. This advancement is especially important in the context of breast cancer, where early diagnosis and assessment of medical therapy responses are paramount to patient care.

Incidental liver lesions on baseline breast MRI: Outcomes on subsequent abdominal imaging.

PURPOSE: To examine outcomes of incidental liver lesions on baseline breast magnetic resonance imaging (MRI) that were further evaluated with dedicated abdominal imaging. METHODS: Consecutive breast MRI reports from 2011 to 2016 were retrospectively reviewed to identify incidental liver lesions. Only patients without prior breast MRI, without prior abdominal imaging, and with subsequent abdominal imaging were included. Patient demographics, breast MRI indication, and final liver lesion diagnosis were recorded. RESULTS: Of 131 women (mean age 53.8 years), 94/131 (71.8%) underwent breast MRI for extent of disease evaluation, 25/131 (19.1%) for high-risk screening, 11/131 (8.4%) for implant evaluation, and 1/131 (0.8%) for problem-solving. Of 131 liver lesions (6-80 mm), 117/131 (89.3%) were deemed benign on subsequent abdominal imaging; 10/131 (7.6%) probably benign; and 4/131 lesions (3.1%) were confirmed breast cancer metastases. Metastatic liver lesions identified on breast MRI were more likely for women with a current diagnosis of breast cancer than for women without a current diagnosis of breast cancer: 4.3% vs 0%. Similarly, metastatic liver lesions identified on breast MRI were more likely for those with a higher prognostic stage (2 or 3) vs a lower prognostic stage (0 or 1) or no current breast cancer: 11.1% vs 0%. CONCLUSION: Baseline breast MRIs showing incidental liver lesions showed unsuspected liver metastases only in women with a current diagnosis of clinical stage 2 or 3 breast cancer. This suggests breast MRI indication and clinical staging of current breast cancer, if present, can help plan management and decisions to obtain follow-up of liver lesions.

Differentiation of mucinous cysts and simple cysts of the liver using preoperative imaging.

PURPOSE: Preoperative radiographic differentiation of mucinous cystic neoplasms (MCN) and simple cysts (SLC) of the liver is challenging. Previous data have demonstrated that the finding of septations arising from the cyst wall without indentation on cross-sectional imaging is associated with MCN. We aim to assess whether this radiographic feature is diagnostic of MCN. METHODS: A prospectively maintained database was queried for patients with a preoperative diagnosis of a cystic liver lesion who subsequently underwent operative intervention. The feature of septations without indentation of the cyst wall was evaluated on cross-sectional imaging obtained within 3 months of operation. Imaging was independently evaluated by three radiologists blinded to pathology and interobserver agreement was compared to assess the diagnostic accuracy of this feature as well as the overall likelihood of the lesion representing a MCN. RESULTS: There were 95 patients who met inclusion criteria; 80 (84%) had SLC on pathology, while 15 (16%) had MCN. Presence of septa without indentation of cyst wall had high sensitivity (range 80-87%), but low specificity (range 48-66%). Interobserver percent agreement (PA) was 51% [κ = 0.35 (95% CI 0.22-0.47)]. Sensitivity among the three radiologists ranged between 20 and 80% and specificity between 71 and 91% for the likelihood of the lesion representing MCN versus SLC, with an area under the curve (AUC) of 0.67-0.79; however, interobserver agreement was fair [κ = 0.40 (95% CI 0.25-0.55), PA = 67%]. CONCLUSION: The presence of septations without indentation of cyst wall demonstrates adequate sensitivity to differentiate MCN and SLC. However, there is variability for detection of this feature and therefore, it alone is of limited clinical value.

Tumor-Nipple Distance of ≥ 1 cm Predicts Negative Nipple Pathology After Neoadjuvant Chemotherapy.

BACKGROUND: As neoadjuvant chemotherapy (NAC) for breast cancer has become more widely used, so has nipple-sparing mastectomy. A common criterion for eligibility is a 1 cm tumor-to-nipple distance (TND), but its suitability after NAC is unclear. In this study, we examined factors predictive of negative nipple pathologic status (NS-) in women undergoing total mastectomy after NAC. METHODS: Women with invasive breast cancer treated with NAC and total mastectomy from August 2014 to April 2018 at our institution were retrospectively identified. Following review of pre- and post-NAC magnetic resonance imaging (MRI) and mammograms, the association of clinicopathologic and imaging variables with NS- was examined and the accuracy of 1 cm TND on imaging for predicting NS- was determined. RESULTS: Among 175 women undergoing 179 mastectomies, 74% of tumors were cT1-T2 and 67% were cN+ on pre-NAC staging; 10% (18/179) had invasive or in situ carcinoma in the nipple on final pathology. On multivariable analysis, after adjusting for age, grade, and tumor stage, three factors, namely number of positive nodes, pre-NAC nipple-areolar complex retraction, and decreasing TND, were significant predictors of nipple involvement (p < 0.05). The likelihood of NS- was higher with increasing TND on pre- and post-NAC imaging (p < 0.05). TND ≥ 1 cm predicted NS- in 97% and 95% of breasts on pre- and post-NAC imaging, respectively. CONCLUSIONS: Increasing TND was associated with a higher likelihood of NS-. A TND ≥ 1 cm on pre- or post-NAC imaging is highly predictive of NS- and could be used to determine eligibility for nipple-sparing mastectomy after NAC.

Accuracy of Magnetic Resonance Imaging-Guided Biopsy to Verify Breast Cancer Pathologic Complete Response After Neoadjuvant Chemotherapy: A Nonrandomized Controlled Trial.

Importance: After neoadjuvant chemotherapy (NAC), pathologic complete response (pCR) is an optimal outcome and a surrogate end point for improved disease-free and overall survival. To date, surgical resection remains the only reliable method for diagnosing pCR. Objective: To evaluate the accuracy of magnetic resonance imaging (MRI)-guided biopsy for diagnosing a pCR after NAC compared with reference-standard surgical resection. Design, Setting, and Participants: Single-arm, phase 1, nonrandomized controlled trial in a single tertiary care cancer center from September 26, 2017, to July 29, 2019. The median follow-up was 1.26 years (interquartile range, 0.85-1.59 years). Data analysis was performed in November 2019. Eligible patients had (1) stage IA to IIIC biopsy-proven operable invasive breast cancer; (2) standard-of-care NAC; (3) MRI before and after NAC, with imaging complete response defined as no residual enhancement on post-NAC MRI; and (4) definitive surgery. Patients were excluded if they were younger than 18 years, had a medical reason precluding study participation, or had a prior history of breast cancer. Interventions: Post-NAC MRI-guided biopsy without the use of intravenous contrast of the tumor bed before definitive surgery. Main Outcomes and Measures: The primary end point was the negative predictive value of MRI-guided biopsy, with true-negative defined as negative results of the biopsy (ie, no residual cancer) corresponding to a surgical pCR. Accuracy, sensitivity, positive predictive value, and specificity were also calculated. Two clinical definitions of pCR were independently evaluated: definition 1 was no residual invasive cancer; definition 2, no residual invasive or in situ cancer. Results: Twenty of 23 patients (87%) had evaluable data (median [interquartile range] age, 51.5 [39.0-57.5] years; 20 women [100%]; 13 White patients [65%]). Of the 20 patients, pre-NAC median tumor size on MRI was 3.0 cm (interquartile range, 2.0-5.0 cm). Nineteen of 20 patients (95%) had invasive ductal carcinoma; 15 of 20 (75%) had stage II cancer; 11 of 20 (55%) had ERBB2 (formerly HER2 or HER2/neu)-positive cancer; and 6 of 20 (30%) had triple-negative cancer. Surgical pathology demonstrated a pCR in 13 of 20 (65%) patients and no pCR in 7 of 20 patients (35%) when pCR definition 1 was used. Results of MRI-guided biopsy had a negative predictive value of 92.8% (95% CI, 66.2%-99.8%), with accuracy of 95% (95% CI, 75.1%-99.9%), sensitivity of 85.8% (95% CI, 42.0%-99.6%), positive predictive value of 100%, and specificity of 100% for pCR definition 1. Only 1 patient had a false-negative MRI-guided biopsy result (surgical pathology showed <0.02 cm of residual invasive cancer). Conclusions and Relevance: This study's results suggest that the accuracy of MRI-guided biopsy to diagnose a post-NAC pCR approaches that of reference-standard surgical resection. MRI-guided biopsy may be a viable alternative to surgical resection for this population after NAC, which supports the need for further investigation. Trial Registration: ClinicalTrials.gov Identifier: NCT03289195.

Waxing and waning pattern of mTOR inhibitor-associated pneumonitis in renal cell carcinoma patients: A retrospective observational study.

OBJECTIVE: mTOR inhibitor-associated pneumonitis is common and often asymptomatic. We describe a waxing and waning pattern of pneumonitis observed on computed tomography (CT) scans of patients with renal cell carcinoma who were being treated with mTOR inhibitor molecular targeted therapy. MATERIALS AND METHODS: In this HIPAA-compliant, IRB-approved retrospective single-institution study, 25 renal cell carcinoma patients were identified who received single-therapy temsirolimus or everolimus between January 2011 and June 2015 and who had chest CT scans available for review both before and after initiation of mTOR inhibitor treatment. A detailed review of the electronic medical record and serial chest CT examinations was performed. RESULTS: Radiologic findings compatible with pneumonitis were identified in 13/25 (52%) patients on mTOR inhibitors in our study. Of the patients with CT findings of pneumonitis, 8/13 (62%) demonstrated a waxing and waning pattern; of whom 7 had clinical symptoms of pneumonitis. Of the 17 patients who received temsirolimus, 9/17 (53%) developed radiologic findings compatible with pneumonitis and 4/9 (44%) developed a waxing and waning pattern. Of the 8 patients who received everolimus, 4/8 (50%) had radiologic findings compatible with pneumonitis and 4/4 (100%) developed a waxing and waning pattern. CONCLUSION: Waxing and waning is an unrecognized pattern of mTOR inhibitor-associated pneumonitis. Recognition of this pattern will promote clinical-radiologic concordance and may facilitate patient management.

Contrast-Enhanced Mammography for Screening Women after Breast Conserving Surgery.

To investigate the value of contrast-enhanced mammography (CEM) compared to full-field digital mammography (FFDM) in screening breast cancer patients after breast-conserving surgery (BCS), this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved retrospective, single-institution study included 971 CEM exams in 541 asymptomatic patients treated with BCS who underwent screening CEM between January 2013 and November 2018. Histopathology, or at least a one-year follow-up, was used as the standard of reference. Twenty-one of 541 patients (3.9%) were diagnosed with ipsi- or contralateral breast cancer: six (28.6%) cancers were seen with low-energy images (equivalent to FFDM), an additional nine (42.9%) cancers were detected only on iodine (contrast-enhanced) images, and six interval cancers were identified within 365 days of a negative screening CEM. Of the 10 ipsilateral cancers detected on CEM, four were detected on low-energy images (40%). Of the five contralateral cancers detected on CEM, two were detected on low-energy images (40%). Overall, the cancer detection rate (CDR) for CEM was 15.4/1000 (15/971), and the positive predictive value (PPV3) of the biopsies performed was 42.9% (15/35). For findings seen on low-energy images, with or without contrast, the CDR was 6.2/1000 (6/971), and the PPV3 of the biopsies performed was 37.5% (6/16). In the post-BCS screening setting, CEM has a higher CDR than FFDM.

Primary lymphoma of the breast: A report of two cases.

Primary breast lymphoma (PBL) should be distinguished from secondary breast lymphoma arising in the setting of lymphoma elsewhere in the body. Multimodality imaging is key to diagnosing PBL, and imaging manifestations thereof may indicate PBL and alter the treatment course. Treatment options including chemotherapy, radiation therapy, and/or surgery depend on histology. We report two cases of PBL, illustrating the transformative impact that multimodality imaging may have on clinical management.

Immunomodulatory Activity of a Colony-stimulating Factor-1 Receptor Inhibitor in Patients with Advanced Refractory Breast or Prostate Cancer: A Phase I Study.

PURPOSE: Tumor-associated macrophages correlate with increased invasiveness, growth, and immunosuppression. Activation of the colony-stimulating factor-1 receptor (CSF-1R) results in proliferation, differentiation, and migration of monocytes/macrophages. This phase I study evaluated the immunologic and clinical activity, and safety profile of CSF-1R inhibition with the mAb LY3022855. PATIENTS AND METHODS: Patients with advanced refractory metastatic breast cancer (MBC) or metastatic castration-resistant prostate cancer (mCRPC) were treated with LY3022855 intravenously in 6-week cycles in cohorts: (A) 1.25 mg/kg every 2 weeks (Q2W); (B) 1.0 mg/kg on weeks 1, 2, 4, and 5; (C) 100 mg once weekly; (D)100 mg Q2W. mCRPC patients were enrolled in cohorts A and B; patients with MBC were enrolled in all cohorts. Efficacy was assessed by RECIST and Prostate Cancer Clinical Trials Working Group 2 criteria. RESULTS: Thirty-four patients (22 MBC; 12 mCRPC) received ≥1 dose of LY3022855. At day 8, circulating CSF-1 levels increased and proinflammatory monocytes CD14DIMCD16BRIGHT decreased. Best RECIST response was stable disease in five patients with MBC (23%; duration, 82-302 days) and three patients with mCRPC (25%; duration, 50-124 days). Two patients with MBC (cohort A) had durable stable disease >9 months and a third patient with MBC had palpable reduction in a nontarget neck mass. Immune-related gene activation in tumor biopsies posttreatment was observed. Common any grade treatment-related adverse events were fatigue, decreased appetite, nausea, asymptomatic increased lipase, and creatine phosphokinase. CONCLUSIONS: LY3022855 was well tolerated and showed evidence of immune modulation. Clinically meaningful stable disease >9 months was observed in two patients with MBC.

PET-CT for Evaluating Breast Cancer Yields Incidental Finding in the Lung.

BACKGROUND: A woman aged 75 years presented with a palpable left axillary lymph node. Mammography showed a spiculated mass in the left breast, demonstrated by biopsy to be triple-negative breast cancer. A positron emission tomography-computed tomography (PET-CT) scan was performed to evaluate the extent of the cancer and revealed an unrelated nonmetastatic, synchronous carcinoid in the left lung. The patient was a nonsmoker and presented with no symptoms of lung disease. DISCUSSION: Advanced imaging modalities used to evaluate the extent of locally advanced breast cancer have been a keystone in decreasing cancer mortality rates. Mammography is considered the gold standard for breast disease evaluation, but sonography is a valuable modality for correlating suspicious findings and evaluating lesions that might not be visible on mammograms. When a breast biopsy confirms metastasis to the axillary lymph nodes, PET-CT is the modality of choice for cancer staging and ruling out distant metastases. CONCLUSION: Imaging tools used to evaluate breast cancer can help determine whether distant metastasis has occurred and in rare cases can help discover other primary cancers. The patient in this case study was 1 of the few patients with an incidental finding of a second nonmetastatic primary malignancy in the lung detected using PET-CT. The risks associated with advanced imaging include exposing patients to additional tests and potentially invasive procedures based on the results. However, in some instances, imaging results can alter the treatment plan and increase survival rates. Further empirical research and case studies are needed to identify clinical outcomes for patients with a second primary cancer.

Contamination artifact that mimics in-situ carcinoma on contrast-enhanced digital mammography.

PURPOSE: Contrast-enhanced digital mammography (CEDM) is an advanced breast imaging technique using iodinated intravenous contrast to detect breast cancer. This article describes imaging features of a skin contamination artifact on CEDM that mimics in-situ carcinoma in a case series. MATERIALS AND METHODS: Five patients were identified whose CEDM images demonstrated apparent calcifications and non-mass enhancement suspicious for in-situ carcinoma, with no subsequent evidence of disease. Retrospective image analysis was performed on the unprocessed image data, processed images, and imaging parameters. Dual-energy mammographic technique was performed on two breast phantoms with varying degrees of topical contrast contamination. RESULTS: Temporal analysis confirmed the suspicious finding was neither an abnormality of the compression paddle nor the receptor. Comparison of LE and HE images demonstrated the suspicious finding attenuated near the K-edge of iodine, suggesting contrast contamination. Iodinated contrast applied to the surface of breast phantoms replicated the artifact, with a pattern of apparent enhancement similar to the appearance of in-situ carcinoma. CONCLUSION: Skin contamination with iodinated contrast can result in an artifact on post-contrast digital mammography that mimics the appearance of in-situ carcinoma.

Thyroid neoplasms: incidental findings on extent of disease evaluation CT for other pediatric malignancies.

PURPOSE: We performed a retrospective analysis to evaluate the risk of thyroid cancer in incidental thyroid nodules (ITNs) discovered on CT in patients with a history of pediatric cancer. METHODS: With IRB approval we reviewed the records of pediatric oncology patients age ≤21y with newly detected thyroid nodules on surveillance CT of the neck, chest, chest/abdomen/pelvis, or PET/CT performed between April 2008 and March 2015. Patients with <6months of follow-up after incidental findings, a history of primary thyroid malignancy, or incomplete records were excluded. RESULTS: The final cohort (N=68) included 35 females and 33 males (mean age 16.0±4.3[SD] years) with a mean follow-up time of 3.7±1.9[SD] years after CT detection of ITN(s). Twenty patients (29.4%) received a follow-up thyroid ultrasound, eleven (16.2%) of whom underwent fine needle aspiration (FNA) for cytopathologic diagnosis. Among these, six (8.8%) underwent thyroid resection, with final pathology demonstrating papillary carcinoma in five (7.4%) and benign pathology in one. CONCLUSIONS: Despite the low incidence of thyroid nodules and low risk of thyroid malignancy in the general pediatric population, we found a significant rate of malignancy in CT-detected ITNs in our pediatric oncology patients, and recommend ultrasound and FNA of these nodules in this high-risk population. LEVEL OF EVIDENCE: Level IV, retrospective study with no comparison group.

Response rates of hepatic arterial infusion pump therapy in patients with metastatic colorectal cancer liver metastases refractory to all standard chemotherapies.

BACKGROUND AND OBJECTIVES: To evaluate the role of hepatic arterial infusion (HAI) in patients with metastatic colorectal cancer (mCRC) liver metastases (LM) refractory to oxaliplatin, irinotecan, and fluorouracil-based treatments. METHODS: A search identified patients with mCRC treated after tumor progression on at least three standard systemic therapies. RESULTS: One hundred and ten patients met criteria for inclusion (i.e., progression on at least three standard agents). Fifty seven patients had LM-only and 53 patients had LM and low volume extrahepatic metastases (LME). Patients with LM-only and LME had a response rate (RR) of 33% and 36%, median survival of 20 months and 11.4 months, respectively. Patients with LM-only had progression free survival of 6 months and hepatic progression free survival of 7.56 months. In a secondary analysis, 46 patients were RECIST-refractory to all standard therapies: LM-only (n = 24) and LME (n = 22). LM-only and LME had a RR of 29% and 36%, and median survival 17.2 months and 9.1 months, respectively. CONCLUSIONS: Patients with refractory mCRC LM can achieve a response to HAI resulting in antitumor activity and improvement in survival. Responses are rarely seen in such heavily treated patients with systemic therapy alone, suggesting a regional directed approach is useful. J. Surg. Oncol. 2016;114:655-663. © 2016 Wiley Periodicals, Inc.

Hepatocellular Carcinoma and Diffusion-Weighted MRI: Detection and Evaluation of Treatment Response.

Differentiating between cancerous tissue and healthy liver parenchyma could represent a challenge with the only conventional Magnetic Resonance (MR) imaging. Diffusion weighted imaging (DWI) exploits different tissue characteristics to conventional Magnetic Resonance Imaging (MRI) sequences that enhance hepatocellular carcinoma (HCC) detection, characterization, and post-treatment evaluation. Detection of HCC is improved by DWI, infact this technology increases conspicuity of lesions that might otherwise not be identified due to obscuration by adjacent vessels or due to low contrast between the lesion and background liver. It is important to remember that DWI combined with contrast-enhanced MRI has higher sensitivity than DWI alone, and that some patients are not eligible for use of contrast on CT and MRI; in these patients DWI has a prominent role. MRI has advanced beyond structural anatomic imaging to now showing pathophysiologic processes. DWI is a promising way to characterize lesions utilizing the inherent contrast within the liver and has the benefit of not requiring contrast injection. DWI improves detection and characterization of HCC. Proposed clinical uses for DWI include: assessing prognosis, predicting response, monitoring response to therapy, and distinguishing tumor recurrence from treatment effect. Ideally, DWI will help risk stratify patients and will participate in prognostic modeling.

The accuracy of pre-operative imaging in the management of hepatic cysts.

BACKGROUND: Biliary cystic tumours (BCT) [biliary cystadenoma (BCA) and cystadenocarcinoma (BCAC)] warrant complete resection. Simple liver cysts (SLC) require fenestration when symptomatic. Distinguishing between BCT and atypical SLC with pre-operative imaging is not well studied. METHODS: All patients undergoing surgery for a pre-operative suspected SLC or BCT between 1992 and 2014 were included. Peri-operative data were retrospectively reviewed. A blind radiological review of pre-operative imaging was performed. RESULTS: Ninety-four patients underwent fenestration (n = 54) or complete excision (n = 40). Final pathology was SLC (n = 74), BCA (n = 15), BCAC (n = 2) and other primary malignancies (n = 3). A frozen section (FS) was performed in 36 patients, impacting management in 10 (27.8%) by avoiding (n = 1) or mandating a liver resection (n = 9). Frozen section results were always concordant with final pathology. Upon blind review, a solitary lesion, suspicious intracystic component, septation and biliary dilatation were associated with BCT (P < 0.05). Diagnostic sensitivity was high (87.5-100%) but specificity was poor (43.1-53.4%). The diagnostic value of imaging was most accurate when negative for BCT (negative predictive value: 92.5-100%). CONCLUSION: Radiological assessment of hepatic cysts is relatively inaccurate as SLC frequently present with concerning features. In the absence of a strong suspicion of malignancy, fenestration and FS should be considered prior to a complete resection.

Saddle pulmonary embolism: is it as bad as it looks? A community hospital experience.

BACKGROUND: Saddle pulmonary embolism represents a large clot and a risk for sudden hemodynamic collapse. However, the clinical presentation and outcomes vary widely. On the basis of the findings of right heart dysfunction on echocardiograms, computed tomography angiography, or cardiac enzyme elevation, some argue for the use of thrombolytics or catheter thrombectomy even for hemodynamically stable patients. OBJECTIVE: To investigate the outcomes and management of patients with saddle pulmonary embolism, including radiographic appearance (estimate of clot burden) and echocardiographic features. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: This study is a retrospective evaluation of all patients with computed tomography angiography positive for pulmonary embolism from June 1, 2004, to February 28, 2009. Two radiologists selected those with saddle pulmonary embolism and evaluated the clot burden score. The clinical information, echocardiography, treatments, and outcomes of these patients were extracted via chart review. Saddle pulmonary embolism was found in 37 of 680 patients (5.4%, 95% confidence interval 4% to 7%) with documented pulmonary embolism on computed tomography angiography. For patients with saddle pulmonary embolism, the median age was 60 yrs and 41% were males. Major comorbidities were neurologic (24%), recent surgery (24%), and malignancy (22%). Transient hypotension occurred in 14% and persistent shock in 8%. One patient required mechanical ventilation. Echocardiography was performed in 27 patients (73%). Right ventricle enlargement and dysfunction were found in 78% and elevated pulmonary artery systolic pressure in 67%. Computed tomography angiography demonstrated a high median pulmonary artery clot burden score of 31 points. The median right ventricle to left ventricle diameter ratio was 1.39. Inferior vena cava filters were placed in 46%. Unfractionated heparin was administered in 33 (87%) and thrombolytics in four (11%). The median hospital length of stay was 9 days. Two of 37 saddle pulmonary embolism patients (5.4%) died in the hospital (95% confidence interval 0.7% to 18%). CONCLUSIONS: Most patients with saddle pulmonary embolism found on computed tomography angiography responded to the standard management for pulmonary embolism with unfractionated heparin. Although ominous in appearance, most patients with saddle pulmonary embolism are hemodynamically stable and do not require thrombolytic therapy or other interventions.