Audit of Prior Screening Mammograms of Screen-Detected Cancers: Implications for the Delay in Breast Cancer Detection.

When cancer is detected in a screening mammogram, on occasion retrospective review of prior screening (pre-index) mammograms indicates a likely presence of cancer. These missed cancers during pre-index screens constitute a delay in detection and diagnosis. This study was undertaken to quantify the missed cancer rate by auditing pre-index screens to improve the quality of mammography screening practice. From a cohort of 135 screen-detected cancers, 120 pre-index screening mammograms could be retrieved and served as the study sample. A consensus read by 2 radiologists who interpreted the pre-index screens in an unblinded manner with full knowledge of cancer location, cancer type, lesion type, and pathology served as the truth or reference standard. Five radiologists interpreted the pre-index screens in a blinded manner. Established performance metrics such as sensitivity and specificity were quantified for each reader in interpreting these pre-index screens in a blinded manner. All five radiologists detected lesions in 8/120 (6.7%) screens. Excluding the 2 readers whose performance was close to random, all the 3 remaining readers detected lesions in 13 pre-index screens. This indicates that there is a delay in diagnosis by at least one cycle from 8/120 (6.7%) to 13/120 (10.8%). There were no observable trends in terms of either the cancer type or the lesion type. Auditing prior screening mammograms in screen-detected cancers can help in identifying the proportion of cases that were missed during interpretation and help in quantifying the delay in breast cancer detection.

Positive Predictive Value of Tomosynthesis-guided Biopsies of Architectural Distortions Seen on Digital Breast Tomosynthesis and without an Ultrasound Correlate.

OBJECTIVE: The objective of the study was to determine the positive predictive value (PPV) of architectural distortions (AD) observed on digital breast tomosynthesis (DBT) and without an ultrasound (US) correlate. MATERIALS AND METHODS: In this single-institution, retrospective study, patients who underwent DBT-guided biopsies of AD without any associated findings on digital mammography (DM) or DBT, and without a correlate on targeted US exam, over a 14-month period were included in this study. All patients had DM and DBT and targeted US exams. The PPV was computed along with the exact 95% confidence limits (CL) using simple binomial proportions, with histopathology as the reference standard. RESULTS: A total of 45 ADs in 45 patients met the inclusion criteria. Histopathology indicated 6/45 (PPV: 13.3%, CL: 5.1-26.8%), ADs were malignant, including one high-risk lesion that was upgraded at surgery. ADs were appreciated only on DBT in 12/45 (26.7%) patients, and on both DBT and DM in 33/45 (73.3%) patients, and the corresponding PPV was 25% (3/12, CL: 5.5-57.2%) and 9.1% (3/33, CL: 1.9-24.3%), respectively. In all analyses, the observed PPV significantly exceeded the 2% probability of malignancy for Breast Imaging Reporting and Data System-3 diagnostic categories (P < 0.004). CONCLUSIONS: The PPV of malignancy in DBT detected AD without an US correlate in our series of 45 cases was 6/45 (13.3%). In the absence of an US correlate, the PPV of AD is lower than that mentioned in prior literature but exceeds the 2% threshold to justify DBT-guided biopsy.

Magnetic Resonance Imaging-Directed Ultrasound Imaging of Non-Mass Enhancement in the Breast: Outcomes and Frequency of Malignancy.

OBJECTIVES: This study was performed to determine the frequency, predictors, and outcomes of ultrasound (US) correlates for non-mass enhancement. METHODS: From January 2005 to December 2011, a retrospective review of 5837 consecutive breast magnetic resonance imaging examinations at our institution identified 918 non-mass enhancing lesions for which follow-up or biopsy was recommended. Retrospective review of the images identified 879 of 918 lesions (96%) meeting criteria for non-mass enhancement. Patient demographics, pathologic results, and the presence of an adjacent landmark were recorded. Targeted US examinations were recommended for 331 of 879 cases (38%), and 284 of 331 women (86%) underwent US evaluations. RESULTS: The US correlate rate for non-mass enhancement was 23% (64 of 284). An adjacent landmark was significantly associated with a US correlate (P < .001). Biopsy was recommended for 43 of 64 correlates (67%). Ultrasound-guided biopsy was performed on 39 of 43 (91%); 7 of 39 (18%) were malignant. No correlate was seen for 220 of 284 lesions (77%). At magnetic resonance imaging-guided biopsy, 14 of 117 (12%) were malignancies. For all biopsied non-mass enhancements, the malignancy rate was 18% (55 of 308) and was significantly more prevalent in the setting of a known index cancer (P < .001), older age (P < .001), the presence of a landmark (P = .002), and larger lesion size (P = .019). CONCLUSIONS: Non-mass enhancement with an adjacent landmark is more likely to have a US correlate compared to non-mass enhancement without an adjacent landmark. Non-mass enhancement in the setting of a known index cancer, older age, a landmark, and larger lesion size is more likely to be malignant. However, no statistical difference was detected in the rate of malignancy between non-mass enhancement with (18%) or without (12%) a correlate. Absence of a correlate does not obviate the need to biopsy suspicious non-mass enhancement.

Radiologic-Pathologic Discordance and Outcome After MRI-Guided Vacuum-Assisted Biopsy.

OBJECTIVE: The purpose of this study was to determine the rate, characteristics, and outcomes of discordant MRI-guided vacuum-assisted biopsy (VAB) in women with suspected breast cancer. MATERIALS AND METHODS: This retrospective study reviewed 1314 MRI-guided VABs performed in 1211 women between 2007 and 2013 and yielded 25 discordant results in 24 women. MRI characteristics; BI-RADS assessments; whether the lesion was missed, partially sampled, or excised at biopsy; and biopsy and surgical pathology results were reviewed. Statistical analyses were performed using Fisher exact and Mann-Whitney U tests. RESULTS: Among 1314 lesions that underwent MRI-guided VAB, 25 results were discordant (1.9%; 95% CI, 1.2-2.8%), and nine lesions with discordant results (36.0%, 95% CI, 18.5-56.9%) were malignant at surgical excision (three invasive ductal carcinoma and six ductal carcinoma in situ). There was no significant association between malignancy and lesion type, size, enhancement pattern, BI-RADS assessment, or clinical indication. Forty-four percent (11/25) of discordant lesions were missed, 48.0% (12/25) were partially sampled, and 8.0% (2/25) appeared to have been excised. Of the nine malignant lesions, 44.4% (4/9) discordant malignant lesions were missed, 44.4% (4/9) were partially sampled, and 11.1% (1/9) appeared to have been excised. Lesion sizes and types were similar in the missed and partially excised groups. CONCLUSION: The potential for false-negative results at MRI-guided VAB underscores the importance of radiologic-histologic correlation and imaging review after biopsy. Rebiopsy or excision in discordant cases is therefore recommended.

Congenital absence of the right pericardium: embryology and imaging.

Though congenital pericardial absence is often asymptomatic, complications can be life threatening. To date, few short case reports, primarily from the pre-CT and MR era, describe congenital absence of the right pericardium. We present a more comprehensive discussion of the embryologic derangements causing such defects and offer an up-to-date review of characteristic radiologic findings. Recognition of characteristic imaging findings of congenital pericardial absence is crucial in guiding diagnosis and management.

Fellow perceptions of training using computer-based endoscopy simulators.

BACKGROUND: Integrating procedural training by using computer-based endoscopic simulators (CBES) into gastroenterology fellowships may facilitate technical skill development, while posing no additional risk to patients. OBJECTIVE: The aim of our study was to survey pediatric gastroenterology fellows about their experiences with and perceptions of CBES as compared with actual procedures, prior to and after exposure to both types of endoscopic learning. DESIGN AND SETTING: All first-year trainees at Children's Hospital Boston (2003-2008) were invited to complete a written, pretraining questionnaire and then perform at least 10 each of CBES endoscopies and colonoscopies prior to performing actual procedures. Fellows completed a written, posttraining questionnaire after 4 months. MAIN OUTCOME MEASUREMENTS: Survey responses. RESULTS: All 25 first-year fellows (12 male, median age 30 years) over the 5-year period participated. Four months into their fellowships, fellows reported simulation to be helpful in increasing procedural skill and confidence. The number of sessions on the simulator was associated with reported increased colonoscopic skill and confidence (P = .032 and P = .007, respectively). All fellows reported it difficult to incorporate CBES into their work schedules. Only 28% of fellows reported performing 20 total CBES procedures, with most simulation sessions reportedly lasting less than 30 minutes. All participants rated faculty instruction with CBES as very helpful. LIMITATIONS: This was a single-site study of pediatric trainees and may be limited in generalizability. CONCLUSION: A few short sessions with CBES may be perceived as useful for endoscopic skill acquisition by pediatric gastroenterology trainees. Further exploration into how to assimilate CBES into busy gastroenterology training programs may be warranted.

Efficiency of propofol versus midazolam and fentanyl sedation at a pediatric teaching hospital: a prospective study.

BACKGROUND: Many pediatric endoscopists are adopting propofol in their practices, with the expectation that propofol will increase their overall efficiency. OBJECTIVE AND SETTING: To compare the efficiency of propofol versus midazolam and fentanyl by measuring elapsed times between initial intravenous administration and patient discharge at a pediatric teaching hospital. DESIGN: Endoscopy times were prospectively collected for consecutive patients who were undergoing either anesthesiologist-administered propofol or endoscopist-administered midazolam and fentanyl. The effect of the type of sedation on these times was assessed by using multiple linear regression by adjusting for other candidate predictors, including concomitant use of other sedatives, endotracheal intubation by anesthesiologists, and the presence of fellow trainees. MAIN OUTCOME MEASUREMENTS: Time to onset of sedation (time sedation started to scope in), procedure time (endoscope in to endoscope out), discharge time (endoscope out to hospital discharge), and total time (sedation started to hospital discharge). RESULTS: The times for 134 children (mean age 12 +/- 5 years) to receive propofol sedation were compared with those of 195 children (13 +/- 5 years) who received midazolam and fentanyl. Midazolam and fentanyl cases disproportionately included EGDs (P < .001) and patients who were classified as American Society of Anesthesiologists I (P < .03). Patients who received propofol had shorter times until sedated, similar procedure times, longer discharge times, and comparable total times. Multivariate analyses confirmed that fellow participation prolonged the procedure times (P < .0001), and endotracheal intubation prolonged propofol times (P <. 01), but adjusting for these did not change the comparison results. CONCLUSIONS: Anesthesiologist-administered propofol sedation in a pediatric teaching endoscopy unit may not lead to faster hospital times when compared with endoscopist-administered midazolam and fentanyl. These results are not explained by controlling for patient characteristics, the presence of a trainee, the sedative doses, or endotracheal intubation for airway management.

Microstream capnography improves patient monitoring during moderate sedation: a randomized, controlled trial.

BACKGROUND: Investigative efforts to improve monitoring during sedation for patients of all ages are part of a national agenda for patient safety. According to the Institute of Medicine, recent technological advances in patient monitoring have contributed to substantially decreased mortality for people receiving general anesthesia in operating room settings. Patient safety has not been similarly targeted for the several million children annually in the United States who receive moderate sedation without endotracheal intubation. Critical event analyses have documented that hypoxemia secondary to depressed respiratory activity is a principal risk factor for near misses and death in this population. Current guidelines for monitoring patient safety during moderate sedation in children call for continuous pulse oximetry and visual assessment, which may not detect alveolar hypoventilation until arterial oxygen desaturation has occurred. Microstream capnography may provide an "early warning system" by generating real-time waveforms of respiratory activity in nonintubated patients. OBJECTIVE: The aim of this study was to determine whether intervention based on capnography indications of alveolar hypoventilation reduces the incidence of arterial oxygen desaturation in nonintubated children receiving moderate sedation for nonsurgical procedures. PARTICIPANTS AND METHODS: We included 163 children undergoing 174 elective gastrointestinal procedures with moderate sedation in a pediatric endoscopy unit in a randomized, controlled trial. All of the patients received routine care, including 2-L supplemental oxygen via nasal cannula. Investigators, patients, and endoscopy staff were blinded to additional capnography monitoring. In the intervention arm, trained independent observers signaled to clinical staff if capnograms indicated alveolar hypoventilation for >15 seconds. In the control arm, observers signaled if capnograms indicated alveolar hypoventilation for >60 seconds. Endoscopy nurses responded to signals in both arms by encouraging patients to breathe deeply, even if routine patient monitoring did not indicate a change in respiratory status. OUTCOME MEASURES: Our primary outcome measure was patient arterial oxygen desaturation defined as a pulse oximetry reading of <95% for >5 seconds. Secondary outcome measures included documented assessments of abnormal ventilation, termination of the procedure secondary to concerns for patient safety, as well as other more rare adverse events including need for bag-mask ventilation, sedation reversal, or seizures. RESULTS: Children randomly assigned to the intervention arm were significantly less likely to experience arterial oxygen desaturation than children in the control arm. Two study patients had documented adverse events, with no procedures terminated for patient safety concerns. Intervention and control patients did not differ in baseline characteristics. Endoscopy staff documented poor ventilation in 3% of all procedures and no apnea. Capnography indicated alveolar hypoventilation during 56% of procedures and apnea during 24%. We found no change in magnitude or statistical significance of the intervention effect when we adjusted the analysis for age, sedative dose, or other covariates. CONCLUSIONS: The results of this controlled effectiveness trial support routine use of microstream capnography to detect alveolar hypoventilation and reduce hypoxemia during procedural sedation in children. In addition, capnography allowed early detection of arterial oxygen desaturation because of alveolar hypoventilation in the presence of supplemental oxygen. The current standard of care for monitoring all patients receiving sedation relies overtly on pulse oximetry, which does not measure ventilation. Most medical societies and regulatory organizations consider moderate sedation to be safe but also acknowledge serious associated risks, including suboptimal ventilation, airway obstruction, apnea, hypoxemia, hypoxia, and cardiopulmonary arrest. The results of this controlled trial suggest that microstream capnography improves the current standard of care for monitoring sedated children by allowing early detection of respiratory compromise, prompting intervention to minimize hypoxemia. Integrating capnography into patient monitoring protocols may ultimately improve the safety of nonintubated patients receiving moderate sedation.