Yield of MR-directed US for MRI-detected breast findings: how often can we avoid MR biopsy?

PURPOSE: To evaluate the yield of MR-directed ultrasound for MRI detected breast findings. METHODS: This retrospective study included 857 consecutive patients who had a breast MRI between January 2017-December 2020 and received a BI-RADS 4 assessment. Only exams recommended for MR-directed ultrasound were included in the study, yielding 765 patients. Findings were characterized by presence or absence of a sonographic correlate. Utilizing the electronic medical record, for those with a sonographic correlate, the size, location, and morphology were noted. Imaging guided (Ultrasound and MRI) pathology results as well as excisional pathology results were recorded. A multivariable logistical regression analysis was used to investigate the clinical utility of MR-directed ultrasound. RESULTS: There were 1262 MRI-detected BI-RADS category 4 findings in 765 patients. Of the 1262 findings, MR-directed ultrasound was performed on 852 (68 %). Of these, 291/852 (34 %) had an ultrasound correlate, including 143/291 (49 %) benign lesions, 81/291 (28 %) malignant lesions, 16/291 (5 %) with high-risk pathology and 51/291 (18 %) unknown due to lost to follow-up. Of those findings with ultrasound correlates, 173/291 (59 %) represented masses, 69/291 (24 %) were regions of non-mass enhancement, 22/291 (7.6 %) were foci and 27/291 (9.3 %) fell into the category of other which included lymph node, cysts, and scar tissue. Masses were significantly more likely to be identified on MR-directed ultrasound (p < 0.0001) compared to foci. CONCLUSION: The yield of MR-directed ultrasound is significantly higher for masses, than foci and non-mass enhancement, which should be taken into consideration when recommending an MR-directed ultrasound.

Bleeding Events After Image-Guided Breast Biopsies: Comparison of Patients Temporarily Discontinuing Versus Maintaining Antithrombotic Therapy During Biopsy.

BACKGROUND. Antithrombic (AT) therapy is commonly temporarily discontinued before breast core needle biopsy (CNB), introducing risks of thrombotic events and diagnostic delay. OBJECTIVE. The purpose of this article was to compare the frequency of postbiopsy bleeding events among patients without AT use, patients temporarily discontinuing AT therapy, and patients maintaining AT therapy during breast CNB. METHODS. This retrospective study included 5302 patients (median age, 52 years) who underwent image-guided breast or axillary CNB between January 1, 2014, and December 31, 2019. From January 1, 2014, to December 31, 2016, patients temporarily discontinued all AT therapy for 5 days before CNB; from January 1, 2017, to December 31, 2019, patients maintained AT therapy during CNB. Immediate postbiopsy mammograms were reviewed for imaging-apparent hematoma. Patients were called 24-48 hours after biopsy and asked regarding palpable hematoma and breast bruise. The EMR was reviewed for clinically significant postbiopsy hematoma (i.e., hematoma requiring drainage, primary care or emergency department visit for persistent symptoms, or hospital admission). Bleeding events were compared among groups, including Firth bias-reduced multivariable logistic regression analysis. RESULTS. During CNB, 4665 patients were not receiving AT therapy, 423 temporarily discontinued AT therapy, and 214 maintained AT therapy. Imaging-apparent hematoma occurred in 3% of patients without AT use, 6% of patients discontinuing AT therapy, and 7% of patients maintaining AT therapy (p = .60 [discontinuing vs maintaining]). Palpable hematoma occurred in 2% of patients without AT use, 4% of patients maintaining AT therapy, and 4% of patients discontinuing AT therapy (p = .92 [discontinuing vs maintaining]). Breast bruise occurred in 2% of patients without AT use, 1% of patients discontinuing AT therapy, and 6% of patients maintaining AT therapy (p < .001 [discontinuing vs maintaining]). In multivariable analysis adjusting for age, biopsy imaging modality, needle gauge, number of biopsy samples, and pathologic result, discontinued AT therapy (using maintained AT therapy as reference) was not a significant independent predictor of imaging-apparent hematoma (p = .23) or palpable hematoma (p = .91) but independently predicted decreased risk of bruise (OR = 0.11, p < .001). No patient developed clinically significant postbiopsy hematoma. CONCLUSION. Frequencies of imaging-apparent and palpable hematoma were not significantly different between patients temporarily discontinuing versus maintaining AT therapy. CLINICAL IMPACT. The findings support the safety of continuing AT therapy during CNB. Patients who maintain AT therapy should be counseled regarding risk of bruise.

Barriers to breast cancer screening are worsened amidst COVID-19 pandemic: A review.

Disparities in screening mammography and barriers to accessing breast cancer screening are most prevalent among racial/ethnic minority and low-income women. The significant breast cancer mortality rates experienced in both Hispanic and African American populations are found to be connected to delayed screening. For these women to follow the screening guidelines outlined by the American College of Radiology and Society of Breast Imaging, they must successfully navigate existing barriers to screening. These barriers include differential access to care, language barriers, and lack of medical insurance. The COVID-19 Pandemic has worsened the barriers to breast cancer screening faced by these groups of women. These barriers need to be addressed or they may further exacerbate disparities.

Adding value in the era of COVID-19: Increasing usage of a patient-centered radiology consultation service.

OBJECTIVE: To examine the effects of COVID-19 pandemic on our department's Radiology Consultation Service (RCS) related to breast imaging, and how utilization of the provided services may have differed as compared to prior to the pandemic. MATERIALS AND METHODS: A retrospective cohort study of patients and health care providers who consulted the RCS, as well as those patients who had a screening mammogram and/or ultrasound between January 1, 2019 and September 1, 2020. Consultations were performed by an RRA, RN and one of 17 breast imaging radiologists assigned to consults on daily. Descriptive statistics were performed to describe the study subject population. RESULTS: Between January 1, 2020 and July 31, 2020, a total of 1623 consultations were performed, in comparison to the control period from the year prior (January 1, 2019 to July 31, 2019), when a total of 1398 consultations were performed, representing a 16% increase in one year. Between March 1, 2020 and June 30, 2020, a total of 679 consultations were performed, in comparison to the control period from the year prior (March 1, 2019 to June 30, 2019), when 583 consultations were performed, representing a 16.5% increase in a four-month period. 350 out of 679 (36.8%) consultations addressed COVID concerns. CONCLUSIONS: While much of radiology experienced an unprecedented decrease in imaging studies during the initial peak of COVID-19 crisis, the RCS at our institution showed a significant increase in services provided, evolving to address pressing concerns related to COVID-19.

Multispectral Imaging for Metallic Biopsy Marker Detection During MRI-Guided Breast Biopsy: A Feasibility Study for Clinical Translation.

PURPOSE: To assess the feasibility and diagnostic accuracy of multispectral MRI (MSI) in the detection and localization of biopsy markers during MRI-guided breast biopsy. METHODS: This prospective study included 20 patients undergoing MR-guided breast biopsy. In 10 patients (Group 1), MSI was acquired following tissue sampling and biopsy marker deployment. In the other 10 patients (Group 2), MSI was acquired following tissue sampling but before biopsy marker deployment (to simulate deployment failure). All patients received post-procedure mammograms. Group 1 and Group 2 designations, in combination with the post-procedure mammogram, served as the reference standard. The diagnostic performance of MSI for biopsy marker identification was independently evaluated by two readers using two-spectral-bin MR and one-spectral-bin MR. The κ statistic was used to assess inter-rater agreement for biopsy marker identification. RESULTS: The sensitivity, specificity, and accuracy of biopsy marker detection for readers 1 and 2 using 2-bin MSI were 90.0% (9/10) and 90.0% (9/10), 100.0% (10/10) and 100.0% (10/10), 95.0% (19/20) and 95.0% (19/20); and using 1-bin MSI were 70.0% (7/10) and 80.0% (8/10), 100.0% (8/8) and 100.0% (10/10), 85.0% (17/20) and 90.0% (18/20). Positive predictive value was 100% for both readers for all numbers of bins. Inter-rater agreement was excellent: κ was 1.0 for 2-bin MSI and 0.81 for 1-bin MSI. CONCLUSION: MSI is a feasible, diagnostically accurate technique for identifying metallic biopsy markers during MRI-guided breast biopsy and may eliminate the need for a post-procedure mammogram.

Breast cancer in women under age 40: A decade of trend analysis at a single institution.

BACKGROUND: Women should be evaluated for breast cancer risk by age 30 to assess for screening need. Recent trends in breast cancer in this population may further inform recommendations. OBJECTIVE: The aim of this study was to analyze trends over time in the rate of breast cancer, tumor characteristics and treatment in women under age 40. METHODS: Retrospective cohort study of women under age 40 at our institution diagnosed with breast cancer from January 2007 to April 2018 was conducted. Patient demographics, tumor characteristics and treatment outcomes were collected. Descriptive statistics and the Mann-Kendell Trend test were calculated. Two-proportion z-tests were used to compare proportions of stage, pathology and treatment between 2007-2013 and 2014-2018. RESULTS: 197 women under age 40 were treated for a new diagnosis of breast cancer at our institution. A higher proportion of women were diagnosed with invasive carcinoma in 2013-2018 (91%) compared to 2007-2012 (78%), p = 0.008. A higher proportion of women were diagnosed with advanced stage disease (stage III-IV) in 2013-2018 (24%) compared to 2007-2012 (2%), p = 0.001. No statistically significant evidence for an increasing trend of overall rate of breast cancer over the last 11 years (p = 0.419) was observed. CONCLUSIONS: While no statistically significant increase in overall rate of breast cancer was noted, an increase in invasive and later staged breast cancers was observed. CLINICAL IMPACT: Rise in more aggressive cancers in a population that is largely not screened may have implications both on the individual young woman's morbidity as well as on a public health level.

Project ScanVan: Mobile mammography services to decrease socioeconomic barriers and racial disparities among medically underserved women in NYC.

OBJECTIVE: To evaluate whether, with access to free screening services, uninsured minority women in NYC are able to successfully manage existing barriers to breast cancer screening. METHODS: This is a retrospective cohort study, with permission to use de-identified data received from Project Renewal's ScanVan in 2019. Project Renewal ScanVan provides clinical breast exams, mammograms, and health education to low-income women. The screening mammograms were conducted in the ScanVan and read by a board-certified radiologist. The electronic medical records were reviewed with respect to the patients' BI-RADS category, insurance status, race, and age. Descriptive statistics were performed and cancer detection rate, recall rate, and positive predictive values (PPV1, PPV2, PPV3) were calculated. RESULTS: In 2019, 66% (2499 of 3745) of patients who used the ScanVan were Hispanic & African American. 43% (1627 of 3745) of the women were uninsured, 15% (579 of 3745) of the women had Medicare, and 18% (676 of 3745) classified as other. 17 out of 3745 patients screened received a new diagnosis of breast cancer, corresponding to a cancer detection rate of 4.5/1000 screened. 258 were recalled, corresponding with a recall rate of 7%. The PPV1 was 6.5% (17/258); PPV2 was 29.8% (17/57); and PPV3 was 34% (17/50). CONCLUSION: Barriers to breast cancer screening include lack of medical insurance, limited access to care, and the absence of a primary care physician. The mobile mammography screening van successfully overcame such barriers, providing uninsured women from racial minority groups with vital breast cancer screening and follow up care.

Bleeding risk after percutaneous breast needle biopsy in patients on anticoagulation therapy.

Image-guided core needle biopsy (CNB) is the standard of care procedure for tissue diagnosis of suspicious breast lesions. While complications are exceedingly rare, the most common complications include bleeding and hematoma formation. With an increasing number of patients on anticoagulation therapy (AT), it is important to determine whether continuation of these medications during CNB increases bleeding risk. While previous studies have demonstrated the safety in continuation of AT during CNB, American College of Radiology (ACR) guidelines recommend practitioners decide whether cessation is necessary on a case-by-case basis as this may put patients at risk for thromboembolic events. The purpose of this review is to analyze the literature on anticoagulation and bleeding risk during CNB to guide clinical practice.

Effect of a communication lecture tutorial on breast imaging trainees' confidence with challenging breast imaging patient interactions.

PURPOSE: The aim of the study was to evaluate the effect of a one-hour lecture based communication curriculum on breast imaging trainees' confidence in communicating with patients in a challenging communication setting such as delivering bad news or radiologic error disclosure. METHODS: 12 breast imaging trainees from an academic fellowship program completed questionnaires before and after a communication tutorial. A four breast imaging specific scenario questionnaire assessed confidence by asking the trainees to rank agreement with statements related to their attitude in those specific settings. 12-month follow-up questionnaire was sent to the graduating fellows assessing their -overall confidence in patient communication, the contribution of the curriculum to their self-perceived communication skill and their likelihood in disclosing a radiologic error to a patient. RESULTS: All trainees completed the pre and post lecture questionnaire. After the communication tutorial, all trainees reported increased confidence in communicating with patients in a variety of challenging settings with pre lecture survey mean confidence score of 38/98 and post lecture survey mean score of 85.3/98, P = 0.003. Three of eight trainees who completed the 12-month follow up questionnaire reported confidence in their communication skills and reported that the tutorial significantly contributed to their communication skill development. All three agreed that they would be likely to disclose a medical error should they encounter it in their future career. CONCLUSIONS: A limited resource one-hour lecture communication tutorial provides effective communication training for breast imaging fellows and is a promising part of a breast imaging curriculum.

Dipole modeling of multispectral signal for detecting metallic biopsy markers during MRI-guided breast biopsy: a pilot study.

PURPOSE: During MRI-guided breast biopsy, a metallic biopsy marker is deployed at the biopsy site to guide future interventions. Conventional MRI during biopsy cannot distinguish such markers from biopsy site air, and a post-biopsy mammogram is therefore performed to localize marker placement. The purpose of this pilot study is to develop dipole modeling of multispectral signal (DIMMS) as an MRI alternative to eliminate the cost, inefficiency, inconvenience, and ionizing radiation of a mammogram for biopsy marker localization. METHODS: DIMMS detects and localizes the biopsy marker by fitting the measured multispectral imaging (MSI) signal to the MRI signal model and marker properties. MSI was performed on phantoms containing titanium biopsy markers and air to illustrate the clinical challenge that DIMMS addresses and on 20 patients undergoing MRI-guided breast biopsy to assess DIMMS feasibility for marker detection. DIMMS was compared to conventional MSI field map thresholding, using the post-procedure mammogram as the reference standard. RESULTS: Biopsy markers were detected and localized in 20 of 20 cases using MSI with automated DIMMS post-processing (using a threshold of 0.7) and in 18 of 20 cases using MSI field mapping (using a threshold of 0.65 kHz). CONCLUSION: MSI with DIMMS post-processing is a feasible technique for biopsy marker detection and localization during MRI-guided breast biopsy. With a 2-min MSI scan, DIMMS is a promising MRI alternative to the standard-of-care post-biopsy mammogram.

Screening Mammography for Women in Their 40s: The Potential Impact of the American Cancer Society and U.S. Preventive Services Task Force Breast Cancer Screening Recommendations.

OBJECTIVE: The purpose of this study was to review screening mammograms obtained in one practice with the primary endpoint of determining the rate of detection of breast cancer and associated prognostic features in women 40-44 and 45-49 years old. MATERIALS AND METHODS: The retrospective cohort study included women in their 40s with breast cancer detected at screening from June 2014 through May 2016. The focus was on cancer detection rate, pathologic findings, and risk factors. RESULTS: A total of 32,762 screens were performed, and 808 biopsies were recommended. These biopsies yielded 224 breast cancers (cancer detection rate, 6.84 per 1000 screens). Women 40-49 years old had 18.8% of cancers detected; 50-59 years, 21.8%; 60-69 years, 32.6%; and 70-79 years, 21.4%. Among the 40- to 49-year-old women, women 40-44 years old underwent 5481 (16.7%) screens, had 132 biopsies recommended, and had 20 breast cancers detected (cancer detection rate, 3.6/1000). Women 45-49 years old underwent 5319 (16.2%) screens, had 108 biopsies recommended, and had 22 breast cancers detected (cancer detection rate, 4.1/1000). Thus, women 40-44 years old had 8.9% and women 45-49 years old had 9.8% of all screen-detected breast cancers. Of these only a small percentage of women with detected cancers had a first-degree relative with breast cancer (40-44 years, 15%; 45-49 years, 32%) or a BRCA mutation (40-44 years, 5%; 45-49 years, 5%), and over 60% of the cancers were invasive. CONCLUSION: Women 40-49 years old had 18.8% of all screen-detected breast cancers. The two cohorts (40-44 and 45-49 years old) had similar incidences of screen-detected breast cancer (8.9%, 9.8%) and cancer detection rates within performance benchmark standards, supporting a similar recommendation for both cohorts and the American College of Radiology recommendation of annual screening mammography starting at age 40.

Breast cancer in women in their thirties (2007-2013): a retrospective review.

Due to an increasing number of breast cancer diagnoses in younger women anecdotally noted at our institution, we conceived of this study %was to retrospectively review the records of women diagnosed with breast cancer under the age of 40 for potentially alterable versus unalterable risk factors in their history. Between 2007 and 2013, there were 52 patients less than 40 years of age with breast cancer at our institution: 79% (41/52) presented with a clinical abnormality (palpable mass, nipple discharge or inversion) and 21% (11/52) were asymptomatic but diagnosed on early screening mammograms. Seventy-five percent (39/52) of the cancers had an invasive component and 87% (45/52) were intermediate to high grade. Sixty percent (31/52) of subjects had stage 0 or I disease, but 40% (21/52) had later stage disease (stage II or greater). The vast majority of the cancers were ER+ (82%) and PR+ (78%). Fifty-six percent (28/50; 2 unknown) of the subjects had a documented history of hormonal contraception. Fifty-three percent (27/51; 1 unknown) of had no family history of breast cancer whatsoever, and 80% (41/51) had no family history of breast cancer in a first degree relative. Six were positive for BRCA 1, 2, or a variant (6/52 = 12%).

Screening mammography for women in their 40s: a retrospective study of the potential impact of the U.S. Preventive Service Task Force's 2009 breast cancer screening recommendations.

OBJECTIVE: The objective of our study was to review screening mammography examinations performed at our institution from 2007 through 2010 with the primary endpoint of determining the incidence of breast cancer and associated histologic and prognostic features in women in their 40s. MATERIALS AND METHODS: Patients who presented for screening mammography who ultimately (i.e., after additional imaging, including diagnostic mammographic views and ultrasound) received a BI-RADS assessment of a category 4 or 5 for a suspicious abnormality were followed retrospectively through completion of care and were analyzed with respect to pathology results after biopsy, treatment, and family history. RESULTS: During the study period, 43,351 screening mammography examinations were performed; 1227 biopsies were recommended on the basis of those studies and yielded 205 breast cancers (cancer detection rate of 4.7 per 1000 screening examinations). These screening examinations included 14,528 (33.5%) screening examinations of patients in their 40s; 413 biopsies were recommended and yielded 39 breast cancers (39/205 = 19%) (cancer detection rate of 2.7 per 1000 screening examinations). More than 50% (21/39) of the cancers in women in their 40s were invasive. Only 8% (3/39) of the women in their 40s with screening-detected breast cancer had a first-degree relative with breast cancer. CONCLUSION: From 2007 through 2010, patients in their 40s accounted for one third of the population undergoing screening mammography and for nearly 20% of the screening-detected breast cancers--more than half of which were invasive. This information should be a useful contribution to counseling women in this age group when discussing whether or not to pursue regular screening mammography.

Using CT perfusion during the early baseline period in aneurysmal subarachnoid hemorrhage to assess for development of vasospasm.

INTRODUCTION: The aim of this study is to evaluate computed tomography perfusion (CTP) during admission baseline period (days 0-3) in aneurysmal subarachnoid hemorrhage (A-SAH) for development of vasospasm. METHODS: Retrospective analysis was performed on A-SAH patients from Dec 2004 to Feb 2007 with CTP on days 0-3. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were analyzed for qualitative perfusion deficits. Quantitative analysis was performed using region-of-interest placement to obtain mean CTP values. Development of vasospasm was determined by a multistage hierarchical reference standard incorporating both imaging and clinical criteria. Student's t test and threshold analysis were performed. RESULTS: Seventy-five patients were included, 37% (28/75) were classified as vasospasm. Mean CTP values in vasospasm compared to no vasospasm groups were: CBF 31.90 ml/100 g/min vs. 39.88 ml/100 g/min (P < 0.05), MTT 7.12 s vs. 5.03 s (P < 0.01), and CBV 1.86 ml/100 g vs. 2.02 ml/100 g (P = 0.058). Fifteen patients had qualitative perfusion deficits with 73% (11/15) developed vasospasm. Optimal threshold for CBF is 24-25 mL/100 g/min with 91% specificity and 50% sensitivity, MTT is 5.5 s with 70% specificity and 61% sensitivity and CBV is 1.7 mL/100 g with 89% specificity and 36% sensitivity. CONCLUSION: These initial results support our hypothesis that A-SAH patients who develop vasospasm may demonstrate early alterations in cerebral perfusion, with statistically significant CBF reduction and MTT prolongation. Overall, CTP has high specificity for development of vasospasm. Future clinical implications include using CTP during the baseline period for early identification of A-SAH patients at high risk for vasospasm to prompt robust preventative measures and treatment.

Developing a new reference standard: is validation necessary?

RATIONALE AND OBJECTIVES: A gold standard is often an imperfect diagnostic test, falling short of achieving 100% accuracy in clinical practice. Using an imperfect gold standard without fully comprehending its limitations and biases can lead to erroneous classification of patients with and without disease. This will ultimately affect treatment decisions and patient outcomes. Therefore, validation is essential before implementing a reference standard into practice. Performing a comprehensive validation process is discussed, along with its advantages and challenges. The different types of validation methods are reviewed. An example from our work in developing a new reference standard for vasospasm diagnosis in aneurysmal subarachnoid hemorrhage patients is provided. CONCLUSION: Employing a new reference standard may result in a definitional shift of the disease and classification scheme of patients; therefore, it is important to also assess the impact of a new reference standard on patient outcomes and its clinical effectiveness.

Validation of a new reference standard for the diagnosis of vasospasm.

RATIONALE AND OBJECTIVES: The purpose of our study is to perform an internal validation of a new reference standard for vasospasm diagnosis in aneurysmal subarachnoid hemorrhage (A-SAH) patients. MATERIALS AND METHODS: A retrospective study was performed on A-SAH patients between January 2002 and May 2009. All patients were applied to this new reference standard using a multistage hierarchical approach incorporating clinical and imaging criteria. An internal validation method was performed in two phases to compare the new reference standard with digital subtraction angiography (DSA) and to assess accuracy. In Phase I, the diagnostic outcomes from DSA at the primary level were compared with the secondary/tertiary levels in the reference standard. In Phase II, the new reference standard was compared with chart diagnosis. Accuracy test characteristics, agreement rates, kappa values, and bias indices were calculated. RESULTS: In Phase I (n = 85), there was 87% agreement rate, 0.674 kappa, and 0.12 bias index. However, there was 100% agreement in patients diagnosed with vasospasm by DSA. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 100%, 61%, 83%, and 100% respectively. In Phase II (n = 137), there was 91% agreement rate, 0.824 kappa, and 0.04 bias index. Sensitivity, specificity, PPV, and NPV were 88%, 95%, 96%, and 87%, respectively. CONCLUSION: Performing validation methods for a new reference standard is an evolving and ongoing process because limitations and bias in the reference standard are identified. Based on the results of this internal validation, a modification in the new reference standard is made at the primary level, resulting in improvement in its accuracy and classification of A-SAH patients.

Pulmonary blastoma in a neonate: a lesion distinct from pleuropulmonary blastoma with unique cytogenetic features.

Pulmonary blastoma is a rare malignant primary lung neoplasm typically seen in adults that accounts for 0.3-1.3% of lung malignancies. It has been categorized as a subtype of sarcomatoid carcinoma according to the current World Health Organization Classification of Lung Tumours and is distinct from the more common pediatric lung tumor pleuropulmonary blastoma. We report a case of neonatal pulmonary blastoma, illustrating the imaging characteristics of this rare tumor. The subject of pediatric lung masses is confusing because the terms pleuropulmonary blastoma and pulmonary blastoma have been used interchangeably in previously reported cases. We recommend use of the current WHO classification to differentiate these lesions as additional cases are described. Additionally, we discuss distinctive cytogenetic features of this case.

Work-in-progress toward incorporating patients' preferences in practice guidelines for imaging aneurysmal subarachnoid hemorrhage.

RATIONALE AND OBJECTIVES: Patient-centered care has become a primary focus in clinical practice. In developing practice guidelines for clinical care, the patients' perspective is an important component. MATERIALS AND METHODS: Patients' preferences are represented in a decision analytic model as quality-of-life weights for different health states associated with the aneurysmal subarachnoid hemorrhage population. The time-tradeoff method is used to obtain the individual patients' preferences, which are directly measured in quality-adjusted life years. An individualized care model is explained as a means of implementing a patient-centered approach into practice guidelines for clinical care. A method for calculating the expected value for societal benefit from improved decision making using an individualized care model is reviewed. RESULTS: We discuss our work-in-progress towards incorporating patients' preferences in a decision analytic model for aneurysmal subarachnoid hemorrhage patients. The main methodologic concerns for using patients' preferences in cost-effectiveness analyses for developing practice guidelines are discussed. CONCLUSION: Emphasis is placed on using patients' preferences and patient-centered outcome measures in cost-effectiveness analyses.

Developing patient-centered outcome measures for evaluating vasospasm in aneurysmal subarachnoid hemorrhage.

RATIONALE AND OBJECTIVES: Patient-centered outcome measures have become an essential focus in research methodology in recent years. This may be particularly challenging in imaging research at the technology assessment level to incorporate patient-centeredness. A primary issue in this field is designing a reference standard that is applicable to the entire study population. MATERIALS AND METHODS: This important element is necessary for translation of findings into clinical practice. In our work, computed tomographic perfusion imaging is being evaluated as a new technology used in aneurysmal subarachnoid hemorrhage patients to detect cerebral vasospasm. We have developed a new reference standard employing a multistage hierarchical design incorporating both clinical and imaging criteria to determine a diagnosis of vasospasm. RESULTS: A flowchart of the reference standard levels is provided for illustration. The limitations and potential biases that may occur using this reference standard are discussed. CONCLUSIONS: This reference standard will be applicable to the entire study population, including those with and without symptoms or further imaging with digital subtraction angiography.