Social Determinants of Long-Term Opioid Use Following Total Knee Arthroplasty.

Total knee arthroplasty (TKA) risks persistent pain and long-term opioid use (LTO). The role of social determinants of health (SDoH) in LTO is not well established. We hypothesized that SDoH would be associated with postsurgical LTO after controlling for relevant demographic and clinical variables. This study utilized data from the Veterans Affairs Surgical Quality Improvement Program, VA Corporate Data Warehouse, and Centers for Medicare and Medicaid Services, including Veterans aged ≥ 65 who underwent elective TKA between 2013 and 2019 with no postsurgical complications or history of significant opioid use. LTO was defined as > 90 days of opioid use beginning within 90 days postsurgery. SDoH variables included the Area Deprivation Index, rurality, and housing instability in the last 12 months identified via medical record screener or International Classification of Diseases, Tenth Revision codes. Multivariable risk adjustment models controlled for demographic and clinical characteristics. Of the 9,064 Veterans, 97% were male, 84.2% white, mean age was 70.6 years, 46.3% rural, 11.2% living in highly deprived areas, and 0.9% with a history of homelessness/housing instability. Only 3.7% (n = 336) developed LTO following TKA. In a logistic regression model of only SDoH variables, housing instability (odds ratio [OR] = 2.38, 95% confidence interval [CI]: 1.09-5.22) and rurality conferred significant risk for LTO. After adjusting for demographic and clinical variables, LTO was only associated with increasing days of opioid supply in the year prior to surgery (OR = 1.52, 95% CI: 1.43-1.63 per 30 days) and the initial opioid fill (OR = 1.07; 95% CI: 1.06-1.08 per day). Our primary hypothesis was not supported; however, our findings do suggest that patients with housing instability may present unique challenges for postoperative pain management and be at higher risk for LTO.

Presentation Acuity and Surgical Outcomes for Patients With Health Insurance Living in Highly Deprived Neighborhoods.

Importance: Insurance coverage expansion has been proposed as a solution to improving health disparities, but insurance expansion alone may be insufficient to alleviate care access barriers. Objective: To assess the association of Area Deprivation Index (ADI) with postsurgical textbook outcomes (TO) and presentation acuity for individuals with private insurance or Medicare. Design, Setting, and Participants: This cohort study used data from the National Surgical Quality Improvement Program (2013-2019) merged with electronic health record data from 3 academic health care systems. Data were analyzed from June 2022 to August 2023. Exposure: Living in a neighborhood with an ADI greater than 85. Main Outcomes and Measures: TO, defined as absence of unplanned reoperations, Clavien-Dindo grade 4 complications, mortality, emergency department visits/observation stays, and readmissions, and presentation acuity, defined as having preoperative acute serious conditions (PASC) and urgent or emergent cases. Results: Among a cohort of 29 924 patients, the mean (SD) age was 60.6 (15.6) years; 16 424 (54.9%) were female, and 13 500 (45.1) were male. A total of 14 306 patients had private insurance and 15 618 had Medicare. Patients in highly deprived neighborhoods (5536 patients [18.5%]), with an ADI greater than 85, had lower/worse odds of TO in both the private insurance group (adjusted odds ratio [aOR], 0.87; 95% CI, 0.76-0.99; P = .04) and Medicare group (aOR, 0.90; 95% CI, 0.82-1.00; P = .04) and higher odds of PASC and urgent or emergent cases. The association of ADIs greater than 85 with TO lost significance after adjusting for PASC and urgent/emergent cases. Differences in the probability of TO between the lowest-risk (ADI ≤85, no PASC, and elective surgery) and highest-risk (ADI >85, PASC, and urgent/emergent surgery) scenarios stratified by frailty were highest for very frail patients (Risk Analysis Index ≥40) with differences of 40.2% and 43.1% for those with private insurance and Medicare, respectively. Conclusions and Relevance: This study found that patients living in highly deprived neighborhoods had lower/worse odds of TO and higher presentation acuity despite having private insurance or Medicare. These findings suggest that insurance coverage expansion alone is insufficient to overcome health care disparities, possibly due to persistent barriers to preventive care and other complex causes of health inequities.

A Surgical Desirability of Outcome Ranking (DOOR) Reveals Complex Relationships Between Race/Ethnicity, Insurance Type, and Neighborhood Deprivation.

OBJECTIVE: Develop an ordinal Desirability of Outcome Ranking (DOOR) for surgical outcomes to examine complex associations of Social Determinants of Health. BACKGROUND: Studies focused on single or binary composite outcomes may not detect health disparities. METHODS: Three health care system cohort study using NSQIP (2013-2019) linked with EHR and risk-adjusted for frailty, preoperative acute serious conditions (PASC), case status and operative stress assessing associations of multilevel Social Determinants of Health of race/ethnicity, insurance type (Private 13,957; Medicare 15,198; Medicaid 2835; Uninsured 2963) and Area Deprivation Index (ADI) on DOOR and the binary Textbook Outcomes (TO). RESULTS: Patients living in highly deprived neighborhoods (ADI>85) had higher odds of PASC [adjusted odds ratio (aOR)=1.13, CI=1.02-1.25, P <0.001] and urgent/emergent cases (aOR=1.23, CI=1.16-1.31, P <0.001). Increased odds of higher/less desirable DOOR scores were associated with patients identifying as Black versus White and on Medicare, Medicaid or Uninsured versus Private insurance. Patients with ADI>85 had lower odds of TO (aOR=0.91, CI=0.85-0.97, P =0.006) until adjusting for insurance. In contrast, patients with ADI>85 had increased odds of higher DOOR (aOR=1.07, CI=1.01-1.14, P <0.021) after adjusting for insurance but similar odds after adjusting for PASC and urgent/emergent cases. CONCLUSIONS: DOOR revealed complex interactions between race/ethnicity, insurance type and neighborhood deprivation. ADI>85 was associated with higher odds of worse DOOR outcomes while TO failed to capture the effect of ADI. Our results suggest that presentation acuity is a critical determinant of worse outcomes in patients in highly deprived neighborhoods and without insurance. Including risk adjustment for living in deprived neighborhoods and urgent/emergent surgeries could improve the accuracy of quality metrics.

Association of Insurance Type with Inpatient Surgical 30-day Readmissions, Emergency Department Visits/Observation Stays, and Costs.

OBJECTIVE: To assess the association of Private, Medicare, and Medicaid/Uninsured insurance type with 30-day Emergency Department visits/Observation Stays (EDOS), readmissions, and costs in a safety-net hospital (SNH) serving diverse socioeconomic status patients. SUMMARY BACKGROUND DATA: Medicare's Hospital Readmission Reduction Program (HRRP) disproportionately penalizes SNHs. METHODS: This retrospective cohort study used inpatient National Surgical Quality Improvement Program (2013-2019) data merged with cost data. Frailty, expanded Operative Stress Score, case status, and insurance type were used to predict odds of EDOS and readmissions, as well as index hospitalization costs. RESULTS: The cohort had 1,477 Private; 1,164 Medicare; and 3,488 Medicaid/Uninsured cases with a patient mean age 52.1 years [SD=14.7] and 46.8% of the cases were performed on male patients. Medicaid/Uninsured (aOR=2.69, CI=2.38-3.05, P<.001) and Medicare (aOR=1.32, CI=1.11-1.56, P=.001) had increased odds of urgent/emergent surgeries and complications versus Private patients. Despite having similar frailty distributions, Medicaid/Uninsured compared to Private patients had higher odds of EDOS (aOR=1.71, CI=1.39-2.11, P<.001), and readmissions (aOR=1.35, CI=1.11-1.65, P=.004), after adjusting for frailty, OSS, and case status, while Medicare patients had similar odds of EDOS and readmissions versus Private. Hospitalization variable cost %change was increased for Medicare (12.5%) and Medicaid/Uninsured (5.9%), but Medicaid/Uninsured was similar to Private after adjusting for urgent/emergent cases. CONCLUSIONS: Increased rates and odds of urgent/emergent cases in Medicaid/Uninsured patients drive increased odds of complications and index hospitalization costs versus Private. SNHs care for higher cost populations while receiving lower reimbursements and are further penalized by the unintended consequences of HRRP. Increasing access to care, especially for Medicaid/Uninsured patients, could reduce urgent/emergent surgeries resulting in fewer complications, EDOS/readmissions, and costs.

Independent Associations of Neighborhood Deprivation and Patient-level Social Determinants of Health with Textbook Outcomes after Inpatient Surgery.

Objective: Assess associations of Social Determinants of Health (SDoH) using Area Deprivation Index (ADI), race/ethnicity and insurance type with Textbook Outcomes (TO). Summary Background Data: Individual- and contextual-level SDoH affect health outcomes, but only one SDoH level is usually included. Methods: Three healthcare system cohort study using National Surgical Quality Improvement Program (2013-2019) linked with ADI risk-adjusted for frailty, case status and operative stress examining TO/TO components (unplanned reoperations, complications, mortality, Emergency Department/Observation Stays and readmissions). Results: Cohort (34,251 cases) mean age 58.3 [SD=16.0], 54.8% females, 14.1% Hispanics, 11.6% Non-Hispanic Blacks, 21.6% with ADI>85, and 81.8% TO. Racial and ethnic minorities, non-Private insurance, and ADI>85 patients had increased odds of urgent/emergent surgeries (aORs range: 1.17-2.83, all P<.001). Non-Hispanic Black patients, ADI>85 and non-Private insurances had lower TO odds (aORs range: 0.55-0.93, all P<.04), but ADI>85 lost significance after including case status. Urgent/emergent versus elective had lower TO odds (aOR=0.51, P<.001). ADI>85 patients had higher complication and mortality odds. Estimated reduction in TO probability was 9.9% (CI=7.2%-12.6%) for urgent/emergent cases, 7.0% (CI=4.6%-9.3%) for Medicaid, and 1.6% (CI=0.2%-3.0%) for non-Hispanic Black patients. TO probability difference for lowest-risk (White-Private-ADI≤85-elective) to highest-risk (Black-Medicaid-ADI>85-urgent/emergent) was 29.8% for very frail patients. Conclusion: Multi-level SDoH had independent effects on TO, predominately affecting outcomes through increased rates/odds of urgent/emergent surgeries driving complications and worse outcomes. Lowest-risk versus highest-risk scenarios demonstrated the magnitude of intersecting SDoH variables. Combination of insurance type and ADI should be used to identify high-risk patients to redesign care pathways to improve outcomes. Risk adjustment including contextual neighborhood deprivation and patient-level SDoH could reduce unintended consequences of value-based programs.

Differentiating Urgent from Elective Cases Matters in Minority Populations: Developing an Ordinal "Desirability of Outcome Ranking" to Increase Granularity and Sensitivity of Surgical Outcomes Assessment.

BACKGROUND: Surgical analyses often focus on single or binary outcomes; we developed an ordinal Desirability of Outcome Ranking (DOOR) for surgery to increase granularity and sensitivity of surgical outcome assessments. Many studies also combine elective and urgent procedures for risk adjustment. We used DOOR to examine complex associations of race/ethnicity and presentation acuity. STUDY DESIGN: NSQIP (2013 to 2019) cohort study assessing DOOR outcomes across race/ethnicity groups risk-adjusted for frailty, operative stress, preoperative acute serious conditions, and elective, urgent, and emergent cases. RESULTS: The cohort included 1,597,199 elective, 340,350 urgent, and 185,073 emergent cases with patient mean age of 60.0 ± 15.8, and 56.4% of the surgeries were performed on female patients. Minority race/ethnicity groups had increased odds of presenting with preoperative acute serious conditions (adjusted odds ratio [aORs] range 1.22 to 1.74), urgent (aOR range 1.04 to 2.21), and emergent (aOR range 1.15 to 2.18) surgeries vs the White group. Black (aOR range 1.23 to 1.34) and Native (aOR range 1.07 to 1.17) groups had increased odds of higher/worse DOOR outcomes; however, the Hispanic group had increased odds of higher/worse DOOR (aOR 1.11, CI 1.10 to 1.13), but decreased odds (aORs range 0.94 to 0.96) after adjusting for case status; the Asian group had better outcomes vs the White group. DOOR outcomes improved in minority groups when using elective vs elective/urgent cases as the reference group. CONCLUSIONS: NSQIP surgical DOOR is a new method to assess outcomes and reveals a complex interplay between race/ethnicity and presentation acuity. Combining elective and urgent cases in risk adjustment may penalize hospitals serving a higher proportion of minority populations. DOOR can be used to improve detection of health disparities and serves as a roadmap for the development of other ordinal surgical outcomes measures. Improving surgical outcomes should focus on decreasing preoperative acute serious conditions and urgent and emergent surgeries, possibly by improving access to care, especially for minority populations.

Cost of Failure to Achieve Textbook Outcomes: Association of Insurance Type with Outcomes and Cumulative Cost for Inpatient Surgery.

BACKGROUND: Surgical outcome/cost analyses typically focus on single outcomes and do not include encounters beyond the index hospitalization. STUDY DESIGN: This cohort study used NSQIP (2013-2019) data with electronic health record and cost data risk-adjusted for frailty, preoperative acute serious conditions (PASC), case status, and operative stress assessing cumulative costs of failure to achieve textbook outcomes defined as absence of 30-day Clavien-Dindo level III and IV complications, emergency department visits/observation stays (EDOS), and readmissions across insurance types (private, Medicare, Medicaid, uninsured). Return costs were defined as costs of all 30-day emergency department visits/observation stays and readmissions. RESULTS: Cases were performed on patients (private 1,506; Medicare 1,218; Medicaid 1,420; uninsured 2,178) with a mean age 52.3 years (SD 14.7) and 47.5% male. Medicaid and uninsured patients had higher odds of presenting with preoperative acute serious conditions (adjusted odds ratios 1.89 and 1.81, respectively) and undergoing urgent/emergent surgeries (adjusted odds ratios 2.23 and 3.02, respectively) vs private. Medicaid and uninsured patients had lower odds of textbook outcomes (adjusted odds ratios 0.53 and 0.78, respectively) and higher odds of emergency department visits/observation stays and readmissions vs private. Not achieving textbook outcomes was associated with a greater than 95.1% increase in cumulative costs. Medicaid patients had a relative increase of 23.1% in cumulative costs vs private, which was 18.2% after adjusting for urgent/emergent cases. Return costs were 37.5% and 65.8% higher for Medicaid and uninsured patients, respectively, vs private. CONCUSIONS: Higher costs for Medicaid patients were partially driven by increased presentation acuity (increased rates/odds of preoperative acute serious conditions and urgent/emergent surgeries) and higher rates of multiple emergency department visits/observation stays and readmission occurrences. Decreasing surgical costs/improving outcomes should focus on reducing urgent/emergent surgeries and improving postoperative care coordination, especially for Medicaid and uninsured populations.

Association of Cumulative Colorectal Surgery Hospital Costs, Readmissions, and Emergency Department/Observation Stays with Insurance Type.

BACKGROUND/PURPOSE: Medicare's Hospital Readmission Reduction Program disproportionately penalizes safety-net hospitals (SNH) caring for vulnerable populations. This study assessed the association of insurance type with 30-day emergency department visits/observation stays (EDOS), readmissions, and cumulative costs in colorectal surgery patients. METHODS: Retrospective inpatient cohort study using the National Surgical Quality Improvement Program (2013-2019) with cost data in a SNH. The odds of EDOS and readmissions and cumulative variable (index hospitalization and all 30-day EDOS and readmissions) costs were modeled adjusting for frailty, case status, presence of a stoma, and open versus laparoscopic surgery. RESULTS: The cohort had 245 private, 195 Medicare, and 590 Medicaid/uninsured cases, with a mean age 55.0 years (SD = 13.3) and 52.9% of the cases were performed on male patients. Most cases were open surgeries (58.7%). Complication rates were 41.8%, EDOS 12.0%, and readmissions 20.1%. Medicaid/uninsured had increased odds of urgent/emergent surgeries (aOR = 2.15, CI = 1.56-2.98, p < 0.001) and complications (aOR = 1.43, CI = 1.02-2.03, p = 0.042) versus private patients. Medicaid/uninsured versus private patients had higher EDOS (16.6% versus 4.1%) and readmissions (22.9% versus 14.3%) rates and higher odds of EDOS (aOR = 4.81, CI = 2.57-10.06, p < 0.001), and readmissions (aOR = 1.62, CI = 1.07-2.50, p = 0.025), while Medicare patients had similar odds versus private. Cumulative variable cost %change was increased for Medicare and Medicaid/uninsured, but Medicaid/uninsured was similar to private after adjusting for urgent/emergent cases. CONCLUSIONS: Increased urgent/emergent cases in Medicaid/uninsured populations drive increased complications odds and higher costs compared to private patients, suggesting lack of access to outpatient care. SNH care for higher cost populations, receive lower reimbursements, and are penalized by value-based programs. Increasing healthcare access for Medicaid/uninsured patients could reduce urgent/emergent surgeries, resulting in fewer complications, EDOS/readmissions, and costs.

Retrospective cohort study comparing surgical inpatient charges, total costs, and variable costs as hospital cost savings measures.

We analyzed differences (charges, total, and variable costs) in estimating cost savings of quality improvement projects using reduction of serious/life-threatening complications (Clavien-Dindo Level IV) and insurance type (Private, Medicare, and Medicaid/Uninsured) to evaluate the cost measures. Multiple measures are used to analyze hospital costs and compare cost outcomes across health systems with differing patient compositions. We used National Surgical Quality Improvement Program inpatient (2013-2019) with charge and cost data in a hospital serving diverse socioeconomic status patients. Simulation was used to estimate variable costs and total costs at 3 proportions of fixed costs (FC). Cases (Private 1517; Medicare 1224; Medicaid/Uninsured 3648) with patient mean age 52.3 years (Standard Deviation = 14.7) and 47.3% male. Medicare (adjusted odds ratio = 1.55, 95% confidence interval = 1.16-2.09, P = .003) and Medicaid/Uninsured (adjusted odds ratio = 1.41, 95% confidence interval = 1.10-1.82, P = .008) had higher odds of complications versus Private. Medicaid/Uninsured had higher relative charges versus Private, while Medicaid/Uninsured and Medicare had higher relative variable and total costs versus Private. Targeting a 15% reduction in serious complications for robust patients undergoing moderate-stress procedures estimated variable cost savings of $286,392. Total cost saving estimates progressively increased with increasing proportions of FC; $443,943 (35% FC), $577,495 (50% FC), and $1184,403 (75% FC). In conclusion, charges did not identify increased costs for Medicare versus Private patients. Complications were associated with > 200% change in costs. Surgical hospitalizations for Medicare and Medicaid/Uninsured patients cost more than Private patients. Variable costs should be used to avoid overestimating potential cost savings of quality improvement interventions, as total costs include fixed costs that are difficult to change in the short term.

Association of Insurance Type With Colorectal Surgery Outcomes and Costs at a Safety-Net Hospital: A Retrospective Observational Study.

Association of insurance type with colorectal surgical complications, textbook outcomes (TO), and cost in a safety-net hospital (SNH). Background: SNHs have higher surgical complications and costs compared to low-burden hospitals. How does presentation acuity and insurance type influence colorectal surgical outcomes? Methods: Retrospective cohort study using single-site National Surgical Quality Improvement Program (2013-2019) with cost data and risk-adjusted by frailty, preoperative serious acute conditions (PASC), case status and open versus laparoscopic to evaluate 30-day reoperations, any complication, Clavien-Dindo IV (CDIV) complications, TO, and hospitalization variable costs. Results: Cases (Private 252; Medicare 207; Medicaid/Uninsured 619) with patient mean age 55.2 years (SD = 13.4) and 53.1% male. Adjusting for frailty, open abdomen, and urgent/emergent cases, Medicaid/Uninsured patients had higher odds of presenting with PASC (adjusted odds ratio [aOR] = 2.02, 95% confidence interval [CI] = 1.22-3.52, P = 0.009) versus Private. Medicaid/Uninsured (aOR = 1.80, 95% CI = 1.28-2.55, P < 0.001) patients were more likely to undergo urgent/emergent surgeries compared to Private. Medicare patients had increased odds of any and CDIV complications while Medicaid/Uninsured had increased odds of any complication, emergency department or observations stays, and readmissions versus Private. Medicare (aOR = 0.51, 95% CI = 0.33-0.88, P = 0.003) and Medicaid/Uninsured (aOR = 0.43, 95% CI = 0.30-0.60, P < 0.001) patients had lower odds of achieving TO versus Private. Variable cost %change increased in Medicaid/Uninsured patients to 13.94% (P = 0.005) versus Private but was similar after adjusting for case status. Urgent/emergent cases (43.23%, P < 0.001) and any complication (78.34%, P < 0.001) increased %change hospitalization costs. Conclusions: Decreasing the incidence of urgent/emergent colorectal surgeries, possibly by improving access to care, could have a greater impact on improving clinical outcomes and decreasing costs, especially in Medicaid/Uninsured insurance type patients.

Multiparametric Assessment of Treatment Response in High-Grade Soft-Tissue Sarcomas with Anatomic and Functional MR Imaging Sequences.

PURPOSE: To determine the added value of quantitative diffusion-weighted and dynamic contrast material-enhanced imaging to conventional magnetic resonance (MR) imaging for assessment of the response of soft-tissue sarcomas to neoadjuvant therapy. MATERIALS AND METHODS: MR imaging examinations in 23 patients with soft-tissue sarcomas who had undergone neoadjuvant therapy were reviewed by two readers during three sessions: conventional imaging (T1-weighted, fluid-sensitive, static postcontrast T1-weighted), conventional with diffusion-weighted imaging, and conventional with diffusion-weighted and dynamic contrast-enhanced imaging. For each session, readers recorded imaging features and determined treatment response. Interobserver agreement was assessed and receiver operating characteristic analysis was performed to evaluate the accuracy of each session for determining response by using results of the histologic analysis as the reference standard. Good response was defined as less than or equal to 5% residual viable tumor. RESULTS: Of the 23 sarcomas, four (17.4%) showed good histologic response (three of four with >95% granulation tissue and <5% necrosis, one of four with 95% necrosis and <5% viable tumor) and 19 (82.6%) showed poor response (viable tumor range, 10%-100%). Interobserver agreement was substantial or excellent for imaging features in all sequences (k = 0.789-1.000). Receiver operating characteristic analysis showed an increase in diagnostic performance with the addition of diffusion-weighted and dynamic contrast-enhanced MR imaging for prediction of response compared with that for conventional imaging alone (areas under the curve, 0.500, 0.676, 0.821 [reader 1] and 0.506, 0.704, 0.833 [reader 2], respectively). CONCLUSION: Adding functional sequences to the conventional MR imaging protocol increases the sensitivity of MR imaging for determining treatment response in soft-tissue sarcomas.

Multiparametric and Multimodality Functional Radiological Imaging for Breast Cancer Diagnosis and Early Treatment Response Assessment.

Breast cancer is the second leading cause of cancer death among US women, and the chance of a woman developing breast cancer sometime during her lifetime is one in eight. Early detection and diagnosis to allow appropriate locoregional and systemic treatment are key to improve the odds of surviving its diagnosis. Emerging data also suggest that different breast cancer subtypes (phenotypes) may respond differently to available adjuvant therapies. There is a growing understanding that not all patients benefit equally from systemic therapies, and therapeutic approaches are being increasingly personalized based on predictive biomarkers of clinical benefit. Optimal use of established and novel radiological imaging methods, such as magnetic resonance imaging and positron emission tomography, which have different biophysical mechanisms can simultaneously identify key functional parameters. These methods provide unique multiparametric radiological signatures of breast cancer, that will improve the accuracy of early diagnosis, help select appropriate therapies for early stage disease, and allow early assessment of therapeutic benefit.

Proton MR spectroscopy in metabolic assessment of musculoskeletal lesions.

OBJECTIVE: The purposes of this review are to describe the principles and method of MR spectroscopy, summarize current published data on musculoskeletal lesions, and report additional cases that have been analyzed with recently developed quantitative methods. CONCLUSION: Proton MR spectroscopy can be used to identify key tissue metabolites and may serve as a useful adjunct to radiographic evaluation of musculoskeletal lesions. A pooled analysis of 122 musculoskeletal tumors revealed that a discrete choline peak has a sensitivity of 88% and specificity of 68% in the detection of malignancy. Modest improvements in diagnostic accuracy in 22 of 122 cases when absolute choline quantification was used encourage the pursuit of development of choline quantification methods.

Dynamic contrast-enhanced MRI of the breast: quantitative method for kinetic curve type assessment.

OBJECTIVE: The type of contrast enhancement kinetic curve (i.e., persistently enhancing, plateau, or washout) seen on dynamic contrast-enhanced MRI (DCE-MRI) of the breast is predictive of malignancy. Qualitative estimates of the type of curve are most commonly used for interpretation of DCE-MRI. The purpose of this study was to compare qualitative and quantitative methods for determining the type of contrast enhancement kinetic curve on DCE-MRI. MATERIALS AND METHODS: Ninety-six patients underwent breast DCE-MRI. The type of DCE-MRI kinetic curve was assessed qualitatively by three radiologists on two occasions. For quantitative assessment, the slope of the washout curve was calculated. Kappa statistics were used to determine inter- and intraobserver agreement for the qualitative method. Matched sample tables, the McNemar test, and receiver operating characteristic (ROC) curve statistics were used to compare quantitative versus qualitative methods for establishing or excluding malignancy. RESULTS: Seventy-eight lesions (77.2%) were malignant and 23 (22.8%) were benign. For the qualitative assessment, the intra- and interobserver agreement was good (kappa = 0.76-0.88), with an area under the ROC curve (AUC) of 0.73-0.77. For the quantitative method, the highest AUC was 0.87, reflecting significantly higher diagnostic accuracies compared with qualitative assessment (p < 0.01 for the difference between the two methods). CONCLUSION: Quantitative assessment of the type of contrast enhancement kinetic curve on breast DCE-MRI resulted in significantly higher diagnostic performance for establishing or excluding malignancy compared with assessment based on the standard qualitative method.

AAPM/RSNA physics tutorials for residents: MR imaging: brief overview and emerging applications.

Magnetic resonance (MR) imaging has become established as a diagnostic and research tool in many areas of medicine because of its ability to provide excellent soft-tissue delineation in different areas of interest. In addition to T1- and T2-weighted imaging, many specialized MR techniques have been designed to extract metabolic or biophysical information. Diffusion-weighted imaging gives insight into the movement of water molecules in tissue, and diffusion-tensor imaging can reveal fiber orientation in the white matter tracts. Metabolic information about the object of interest can be obtained with spectroscopy of protons, in addition to imaging of other nuclei, such as sodium. Dynamic contrast material-enhanced imaging and recently proton spectroscopy play an important role in oncologic imaging. When these techniques are combined, they can assist the physician in making a diagnosis or monitoring a treatment regimen. One of the major advantages of the different types of MR imaging is the ability of the operator to manipulate image contrast with a variety of selectable parameters that affect the kind and quality of the information provided. The elements used to obtain MR images and the factors that affect formation of an MR image include MR instrumentation, localization of the MR signal, gradients, k-space, and pulse sequences.

Assessment of response of uterine fibroids and myometrium to embolization using diffusion-weighted echoplanar MR imaging.

Our objective was to evaluate the role of echoplanar diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps in the assessment of response of uterine fibroids and myometrium to uterine fibroid embolization (UFE). We evaluated 32 fibroids in 11 patients treated with UFE. Treated lesions had low ADC values compared to untreated lesions. Furthermore, ADC values of the myometrium did not significantly change after embolization, suggesting maintained myometrial viability after embolization. DWI and ADC maps, by providing functional information at a cellular level, may serve as imaging tools for assessing treatment response after UFE.

Assessment of transient ischemic attack with diffusion- and perfusion-weighted imaging.

BACKGROUND: Diagnosing TIA can be difficult, since evidence of brain ischemia is habitually lacking on CT and conventional MR imaging. It has been suggested that patients with acute brain infarction on neuroimaging should be considered stroke cases instead of TIA, regardless of duration of symptoms, implying that optimal diagnostic methods need to be utilized. We therefore postulated that perfusion-weighted MR imaging (PW imaging) would be useful in the diagnosis of TIA. METHODS: Retrospective analysis of 22 patients with reversible neurologic symptoms lasting less than 24 hours, assessed with DW and PW imaging. RESULTS: MR imaging was abnormal in 15 patients (68%): 12 had abnormal DW imaging, four had both DW and PW imaging defects (all with a mismatch) and three had an isolated PW imaging abnormality. There were no differences in symptom duration, stroke etiology or cardiovascular risk factors between patients with abnormal MR imaging and those with unremarkable scan. Patients with mismatch were more likely to need conventional angiography or other cerebrovascular procedures. CONCLUSION: The combined use of DW imaging and PW imaging provided evidence of brain ischemia in most patients with clinical diagnosis of TIA. Prospective studies using follow-up MR imaging are required to determine the outcome of affected tissue, as well as the clinical implications of DW-PW imaging abnormalities.

Multiparametric iterative self-organizing MR imaging data analysis technique for assessment of tissue viability in acute cerebral ischemia.

BACKGROUND AND PURPOSE: Defining viability and the potential for recovery of ischemic brain tissue can be very valuable for patient selection for acute stroke therapies. Multiparametric MR imaging analysis of ischemic lesions indicates that the ischemic lesion is inhomogeneous in degree of ischemic injury and recovery potential. We sought to define MR imaging characteristics of ischemic lesions that are compatible with viable tissue. METHODS: We included patients with supratentorial ischemic stroke who underwent multiparametric MR imaging studies (axial multi-spin-echo T2-weighted imaging, T1-weighted imaging, and diffusion-weighted imaging) at the acute (< 24 hours) and outcome (3 months) phases of stroke. Using the algorithm Iterative Self-Organizing Data Analysis Technique (ISODATA), the lesion was segmented into clusters and each was assigned a number, called the tissue signature (white matter = 1, CSF = 12, all others between these two). Recovery was defined as at least a 20% size reduction from the acute phase ISODATA lesion volume to the outcome phase T2-weighted imaging lesion volume. The tissue signature data were collapsed into the following categories: < or = 3, 4, 5, and > or = 6. Logistic regression analysis included the following parameters: lesion volume, tissue signature value, apparent diffusion coefficient (ADC) value, relative ADC (rADC) expressed as a ratio, T2 value, and T2 ratio. The model with the largest goodness of fit value was selected. RESULTS: We included 48 patients (female-male ratio, 26:22; age, 64 [+/-14] years; 15 treated with recombinant tissue plasminogen activator [rt-PA] within 3 hours of onset; median National Institutes of Health Stroke Scale score, 7 [range, 2-26]). Median symptom onset-to-MR imaging time interval was 9.5 hours. With ISODATA processing, we generated 200 region-of-interest tissue records (one to nine tissue records per patient). Regarding tissue recovery, we detected a three-way interaction among ADC, ISODATA tissue signature, and previous treatment with rt-PA (P = .003). In the group not treated with rt-PA, ischemic tissues with acute rADC greater than the median (0.79) and tissue signature < or = 4 were more likely to recover (80% vs. 31% and 13%, odds ratio [95% CI]: 0.12 [0.05, 0.30] and 0.04 [0.01, 0.18] for tissue signatures 5 and 6, respectively). CONCLUSION: ISODATA multiparametric MR imaging of acute stroke clearly shows inhomogeneity and different viability of the ischemic lesion. Ischemic tissues with lower acute phase ISODATA tissue signature values (< or = 4) and higher rADC values (> or = 0.79) are much more likely to recover than those with higher signature values or lower rADC values. The effect of these factors on tissue recovery, however, is dependent on whether preceding treatment with rt-PA had been performed. Our approach can be a valuable tool in the design of therapeutic stroke trials with an extended time window.