Epidemiology of asylum seekers and refugees at the Mexico-US border: a cross-sectional analysis from the migrant settlement camp in Matamoros, Mexico.

BACKGROUND: The number of migrants and asylum seekers at the Mexico-US border has increased to historic levels. Our objective was to determine the medical diagnoses and treatments of migrating people seeking care in humanitarian clinics in Matamoros, Mexico. METHODS: We conducted a cross-sectional study of patient encounters by migrating people through a humanitarian clinic in Matamoros, Mexico, from November 22, 2019, to March 18, 2021. The clinics were operated by Global Response Medicine in concert with local non-governmental organizations. Clinical encounters were each coded to the appropriate ICD-10/CPT code and categorized according to organ system. We categorized medications using the WHO List of Essential Medicines and used multivariable logistic regression to determine associations between demographic variables and condition frequency. RESULTS: We found a total of 8,156 clinical encounters, which included 9,744 diagnoses encompassing 132 conditions (median age 26.8 years, female sex 58.2%). People originated from 24 countries, with the majority from Central America (n = 5598, 68.6%). The most common conditions were respiratory (n = 1466, 15.0%), musculoskeletal (n = 1081, 11.1%), and skin diseases (n = 473, 4.8%). Children were at higher risk for respiratory disease (aOR = 1.84, 95% CI: 1.61-2.10), while older adults had greater risk for joint disorders (aOR = 3.35, 95% CI: 1.73-6.02). Women had decreased risk for injury (aOR = 0.50, 95% CI: 0.40-0.63) and higher risk for genitourinary diseases (aOR = 4.99, 95% CI: 3.72-6.85) compared with men. Among 10,405 medications administered, analgesics were the most common (n = 3190, 30.7%) followed by anti-infectives (n = 2175, 21.1%). CONCLUSIONS: In this large study of a migrating population at the Mexico-US border, we found a variety of clinical conditions, with respiratory, musculoskeletal, and skin illnesses the most common in this study period which encompassed a period of restrictive immigration policy and the first year of the COVID-19 pandemic.

Life Over Limb: Why Not Both? Revisiting Tourniquet Practices Based on Lessons Learned From the War in Ukraine.

The use of tourniquets for life-threatening limb hemorrhage is standard of care in military and civilian medicine. The United States (U.S.) Department of Defense (DoD) Committee on Tactical Combat Casualty Care (CoTCCC) guidelines, as part of the Joint Trauma System, support the application of tourniquets within a structured system reliant on highly trained medics and expeditious evacuation. Current practices by entities such as the DoD and North Atlantic Treaty Organization (NATO) are supported by evidence collected in counter-insurgency operations and other conflicts in which transport times to care rarely went beyond one hour, and casualty rates and tactical situations rarely exceeded capabilities. Tourniquets cause complications when misused or utilized for prolonged durations, and in near-peer or peer-peer conflicts, contested airspace and the impact of high-attrition warfare may increase time to definitive care and limit training resources. We present a series of cases from the war in Ukraine that suggest tourniquet practices are contributing to complications such as limb amputation, overall morbidity and mortality, and increased burden on the medical system. We discuss factors that contribute to this phenomenon and propose interventions for use in current and future similar contexts, with the ultimate goal of reducing morbidity and mortality.

Molecular mechanism of phosphopeptide neoantigen immunogenicity.

Altered protein phosphorylation in cancer cells often leads to surface presentation of phosphopeptide neoantigens. However, their role in cancer immunogenicity remains unclear. Here we describe a mechanism by which an HLA-B*0702-specific acute myeloid leukemia phosphoneoantigen, pMLL747-755 (EPR(pS)PSHSM), is recognized by a cognate T cell receptor named TCR27, a candidate for cancer immunotherapy. We show that the replacement of phosphoserine P4 with serine or phosphomimetics does not affect pMHC conformation or peptide-MHC affinity but abrogates TCR27-dependent T cell activation and weakens binding between TCR27 and pMHC. Here we describe the crystal structures for TCR27 and cognate pMHC, map of the interface produced by nuclear magnetic resonance, and a ternary complex generated using information-driven protein docking. Our data show that non-covalent interactions between the epitope phosphate group and TCR27 are crucial for TCR specificity. This study supports development of new treatment options for cancer patients through target expansion and TCR optimization.

Public Health Challenges and Barriers to Health Care Access for Asylum Seekers at the U.S.-Mexico Border in Matamoros, Mexico.

The Migrant Protection Protocols (MPP) and border closure to asylum seekers during the COVID-19 pandemic created a humanitarian crisis at the U.S.-Mexico border. This paper outlines the public health challenges and health care access barriers for asylum seekers living in a tent encampment in Matamoros, Mexico resulting from these policies. Thirty participants, including asylum seekers (n=20) and health care professionals (n=10) in the Matamoros asylum camp, were interviewed. Public health challenges included environmental exposures and inadequate infrastructure; poor sanitation and disease control; and limited safety, nutrition, education, and employment. Health care access barriers included lack of continuity of care and emergency services, resource insufficiencies, and interpersonal barriers. Policy responses to address these challenges include outlawing MPP and other immigration policies that infringe on human rights, collaborating with international partners, and implementing more creative and community-based approaches to asylum processing.

U.S. medical student knowledge and interest in asylum seeker medical care.

CONTEXT: Asylum seekers face significant and unique healthcare challenges, requiring healthcare practitioners, specifically in primary care, to be trained to care for this patient population. However, there is limited understanding of medical students' interest in and future ability to care for the population of asylum seekers in the United States. PROJECT AIMS: We aim to understand U.S. medical students' interest, experience, and knowledge in providing care for asylum seekers to assess the need for change in the ways in which medical schools introduce asylum seeker care to learners. DESCRIPTION: A 23-question survey was administered to U.S. medical students at four institutions with asylum programmes affiliated with Physicians for Human Rights (PHR) from June 2020 to March 2021, querying various aspects of providing care to asylum seekers. OUTCOMES: Of the approximately 2846 students who received the survey, 436 students (15%) completed it in its entirety. Most respondents desired training about caring for asylum seekers (91%). Over half (52%) rated their knowledge of asylum issues overall as 'poor' or 'none', and 73% thought their medical school's curriculum on asylum seeker health needed improvement. CONCLUSIONS: Medical students at schools with affiliated asylum clinics desire to care for asylum seeker patients but feel unprepared to do so, highlighting an unmet need for formal asylum education in U.S. medical schools.

Identifying Strategies to Boost COVID-19 Vaccine Acceptance in the United States.

This study presents the results of an evaluation of the root causes of COVID-19 vaccine hesitancy to inform strategies to boost vaccine acceptance among vaccine-hesitant populations in the United States. The authors conducted a literature review of the causes of vaccine hesitancy and vaccine acceptance; focus groups with patients, pre-hospital first responders, and hospital-based health care providers; a social media platform sentiment analysis to review attitudes regarding the COVID-19 vaccine; and a roundtable discussion with experts on vaccine hesitancy. Drawing on this mixed-methods analysis, the authors recommend strategies to help boost COVID-19 vaccine acceptance in the United States, grouping them according to three overall goals: boosting confidence in the safety and effectiveness of the COVID-19 vaccines, combating complacency about the pandemic, and increasing the convenience of getting vaccinated. The authors emphasize that combating misinformation about the COVID-19 vaccine is key to achieving these goals. These recommendations can inform the development of a toolkit of strategies to reach herd immunity and end the pandemic.

ECPR2: Expert Consensus on PeRcutaneous Cannulation for Extracorporeal CardioPulmonary Resuscitation.

AIM: Extracorporeal cardiopulmonary resuscitation (ECPR) has emerged as a promising resuscitation strategy for select patients suffering from refractory out-of-hospital cardiac arrest (OHCA), though limited data exist regarding the best practices for ECPR initiation after OHCA. METHODS: We utilized a modified Delphi process consisting of two survey rounds and a virtual consensus meeting to systematically identify detailed best practices for ECPR initiation following adult non-traumatic OHCA. A modified Delphi process builds content validity and is an accepted method to develop consensus by eliciting expert opinions through multiple rounds of questionnaires. Consensus was achieved when items reached a high level of agreement, defined as greater than 80% responses for a particular item rated a 4 or 5 on a 5-point Likert scale. RESULTS: Snowball sampling generated a panel of 14 content experts, composed of physicians from four continents and five primary specialties. Seven existing institutional protocols for ECPR cannulation following OHCA were identified and merged into a single comprehensive list of 207 items. The panel reached consensus on 101 items meeting final criteria for inclusion: Prior to Patient Arrival (13 items), Inclusion Criteria (8), Exclusion Criteria (7), Patient Arrival (8), ECPR Cannulation (21), Go On Pump (18), and Post-Cannulation (26). CONCLUSION: We present a list of items for ECPR initiation following adult nontraumatic OHCA, generated using a modified Delphi process from an international panel of content experts. These findings may benefit centers currently performing ECPR in quality assurance and serve as a template for new ECPR programs.

Detection of Hemodynamic Status Using an Analytic Based on an Electrocardiogram Lead Waveform.

OBJECTIVES: Delayed identification of hemodynamic deterioration remains a persistent issue for in-hospital patient care. Clinicians continue to rely on vital signs associated with tachycardia and hypotension to identify hemodynamically unstable patients. A novel, noninvasive technology, the Analytic for Hemodynamic Instability (AHI), uses only the continuous electrocardiogram (ECG) signal from a typical hospital multiparameter telemetry monitor to monitor hemodynamics. The intent of this study was to determine if AHI is able to predict hemodynamic instability without the need for continuous direct measurement of blood pressure. DESIGN: Retrospective cohort study. SETTING: Single quaternary care academic health system in Michigan. PATIENTS: Hospitalized adult patients between November 2019 and February 2020 undergoing continuous ECG and intra-arterial blood pressure monitoring in an intensive care setting. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One million two hundred fifty-two thousand seven hundred forty-two 5-minute windows of the analytic output were analyzed from 597 consecutive adult patients. AHI outputs were compared with vital sign indications of hemodynamic instability (heart rate > 100 beats/min, systolic blood pressure < 90 mm Hg, and shock index of > 1) in the same window. The observed sensitivity and specificity of AHI were 96.9% and 79.0%, respectively, with an area under the curve (AUC) of 0.90 for heart rate and systolic blood pressure. For the shock index analysis, AHI's sensitivity was 72.0% and specificity was 80.3% with an AUC of 0.81. CONCLUSIONS: The AHI-derived hemodynamic status appropriately detected the various gold standard indications of hemodynamic instability (hypotension, tachycardia and hypotension, and shock index > 1). AHI may provide continuous dynamic hemodynamic monitoring capabilities in patients who traditionally have intermittent static vital sign measurements.

Challenges and Effects of the COVID-19 Pandemic on Asylum Seeker Health at the U.S.-Mexico Border.

Purpose: The coronavirus disease 2019 (COVID-19) pandemic presents health care challenges to asylum seekers living in congregate encampments, including those along the U.S.-Mexico border. It is necessary to understand the impact of the pandemic among this population to address health care needs, reduce transmission, and diminish COVID-19-related morbidity. Methods: Thirty interviews were conducted with asylum seekers and health care professionals in a temporary camp in Matamoros, Mexico to determine challenges, perceptions, and effects of the COVID-19 pandemic. Interviews were coded in NVivo12 by using a team-based approach. Results: The pandemic caused significant mental health burdens but no perceived adverse physical effects, with the U.S. border closure and health care access barriers as more pressing concerns. Participants reported access to information about COVID-19 but had varied levels of knowledge and adherence to disease reduction strategies due to camp conditions. Most participants believed that they had special protection from COVID-19, including strong immune systems or from God. The nongovernmental organizations providing health care and sanitation faced multiple challenges to implement new policies to manage COVID-19. The institution of required temperature checks and quarantine of COVID-19 positive patients led to distrust, decreased seeking of health care services among asylum seekers, and possible underreporting of COVID-19 cases. Conclusion: Our findings among asylum seekers in a Matamoros camp highlight the challenges to implementing disease reduction policies in low-resource congregate camps. Policies to address disease outbreaks focusing on the social determinants of health, health care access barriers, and community engagement may be more acceptable to asylum seekers, suggesting the need for effective strategies to provide prevention information that complements such measures.

Is a Lumbar Puncture Required to Rule Out Atraumatic Subarachnoid Hemorrhage in Emergency Department Patients With Headache and Normal Brain Computed Tomography More Than Six Hours After Symptom Onset?

BACKGROUND: Atraumatic subarachnoid hemorrhage (SAH) is a deadly condition that most commonly presents as acute, severe headache. Controversy exists concerning evaluation of SAH based on the time from onset of symptoms, specifically if the headache occurred > 6 h prior to patient presentation. CLINICAL QUESTION: Do patients undergoing evaluation for atraumatic SAH who have a negative computed tomography (CT) scan of the head obtained more than 6 h after symptom onset require a subsequent lumbar puncture to rule out the diagnosis? EVIDENCE REVIEW: Studies retrieved included a retrospective cohort study, two prospective cohort studies, and a case-control study. These studies provide estimates of the diagnostic accuracy of head CT imaging obtained > 6 h from symptom onset and diagnostic test characteristics of subsequent lumbar puncture. CONCLUSION: The probability of SAH above which emergency clinicians should perform a lumbar puncture is 1.0%. This threshold is essentially the same as the estimated probability of SAH in patients with a negative head CT obtained more than 6 h from symptom onset. Emergency physicians might reasonably decide to either perform or forego this procedure. Consequently, we contend that the decision whether to perform lumbar puncture in these instances is an excellent candidate for shared decision-making.

Predicting severe outcomes in Covid-19 related illness using only patient demographics, comorbidities and symptoms.

OBJECTIVE: Development of a risk-stratification model to predict severe Covid-19 related illness, using only presenting symptoms, comorbidities and demographic data. MATERIALS AND METHODS: We performed a case-control study with cases being those with severe disease, defined as ICU admission, mechanical ventilation, death or discharge to hospice, and controls being those with non-severe disease. Predictor variables included patient demographics, symptoms and past medical history. Participants were 556 patients with laboratory confirmed Covid-19 and were included consecutively after presenting to the emergency department at a tertiary care center from March 1, 2020 to April 21, 2020 RESULTS: Most common symptoms included cough (82%), dyspnea (75%), and fever/chills (77%), with 96% reporting at least one of these. Multivariable logistic regression analysis found that increasing age (adjusted odds ratio [OR], 1.05; 95% confidence interval [CI], 1.03-1.06), dyspnea (OR, 2.56; 95% CI: 1.51-4.33), male sex (OR, 1.70; 95% CI: 1.10-2.64), immunocompromised status (OR, 2.22; 95% CI: 1.17-4.16) and CKD (OR, 1.76; 95% CI: 1.01-3.06) were significant predictors of severe Covid-19 infection. Hyperlipidemia was found to be negatively associated with severe disease (OR, 0.54; 95% CI: 0.33-0.90). A predictive equation based on these variables demonstrated fair ability to discriminate severe vs non-severe outcomes using only this historical information (AUC: 0.76). CONCLUSIONS: Severe Covid-19 illness can be predicted using data that could be obtained from a remote screening. With validation, this model could possibly be used for remote triage to prioritize evaluation based on susceptibility to severe disease while avoiding unnecessary waiting room exposure.

The scientific term paper at the Charité: a project report on concept, implementation, and students' evaluation and learning.

Aim: Better training in scientific skills, such as the ability to conduct research independently, has been one of the main drivers of reform in medical education. The aim of this article is to report on the scientific term paper module in the modular curriculum of medicine (MCM) at the Charité. This module is an established example of undergraduate medical students conducting their own scientific investigations. Project outline: A faculty-wide, outcome-oriented process resulted in a four-week module for writing a scientific term paper in the 6th semester of the MCM as part of a longitudinal science curriculum. Acquired competencies were assessed through a written term paper and an oral presentation. Two student cohorts (winter terms 2013 and 2014) were surveyed on how they rated the module concept, organizational aspects and the quality of support. We further analysed the chosen topics of the papers as well as student assessment results. Results: The student evaluation (return rates of 193 and 197, 71% and 77%) showed high overall satisfaction with the module. This result was evident in the high rating of the module concept and organizational aspects, a positive attitude towards scientific research, and strong motivation to pursue further scientific research. There was a wide spectrum of term paper topics with a focus on literature reviews. Most of the student work was assessed as good or very good. Conclusion: The scientific term paper module has proven itself as a curricular concept for students to perform own scientific research in the MCM, with strong acceptance and good performance by students. This project report can serve as basis and guidance for development and further improvements to promote scientific competencies in undergraduate medical education in other faculties.

Molecular basis for inner kinetochore configuration through RWD domain-peptide interactions.

Kinetochores are dynamic cellular structures that connect chromosomes to microtubules. They form from multi-protein assemblies that are evolutionarily conserved between yeasts and humans. One of these assemblies-COMA-consists of subunits Ame1CENP-U, Ctf19CENP-P, Mcm21CENP-O and Okp1CENP-Q A description of COMA molecular organization has so far been missing. We defined the subunit topology of COMA, bound with inner kinetochore proteins Nkp1 and Nkp2, from the yeast Kluyveromyces lactis, with nanoflow electrospray ionization mass spectrometry, and mapped intermolecular contacts with hydrogen-deuterium exchange coupled to mass spectrometry. Our data suggest that the essential Okp1 subunit is a multi-segmented nexus with distinct binding sites for Ame1, Nkp1-Nkp2 and Ctf19-Mcm21. Our crystal structure of the Ctf19-Mcm21 RWD domains bound with Okp1 shows the molecular contacts of this important inner kinetochore joint. The Ctf19-Mcm21 binding motif in Okp1 configures a branch of mitotic inner kinetochores, by tethering Ctf19-Mcm21 and Chl4CENP-N-Iml3CENP-L Absence of this motif results in dependence on the mitotic checkpoint for viability.

Digital breast tomosynthesis versus full-field digital mammography-Which modality provides more accurate prediction of margin status in specimen radiography?

OBJECTIVES: To evaluate the reliability of tumor margin assessment in specimen radiography (SR) using digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) in comparison to postoperative histopathology margin status as the gold standard. METHODS: After ethics committee approval, 102 consecutive patients who underwent breast conservative surgery for nonpalpable proven breast cancer were prospectively included. All patients underwent ultrasound/mammography-guided wire localization of their lesions. After excision, each specimen was marked for orientation and imaged using FFDM and DBT. Two blinded radiologists (R1, R2) independently analyzed images acquired with both modalities. Readers identified in which direction the lesion was closest to the specimen margin and to measure the margin width. Their findings were compared with the final histopathological analysis. True positive margin status was defined as a margin measuring <1mm for invasive cancer and 5mm for ductal carcinoma in situ (DCIS) at imaging and pathology. RESULTS: For FFDM, correct margin direction was identified in 45 cases (44%) by R1 and in 37 cases (36%) by R2. For DBT, 69 cases (68%) were correctly identified by R1 and 70 cases (69%) by R2. Overall accuracy was 40% for FFDM and 69% for DBT; the difference was statistically significant (p<0.0001). Sensitivity in terms of correct assessment of margin status was significantly better for DBT than FFDM (77% versus 62%). CONCLUSION: SR using DBT is significantly superior to FFDM regarding identification of the closest margin and sensitivity in assessment of margin status.

Contrast-enhanced spectral mammography vs. mammography and MRI - clinical performance in a multi-reader evaluation.

OBJECTIVES: To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) to digital mammography (MG) and magnetic resonance imaging (MRI) in a prospective two-centre, multi-reader study. METHODS: One hundred seventy-eight women (mean age 53 years) with invasive breast cancer and/or DCIS were included after ethics board approval. MG, CESM and CESM + MG were evaluated by three blinded radiologists based on amended ACR BI-RADS criteria. MRI was assessed by another group of three readers. Receiver-operating characteristic (ROC) curves were compared. Size measurements for the 70 lesions detected by all readers in each modality were correlated with pathology. RESULTS: Reading results for 604 lesions were available (273 malignant, 4 high-risk, 327 benign). The area under the ROC curve was significantly larger for CESM alone (0.84) and CESM + MG (0.83) compared to MG (0.76) (largest advantage in dense breasts) while it was not significantly different from MRI (0.85). Pearson correlation coefficients for size comparison were 0.61 for MG, 0.69 for CESM, 0.70 for CESM + MG and 0.79 for MRI. CONCLUSIONS: This study showed that CESM, alone and in combination with MG, is as accurate as MRI but is superior to MG for lesion detection. Patients with dense breasts benefitted most from CESM with the smallest additional dose compared to MG. KEY POINTS: • CESM has comparable diagnostic performance (ROC-AUC) to MRI for breast cancer diagnostics. • CESM in combination with MG does not improve diagnostic performance. • CESM has lower sensitivity but higher specificity than MRI. • Sensitivity differences are more pronounced in dense and not significant in non-dense breasts. • CESM and MRI are significantly superior to MG, particularly in dense breasts.

Correlation of contrast agent kinetics between iodinated contrast-enhanced spectral tomosynthesis and gadolinium-enhanced MRI of breast lesions.

OBJECTIVES: Assessment of contrast agent kinetics in contrast-enhanced MRI (CE-MRI) with gadolinium-containing contrast agents offers the opportunity to predict breast lesion malignancy. The goal of our study was to determine if similar patterns exist for spectral contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated contrast agent. METHODS: The protocol of our prospective study was approved by the relevant institutional review board and the German Federal Office for Radiation Protection. All patients provided written informed consent. We included 21 women with a mean age of 62.4 years. All underwent ultrasound-guided biopsy of a suspect breast lesion, spectral CE-DBT and CE-MRI. For every breast lesion, contrast agent kinetics was assessed by signal intensity-time curves for spectral CE-DBT and CE-MRI. Statistical comparison used Cohen's kappa and Spearman's rho test. RESULTS: Spearman's rho of 0.49 showed significant (P = 0.036) correlation regarding the contrast agent kinetics in signal intensity-time curves for spectral CE-DBT and CE-MRI. Cohen's kappa indicated moderate agreement (kappa = 0.438). CONCLUSION: There is a statistically significant correlation between contrast agent kinetics in the signal intensity-time curves for spectral CE-DBT and CE-MRI. Observing intralesional contrast agent kinetics in spectral CE-DBT may aid evaluation of malignant breast lesions. KEY POINTS: • Contrast agent kinetics can be assessed using spectral digital breast tomosynthesis (DBT). • Contrast agent kinetics patterns in spectral DBT are similar to those in contrast-enhanced MRI. • Multiple contrast enhancement for spectral DBT gives additional diagnostic information.

Pharmacokinetic approach for dynamic breast MRI to indicate signal intensity time curves of benign and malignant lesions by using the tumor flow residence time.

OBJECTIVE: The objective of this study was to evaluate a novel pharmacokinetic approach integrating a tumor model in a whole-body pharmacokinetic model to simulate contrast media-induced signal intensity time curves of breast tumors on dynamic contrast-enhanced magnetic resonance mammography. MATERIALS AND METHODS: A recently developed, whole-body pharmacokinetic model, which describes the distribution and excretion of renally discharged contrast media, has been expanded by integrating a tumor model. The parameters of the general approach including exchange between plasma and interstitium were set as fixed values; only 2 tumor-specific parameters, blood volume fraction Vblood and blood flow kt, were varied. These parameters were adjusted with regard to signal intensity time course data of histologically verified benign and malignant mass-like breast lesions on clinical magnetic resonance imaging examinations (1.5 T) using 2 different contrast media (gadopentetate dimeglumine and gadoterate meglumine) and 2 application doses (0.1 and 0.2 mmol kg body weight). Thus, measured signal intensity time curves were compared with simulated gadolinium (Gd) concentration time curves calculated by the pharmacokinetic model. RESULTS: Benign lesions showed continuous signal increase; malignant tumors presented fast initial signal increase followed by washout effect. According to the pharmacokinetic approach, the variation of the Vblood/kt ratio, which defined the tumor flow residence time τr, led to Gd concentration time curves congruent with the shapes of the measured signal intensity time curves. Low values of τr were characteristic for malignant tumors, and high values were typical for benign lesions; τr of 200 seconds best separated malignant from benign tumors. Thus, the dynamic magnetic resonance imaging data can be well approximated by the pharmacokinetic model considering 2 contrast media and application doses. The calculated Gd concentration time curves of 0.1 mmol kg body weight gadopentetate dimeglumine and gadoterate meglumine overlapped for benign lesions; the curve of gadoterate meglumine was by a factor of 0.8 below the curve of gadopentetate dimeglumine for malignant tumors. Doubling the application dose of gadopentetate dimeglumine from 0.1 to 0.2 mmol kg led to an increase in the Gd concentration time curves for benign lesions but not for malignant tumors. High Gd concentrations with values greater than 1 mmol L were calculated in the vessels of the malignant tumors, outside the determined range of the linear relationship between Gd concentration and signal intensity due to saturation effects. CONCLUSIONS: On the basis of this pharmacokinetic model, the contrast media-induced time curves on dynamic contrast-enhanced magnetic resonance mammography can be classified by a single kinetic parameter, the tumor flow residence time τr, into benign (τr >200 seconds) and malignant (τr <200 seconds) curve shapes. Possible clinical application of this model is to create pharmacokinetic maps, displaying tumor flow residence times, for computer-assisted diagnosis, which may be integrated into clinical routine for the diagnosis of breast lesions.