Cardiac Magnetic Resonance Can Exclude Clinically Relevant Coronary Artery Disease

MedicalResearch.com Interview with:

Pr. Juerg Schwitter MD Médecin Chef Cardiologie Directeur du Centre de la RM Cardiaque du CHUV Centre Hospitalier Universitaire Vaudois - CHUV Suisse

Pr. Schwitter

Pr. Juerg Schwitter MD
Médecin Chef Cardiologie
Directeur du Centre de la RM Cardiaque du CHUV
Centre Hospitalier Universitaire Vaudois – CHUV
Suisse 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Coronary artery disease (CAD) is still one of the leading causes of death in the industrialized world and as such, it is also an important cost driver in the health care systems of most countries. For the European Union, the estimated costs for CAD management were 60 billion Euros in 2009, of which approximately 20 billion Euros were attributed to direct health care costs (1). In 2015, the total costs of CAD management in the United States were estimated to be 47 billion dollars (2).

Substantial progress has been achieved regarding the treatment of CAD including drug treatment but also revascularizations procedures. There exists a large body of evidence demonstrating myocardial ischemia as one of the most important factors determining the patient’s prognosis and reduction of ischemia has been shown to improve outcome.

On the other hand, techniques to detect CAD, i.e. relevant myocardial ischemia, were insufficient in the past. Evaluation of myocardial perfusion by first-pass perfusion cardiac magnetic resonance (CMR) is now closing this gap (3) and CMR is recommended by most international guidelines for the work-up of known or suspected CAD (4,5).

Still, a major issue was not clarified until now, i.e. “how much ischemia is required to trigger revascularization procedures”. Thus, this large study was undertaken to assess at which level of ischemia burden, patients can be safely deferred from revascularization and can be managed by risk factor treatment only. Of note, this crucial question was addressed in both, patients with suspected CAD but also in patients with known (and sometimes already advanced) CAD, thereby answering this question in the setting of daily clinical practice.

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Ischemic Stroke: Collateral Blood Vessels Detected by Arterial Spin Labeling MRI Correlates With Good Neurological Outcome

MedicalResearch.com Interview with:
Jalal B. Andre M.D., D.A.B.R.®

Drector of neurological MRI and
MRI safety officer at Harborview Medical Center
University of Washington 

MedicalResearch.com: What is the background for this study?

Response: Acute ischemic stroke (AIS) patients with good collaterals have better clinical outcomes. AIS is characterized by an ischemic penumbra, a region of salvageable brain tissue, that surrounds a core of irreversible ischemic infarct. The penumbra is tenuously perfused by collateral blood vessels which, if extensive enough, can maintain penumbral perfusion, improving the odds that a larger volume of brain tissue will survive. Standard, first-line methods for evaluating collaterals in the acute setting include CT angiography, MR angiography, and (less commonly) digital subtraction angiography. Arterial spin labeling (ASL) is an emerging MRI technique that assesses cerebral perfusion. Its advantages include relatively short scan time (4-6 minutes), lack of ionizing radiation, and independence from an exogenous contrast agent (contraindicated in patients with impaired renal function or documented sensitivity). Collaterals can be identified within ASL images as foci of curvilinear hyperintensity bordering regions of hypoperfusion. We sought to explore a novel relationship between the presence of ASL collaterals (ASLc) and neurological outcome in acute ischemic stroke patients.

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Clinical Outcomes Following a Low-Suspicion MRI for Prostate Cancer

MedicalResearch.com Interview with:

Lars Boesen MD PhD Department of Urology Herlev Gentofte University Hospital Herlev

Dr. Boessen

Lars Boesen MD PhD
Department of Urology
Herlev Gentofte University Hospital
Herlev

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Transrectal ultrasound-guided biopsies (TRUS-bx) traditionally used for detecting prostate cancer (PCa) are prone to sampling errors due to difficulties in target identification. Therefore, concerns about the possibility of missing significant prostate cancer result in men with negative biopsy results frequently undergo repeated biopsies, leading to increased medical costs, patient anxiety and morbidity.

Multiparametric MRI (mp-MRI) has become increasingly important in prostate cancer diagnosis. A suspicious lesion can be targeted by MRI-guided biopsies and improve diagnosis. Conversely, a normal mp-MRI may non-invasively exclude the possibility of an aggressive disease, avoiding the need for further biopsies. However, there are no current guidelines for clinicians whether standard repeated biopsies (TRUS-bx) should be performed in men with either a low-suspicion mp-MRI or benign MRI-targeted biopsies of a suspicious lesion and the clinical outcome and future risk of detecting significant prostate cancer following these findings is unknown.

Therefore, we assessed the risk of being diagnosed with prostate cancer after either a low-suspicion mp-MRI or benign targeted biopsies of a suspicious lesion in men with prior negative TRUS-bx, but a persistent clinical suspicion of missed significant cancer over a follow-up period of at least three years. Our results suggest that a low-suspicion MRI in men with prior negative TRUS-bx can be used non-invasively in ruling out longer term significant cancer and immediate repeated biopsies are of limited clinical value and might be avoided even if prostate-specific-antigen levels are persistently elevated.

MedicalResearch.com: What should readers take away from your report?

Response: A low-suspicion mp-MRI in a man with prior negative TRUS-bx has a high accuracy in ruling out a significant aggressive prostate cancer during follow-up of at least three years. Thus, immediate repeated biopsies rarely find significant disease and could be avoided even if the prostate-specific-antigen level is persistently elevated.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Our results should be verified in larger prospective studies with a longer follow-up period to assess other clinical endpoints that include disease progression, cancer specific mortality and associated costs with an mp-MRI approach.

There are no disclosures or conflicts of interest

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:
J Urol. 2017 Feb 21. pii: S0022-5347(17)30297-5. doi: 10.1016/j.juro.2017.02.073. [Epub ahead of print]
Clinical outcome following a low-suspicion multiparametric prostate MRI or benign MRI-guided biopsy to detect prostate cancer: A follow-up study in men with prior negative transrectal ultrasound-guided biopsies.
Boesen L1, Nørgaard N2, Løgager V3, Thomsen HS4.
Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Subtle Differences in Brain Volume Detected On MRI In ADHD

MedicalResearch.com Interview with:
M. (Martine) Hoogman PhD.

Postdoc and PI of ENIGMA-ADHD
Radboud universitair medisch centrum
Department of Human Genetics
Nijmegen, The Netherlands

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: There are many neuro-imaging studies aimed at investigating structural brain changes related to ADHD, but the results are often inconclusive.

There are two main reasons for this:

1) the small sample size of the studies and
2) the heterogeneous methods used.

We tried to address these issues by forming an international collaboration to provide a sample size sufficient to detect even small effects in volume differences. And in addition, we analyzed all the raw scans again using homogenized methods. There are data of more than 1700 patients (aged 4-63 years of age) and more than 1500 healthy controls in our dataset, coming from 23 sites around the world. We studied the possible volume differences between cases and controls of 7 subcortical regions and intracranial volume by performing mega- and meta-analysis.

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Can Patients With A Pacemaker or Defibrillator Get An MRI?

MedicalResearch.com Interview with:

Robert Russo, MD, PhD, FACC The Scripps Research Institute The La Jolla Cardiovascular Research Institute

Dr. Robert Russo

Robert Russo, MD, PhD, FACC
The Scripps Research Institute
The La Jolla Cardiovascular Research Institute 

MedicalResearch.com: What is the background for this study?

Response: For an estimated 2 million people in the United States and an additional 6 million people worldwide, the presence of a non-MRI-conditional pacemaker or implantable cardioverter defibrillator (ICD) is considered a contraindication to magnetic resonance imaging. This creates a dilemma for at least half of these patients, who are predicted to require an MRI scan during their lifetime after a cardiac device has been implanted. Safety concerns for patients with an implanted cardiac device undergoing MRI are related to the potential for magnetic field-induced cardiac lead heating resulting in myocardial thermal injury, and a detrimental change in pacing properties. As a result, patients with an implanted device have long been denied access to MRI, although it may have been the most appropriate diagnostic imaging modality for their clinical care. Despite the development of MRI-conditional cardiac devices, a strategy for mitigating risks for patients with non MRI-conditional devices and leads will remain an enduring problem for the foreseeable future due to an ever increasing demand for MRI and the large number of previously and currently implanted non-MRI-conditional devices.

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PET Scanning Highlights Link Between Stress and Heart Disease

MedicalResearch.com Interview with:

Dr Ahmed Tawakol MD Massachusetts General Hospital and Harvard Medical Schoo

Dr Ahmed Tawakol

Dr Ahmed Tawakol MD
Co-Director, Cardiac MR PET CT Program
Massachusetts General Hospital and
Harvard Medical School 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: While the link between stress and heart disease has long been established, the mechanism mediating that risk hasn’t been clearly understood. Animal studies showed that stress activates bone marrow to produce white blood cells, leading to arterial inflammation.  This study suggests an analogous path exists in humans. Moreover, this study identifies, for the first time in animal models or humans, the region of the brain (the amygdala) that links stress to the risk of heart attack and stroke.

The paper reports on two complementary studies.

The first analyzed imaging and medical records data from almost 300 individuals who had PET/CT brain imaging, primarily for cancer screening, using a radiopharmaceutical called FDG that both measures the activity of areas within the brain and reflects inflammation within arteries.  All participants in that study had no active cancer or cardiovascular disease at the time of imaging and each had information in their medical records on at least three additional clinical visits after imaging.

The second study enrolled 13 individuals with a history of post-traumatic stress disorder, who were evaluated for their current levels of perceived stress and received FDG-PET scanning to measure both amygdala activity and arterial inflammation.

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MRI Can Better Diagnose Fetal Brain Abnormalities in-Utero

MedicalResearch.com Interview with:
Prof Paul D Griffiths, FRCR and

Cara Mooney, Study Manager: MERIDIAN
Clinical Trials Research Unit
The University of Sheffield 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Around three in every 1000 pregnancies is complicated by a fetal abnormality. In the UK Ultrasonography (USS) has, for many years, been the mainstay of antenatal screening and detailed anomaly scanning to detect such abnormalities.  However previous studies have suggested that in utero Magnetic Resonance (iuMR) imaging may be a useful adjunct to USS for detecting these brain abnormalities in the developing fetus.

This study was designed to test the diagnostic accuracy and clinical impact of introducing fetal MR in to the diagnostic pathway.

Our results show that iuMR has an overall diagnostic accuracy of 93% compared to ultrasound at 68%, this is an increase in diagnostic accuracy of 25%. When divided into gestational age group the improvement in diagnostic accuracy ranged from 23% in the 18-23 week group, and 29% in the 24 week and over group.

IuMR provided additional diagnostic information in 49% of cases, changed prognostic information in at least 20% and the contribution to clinical management was felt to be at least ‘significant’ in 35% of cases. IuMR also had high patient acceptability with at least 95% of women stating that they would have an iuMR if a future pregnancy were complicated by a fetal brain abnormality.

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Cerebral Perfusion Is Perturbed by Preterm Birth and Brain Injury

MedicalResearch.com Interview with:
Eman S. Mahdi, MD, MBChB
Pediatric Radiology Fellow

Catherine Limperopoulos, PhD Director, Developing Brain Research Laboratory Co-Director of Research, Division of Neonatology Diagnostic Imaging and Radiology Children’s National Health System Washington, DC

Dr. Catherine Limperopoulos

Catherine Limperopoulos, PhD
Director, Developing Brain Research Laboratory
Co-Director of Research, Division of Neonatology
Diagnostic Imaging and Radiology
Children’s National Health System
Washington, DC

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Premature birth is a major public health concern in the United States affecting 1 in 10 infants each year. Prematurity-related brain injury is very common and associated with a high prevalence of brain injury and accompanying lifelong neurodevelopmental morbidities.

Early disturbances in systemic and cerebral hemodynamics are thought to mediate prematurity-related brain injury. The extent to which cerebral blood flow (CBF) is disturbed in preterm birth is poorly understood, in large part because of the lack of monitoring techniques that can directly and non-invasively measure cerebral blood flow.

We report for the first time early disturbances in global and regional cerebral blood flow in preterm infants following brain injury on conventional magnetic resonance imaging (MRI) over the third trimester of ex-uterine life using arterial spin labelling images. In terms of regional differences, we saw a marked decrease in blood flow to the thalamus and the pons, regions known to be metabolically active during this time.

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God Activates Reward Centers In Brain

MedicalResearch.com Interview with:

Jeffrey S. Anderson, MD, PhD Director the fMRI Neurosurgical Mapping Service Principal Investigator for the Utah Functional Neuroimaging Laboratory University of Utah

Dr. Jeffrey S. Anderson

Jeffrey S. Anderson, MD, PhD
Director the fMRI Neurosurgical Mapping Service
Principal Investigator for the Utah Functional Neuroimaging Laboratory
University of Utah

MedicalResearch.com: What is your study about?

Response: Billions of people find meaning in life and make choices based on religious and spiritual experiences. These experiences range from epiphanies that change the lives of celebrated mystics to subtle feelings of peace and joy in the lives of neighbors, friends, or family members that are interpreted as spiritual, divine, or transcendent.

Astonishingly, with all we understand about the brain, we still know very little about how the brain participates in these experiences. We set out to answer what brain networks are involved in representing spiritual feelings in one group of people, devout Mormons.
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Virtual Reality Systems Can Generate Immersive 3D Images of Fetuses

Close-up of fetus at 26 weeks RSNA16

Close-up of fetus at 26 weeks

MedicalResearch.com Interview with:
Dr. Heron Werner Junior
Clínica de Diagnóstico por Imagem – CDPI
Rio de Janeiro – Brazil

MedicalResearch.com: What is the background for this study?

Response: A growing number of technological advancements in obtaining and viewing images through noninvasive techniques have brought major breakthroughs in fetal medicine.

In general, two main technologies are used to obtain images within the uterus during pregnancy i.e. ultrasound (US) and magnetic resonance imaging (MRI).

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Brain Gray Matter Volume Predictive of Weight Loss Success

MedicalResearch.com Interview with:
Fatemeh Mokhtari

Medical Imaging PhD Student
VT-WFU SBES

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: The objective of this study was to use baseline anatomical brain MRI scans to prospectively predict weight loss success following an intensive lifestyle intervention. In the study, 52 participants, age 60 to 79, were recruited from the Cooperative Lifestyle Interventions Programs II (CLIP-II) project. The participants were overweight or obese (BMI greater than 28 and less than 42) and had a history of either cardiovascular disease or metabolic syndrome. All participants had a baseline MRI scan, and then were randomized to one of three groups – diet only, diet plus aerobic exercise training or diet plus resistance exercise training. The goal of the 18-month diet and exercise program was a weight loss of 7 to 10 percent of body mass.
Basic brain structure information garnered from the MRIs was classified using a support vector machine, a type of computerized predictive algorithm. Specifically, we trained a computational predictive model which mapped each subject’s brain scan to weight loss performance. Predictions were based on baseline brain gray and white matter volume from the participants’ MRIs and compared to the study participants’ actual weight loss after the 18 months. The accuracy of the model was then tested, and our prediction algorithms were 78% accurate in predicting successful weight loss. Brain gray matter volume provided higher prediction accuracy compared with white matter and the combination of the two outperformed either one alone.

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Computer Bests Neuroradiologists in Distinguishing Tumor Recurrence From Radiation Necrosis

MedicalResearch.com Interview with:

Dr. Pallavi Tiwari PhD Assistant Professor biomedical engineering Case Western Reserve University

Dr. Pallavi Tiwari

Dr. Pallavi Tiwari PhD
Assistant Professor biomedical engineering
Case Western Reserve University

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: One of the biggest challenges in neuro-oncology currently is distinguishing radionecrosis, a side-effect of aggressive radiation, from tumor recurrence on imaging. Surgical intervention is the only means of definitive diagnosis, but suffers from considerable morbidity and mortality. The treatments for radionecrosis and cancer recurrence are very different. Early identification of the two conditions can help speed prognosis, therapy, and improve patient outcomes.

The purpose of this feasibility study was to evaluate the role of machine learning algorithms along with computer extracted texture features, also known as radiomic features, in distinguishing radionecrosis and tumor recurrence on routine MRI scans (T1w, T2w, FLAIR). The radiomic algorithms were trained on 43 studies from our local collaborating institution – University Hospitals Case Medical Center, and tested on 15 studies at a collaborating institution, University of Texas Southwest Medical Center. We further compared the performance of the radiomic techniques with two expert readers.

Our results demonstrated that radiomic features can identify subtle differences in quantitative measurements of tumor heterogeneity on routine MRIs, that are not visually appreciable to human readers. Of the 15 test studies, the radiomics algorithm could identify 12 of 15 correctly, while expert 1 could identify 7 of 15, and expert 2, 8 of 15.

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