Body composition as a novel biomarker of recurrence risk in patients with triple-negative breast cancer.

Background And Hypothesis: Triple-negative breast cancer (TNBC) patients are at increased risk for recurrence compared to other subtypes of breast cancer. Previous evidence showed that adiposity may contribute to worsened cancer control. Current measures of obesity, such as body-mass index (BMI), are poor surrogates of adiposity, while visceral-to-subcutaneous adiposity ratio (VSR), which can be measured from routine computed tomography (CT) imaging, is a direct adiposity measure.

Late lesion growth following endovascular therapy: is 24 hours too early to assess acute infarct size including the effects of secondary injury?

Introduction Stroke lesion volume on MRI or CT provides objective evidence of tissue injury as a consequence of ischemic stroke. Measurement of "final" lesion volume at 24hr following endovascular therapy (post-EVT) has been used in multiple studies as a surrogate for clinical outcome. However, despite successful recanalization, a significant proportion of patients do not experience favorable clinical outcome.

In vivo lymph node CEST-Dixon MRI in breast cancer patients with metastatic lymph node involvement.

Purpose: Axillary lymph nodes (LNs) often present a reservoir for metastatic breast cancer, yet metastatic LN involvement cannot be discerned definitively using diagnostic imaging. This study investigated whether in vivo CEST may discriminate LNs with versus without metastatic involvement.

Methods: 3T MRI was performed in patients with breast cancer before clinically-indicated mastectomy or lumpectomy with LN removal, after which LN metastasic involvement was determined using histological evaluation.

Post-ischemic hyperemia following endovascular therapy for acute stroke is associated with lesion growth.

A substantial proportion of acute stroke patients fail to recover following successful endovascular therapy (EVT) and injury to the brain and vasculature secondary to reperfusion may be a contributor. Acute stroke patients were included with: i) large vessel occlusion of the anterior circulation, ii) successful recanalization, and iii) evaluable MRI early after EVT. Presence of hyperemia on MRI perfusion was assessed by consensus using a modified ASPECTS.

-----Comparison of T1-Post and FLAIR-Post MRI for identification of traumatic meningeal enhancement in traumatic brain injury patients.

Traumatic meningeal enhancement (TME) is a novel biomarker observed on post-contrast fluid-attenuated inversion recovery (FLAIR) in patients who undergo contrast-enhanced magnetic resonance imaging (MRI) after suspected traumatic brain injury (TBI). TME may be seen on acute MRI despite the absence of other trauma-related intracranial findings. In this study we compare conspicuity of TME on FLAIR post-contrast and T1 weighted imaging (T1WI) post-contrast, and investigate if TME is best detected by FLAIR post-contrast or T1WI post-contrast sequences.

Arterial CO pressure changes during hypercapnia are associated with changes in brain parenchymal volume.

The Monro-Kellie hypothesis (MKH) states that volume changes in any intracranial component (blood, brain tissue, cerebrospinal fluid) should be counterbalanced by a co-occurring opposite change to maintain intracranial pressure within the fixed volume of the cranium. In this feasibility study, we investigate the MKH application to structural magnetic resonance imaging (MRI) in observing compensating intracranial volume changes during hypercapnia, which causes an increase in cerebral blood volume. Seven healthy subjects aged from 24 to 64 years (median 32), 4 males and 3 females, underwent a 3-T three-dimensional T1-weighted MRI under normocapnia and under hypercapnia.

The association between BOLD-based cerebrovascular reactivity (CVR) and end-tidal CO in healthy subjects.

Cerebrovascular reactivity (CVR) mapping using CO-inhalation can provide important insight into vascular health. At present, blood-oxygenation-level-dependent (BOLD) MRI acquisition is the most commonly used CVR method due to its high sensitivity, high spatial resolution, and relatively straightforward processing. However, large variations in CVR across subjects and across different sessions of the same subject are often observed, which can cloud the ability of this promising measure in detecting diseases or monitoring treatment responses.

Subarachnoid Hemorrhage and Cerebral Perfusion Are Associated with Brain Volume Decrease in a Cohort of Predominantly Mild Traumatic Brain Injury Patients.

Biomarkers are needed to identify traumatic brain injury (TBI) patients at risk for accelerated brain volume loss and its associated functional impairment. Subarachnoid hemorrhage (SAH) has been shown to affect cerebral volume and perfusion, possibly by induction of inflammation and vasospasm. The purpose of this study was to assess the impact of SAH due to trauma on cerebral perfusion and brain volume.

Characterization of MRI techniques to assess neonatal brain oxygenation and blood flow.

There is increasing interest in applying physiological MRI in neonates, based on the premise that physiological parameters may provide an early biomarker of neonatal brain health and injury. Two commonly used techniques are oxygen extraction fraction (OEF) measurement using T -relaxation-under-spin-tagging (TRUST) MRI and cerebral blood flow measurement using phase-contrast (PC) quantitative flow MRI, which collectively provide an assessment of the brain's oxygen consumption. However, prior research has only demonstrated proof of principle of these methods in neonates, without characterization or benchmarking of the techniques.

Prevalence and vascular risk factors of basal ganglia calcifications in patients at risk for cerebrovascular disease.

Background And Purpose: Risk factors for and meaning of basal ganglia calcifications outside Fahr syndrome are poorly understood. We aimed to assess the prevalence of basal ganglia calcifications and the association with vascular risk factors.

Materials And Methods: 1133 patients suspected of acute ischemic stroke from the Dutch acute stroke (DUST) study who underwent thin-slice unenhanced brain CT were analyzed.

Identifying perfusion deficits on CT perfusion images using temporal similarity perfusion (TSP) mapping.

Objectives: Deconvolution-derived maps of CT perfusion (CTP) data may be confounded by transit delays. We propose temporal similarity perfusion (TSP) analysis to decrease CTP maps' dependence on transit times and investigate its sensitivity to detect perfusion deficits.

Methods: CTP data of acute stroke patients obtained within 9 h of symptom onset was analyzed using a delay-insensitive singular value decomposition method and with TSP.

Microstructural White Matter Abnormalities and Cognitive Impairment After Aneurysmal Subarachnoid Hemorrhage.

Background and Purpose- Aneurysmal subarachnoid hemorrhage (aSAH) may have detrimental effects on white matter microstructure, which may in turn explain the cognitive impairments that occur often after aSAH. We investigated (1) whether the white matter microstructure is altered in patients with aSAH compared with patients with an unruptured intracranial aneurysm and (2) whether these abnormalities are associated with cognitive impairment 3 months after ictus. Methods- Forty-nine patients with aSAH and 22 patients with an unruptured intracranial aneurysm underwent 3T brain magnetic resonance imaging, including a high-resolution diffusion tensor imaging sequence.

Risk factors for atherosclerotic and medial arterial calcification of the intracranial internal carotid artery.

Background And Aims: Calcifications of the intracranial internal carotid artery (iICA) are an important risk factor for stroke. The calcifications can occur both in the intimal and medial layer of the vascular wall. The aim of this study is to assess whether medial calcification in the iICA is differently related to risk factors for cardiovascular disease, compared to intimal calcification.

Effect sizes of BOLD CVR, resting-state signal fluctuations and time delay measures for the assessment of hemodynamic impairment in carotid occlusion patients.

Background And Purpose: The BOLD signal amplitude as a response to a hypercapnia stimulus is commonly used to assess cerebrovascular reserve. Despite recent advances, the implementation remains cumbersome and alternative ways to assess hemodynamic impairment are desirable. Resting-state BOLD signal fluctuations (rsBOLD) have been proposed however data on its sensitivity and dependence on baseline venous cerebral blood volume (vCBV) is limited.

Fast CSF MRI for brain segmentation; Cross-validation by comparison with 3D T1-based brain segmentation methods.

Objective: In previous work we have developed a fast sequence that focusses on cerebrospinal fluid (CSF) based on the long T2 of CSF. By processing the data obtained with this CSF MRI sequence, brain parenchymal volume (BPV) and intracranial volume (ICV) can be automatically obtained. The aim of this study was to assess the precision of the BPV and ICV measurements of the CSF MRI sequence and to validate the CSF MRI sequence by comparison with 3D T1-based brain segmentation methods.

Hippocampal calcification on brain CT: prevalence and risk factors in a cerebrovascular cohort.

Objectives: Recently, hippocampal calcification as observed on brain CT examinations was identified in over 20% of people over 50 years of age and a relation between hippocampal calcification and cognitive decline was shown. We determined the prevalence and investigated the vascular risk factors of hippocampal calcification in patients with cerebrovascular disease.

Methods: Hippocampal calcification was scored bilaterally on presence and severity on CT examinations in a cohort of 1130 patients with (suspected) acute ischaemic stroke.

Cerebrovascular reactivity (CVR) MRI with CO2 challenge: A technical review.

Cerebrovascular reactivity (CVR) is an indicator of cerebrovascular reserve and provides important information about vascular health in a range of brain conditions and diseases. Unlike steady-state vascular parameters, such as cerebral blood flow (CBF) and cerebral blood volume (CBV), CVR measures the ability of cerebral vessels to dilate or constrict in response to challenges or maneuvers. Therefore, CVR mapping requires a physiological challenge while monitoring the corresponding hemodynamic changes in the brain.

Arterial-spin-labeling (ASL) perfusion MRI predicts cognitive function in elderly individuals: A 4-year longitudinal study.

Background: With the disappointing outcomes of clinical trials on patients with Alzheimer's disease or mild cognitive impairment (MCI), there is increasing attention to understanding cognitive decline in normal elderly individuals, with the goal of identifying subjects who are most susceptible to imminent cognitive impairment.

Purpose/hypothesis: To evaluate the potential of cerebral blood flow (CBF) as a biomarker by investigating the relationship between CBF at baseline and cognition at follow-up.

Study Type: Prospective longitudinal study with a 4-year time interval.

Magnetic resonance imaging and brain injury in the chronic phase after aneurysmal subarachnoid hemorrhage: A systematic review.

Background Case-fatality rates after aneurysmal subarachnoid hemorrhage have decreased over the past decades. However, many patients who survive an aneurysmal subarachnoid hemorrhage have long-term functional and cognitive impairments. Aims We sought to review all data on conventional brain MRI obtained in the chronic phase after aneurysmal subarachnoid hemorrhage to (1) analyze the proportion of patients with cerebral infarction or brain volume changes; (2) investigate baseline determinants predictive of MRI-detected damage; and (3) assess if brain damage is predictive of patient outcome.

Spatial distribution of flow and oxygenation in the cerebral venous drainage system.

Purpose: To investigate the venous oxygenation and flow in the brain, and determine how they might change under challenged states.

Materials And Methods: Eight healthy human subjects (24-37 years) were studied. T -relaxation under spin tagging (TRUST) magnetic resonance imaging (MRI) and phase-contrast MRI were performed to measure venous oxygenation and venous blood flow, respectively, in the superior sagittal sinus (SSS), the straight sinus (SS), and the internal jugular veins (IJVs).

Computed Tomographic Distinction of Intimal and Medial Calcification in the Intracranial Internal Carotid Artery.

Background: Intracranial internal carotid artery (iICA) calcification is associated with stroke and is often seen as a proxy of atherosclerosis of the intima. However, it was recently shown that these calcifications are predominantly located in the tunica media and internal elastic lamina (medial calcification). Intimal and medial calcifications are thought to have a different pathogenesis and clinical consequences and can only be distinguished through ex vivo histological analysis.

Hippocampal Calcification on Computed Tomography in Relation to Cognitive Decline in Memory Clinic Patients: A Case-Control Study.

Background: It was recently shown that calcification of the hippocampus can be detected on computed tomography (CT) images and these calcifications occur in up to 20% of people over 50 years of age. However, little is known about hippocampal calcification and its relation to cognition and cognitive decline. Therefore, the aim of this study was to (1) determine the prevalence of hippocampal calcification on CT in memory clinic patients controls, and (2) to assess its relation with cognitive decline.