Time and diffusion lesion size in major anterior circulation ischemic strokes.

BACKGROUND AND PURPOSE: Major anterior circulation ischemic strokes caused by occlusion of the distal internal carotid artery or proximal middle cerebral artery or both account for about one third of ischemic strokes with mostly poor outcomes. These strokes are treatable by intravenous tissue-type plasminogen activator and endovascular methods. However, dynamics of infarct growth in these strokes are poorly documented. The purpose was to help understand infarct growth dynamics by measuring acute infarct size with diffusion-weighted imaging (DWI) at known times after stroke onset in patients with documented internal carotid artery/middle cerebral artery occlusions. METHODS: Retrospectively, we included 47 consecutive patients with documented internal carotid artery/middle cerebral artery occlusions who underwent DWI within 30 hours of stroke onset. Prospectively, 139 patients were identified using the same inclusion criteria. DWI lesion volumes were measured and correlated to time since stroke onset. Perfusion data were reviewed in those who underwent perfusion imaging. RESULTS: Acute infarct volumes ranged from 0.41 to 318.3 mL. Infarct size and time did not correlate (R2=0.001). The majority of patients had DWI lesions that were <25% the territory at risk (<70 mL) whether they were imaged <8 or >8 hours after stroke onset. DWI lesions corresponded to areas of greatly reduced perfusion. CONCLUSIONS: Poor correlation between infarct volume and time after stroke onset suggests that there are factors more powerful than time in determining infarct size within the first 30 hours. The observations suggest that highly variable cerebral perfusion via the collateral circulation may primarily determine infarct growth dynamics. If verified, clinical implications include the possibility of treating many patients outside traditional time windows.

Spine MRI Identifies Clinically Relevant Findings in Patients With Cancer Presenting With Back Pain.

STUDY DESIGN: This is a retrospective, cross-sectional study. OBJECTIVE: The primary aim was to identify the diagnostic yield of spine magnetic resonance imaging (MRI) in detecting malignant pathology in cancer patients with back pain. We also sought to evaluate the role of MRI extent ( i.e. regional vs. total) in identifying malignant pathology. SUMMARY OF BACKGROUND DATA: No prior study has systematically investigated the yield of spine MRI in a large cohort of cancer patients. METHODS: Spine MRI reports from 2017 to 2021 for back pain (acute and nonspecified chronicity) in cancer patients were reviewed to identify clinically relevant findings: malignant (1) epidural, (2) leptomeningeal, (3) intramedullary, (4) osseous disease, and (5) fracture. Logistic regression was used to evaluate the association between MRI extent and the presence of cancer-related findings. For patients with multiple MRIs, short-interval scans (≤4 mo) were evaluated to assess the yield of repeat imaging. RESULTS: At least one cancer-related finding was identified on 52% of 5989 spine MRIs ordered for back pain and 57% of 1130 spine MRIs ordered specifically for acute back pain. The most common pathology was malignant osseous disease (2545; 43%). Across all five categories, most findings (77%-89%) were new/progressive. Odds of identifying a finding were significantly higher with total versus regional spine MRIs ( P <0.001). Although only 14 patients had a positive regional MRI followed shortly by a positive total spine MRI, most of these repeat total spine MRIs (78%) identified findings outside the scope of the initial regional scan. Twenty-one patients had both computed tomography and MRI within 30 days of each other; eight (38%) had compression fractures appreciated on MRI but not on computed tomography. CONCLUSIONS: Our findings suggest imaging the total spine in cancer patients with back pain given higher odds of identifying malignant pathology and instances of capturing otherwise not visualized disease. Further work is warranted to confirm these findings.

Neuroimaging and Neurocognitive Outcomes in Older Patients with Multiple Myeloma Treated with Chemotherapy and Autologous Stem Cell Transplantation.

Background Many patients with hematological malignancies treated with stem cell transplantation (SCT) experience cognitive dysfunction. However, few studies have investigated treatment-related neurotoxicity in older adults with multiple myeloma (MM) treated with high dose chemotherapy (HDC) and autologous SCT (HDC/ASCT). In this study, we examined gray matter (GM) volume, resting state functional connectivity (RSFC), neurocognitive function (NF), and proinflammatory cytokines (PCy) in older patients with MM pre- and post-HDC/ASCT. Methods Eighteen MM patients underwent magnetic resonance imaging, neurocognitive tests, and serum PCy measurement prior to HDC/ASCT, and fifteen patients completed follow ups an average of five months post-HDC/ASCT. Results There were significant decreases in RSFC from pre- to post-HDC/ASCT in (1) the central executive network (CEN) involving the left dorsolateral prefrontal cortex and right posterior parietal cortex (p = 0.022), and (2) the CEN involving the right posterior parietal cortex and the salience network involving the right dorsal anterior cingulate cortex (p = 0.029); these comparisons were no longer significant after multiple comparisons correction. There were no significant changes in GM volumes or NF, except for improvement in attention (Digit Span Backward, p = 0.03). There were significant increases in several PCy post-HDC/ASCT (p ≤ 0.05). Conclusions This pilot study showed decreased RSFC involving the left frontal, right posterior parietal and right anterior cingulate cortices in MM patients post-HDC/ASCT, relatively stable NF, and increases in PCy. These findings are congruent with studies in patients with hematological malignancies and other cancers and provide supporting evidence for the vulnerability of frontoparietal regions to chemotherapy adverse effects.

Neuroimaging and Neurocognitive Outcomes in Older Patients with Multiple Myeloma Treated with Chemotherapy and Autologous Stem Cell Transplantation.

There is a paucity of research on treatment-related neurotoxicity in older adults with multiple myeloma (MM) treated with high-dose chemotherapy (HDC) and autologous SCT (HDC/ASCT), despite the increasing use of this regimen. We examined resting state functional connectivity (RSFC), gray matter (GM) volume, neurocognitive function (NF), and proinflammatory cytokines (PCy) in older patients with MM pre- and post-HDC/ASCT. Eighteen patients underwent MRI, NF tests, and serum PCy measurements prior to HDC/ASCT, and fifteen patients completed a follow up five-months post-HDC/ASCT. There were significant decreases in RSFC post-HDC/ASCT in (1) the central executive network (CEN) involving the left dorsolateral prefrontal cortex and right posterior parietal cortex (p = 0.022) and (2) the CEN involving the right posterior parietal cortex and the salience network involving the right dorsal anterior cingulate cortex (p = 0.029). There were no significant changes in GM or NF, except for improvements in attention (Digit Span Backward, p = 0.03). There were significant increases in several PCy post-HDC/ASCT (p ≤ 0.05). In conclusion, RSFC decreased in frontal, parietal, and cingulate cortices post-HDC/ASCT, NF was relatively stable, and several PCy increased. These findings are congruent with other studies in cancer patients and provide supporting evidence for the vulnerability of frontoparietal regions to chemotherapy's adverse effects.

Altered regional homogeneity in patients with ovarian cancer treated with chemotherapy: a resting state fMRI study.

Many patients treated with chemotherapy for non-central nervous system (CNS) cancers experience cognitive dysfunction. However, few studies have investigated treatment-related neurotoxicity in women with ovarian cancer. The goal of this study was to assess regional brain function in patients with ovarian cancer after first-line chemotherapy. Seventeen patients with ovarian cancer and seventeen healthy controls matched for gender, age and education participated in the study. The patients were evaluated 1-4 months after completion of first line taxane/platinum chemotherapy. All participants underwent resting state functional MRI (rsfMRI) and regional homogeneity (ReHo) indices were calculated. The results showed that patients had significantly decreased average ReHo values in the left middle frontal gyrus, medial prefrontal cortex, and right superior parietal lobule, compared to healthy controls. This is the first rsfMRI study showing ReHo alterations in frontal and parietal regions in patients with ovarian cancer treated with first-line chemotherapy. The findings are overall congruent with prior studies in non-CNS cancer populations and provide supporting evidence for the prevailing notion that frontal areas are particularly vulnerable to the adverse effects of chemotherapy.

Inflammatory Leptomeningeal Cytokines Mediate COVID-19 Neurologic Symptoms in Cancer Patients.

SARS-CoV-2 infection induces a wide spectrum of neurologic dysfunction that emerges weeks after the acute respiratory infection. To better understand this pathology, we prospectively analyzed of a cohort of cancer patients with neurologic manifestations of COVID-19, including a targeted proteomics analysis of the cerebrospinal fluid. We find that cancer patients with neurologic sequelae of COVID-19 harbor leptomeningeal inflammatory cytokines in the absence of viral neuroinvasion. The majority of these inflammatory mediators are driven by type II interferon and are known to induce neuronal injury in other disease states. In these patients, levels of matrix metalloproteinase-10 within the spinal fluid correlate with the degree of neurologic dysfunction. Furthermore, this neuroinflammatory process persists weeks after convalescence from acute respiratory infection. These prolonged neurologic sequelae following systemic cytokine release syndrome lead to long-term neurocognitive dysfunction. Our findings suggest a role for anti-inflammatory treatment(s) in the management of neurologic complications of COVID-19 infection.

Inflammatory leptomeningeal cytokines mediate delayed COVID-19 encephalopathy.

SARS-CoV-2 infection induces a wide spectrum of neurologic dysfunction. Here we show that a particularly vulnerable population with neurologic manifestations of COVID-19 harbor an influx of inflammatory cytokines within the cerebrospinal fluid in the absence of viral neuro-invasion. The majority of these inflammatory mediators are driven by type 2 interferon and are known to induce neuronal injury in other disease models. Levels of matrix metalloproteinase-10 within the spinal fluid correlate with the degree of neurologic dysfunction. Furthermore, this neuroinflammatory process persists weeks following convalescence from the acute respiratory infection. These prolonged neurologic sequelae following a systemic cytokine release syndrome lead to long-term neurocognitive dysfunction with a wide range of phenotypes.

A subjective and objective comparison of tissue contrast and imaging artifacts present in routine spin echoes and in iterative decomposition of asymmetric spin echoes for soft tissue neck MRI.

OBJECTIVE: FSE sequences play key roles in neck MRI despite the susceptibility issues in neck region. Iterative decomposition of asymmetric echoes (IDEAL, GE) is a promising method that separates fat and water images resulting in high SNR and improved fat suppression. We tested how neck tissue contrasts, image artifacts and fat separation as opposed to fat suppression in terms of image quality compare between routine and IDEAL FSE. METHODS: IDEAL based and routine T1 and T2-weighted FSE sequences were applied for neck MRI at 1.5T and 3T. Overall image quality including fat suppression, tissue contrast, image artifacts and lesion conspicuity were subjectively assessed for 20 patients clinically indicated for neck MRI. Quantitative tissue contrast estimates from parotid area were compared between IDEAL and routine FSE for 7 patients. Four patients with oncocytoma were also reviewed to assess benefits of separately reconstructed fat specific image sets. RESULTS: Subjective tissue contrast and overall image quality including image sharpness, fat suppression and image artifacts were superior for IDEAL sequences. For oncocytoma fat specific IDEAL images provided additional information. Objective CNR estimates from a central slice were equivalent for IDEAL and routine FSE at both field strengths. CONCLUSIONS: We demonstrated that high SNR inherent in IDEAL FSE consistently translates into high tissue contrast with image quality advantages in neck anatomy where large susceptibility variation and physiological motions reduce image quality for conventional FSE T1 and T2. However, the objective contrast estimates for parotid gland at isocenter were statistically equivalent for IDEAL and conventional FSE perhaps because at or near isocenter routine FSE works well. Additionally, fat specific IDEAL image sets add to diagnostic specificity for fat deficient lesions.

Imaging of Pediatric Orbital Diseases.

This article reviews a variety of congenital and developmental disorders of the pediatric orbit with particular emphasis on ocular lesions, followed by a description of developmental and neoplastic orbital and ocular masses. The relationship of these diseases to various syndromes and/or known genetic mutations is also highlighted.

Imaging Patterns and Management Algorithms in Acute Stroke: An Update for the Emergency Radiologist.

Neuroimaging plays a key role in the initial work-up of patients with symptoms of acute stroke. Understanding the advantages and limitations of available CT and MR imaging techniques and how to use them optimally in the emergency setting is crucial for accurately making the diagnosis of acute stroke and for rapidly determining appropriate treatment.