Daniel S. Chow Selected as AJNR’s Next Editorial Fellow

Hillary R. Kelly

Daniel S. Chow

We at the AJNR are again gratified by the number of extremely qualified individuals who applied for the Editorial Fellowship position. From multiple applicants, Dr. Daniel S. Chow from the University of California, San Francisco was selected to serve as our fourth Editorial Fellow.

Dr. Chow graduated from UC Riverside with a degree in Biological Sciences, and then attended the David Geffen School of Medicine at University of California, Los Angeles. He completed his radiology residency at Columbia University Medical Center – New York Presbyterian, and is currently a fellow in neuroradiology at UCSF. Dr. Chow is author or co-author on 28 manuscripts and has served as an active reviewer for the journal.

During his Editorial Fellowship he will participate in all AJNR activities including, but not limited to, manuscript evaluation and selection, editorial-related research, and conferences. The AJNR family is pleased to welcome Dr. Chow.… Continue reading >>

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Fellows’ Journal Club Recap: Computational Identification of Tumor Anatomic Location Associated with Survival in 2 Large Cohorts of Human Primary Glioblastomas

Please check out the accompanying podcast of this blog post (discussion of this article begins at 8:30)

Glioblastoma is a heterogeneous group of cancers, genetically, molecularly and characteristically on imaging studies. Prior studies have supported the relationship between tumor location and clinical prognosis. These studies have been based on qualitative assessment of tumor location. The purpose of this study was to quantitatively localize tumors and find associations with tumor molecular profiles, patient characteristics and clinical outcomes. The goal would be to finding imaging characteristics that can provide insight into prognosis and guide personalized therapy.

Two cohort populations with glioblastoma were retrospectively examined, one from the Stanford University Medical Center and one from the Cancer Genome Atlas (TCGA). The Stanford population was used for algorithm training, and the TCGA population was used to validate the algorithm. The contrast-enhanced portions of the tumor plus the central necrotic core were included in the analysis. The training cohort was stratified into poor and good survival groups defined by 17 months.

Tumors located in the right periventricular white matter were associated with poor prognosis. The testing cohort confirmed these findings. No voxels were found to be associated with the good survival group. This study affirmed prior studies, which showed that deep white matter tracts and ependymal region were associated with poor prognosis. The authors postulate that the specific laterality related to tumor prognosis may be due to delayed clinical presentation of the tumor. The majority of eloquent function of the brain is typically found in the left hemisphere and therefore, tumors in the right side of the brain may be subclinical for a longer period of time.

The hypoxia pathway enrichment and stem cell PDGFRA amplification were the distinct molecular profiles associated with tumors in the right periatrial white matter. Proangiogenic factors are … Continue reading >>

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Giant Intracranial Aneurysms at 7T MRI

Fellows’ Journal Club

Seven giant intracranial aneurysms were evaluated, and 2 aneurysms were available for histopathologic examination. Aneurysm walls were depicted as hypointense in TOF-MRA and SWI sequences with excellent contrast ratios to adjacent brain parenchyma. A triple-layered microstructure of the aneurysm walls was visualized in all aneurysms in TOF-MRA and SWI. This could be related to iron deposition in the wall, and similar findings were seen in 2 available histopathologic specimens. In vivo 7T TOF-MRA and SWI can delineate the aneurysm wall and the triple-layered wall microstructure in giant intracranial aneurysms.

Summary

Click image to enlarge

Click image to enlarge

Giant intracranial aneurysms are rare vascular pathologies associated with high morbidity and mortality. The purpose of this in vivo study was to assess giant intracranial aneurysms and their wall microstructure by 7T MR imaging, previously only visualized in histopathologic examinations. Seven giant intracranial aneurysms were evaluated, and 2 aneurysms were available for histopathologic examination. Six of 7 (85.7%) showed intraluminal thrombus of various sizes. Aneurysm walls were depicted as hypointense in TOF-MRA and SWI sequences with excellent contrast ratios to adjacent brain parenchyma (range, 0.01–0.60 and 0.58–0.96, respectively). The triple-layered microstructure of the aneurysm walls was visualized in all aneurysms in TOF-MRA and SWI. This could be related to iron deposition in the wall, similar to the findings in 2 available histopathologic specimens. In vivo 7T TOF-MRA and SWI can delineate the aneurysm wall and the triple-layered wall microstructure in giant intracranial aneurysms.

Read this article: http://bit.ly/GiantICAneurysms-7TContinue reading >>

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Computational Identification of Tumor Anatomic Location Associated with Survival in 2 Large Cohorts of Human Primary Glioblastomas

Editor’s Choice

Preoperative T1 anatomic MR images of 384 patients with glioblastomas were evaluated by an automated computational image-analysis pipeline to determine the anatomic locations of tumor in each patient. Voxel-based differences in tumor location between good and poor survival groups identified in the training cohort were used to classify patients in The Cancer Genome Atlas cohort into 2 brain-location groups, for which clinical features, messenger RNA expression, and copy number changes were compared. Tumors in the right occipitotemporal periventricular white matter were significantly associated with poor survival in both training and test cohorts. Tumors in the right periatrial location were associated with hypoxia pathway enrichment and PDGFRA amplification. The authors conclude that voxel-based location in glioblastoma is associated with patient outcome and may have a potential role for guiding personalized treatment.

Abstract

Figure 1 from Liu et al, Computational Identification of Tumor Anatomic Location Associated with Survival in 2 Large Cohorts of Human Primary Glioblastomas, AJNR 2016

Click image to enlarge

BACKGROUND AND PURPOSE

Tumor location has been shown to be a significant prognostic factor in patients with glioblastoma. The purpose of this study was to characterize glioblastoma lesions by identifying MR imaging voxel-based tumor location features that are associated with tumor molecular profiles, patient characteristics, and clinical outcomes.

MATERIALS AND METHODS

Preoperative T1 anatomic MR images of 384 patients with glioblastomas were obtained from 2 independent cohorts (n = 253 from the Stanford University Medical Center for training and n = 131 from The Cancer Genome Atlas for validation). An automated computational image-analysis pipeline was developed to determine the anatomic locations of tumor in each patient. Voxel-based differences in tumor location between good (overall survival of >17 months) and poor (overall survival of <11 months) survival groups identified in the training cohort were used to classify patients in The Cancer Genome Atlas cohort into 2 brain-location groups, for which clinical features, messenger RNA expression, and copy number changes were compared to elucidate

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Journal Scan – This Month in Other Journals, April 2016

  1. Benarroch EE. Choroid plexus-CSF system: Recent developments and clinical correlations. Neurology. 2016;86(3):286–96. doi:10.1212/WNL.0000000000002298.

Excellent comprehensive review of the role and function of the choroid plexus in health and disease.  2 Tables and 1 graphic.

Fun facts you have learned, and then probably forgotten. I sure have.

-80% of CSF is secreted by the choroid plexus (20% from brain interstitial space)

-Choroid plexus secretes CSF at a rate of 0.4 mL/min/g of tissue

-500 cc per day

-Total volume of 150cc, so the CSF exchanges 3-4X per day

-Main determinants of CSF secretion are the active secretion of Na+ via the Na+-K+ ATPase and the production of bicarbonate by action of carbonic anhydrase in choroid epithelial cells

– Three parts of the glymphatic system: 1) para-arterial CSF influx; 2) paravenous interstitial fluid clearance route; 3) transparenchymal pathway depending on astroglial water transport via AQP4 channels

-Glymphatic system estimated to remove 40%–80% of solutes and proteins, including amyloid-beta peptide and tau, from the superficial cerebral cortex

  1. Cui Z, Pan L, Song H, et al. Intraoperative MRI for optimizing electrode placement for deep brain stimulation of the subthalamic nucleus in Parkinson disease. J Neurosurg. 2016;124(1):62–69. doi:10.3171/2015.1.JNS141534.

The authors note that various methods have been used to localize the subthalamic nucleus (STN), including MRI, brain atlas–imaging fusion for preoperative planning, intraoperative microelectrode recording (MER), intraoperative MRI (iMRI), temporary efficacy during the operation, postoperative MRI, and sustained effect during the postoperative period.  In this study, 206 DBS electrodes were implanted in the STN in 110 patients with Parkinson disease. All patients underwent intraoperative MRI after implantation to define the accuracy of lead placement. Fifty-six DBS electrode positions in 35 patients deviated from the center of the STN, according to the result of the initial post-placement iMRI scans. After adjustment … Continue reading >>

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Vascular and Interventional Imaging: Case Review Series, 3rd Ed.

Saad WE, Khaja MS, Vedantham S. Vascular and Interventional Imaging: Case Review Series. 3rd ed. Elsevier; 2016; 584 pp; 1000 ill; $54.99

vascular-interventional-imag_SaadLearning about interventional radiology is difficult for residents and practicing radiologists alike. This book showcases 170 cases ranging from the ‘bread and butter’ cases, like diagnosis and management of acute DVT, to the more esoteric, such as primary leiomyosarcoma of the IVC, portal vein access for islet cell transplant, and Abernathy syndrome. While no one book could completely cover the ever-expanding field of interventional radiology, these 170 cases are fairly comprehensive without being onerous. The majority of cases are new since the second edition. All images are of high quality. Importantly, as well, to reflect the format of the new core exam, all questions are in multiple-choice format.

In any radiology text, nothing can be more frustrating than not having arrows to label the abnormality.  In interventional radiology, most cases in the real world and in testing situations are not eye tests. But, the whole point of the case can be missed if you are not sure of which area is abnormal or if you incorrectly assume you are looking at the finding. On the other hand, in a quiz book, the reader wants to peruse the images before the ‘arrow-sign’ gives away the diagnosis. This book has come up with a compromise—all initial images are unlabeled. At the end of the book is a supplemental figures section in which figures are labeled, as are subsequent intraprocedural or postprocedural images, which may have given away how to approach the case if presented earlier. This is a unique solution allowing this book to be both didactic as well as allowing the reader to quiz him or herself. In any book spanning 550 pages, entropy will creep in. Typographical … Continue reading >>

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Neuro-Ophthalmology Illustrated

Biousse V, Newman NJ. Neuro-Ophthalmology Illustrated. 2nd ed. Thieme; 2015; 789 pp; $109.99

neuro-ophthalmology_Biousse_NewmanThis is an all-encompassing neuro-ophthalmology textbook containing the entire breadth of diseases encountered in neuro-ophthalmology, such as visual loss, retinal disorders, optic neuropathies, pupillary disorders, diplopia, and cavernous sinus lesions, among others. It is written with neuro-ophthalmologists in mind but has detailed explanations and illustrations of pathologies that neuroradiologists encounter on a daily basis.

This book has 649 pages, 21 chapters, and 2 contributors (Drs. Biousse and Newman). The book has many figures, illustrations, and diagrams, many of which are for the clinicians, such as the funduscopic images, Humphrey visual field tests, and others that are very helpful in understanding disease pathology. For example, the visual fields chapter has great diagrams, showing 11 different visual field defects determined by the site of the lesion; the lesion site is numbered in a very easy-to-follow diagrammatic sketch. There are boxes containing “Pearls”, which are teaching points that are important to know. Throughout the book there are tables that emphasize and summarize certain points discussed in the text, which are very helpful in organizing the information given. In addition, there are radiologic images (both CT and MR) that are pertinent to the pathology being discussed. One can, therefore, have a complete picture of a disease state, which includes the clinical examination, the visual field, and the corresponding neuroimaging.

The first 4 chapters deal with the basics, including the neuro-ophthalmic examination, funduscopic examination, visual fields, and ancillary testing commonly used in neuro-ophthalmology (which includes the Neuroimaging section). The next 17 chapters are devoted to pathology.

There is a section in chapter 4 devoted to imaging of the orbits and visual pathways and which includes both CT and MRI. This section includes tables such as one describing the advantages and disadvantages … Continue reading >>

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Using Body Mass Index to Predict Needle Length in Fluoroscopy-Guided Lumbar Punctures

Fellows’ Journal Club

Editor’s Comment

The authors evaluated patients who underwent oblique interlaminar-approach fluoroscopy-guided lumbar punctures and had cross-sectional imaging of the lumbar spine within 1 year of the lumbar puncture to devise a formula for the appropriate needle length based on BMI. They determined the formula to predict the needle length as Skin-Canal Distance (inches) = 0.077 x BMI + 0.88.

Abstract

Click image to enlarge

Click image to enlarge

BACKGROUND AND PURPOSE

Predicting the appropriate needle length to use in oblique interlaminar-approach fluoroscopy-guided lumbar punctures in patients with a large body mass index is difficult. Using the wrong needle length can lead to an increased radiation dose and patient discomfort. We hypothesized that body mass index could help determine the appropriate needle length to use in patients.

MATERIALS AND METHODS

We randomly selected patients who underwent oblique interlaminar-approach fluoroscopy-guided lumbar punctures and had cross-sectional imaging of the lumbar spine within 1 year of imaging (n = 50). The distance from the skin to the midlumbar spinal canal (skin-canal distance) at the level of the lumbar puncture was measured by using an oblique angle of 8.6°, which is an average of angles most often used to perform the procedure. A formula was devised using the skin-canal distance and body mass index to predict the appropriate needle length, subsequently confirmed in 45 patients.

RESULTS

The body mass index and skin-canal distance were significantly higher (P < .001) in patients who underwent fluoroscopy-guided lumbar puncture with 5- or 7-inch needles (n = 22) than in patients requiring 3.5-inch needles (n = 28). Using linear regression, we determined the formula to predict the needle length as Skin-Canal Distance (inches) = 0.077 × Body Mass Index + 0.88. We found a strong correlation (P< .001) between the predicted and actual skin

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Stent-Assisted Coil Embolization of Intracranial Aneurysms: Complications in Acutely Ruptured versus Unruptured Aneurysms

Editor’s Choice

Editor’s Comment

The authors evaluated complications in a cohort of 45 patients with acutely ruptured aneurysms and 47 with unruptured aneurysms. All were treated with stent-assisted coiling. The permanent complication rate in ruptured aneurysms was 11*. Five of 45 patients had an early rebleed from the treated aneurysm after 3–45 days, and in 4 this rebleed was fatal. Thromboembolic complications occurred in 2 patients with unruptured aneurysms. The authors conclude that the complication rate in ruptured aneurysms was 10 times higher than in unruptured aneurysms.

Abstract

Click to enlarge image

Click to enlarge image

BACKGROUND AND PURPOSE

The use of stents in the setting of SAH is controversial because of concerns about the efficacy and risk of dual antiplatelet therapy. We compare complications of stent-assisted coil embolization in patients with acutely ruptured aneurysms with complications in patients with unruptured aneurysms.

MATERIALS AND METHODS

Between February 2007 and March 2015, 45 acutely ruptured aneurysms and 47 unruptured aneurysms were treated with stent-assisted coiling. Patients with ruptured aneurysms were not pretreated with antiplatelet medication but received intravenous aspirin during the procedure. Thromboembolic events and early rebleeds were recorded.

RESULTS

In ruptured aneurysms, 9 of 45 patients had thromboembolic complications. Four patients remained asymptomatic, 4 developed infarctions, and 1 patient died. The permanent complication rate in ruptured aneurysms was 11% (95% CI, 4%–24%). Five of 45 patients (11%; 95% CI, 4%–24%) had an early rebleed from the treated aneurysm after 3–45 days, and in 4, this rebleed was fatal. In 46 patients with 47 unruptured aneurysms, thromboembolic complications occurred in 2. One patient remained asymptomatic; the other had a thalamus infarction. The complication rate in unruptured aneurysms was 2.2% (1 of 46; 95% CI, 0.01%–12%). No first-time hemorrhages occurred in 46 patients with 47 aneurysms during 6 months of follow-up.

CONCLUSIONS

The complication rate of

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Diagnostic Pathology: Neuropathology and Head & Neck Pathology

Covers of Diagnostic Pathology editions Neuropathology and Head and Neck PathologyKleinschmidt-Demasters BK, Rodriguez F, Tihan T, et al. Diagnostic Pathology: Neuropathology. 2nd ed. AMIRSYS Elsevier; 2016; 864 pp; 2800 ill; 224.99

Thompson LDR, Wenig BM, et al. Diagnostic Pathology: Head & Neck. 2nd ed. AMIRSYS Elsevier; 2017; 1192 pp; 3000 ill; $247.49

In two newly published and remarkable diagnostic pathology textbooks, both second editions, one on neuropathology and one on head and neck pathology, the neuroradiologist has access to vividly illustrated and comprehensive details relating to the histopathology and some gross pathology in a wide range of abnormalities. There are so many plaudits one could give for these books that it is difficult to know where to start.

The neuropathology text is edited by Drs. Kleinschmidt-Demasters, Rodríguez, and Tihan, with major contributions from Drs. Burger, Scheithauer, Ersen, and Rushing. The text is more encompassing in score and somewhat more descriptive in the text material than the prior edition. Interestingly, the beginning of the book starts with a 2-page run down of what is new in WHO Classifications. Highlighted are diffuse astrocytomas, oligodenrogliomas, and other tumoral redesignations. Most, as one can imagine, rely on genetic definitions and explanations. In the neuropathology text there are 2 parts—the first, on neoplastic, and the second, on non-neoplastic pathologies. The former contains (as in the 1st edition) 5 sections: Brain and Cord, Sella, Meninges, Nerves, and Tumoral Syndromes, while the latter contains 4 sections: Benign Cysts, Infections and Inflammations, Vascular Disease, and a short segment on cortical dysplasia.

What is beautiful about this book, and also about the head and neck pathology book, is the widespread integration of the imaging and classic pathology of the same entity. Not only does one get a deep sense of the underlying causes of the familiar imaging findings, but one is also educated in virtually all … Continue reading >>

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