Intra- and Extraluminal Structural and Functional Venous Anomalies in Multiple Sclerosis, as Evidenced by 2 Noninvasive Imaging Techniques • K. Dolic, K. Marr, V. Valnarov, M.G. Dwyer, E. Carl, Y. Karmon, C. Kennedy, C. Brooks, C. Kilanowski, K. Hunt, A.H. Siddiqui, D. Hojnacki, B. Weinstock-Guttman, and R. Zivadinov
Here is another article that should add to the controversy over the relationship between MS and venous anomalies. The authors assessed the utility of sonography and MRV (2 different techniques) for detecting intra- and extraluminal venous abnormalities in 150 patients with MS and 63 matched controls. Results were as follows: patients with MS had significantly more intraluminal and structural abnormalities than controls and patients with progressive MS had more extraluminal and flow abnormalities than those with nonprogressive disease.

Hospitalization Costs for Endovascular and Surgical Treatment of Unruptured Cerebral Aneurysms in the United States Are Substantially Higher Than Medicare Payments • W. Brinjikji, D.F. Kallmes, G. Lanzino, and H.J. Cloft
Aneurysm clipping is associated with longer hospital stays and higher total charges. Because coiling of aneurysms has become routine, it is important to know how much we are getting paid for these 2 procedures. For uncomplicated treatments, the average Medicare payment for clipping and coiling was 49% and 53%, respectively. For patients with major complications, the average percentage payments decreased to 34% and 41% for coiling and clipping, respectively. Therefore, hospitalization costs for patients undergoing clipping and coiling of unruptured cerebral aneurysms are substantially higher than Medicare payments.

Idiopathic Thoracic Spinal Cord Herniation: Retrospective Analysis Supporting a Mechanism of Diskogenic Dural Injury and Subsequent Tamponade • M. Brus-Ramer and W.P. Dillon
Cord herniation is a rare but treatable condition of uncertain etiology and, if you have been following AJNR’s Blog, there has been considerable discussion of this entity among our readers. Here the authors postulate that anterior disk herniations erode the dura and then the cord becomes anteriorly displaced to tamponade the defect, resulting in a progressive myelopathy. To prove their point, the authors retrospectively reviewed their own cases and all published ones. In more than two-thirds of cases the herniations occurred at disk levels supporting their hypothesis.

Fellows’ Journal Club

Quality Control in Neuroradiology: Discrepancies in Image Interpretation among Academic Neuroradiologists • L.S. Babiarz and D.M. Yousem
This article should interest our fellows because most of them train at academic institutions. These authors looked at 1000 neuroimaging studies that had follow-up imaging and rated the discrepancies found in the reports. Nearly 88% of follow-up studies agreed with the original reports and there was a 2% rate of clinically significant interpretation discrepancies (8 CT and 12 MRI) among neuroradiologists. Most discrepancies involved interpretation of vascular and neoplastic lesions. This threshold could potentially serve to design future practice quality improvement studies.

Utilization Rates of Neuroradiology across Neuroscience Specialties in the Private Office Setting: Who Owns or Leases the Scanners on Which Studies Are Performed? • L.S. Babiarz, D.M. Yousem, L. Parker, D.C. Levin, and V. Rao
All of us are interested in interpreting studies with high relative value units and this trend extends to imaging studies interpreted by nonradiologists. Here, the authors used 10 years of data from the Centers for Medicare and Medicaid Services to assess this issue in regard to CT and MRI studies. During this period of time, utilization rates of MRI and CT studies grew by 2.5% and 2.1%, respectively. In 2008 only 56.6% of fees were charged by radiologists, followed by independent testing facilities, other specialists, neurologists, and neurosurgeons. The authors concluded that all nonradiologists showed greater overall utilization growth in private office neuroradiology than did radiologists. Also, nonradiologists generally showed greater utilization increases in MR than CT. Radiologists’ private office neuroradiology technical fee share shrank from 83.6% to 56.6% between 1998 and 2008.

Quantification of Thrombus Hounsfield Units on Noncontrast CT Predicts Stroke Subtype and Early Recanalization after Intravenous Recombinant Tissue Plasminogen Activator • J. Puig, S. Pedraza, A. Demchuk, J. Daunis-i-Estadella, H. Termes, G. Blasco, G. Soria, I. Boada, S. Remollo, J. Baños, J. Serena, and M. Castellanos
Anecdotally we know that high-density clots are probably more organized and difficult to lyse. These investigators calculated HU values for MCA thrombi on noncontrast CT within 4.5 hours of symptom onset and correlated it with successful recanalization after intravenous tPA treatment given 169 +/− 102 minutes thereafter. Best outcomes were achieved for M1, low-density, and thrombi not originating from the heart. Worse outcomes were related to high-density thrombi and those originating from the heart.

Pediatric Intracranial Aneurysms: New and Enlarging Aneurysms after Index Aneurysm Treatment or Observation • S.W. Hetts, J.D. English, C.F. Dowd, R.T. Higashida, J.T. Scanlon, and V.V. Halbach
Although de novo intracranial aneurysms are very rare, their incidence is increased in children with other aneurysms. These authors sought to determine the factors that result in new or rapidly enlarging aneurysms in children. They reviewed 114 aneurysms not associated with other vascular malformations and found that 8.4% of children developed new or enlarging aneurysms. Nearly all of these patients had originally presented with fusiform aneurysms. Other features that lead to new or enlarging aneurysms included multiple aneurysms at presentation and immunosuppression. New aneurysms generally occurred 4 years after the initial one was diagnosed and at locations distal to the initial site.

Deep Medullary Vein Involvement in Neonates with Brain Damage: An MR Imaging Study • F. Arrigoni, C. Parazzini, A. Righini, C. Doneda, L.A. Ramenghi, G. Lista, and F. Triulzi
These investigators report a new finding that may lead to the development of periventricular leukomalacia in premature infants. They analyzed conventional T1 and T2 images in 21 babies who showed areas of low T2 signal corresponding to the deep medullary veins. These abnormalities were found in association with cavities or cysts and, when followed, about 25% of patients developed typical MRI indications of periventricular leukomalacia. The authors suggest these findings may be related to venous thrombosis or engorgement and precede the onset of periventricular leukomalacia.

Systematic Differences between Lean and Obese Adolescents in Brain Spin-Lattice Relaxation Time: A Quantitative Study • F. Cazettes, W.H. Tsui, G. Johnson, R.G. Steen, and A. Convit
In this provocative study, the authors sought changes in the brain structure of obese teenagers when compared with lean individuals. They used T1 as a surrogate marker of brain maturation in 2 sequences and compared it with values obtained from a control (lean) group. Some surprising findings: obese subjects had lower HDL, higher LDL, higher fasting glucose, smaller brain volumes, and significantly different T1 values in the frontal and parietal lobes. Next step: to assess if these findings impact neurodevelopment during adolescence and beyond.

Fellows’ Journal Club

High Signal Intensity on T2-Weighted MR Imaging at Term-Equivalent Age in Preterm Infants Does Not Predict 2-Year Neurodevelopmental Outcomes • H. Kidokoro, P.J. Anderson, L.W. Doyle, J.J. Neil, and T.E. Inder
High T2 signal throughout the neonatal brain has always been thought to correlate with poor neurodevelopmental outcome. Here, 160 preterm babies with this finding were evaluated and T2 data correlated with ADC and fractional anisotropy values. Neurodevelopment was assessed 2 years later. Although high T2 signal correlated with higher ADC and lower FA values, it had no correlation with neurodevelopmental outcomes.

Whole-Brain Perfusion CT Patterns of Brain Arteriovenous Malformations: A Pilot Study in 18 Patients • D.J. Kim and T. Krings
Can the pattern of whole-brain perfusion be different from patient to patient among those who harbor brain AVMs? Can it be used to explain different clinical manifestations and presentations? Eighteen patients with brain AVMs were studied using CT perfusion. Major patterns were recognized as follows: about 50% of patients had arterial “steal” and presented with either seizures or focal deficits and the others had a “venous congestion” pattern and their symptoms were variable. These patterns start to shed light on the effects of AVMs on the brain as a whole and seem to indicate that presentations may be related to perfusion abnormalities.

Interpretation Errors in CT Angiography of the Head and Neck and the Benefit of Double Reading • K. Lian, A. Bharatha, R.I. Aviv, and S.P. Symons
Because there is considerable information and a large number of images to look at in CTA studies of the neck and brain, it is easy to overlook important findings. Does double reading reduce mistake rates? For this purpose, 503 studies were reviewed. Of these, 144 were reported by a single neuroradiologist, 209 by 1 staff member and 1 resident, and 150 by 1 staff neuroradiologist and 1 fellow. The overall rate of misses was 4% and it was double when the staff neuroradiologist alone interpreted the studies. Thus, double reading reduces but does not completely eliminate errors. The most commonly missed findings were small aneurysms.

Mortality in the Vertebroplasty Population • R.J. McDonald, S.J. Achenbach, E.J. Atkinson, L.A. Gray, H.J. Cloft, L.J. Melton III, and D.F. Kallmes
More controversy with regard to vertebroplasty: Do vertebroplasties affect mortality rates? These well-seasoned investigators compared 524 vertebroplasty patients with refractory osteoporotic fractures with 589 patients not treated by the procedure. When compared with the general population, vertebroplasty patients showed 77% of the expected survival and when compared with patients with symptomatic or asymptomatic vertebral fractures, vertebroplasty recipients retained a 17% greater mortality risk. Conclusion: mortality rates were worse for vertebroplasty patients when compared with those of patients with untreated asymptomatic fractures, and similar if compared with patients with untreated symptomatic fractures.

Cerebral Ischemia Complicating Intracranial Aneurysm: A Warning Sign of Imminent Rupture? • B. Guillon, B. Daumas-Duport, O. Delaroche, K. Warin-Fresse, M. Sévin, F. Hérisson, E. Auffray-Calvier, and H. Desal
Here is another indication that an aneurysm may be close to rupture: ischemic stroke in the same territory distal to it. Although distal infarctions are known to occur with giant thrombosed aneurysms, these authors describe similar findings in 9 patients with small, non-thrombosed aneurysms. Thus infarctions in this situation are rare, but generally precede SAH and acute management with embolization is needed. Caveat: many of these patients will necessitate thrombolysis for their strokes, an issue that complicates the management of the aneurysms.

Carotid Plaque Enhancement and Symptom Correlations: An Evaluation by Using Multidetector Row CT Angiography • L. Saba and G. Mallarini
CT offers the possibility of obtaining CTA and at the same time evaluating the substance of carotid artery plaques. In this investigation, 97 patients underwent CTA and their plaques were assessed for contrast enhancement and correlated with symptoms. Plaque contrast enhancement was seen in nearly 75% of noncalcified lesions and its presence strongly correlated with neurologic symptoms. Contrast enhancement was more common in fatty than in mixed density plaques.

Fellows’ Journal Club

Tectorial Membrane Injury: Frequently Overlooked in Pediatric Traumatic Head Injury • A. Meoded, S. Singhi, A. Poretti, A. Eran, A. Tekes, and T.A.G.M. Huisman
Tectorial membrane injury is uncommon and may be associated with the presence of retroclival epidural hematoma. These authors retrospectively reviewed 10 children with this type of epidural hematoma to determine the rate of tectorial membrane rupture and correlated it with imaging and clinical findings. Seventy percent of subjects showed tectorial membrane damage, none had injuries to the brain stem, spinal cord, vertebrae, or subluxations, and symptoms were minimal. Although most tectorial membrane injuries initially may be managed conservatively, some will necessitate craniocervical fixation to avoid instability.

Follow-Up MR Imaging of the Alar and Transverse Ligaments after Whiplash Injury: A Prospective Controlled Study • N. Vetti, J. Kråkenes, T. Ask, K.A. Erdal, M.D.N. Torkildsen, J. Rørvik, N.E. Gilhus, and A. Espeland
Whiplash injuries may damage the anterior longitudinal ligament, which is not critical because as long as the injury is isolated the spine remains stable. These authors studied 91 patients acutely and 12 months after whiplash injury with special attention to damaged transverse and alar ligaments. High proton density signal was seen in both injured and control patients with similar prevalence. Moreover, in those with a history of whiplash injury, these areas of high signal were seen in identical numbers acutely and on follow-up studies. Thus, these high signal areas, commonly assumed to represent injury to the ligaments, cannot be solely explained by trauma.

A Comprehensive Review of MR Imaging Changes following Radiosurgery to 500 Brain Metastases • T.R. Patel, B.J. McHugh, W.L. Bi, F.J. Minja, J.P.S. Knisely, and V.L. Chiang
Many times we are called to assess the effects of gamma knife treatment on tumors. Here, the authors evaluated more than 500 metastases treated by this method with MRI and measured tumor volumes over time. One-third of patients showed increased tumor size 6 weeks to 15 months after treatment while the others had lesions that remained stable or decreased in size. Those patients with tumors that increased in size had survival periods nearly twice as long as the others. Thus, gamma knife surgery may result in lesion “pseudoprogression.”

Metabolic Abnormalities in Pain-Processing Regions of Patients with Fibromyalgia: A 3T MR Spectroscopy Study • P. Feraco, A. Bacci, Fab. Pedrabissi, L. Passamonti, G. Zampogna, Fed. Pedrabissi, N. Malavolta, and M. Leonardi
As neuroradiologists we see many spine studies for fibromyalgia and wonder about the significance of this condition (is it a real disease?). Here, the authors used MR spectroscopy to assess metabolic alterations in brain regions associated with pain reception (thalami and ventrolateral prefrontal cortex). Using 3T single-voxel MRS, they studied 12 patients and 12 healthy controls and analyzed their data using an LCModel. Glx/Cr and Glu/Cr ratios in the cortex were significantly higher in patients than in controls but no differences were found in the thalami. The authors conclude that these MRS abnormalities support an imbalance in the pain processing areas that underlie fibromyalgia.

Sharp Curvature of Frontal Lobe White Matter Pathways in Children with Autism Spectrum Disorders: Tract-Based Morphometry Analysis • J.-W. Jeong, A.K. Kumar, S.K. Sundaram, H.T. Chugani, and D.C. Chugani
These authors had previously observed abnormalities in the frontal white matter tracts in autistic children and decided to investigate the curvature of these tracts. Thirty-four autistic and 14 control children were imaged and curvature, fractional anisotropy, and axial and radial diffusivity were assessed in 3 frontal lobe fiber tracts. Higher curvatures were found in autistic subjects than in controls. The authors propose that their findings may be the result of thinner axons in these locations. For more on neural phenotyping of autistic brains, see the Jou et al article. It is becoming clear that white matter tract arrangement and neuronal connectivity may be an important substrate of autism.

Structural Neural Phenotype of Autism: Preliminary Evidence from a Diffusion Tensor Imaging Study Using Tract-Based Spatial Statistics • R.J. Jou, N. Mateljevic, M.D. Kaiser, D.R. Sugrue, F.R. Volkmar, and K.A. Pelphrey
The search for an explanation of autism continues and this article supports the hypothesis that aberrations in neuronal connectivity are important defects in this disorder. Fifteen autistic and 8 control boys underwent DTI and fractional anisotropy was used as a measure of fiber tract integrity. FA for each fiber tract affected was correlated with scores of the Social Responsiveness Scale. Autistic patients showed bilateral FA reductions in numerous association, commissural, and projection tracts. Conclusion: DTI shows abnormalities in many long-range fiber tracts suggesting corticocortical connection defects. Because of the type of tracts affected, autism may have a specific neural phenotype.

Fellows’ Journal Club

Lowering the Dose in Head CT Using Adaptive Statistical Iterative Reconstruction • K. Kilic, G. Erbas, M. Guryildirim, M. Arac, E. Ilgit, and B. Coskun
To avoid increased radiation exposure and subsequent long-term risk of cancer, iterative reconstruction is a means of lowering the dose on CT studies. Here, the authors compared head CT scans obtained via standard dose with low-dose (31% less) iterative reconstruction. Signal-to-noise and contrast-to-noise ratios as well as image noise, sharpness, artifacts, and diagnostic acceptability were assessed. Overall these parameters were judged to be better in the standard-dose CT, but those obtained with the lower dose and iterative reconstruction were judged acceptable. Thus, iterative reconstruction appears to be useful in adult head CT examinations. (Editor’s Note: This technique would be ideal in children where radiation dosage is of utmost concern. At my institution we use it for all head and neck studies, but not for temporal bone or paranasal sinus studies as we have found that bone detail may be less than optimal.)

Trainee Misinterpretations on Pediatric Neuroimaging Studies: Classification, Imaging Analysis, and Outcome Assessment • C.V.A. Guimaraes, J.L. Leach, and B.V. Jones
Do trainees make mistakes when interpreting pediatric neuroimaging studies? These authors reviewed trainee reports performed without initial attending physician assessments. They looked at the type of errors and in which type of examinations these occurred and classified the findings according to the severity of discrepancy and its effect on patient management. In nearly 3500 reports there were 143 discrepancies, mostly in CT studies. Only 6 (0.17%) were severe and potentially life-threatening. The most common discrepancies involved fractures and head and neck studies. Discrepancies were higher in interpretations done by third- and fourth-year residents than in those read by fellows.

Oncocytoma: The Vanishing Parotid Mass • N.D. Patel, A. van Zante, D.W. Eisele, H.R. Harnsberger, and C.M. Glastonbury
This is a small retrospective study of a rare lesion, so why include it here? The report describes a previously unknown imaging feature of parotid gland oncocytomas, which appears to be specific for these tumors. All were hypointense with respect to the surrounding gland on precontrast T1 images, but became invisible on postcontrast fat-suppressed T1- and T2-weighted sequences (thus the title of the article). The illustrations are convincing but because this is a retrospective analysis, I wonder how many oncocytomas will show this imaging behavior.

J. Puig, S. Pedraza, G. Blasco, J. Daunis-i-Estadella, F. Prados, S. Remollo, A.
Prats-Galino, G. Soria, I. Boada, M. Castellanos, and J. Serena.
Acute Damage to the Posterior Limb of the Internal Capsule on Diffusion Tensor Tractography as an Early Imaging Predictor of Motor Outcome after
Stroke. AJNR Am J Neuroradiol, May 2011; 32: 857 – 86

J. Puig, S. Pedraza, G. Blasco, J. Daunis-i-Estadella, A. Prats, F. Prados, I. Boada, M. Castellanos, J. Sánchez-González, S. Remollo, G. Laguillo, A.M. Quiles, E. Gómez, and J. Serena. Wallerian Degeneration in the Corticospinal
Tract Evaluated by Diffusion Tensor Imaging Correlates with Motor Deficit 30
Days after Middle Cerebral Artery Ischemic Stroke. AJNR Am J
Neuroradiol, Aug 2010; 31: 1324 – 1330.

Both articles were previously selected as part of our “Editor’s Choice” series.  We congratulate Dr. Puig and urge our subscribers to read these important publications.

Microembolic Signal Monitoring after Coiling of Unruptured Cerebral Aneurysms: An Observational Analysis of 123 Cases • G.A. Schubert, C. Thomé, M. Seiz, C. Douville, and J. Eskridge
Thromboembolic complications occur during 5–60% of all aneurysm coiling procedures and 3–6% are clinically symptomatic. These authors utilized transcranial Doppler to detect microemboli after coiling and then correlated their presence with patient demographics, aneurysm size, type of procedure and complication, medication, and clinical outcome in 123 patients. Procedures involving larger aneurysms, stent assistance, and incomplete occlusions were associated with greater risk of microemboli and heparinization played an important role in prevention.

Short- and Intermediate-Term Angiographic and Clinical Outcomes of Patients with Various Grades of Coil Protrusions Following Embolization of Intracranial Aneurysms • M. Abdihalim, S.H. Kim, A. Maud, M. F. K. Suri, N. Tariq, and A.I. Qureshi
After embolization, not uncommonly one sees coils protruding outside of the aneurysm into the lumen of the parent artery. What does this mean? The authors identified 256 patients with this finding from 3 different medical centers and set out to assess their short- and intermediate-term outcomes. They graded coil protrusions from a single loop projecting into less than half of the parent artery (grade 1) to those protruding into more than half (grade 3). Most protrusions in the series were grade 1. All patients were placed on aspirin and complications were not directly related to coil protrusions. The authors concluded that antiplatelet therapy is efficacious in preventing vessel thrombosis in this situation.

Transverse Sinus Stenting for Idiopathic Intracranial Hypertension: A Review of 52 Patients and of Model Predictions • R.M. Ahmed, M. Wilkinson, G.D. Parker, M.J. Thurtell, J. Macdonald, P.J. McCluskey, R. Allan, V. Dunne, M. Hanlon, B.K. Owler, and G.M. Halmagyi
Current thinking is that transverse sinus stenosis with significant pressure gradient across the narrowing may play a role in pseudotumor cerebri and that treatment may improve symptoms. Here, the authors review their experience with 52 patients who were clinically followed for 2–8 months after stenting. During this time all pressure gradients improved and symptoms were abolished. Symptom relapse occurred in 6 patients and all showed sinus restenosis. At the end of the study period, 49 of 52 patients were cured of their headaches and the authors concluded that transverse sinus stenting is beneficial in this clinical setting.

Fellows’ Journal Club

Low-Dose Temporal Bone CT in Infants and Young Children: Effective Dose and Image Quality • C.B. Nauer, A. Rieke, C. Zubler, C. Candreia, A. Arnold, and P. Senn
If your institution is like ours, you must perform many temporal bone CT studies in children and worry about radiation exposure. These authors compared techniques using 80 kV/90–100 mAs (low dose) and 140kV/170 mAs (high dose) for temporal bone CT studies in children aged 5 years. Neuroradiologists and otologists evaluated 23 structures in those studies. Low-dose CT was given lower scores but these differences were only significant when otologists evaluated the studies. Thus, the image quality of low-dose CT was perceived as insufficient by our clinical colleagues.

Impact of Brain Tumor Location on Morbidity and Mortality: A Retrospective Functional MR Imaging Study • J.M. Wood, B. Kundu, A. Utter, T.A. Gallagher, J. Voss, V.A. Nair, J.S. Kuo, A.S. Field, C.H. Moritz, M.E. Meyerand, and V. Prabhakaran
These investigators assessed the relationship between the distance of tumor border to eloquent brain regions (motor and language) identified by fMRI and pre- and postoperative morbidity and mortality. Factors that affected patient motor and language presentation and outcomes were close proximity of tumor to functional areas and advanced age. Right-handedness affected only language deficits. Variables that influenced survival included tumor grade, location, and proximity to language and motor areas. These findings indicate that tumors may affect language and motor function differently, depending on tumor lesion to activation distance. Overall, the data support the use of fMRI as a tool to evaluate patient prognosis and are directly applicable to preoperative neurosurgical planning.

Joubert Syndrome and Related Disorders: Spectrum of Neuroimaging Findings in 75 Patients • A. Poretti, T.A.G.M. Huisman, I. Scheer, and E. Boltshauser
In this nice Clinical Report, the authors review not only the classic features of Joubert syndrome (vermian hypoplasia and molar tooth sign) but also other lesser known features found in 75 patients. All showed vermian abnormalities and molar tooth sign and, in addition, the following findings were also quite common: enlarged posterior fossa, brain stem abnormalities, callosal dysgenesis with malrotation of the hippocampi, cephaloceles, and ventricular dilation. No correlation between imaging findings and genotype was detected.

Predictors of Unfavorable Outcome in Intracranial Angioplasty and Stenting in a Single-Center Comparison: Results from the Borgess Medical Center-Intracranial Revascularization Registry • F. Al-Ali, T. Cree, S. Hall, S. Louis, K. Major, S. Smoker, and S. Walker
Is it better to perform angioplasty or stent intracranial stenoses? In a registry of 140 patients the overall stroke rate after procedures was 13%, with the lowest rate in those treated with angioplasty only (4.5%) versus those who received stents (11–25%, depending on the technique used). Dilation success rate was higher with stenting and restenosis rate was higher with angioplasty only. Dissections more commonly occurred in the first 30 days postprocedure, infarcts more often originated from regions supplied by perforating arteries, and patients with eccentric stenoses were more likely to have stroke than those with concentric ones.

How Effective Is Endovascular Intracranial Revascularization in Stroke Prevention? Results from Borgess Medical Center Intracranial Revascularization Registry • F. Al-Ali, T. Cree, L. Duan, S. Hall, A. Jefferson, S. Louis, K. Major, S. Smoker, and S. Walker
The well-designed and well-known Warfarin-Aspirin Symptomatic Intracranial Disease study concluded that the risk of stroke was 18% at 1 year in patients with symptomatic and significant intracranial arterial stenosis and that warfarin offered no benefit over aspirin alone. Here, the authors compared those data with their own patients treated with angioplasty alone, balloon-assisted stents, and self-expanding stents. The overall 1-year stroke risk among their patients was 19% and the stroke probability per device was lowest for angioplasty and highest for the self-expanding stent.

Isolated Diffusion Restriction Precedes the Development of Enhancing Tumor in a Subset of Patients with Glioblastoma • A. Gupta, R.J. Young, S. Karimi, S. Sood, Z. Zhang, Q. Mo, P.H. Gutin, A.I. Holodny, and A.B. Lassman
We know that tumor contrast enhancement is preceded by development of increased perfusion and abnormal MR spectroscopy findings. Here, the authors determined that restricted diffusion also occurs before contrast enhancement in some glioblastomas. Visibly restricted apparent diffusion coefficient was found in 32% of patients undergoing treatment and 85% of those with nonenhancing low-ADC lesions went on to develop contrast enhancement at the site of restricted diffusion, implying tumor progression regardless of type of therapy. Conclusion: In a subset of patients with glioblastoma, development of a new focus of restricted diffusion during treatment may precede the development of new enhancing tumor.

Fellows’ Journal Club

The Relation of Carotid Calcium Volume with Carotid Artery Stenosis in Symptomatic Patients • H.A. Marquering, C.B.L.M. Majoie, L. Smagge, A.G. Kurvers, H.A. Gratama van Andel, R. van den Berg, and P.J. Nederkoorn
Is calcium volume a surrogate marker for carotid artery stenosis? These authors explored the relationship between calcium volume and stenosis as seen on CT angiography studies. In symptomatic sides calcium volumes were not related to stenosis degrees, and in asymptomatic sides were only weakly related. Their conclusion was that calcium volume cannot be used to estimate or predict degree of stenosis even in symptomatic patients.

Clinical Correlates of White Matter Blood Flow Perfusion Changes in Sturge-Weber Syndrome: A Dynamic MR Perfusion-Weighted Imaging Study •  Y. Miao, C. Juhász, J. Wu, B. Tarabishy, Z. Lang, M.E. Behen, Z. Kou, Y. Ye, H.T. Chugani, and J. Hu
Brain ischemia in Sturge-Weber syndrome is probably venous in origin but it leads to changes in arterial perfusion in the affected regions. These authors used perfusion imaging and correlated its results with brain atrophy, seizures, and IQ in 14 children. High and low perfusion rates were found in 5 and 9 children, respectively. Brain atrophy, longer duration epilepsy, and more frequent seizures were more common with low perfusion but no relationship between perfusion and IQ was found. Decreased perfusion thus is associated with more severe and chronic clinical findings in patients with Sturge-Weber syndrome.

Diffusion-Weighted Imaging of Hyperacute Cerebral Hypoglycemia • P. Schmidt, J. Böttcher, A. Ragoschke-Schumm, H.J. Mentzel, G. Wolf, U.A. Müller, W.A. Kaiser, T.E. Mayer, and A. Saemann
In this interesting experiment, the authors set out to determine if acute hypoglycemia induces diffusion-weighted imaging–visible changes. Ten patients undergoing insulin stress testing were continuously imaged with DWI until their blood glucose levels were less than 2.0 mmol/L (lower limit of normal: 3.9 mmol/L). The authors found no DWI alterations in the brains of these patients, thus concluding acute hypoglycemia does not result in visible changes.

Longitudinal Whole-Brain N-Acetylaspartate Concentration in Healthy Adults • D.J. Rigotti, I.I. Kirov, B. Djavadi, N. Perry, J.S. Babb, and O. Gonen
This article addresses the issue of neuronal changes over time. N-acetylaspartate is surrogate marker of neuronal viability and integrity as seen on hydrogen MR spectroscopy. Here, the authors utilized their own method of measuring whole-brain NAA in a small cohort of healthy adults with each receiving 4 scans (baseline and annual) during a 3-year period. The data were converted to absolute millimole concentrations of this metabolite. They found that whole-brain NAA was stable over a 3-year period in healthy adults. It qualifies therefore as a biomarker for global neuronal loss and dysfunction in diffuse neurologic disorders that may be well worth considering as a secondary outcome measure candidate for clinical trials.

Thalamic Damage Predicts the Evolution of Primary-Progressive Multiple Sclerosis at 5 Years • S. Mesaros, M.A. Rocca, E. Pagani, M.P. Sormani, M. Petrolini, G. Comi, and M. Filippi
The importance of gray matter lesions in multiple sclerosis cannot be underestimated. These authors used diffusion tensor imaging from the thalami of patients with primary-progressive MS to assess its ability in predicting long-term disability accumulation. They examined conventional MR and DTI studies of 54 patients (and 8 controls) at baseline, 15 months, and 5 years. Patients were reassessed clinically at 5 years. At baseline and follow-up, measures of lesion load, brain atrophy, and normalized thalamic volume were obtained. Mean diffusivity and fractional anisotropy histograms of the normal-appearing white matter, the whole gray matter without the thalami, and, last, the thalami were obtained. A multivariate analysis was used to evaluate the predictors of long-term neurologic deterioration. They concluded that short-term accrual of thalamic damage and the severity of involvement in the normal-appearing white matter predict long-term accumulation of disability in PPMS as measured by the Expanded Disability Status Scale.

Apparent Diffusion Coefficient Mapping for Sinonasal Diseases: Differentiation of Benign and Malignant Lesions • M. Sasaki, S. Eida, M. Sumi, and T. Nakamura
Because CT and conventional MR imaging findings of sinonasal lesions overlap considerably, these authors decided to evaluate the utility of diffusion-weighted imaging in differentiating these lesions. They obtained apparent diffusion coefficient values in 61 proved lesions (19 benign, 28 malignant, and 14 inflammatory). As expected, ADC values of malignant lesions were much lower than those of the other 2 types. Additionally, the higher the percentage area of the tumor that had low ADC, the greater was the chance of it being malignant. If 78% of lesion area had low ADC, the ability to differentiate between malignant and benign reached a 94% specificity. ADCs could also differentiate lymphoma from other malignant tumors. Conclusions: ADC mapping may be an effective MR imaging tool for the differentiation of benign/inflammatory lesions from malignant tumors in the sinonasal area.

Fellows’ Journal Club

Safety of High Doses of Urokinase and Reteplase for Acute Ischemic Stroke • V. Misra, R. El Khoury, R. Arora, P.R. Chen, S. Suzuki, N. Harun, N.R. Gonzales, A.D. Barreto, J.C. Grotta, and S.I. Savitz
If a patient has previously received tissue plasminogen activator for cerebral ischemia, is it safe to give him or her urokinase or reteplase intra-arterially for persistent arterial occlusion? If yes, how much can be given? Here, the authors addressed those questions. During a 10-year period they collected data from 197 such patients (72 had received UK and the others RT). Demographics, baseline National Institutes of Health Stroke Scale scores, recanalization rates, rates of attempted mechanical thrombectomy, mortality, symptomatic hemorrhage, and discharge modified Rankin Scale scores were collected. Mechanical thrombolysis was attempted in 60-72% of patients in both groups. The authors found no correlation between symptomatic intracranial hemorrhages and administration of either UK or RT. There was no correlation between mortality and doses of either drug. They concluded that high intra-arterial doses of UK and RT may be safe when given with or without mechanical thrombectomy in patients with acute ischemic stroke, despite already having received a full dose of intravenous rtPA.

Influence of Nomenclature in the Interpretation of Lumbar Disk Contour on MR Imaging: A Comparison of the Agreement Using the Combined Task Force and the Nordic Nomenclatures • E. Arana, F.M. Kovacs, A. Royuela, A. Estremera, H. Sarasíbar, G. Amengual, I. Galarraga, C. Martínez, A. Muriel, V. Abraira, J. Zamora, and C. Campillo
There is little agreement between observers when reporting disk abnormalities. These authors evaluated the influence of using criteria set by the Combined Task Force (of which ASNR is a member) and the Nordic Modic Consensus Group Classification in the interpretation of lumbar disk contour. Among the variables assessed on the Nordic form, those analyzed for this study were Schmorl nodes (yes/no) and disk contour (normal, bulging, protrusion [focal or broad-based], and hernia [extrusion or sequestration]). With the CTF form, the recorded variables were intravertebral herniation (yes/no) and disk contour (normal, symmetric bulging disk, focal-based herniation, broad-based herniation, and extrusion). The categorization of intra- and interobserver agreement proved the same across nomenclatures. Intraobserver reliability was substantial for intravertebral herniations and disk contour abnormalities. Interobserver reliability was moderate for intravertebral herniations and fair-to-moderate for disk contour. Conclusions: in clinical practice, regardless of the specific nomenclature used, a standardized nomenclature supports only moderate interobserver agreement. The Nordic nomenclature increases self-confidence in an individual observer’s report, but is less clear regarding the classification of disks as normal versus bulging.

Transient Hyperintensity in the Subthalamic Nucleus and Globus Pallidus of Newborns on T1-Weighted Images • T. Taoka, N. Aida, T. Ochi, Y. Takahashi, T. Akashi, T. Miyasaka, A. Iwamura, M. Sakamoto, and K. Kichikawa
In newborns, high signal intensity in the subthalamic nuclei may be indicative of cerebral ischemia, particularly in combination with high signal in the posterior putamen. This article describes transient and normal high signal intensity in the subthalamic nuclei and globi pallidus. Seventy-nine neonates who had normal examinations 2 years later were included in the study. The authors performed qualitative and quantitative evaluations of these 2 regions on T1- and T2-weighted images and correlated their results with postnatal and gestational ages. With increasing postnatal age at examination, the high signal intensity on the T1-weighted images for both subthalamic and globi pallidus diminished. Although the disappearance of this hyperintensity was well correlated with the postnatal age at examination for both the qualitative and quantitative studies, there was no correlation with gestational age at examination. For the T2 images, there was no correlation with either the postnatal age or gestational age at examination.

Acute Damage to the Posterior Limb of the Internal Capsule on Diffusion Tensor Tractography as an Early Imaging Predictor of Motor Outcome after Stroke • J. Puig, S. Pedraza, G. Blasco, J. Daunis-i-Estadella, F. Prados, S. Remollo, A. Prats-Galino, G. Soria, I. Boada, M. Castellanos, and J. Serena
Practical applications of diffusion tensor imaging are few, but this seems to be an interesting and a potentially important one: can it be used to predict motor outcome after stroke? Sixty patients within 12 hours of stroke were assessed with tractography at 5 different locations in the corticospinal tracts at admission, and at days 3 and 30. Patients with acute damage to the posterior limb of the internal capsule had the worst outcome and clinical severity at presentation. Conclusions: In the acute setting, tractography is promising for stroke mapping to predict motor outcome. Acute corticospinal tract damage at the level of the posterior limb of the internal capsule is a significant predictor of unfavorable motor outcome.

Value of MR Venography for Detection of Internal Jugular Vein Anomalies in Multiple Sclerosis: A Pilot Longitudinal Study • R. Zivadinov, R. Galeotti, D. Hojnacki, E. Menegatti, M.G. Dwyer, C. Schirda, A.M Malagoni, K. Marr, C. Kennedy, I. Bartolomei, C. Magnano, F. Salvi, B. Weinstock-Guttman, and P. Zamboni
The role of chronic venous insufficiency in multiple sclerosis is controversial. The diagnosis is generally made with Doppler sonography and/or invasive catheter venography. Here, the authors assessed the role of MR venography in this situation. Ten patients with MS were assessed and compared with controls. Six patients with MS were treated with angioplasty and evaluated 6 months thereafter; similarly 6 controls were re-assessed at 6 months. Two different MRV methods were used. Although the agreement between Doppler and both MRV studies was high, there was a 60-70% lack of agreement between both MRV studies and catheter venography. Therefore, both pre- and posttreatment, MRV was of little value in the diagnosis of chronic venous insufficiency.

Potential of Integrated [18F] Fluorodeoxyglucose Positron-Emission Tomography/CT in Identifying Vulnerable Carotid Plaques • R.M. Kwee, M.T.B. Truijman, W.H. Mess, G.J.J. Teule, J.W.M. ter Berg, C.L. Franke, A.G.G.C. Korten, B.J. Meems, M.H. Prins, J.M.A. van Engelshoven, J. E. Wildberger, R.J. van Oostenbrugge, and M.E. Kooi
It is known that risk of cerebrovascular accident is not only associated with degree of carotid artery stenosis but probably more importantly with type of plaque: vulnerable vs stable. Myriad studies have looked at this issue with high-resolution MR imaging but the present one used FDG-PET and CT. Fifty patients with transient ischemic attack/stroke who had ipsilateral stenosis and plaque along with contralateral asymptomatic plaque were imaged. High uptake was seen in ipsilateral plaques when compared with contralateral asymptomatic ones but these differences were not significant. CT also showed larger lipid-rich necrotic cores and thicker arterial walls in symptomatic plaques, but again these differences were not significant. Thus, it remains to be determined if the combination of FDG-PET/CT is valuable.

Fellows’ Journal Club

Cerebral Blood Flow Thresholds for Tissue Infarction in Patients with Acute Ischemic Stroke Treated with Intra-Arterial Revascularization Therapy Depend on Timing of Reperfusion • K. Mui, A.J. Yoo, L. Verduzco, W.A. Copen, J.A. Hirsch, R.G. González, and P.W. Schaefer
These investigators sought to determine if cerebral blood flow thresholds for tissue infarction depend on the timing of recanalization in patients with acute stroke treated with intra-arterial thrombolysis. In 26 such patients they obtained CBF ratios in the core, penumbra that infarcted, and penumbra that did not infarct. CBF ratios in tissues that reperfused before 6 hours were compared with those that reperfused at more than 6 hours. The authors found CBF thresholds for tissue infarction in patients with acute stroke are lower in tissue that reperfused at earlier time points, so these thresholds may be useful in selecting patients who may benefit from thrombolysis.

Is It Possible to Recognize Cervical Artery Dissection on Stroke Brain MR Imaging? A Matched Case-Control Study • O. Naggara, F. Soares, E. Touze, D. Roy, X. Leclerc, J.-P. Pruvo, J.-L. Mas, J.-F. Meder, and C. Oppenheim
Arterial dissections are not uncommonly found in patients with acute stroke. Do we need a special protocol or can these be diagnosed on the standard brain MR imaging study? In 103 consecutive patients, the authors were able to identify 77 in whom the fat-suppressed T1 images showed mural internal carotid artery clot. These studies were retrospectively reviewed by 2 blinded observers who looked at 5 different sequences from the 77 patients and 77 controls. Seventy-seven percent of patients and 95% of controls were correctly classified. Thus, initial brain MR imaging can correctly suggest cervical arterial dissection in more than two-thirds of cases. This may have practical implications in patients with stroke and delayed cervical MR angiography or in those who are not initially suspected of having CAD.

Is Fasting Necessary for Elective Cerebral Angiography? • O.-K. Kwon, C.W. Oh, H. Park, J.S. Bang, H.-J. Bae, M.K. Han, S.-H. Park, M.H. Han, H.-S. Kang, S.-K. Park, G. Whang, B.-C. Kim, and S.-C. Jin
Did the patient eat breakfast? Can the angiogram be done as planned? This is something that we still grapple with and it affects our daily diagnostic angiogram schedule. We have all been taught that a patient has to fast before cerebral angiography, but is it really necessary? In this study, more than 2500 patients were given the choice of fasting or not before the procedure and were evaluated for nausea, vomiting, and pulmonary aspiration during the 24 hours postprocedure. If these effects occurred within 1 hour of the angiogram they were considered to be associated with it. The incidence of nausea/vomiting was 1% and no aspirations occurred. This article suggests that fasting may not be necessary for patients who undergo elective cerebral angiography.

Have Referral Patterns for Vertebroplasty Changed since Publication of the Placebo-Controlled Trials? • M.T. Luetmer and D.F. Kallmes
Here is an article analyzing some of the consequences of the 2 famous (infamous?) randomized vertebroplasty trials published in the New England Journal of Medicine in August 2009. Curiously, it is by some of the same authors. They looked at monthly referral patterns for nearly 1200 patients during a 6-year period extending from 2004 to 2010. Although this article represents the experience of only 1 institution, the number of vertebroplasties dropped from 18 to 11 per month after August 2009. The percentage of patients who underwent the procedure increased slightly, meaning that perhaps patient selection has also changed. The authors concluded that the number of vertebroplasty referrals to the Mayo Clinic decreased significantly since the publication of INVEST and the Australian Trial, yet they continue to offer the procedure to a high proportion of referred patients.

Hippocampal Shape Deformation in Female Patients with Unremitting Major Depressive Disorder • W.S. Tae, S.S. Kim, K.U. Lee, E.C. Nam, J.W. Choi, and J.I. Park
Although the fact is that hippocampal atrophy occurs in patients with major depression, shape contractions also happen but have been found to be inconsistent. Here, the authors used shape analysis to study the hippocampi in 21 women with major depression and 21 control subjects. Both hippocampi were small in patients compared with controls. Regional shape contractions were found in the ambient gyrus, basal hippocampal head, posterior subiculum, and dorsal hippocampus of the left hemisphere. The right hippocampus showed a similar pattern but was less atrophic compared with the left hippocampus. The authors concluded that atrophy and regional shape contractions in the hippocampi of patients with major depression were more dominant on the left side. The causes of hippocampal damage could be hypersecretion of glucocorticoids contributing to neuronal death or the failure of adult neurogenesis in the dentate gyrus.

Association of Olfactory Bulb Volume and Olfactory Sulcus Depth with Olfactory Function in Patients with Parkinson Disease • J. Wang, H. You, J.-F. Liu, D.-F. Ni, Z.-X. Zhang, and J. Guan
Before reading this article, I did not know that olfactory problems are as common as tremor in patients with Parkinson disease (70-90%). After rigidity/akinesia, olfactory dysfunction is the second most common symptom. Actually, Parkinson disease may be an olfactory disorder! Lewy bodies and subsequent atrophy happen initially in the olfactory bulbs and entorhinal cortex. The authors looked at olfactory bulb volume and depth of the olfactory sulci, correlated their findings with olfactometric tests, and compared their 20 patients with healthy controls. Abnormal volumes, depths, and olfaction tests were present in all patients with Parkinson disease but not in the controls. Their results provide evidence that early olfactory dysfunction in patients with Parkinson disease may be a primary consequence of damage to the olfactory bulb. Neuroimaging of olfactory structures together with the assessment of olfactory function may be used to identify patients with Parkinson disease.

Fellows’ Journal Club

Frequency and Location of Dilated Virchow-Robin Spaces in Elderly People: A Population-Based 3D MR Imaging Study • Y.-C. Zhu, C. Dufouil, B. Mazoyer, A. Soumaré, F. Ricolfi, C. Tzourio, and H. Chabriat
More about the perivascular spaces…where exactly are they located in older folks? We have come to accept the fact that as we get older, we have more of these and that patients with cerebrovascular disease also have more PVS. The authors used 3T and T1-weighted images from nearly 2000 individuals to evaluate the PVS. Dilated PVS were seen in the basal ganglia and white matter in all subjects and correlated with advancing age. Dilated PVS in the basal ganglia were more common in men. Large PVS were seen in one-third of individuals. Conclusion: dilated PVS were always detected in the basal ganglia or white matter in elderly people, and large PVS were also prevalent.

Carotid Artery Stenting without Angioplasty and Cerebral Protection: A Single-Center Experience with up to 7 Years’ Follow-Up • S. Baldi, T. Zander, M. Rabellino, G. González, and M. Maynar
When stenting a carotid artery there are options: performing angioplasty simultaneously and/or protecting the brain with specific distal devices. Do these 2 options make a difference in a patient’s outcome? Here, the authors prospectively identified 255 patients with symptomatic stenoses and/or high-risk morphology plaques and performed neurologic and carotid sonography before the procedure and at 1, 3, 6, and 12 months thereafter. The technique was successful in 99% of patients and complications were few, with 2 strokes (only 1 was disabling) and 1 transient ischemic attack. Nineteen patients re-stenosed and had to undergo angioplasties in follow-up sessions. The authors concluded that carotid stenting without angioplasty and protection is effective and safe with few complications and satisfactory clinical results.

Prediction of Disease-Free Survival in Patients with Squamous Cell Carcinomas of the Head and Neck Using Dynamic Contrast-Enhanced MR Imaging • S. Chawla, S. Kim, L.A. Loevner, W.-T. Hwang, G. Weinstein, A. Chalian, H. Quon, and H. Poptani
This article attempts to employ Ktrans obtained from dynamic contrast-enhanced MR studies as a biomarker to establish prognosis in patients with squamous cell carcinomas of the head and neck. The authors measured the period of disease-free survival in 57 patients from the end date of chemoradiation therapy (either death or last clinical visit were taken as end points). Pretreatment Ktrans and nodal volume were computed from the largest metastatic node, and median pretreatment Ktrans and volume were used to divide patients into 2 groups. Thirteen of 57 patients had died by the last follow-up. Patients with higher pretreatment Ktrans values had prolonged disease-free survival compared with patients with lower Ktrans values. However, there was no significant difference in disease-free survival when nodal volume was used as a predictor. The conclusion: pretreatment Ktrans may be a useful prognostic marker in head and neck SCC.