Fellows’ Journal Club

Apparent Diffusion Coefficient Histograms of Human Papillomavirus–Positive and Human Papillomavirus–Negative Head and Neck Squamous Cell Carcinoma: Assessment of Tumor Heterogeneity and Comparison with Histopathology

Fellows’ Journal Club

One hundred five consecutive patients with primary oropharyngeal and oral cavity head and neck squamous cell carcinoma underwent MR imaging with anatomic and DWI sequences. The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. Diffusion phenotypes of human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas showed significant differences, which reflect their distinct degree of tumor heterogeneity.

Comparison of Clinical Outcomes of Intracranial Aneurysms: Procedural Rupture versus Spontaneous Rupture

Fellows’ Journal Club

This was a retrospective review of 1340 patients with 1595 unruptured saccular intracranial aneurysms that underwent endovascular coil embolization between February 2010 and December 2014. The clinical outcomes of patients with procedural rupture of saccular intracranial aneurysms were compared with those of 198 patients presenting with spontaneously ruptured aneurysms. Procedural rupture developed in 19 patients, and the morbidity related to procedural rupture was 26.3% with no mortality. Hunt and Hess scale grades and hospitalization days of patients with procedural rupture were equivalent to those of patients presenting with spontaneous aneurysm rupture. In multivariate analysis, spontaneous aneurysm rupture was a significant risk factor for worse clinical outcome. This study showed better clinical outcomes in the procedural-rupture group.

Arterial Spin-Labeling Perfusion MR Imaging Demonstrates Regional CBF Decrease in Idiopathic Normal Pressure Hydrocephalus

Fellows’ Journal Club

The authors assessed regional CBF in patients with idiopathic normal pressure hydrocephalus compared with healthy controls using the noninvasive quantitative arterial spin-labeling MR imaging technique. Twenty-one consecutive patients with NPH and 21 age- and sex-matched randomly selected healthy controls from a population registry were prospectively included. In patients with idiopathic NPH, perfusion was reduced in the periventricular white matter,lentiform nucleus, and thalamus compared with controls. They conclude that using pseudocontinuous ASL, they confirmed the findings of reduced perfusion in the periventricular white matter, basal ganglia, and thalamus in patients with idiopathic NPH previously observed with other imaging techniques.

Localizing the L5 Vertebra Using Nerve Morphology on MRI: An Accurate and Reliable Technique

Fellows’ Journal Club

The authors sought to determine whether the L5 vertebra could be accurately localized by using nerve morphology on MR imaging. A sample of 108 cases with full spine MR imaging were numbered from the C2 vertebral body to the sacrum. The reference standard of numbering by full spine imaging was compared with the nerve morphology numbering method with 5 blinded raters. The percentage of perfect agreement with the reference standard was 98.1%, which was preserved in transitional and numeric variation states. The iliolumbar ligament localization method showed 83.3% perfect agreement with the reference standard.

Improved Detection of Anterior Circulation Occlusions: The “Delayed Vessel Sign” on Multiphase CT Angiography

Fellows’ Journal Club

The authors evaluated 23 distal anterior circulation occlusions during a 2-year period. Ten M1-segment occlusions and 10 cases without a vessel occlusion were also included. There was significant improvement in the sensitivity of detection of distal anterior circulation vessel occlusions, overall confidence, and time taken to interpret with multiphase CTA compared with single-phase CTA. The delayed vessel sign is a reliable indicator of anterior circulation vessel occlusion, particularly in cases involving distal branches.

Multinodular and Vacuolating Neuronal Tumor of the Cerebrum: A New “Leave Me Alone” Lesion with a Characteristic Imaging Pattern

Fellows’ Journal Club

The most recent 2016 WHO classification includes MVNT as a unique cytoarchitectural pattern of gangliocytoma, though it remains unclear whether MVNT is a true neoplastic process or a dysplastic hamartomatous/malformative lesion. The authors report 33 cases of presumed multinodular and vacuolating neuronal tumor of the cerebrum that exhibit a remarkably similar pattern of imaging findings consisting of a subcortical cluster of nodular lesions. They conclude that these are benign, nonaggressive lesions that do not require biopsy in asymptomatic patients and behave more like a malformative process than a true neoplasm.

Analysis of 30 Spinal Angiograms Falsely Reported as Normal in 18 Patients with Subsequently Documented Spinal Vascular Malformations

Fellows’ Journal Club

Eighteen patients with 19 lesions underwent a total of 30 negative spinal angiograms. The lesions included 9 epidural arteriovenous fistulas, 8 dural arteriovenous fistulas, and 2 perimedullary arteriovenous fistulas. Seventeen patients underwent endovascular (11) or surgical (6) treatment, with a delay ranging between 1 week and 32 months; the Aminoff-Logue score improved in 76.5%. Causes of the inadequate results included: 1) lesion angiographically documented but not identified (55.6%); 2) region of interest not documented (29.6%); or 3) level investigated but injection technically inadequate (14.8%). All the angiograms falsely reported as normal were caused by correctible, operator-dependent factors.

Influence of Carotid Siphon Anatomy on Brain Aneurysm Presentation

Fellows’ Journal Club

Lateral view DSA images of 692 consecutive patients with intracranial aneurysms treated at the authors’ institution were reviewed and had their angles measured. Data on the location, presentation, and size of the lesions were collected and evaluated by multivariate analysis in relation to the measured angles. Multivariate analysis showed an association between angles of >15.40° and rupture (P = .005), postsiphon location (P = .034), and aneurysm size of >1.001 mm (P = .015). These findings may be associated with the hemodynamic interactions of blood flow and the curvature of the carotid siphon.

Diagnostic Performance of a 10-Minute Gadolinium-Enhanced Brain MRI Protocol Compared with the Standard Clinical Protocol for Detection of Intracranial Enhancing Lesions

Fellows’ Journal Club

A total of 53 patients underwent MR imaging consisting of 5 basic fast precontrast sequences plus standard and accelerated versions of the same postcontrast T1WI sequences. Two neuroradiologists assessed the image quality and the final diagnosis for each set of postcontrast sequences and compared their performances. The 10-minute brain MR imaging protocol with contrast was comparable in diagnostic performance with the standard protocol in an inpatient motion-prone population, with the additional benefits of reducing acquisition times and image artifacts.

Functional Connectivity in Virally Suppressed Patients with HIV-Associated Neurocognitive Disorder: A Resting-State Analysis

Fellows’ Journal Club

Eighteen patients with active HIV-associated neurocognitive disorder (recent diagnosis with progressing symptoms) on combination antiretroviral therapy with viral suppression in both blood and CSF and 9 demographically matched control subjects underwent resting-state functional MR imaging. The connectivity in the 6 known neural networks was assessed. There were significant group differences between the control and HIV-associated neurocognitive disorder groups in the salience and executive networks. The authors conclude that active HIV-associated neurocognitive disorder in virally suppressed patients is associated with significantly decreased connectivity in the salience and executive networks, thereby making it potentially useful as a biomarker.