Stefan C.A. Steens

Obstetric Brachial Plexus Lesions: CT Myelography

PURPOSE To evaluate the value of computed tomographic (CT) myelography in the detection of root damage and differentiation of root avulsions from neurotmesis in a large cohort of patients with an obstetric brachial plexus lesion (OBPL). MATERIALS AND METHODS Institutional review board approval was obtained. Informed consent was waived by the medical ethics committee. One hundred eighteen patients with OBPL born in the cephalic position and six patients born in the breech position were selected for surgery by two neurosurgeons in a multidisciplinary team. Functional loss of the C5 through T1 innervated muscles was noted. All patients underwent preoperative CT myelography at an average age of 19 weeks. CT myelographic examination results were reviewed by two radiologists, who were blinded to the clinical findings, for the presence of root avulsions and pseudocysts. Interobserver agreement was assessed by calculating κ values. RESULTS CT myelographic results showed root avulsions in at least one level in 66 (56%) of 118 patients born in the cephalic position and in six (100%) of six patients born in the breech position. Levels C7 and C8 showed the most root avulsions, even if not expected from clinical examination results. A large number of root avulsions showed pseudocysts (73 [68%] of 107 levels in patients born in the cephalic position and 11 [73%] of 15 levels in patients born in the breech position). CONCLUSION CT myelographic results showed root avulsions in more than half of patients with OBPL. Root avulsions were even detected at levels that were not expected at clinical examination. Because root avulsions require specific reconstructive techniques, CT myelography is recommended for every preoperative patient with OBPL.

Cognitive functioning, wellbeing and brain correlates in HIV-1 infected patients on long-term combination antiretroviral therapy

Objective:The objective of the current study is to integrate results from extensive neuropsychological assessment, subjective wellbeing reports and structural neuroimaging findings in successfully treated HIV-infected patients in comparison with a HIV-negative control group. Design:A cross-sectional study. Methods:Neuropsychological functioning and self-reported wellbeing were assessed in a group of 102 virologically suppressed HIV-infected patients on combination antiretroviral therapy (cART) and 56 controls. Both groups underwent magnetic resonance (MR) examinations and grey matter, white matter and subcortical volumes were determined. Brain parenchymal fraction (BPF) was calculated as an estimated measure of global brain atrophy. Results:HIV-infected patients showed worse information processing speed (P = 0.01) and motor function (P = 0.03) than controls. Also, higher levels of anxiety and depressive symptoms, somatic and cognitive complaints, sleep problems and health distress were found, as well as lower levels of general health perceptions, social functioning and energy (P < 0.05). No differences in wellbeing reports were found between patients on regimens containing either efavirenz or nevirapine and patients on cART without these drugs (P > 0.05). Patients had a smaller BPF (P = 0.04) and thalamus (P = 0.05) than controls. A lower BPF was related to worse motor function and information processing speed in the patients. A smaller thalamus volume was related to lower motor function in the patient group and lower speed of information processing in the controls. Conclusion:No profound deficits were found in the current study. The present results demonstrate that HIV has a minor impact on brain, cognition and wellbeing among HIV-infected patients who are otherwise healthy and maintained on a good control of cART.

Nigrosome-1 on Susceptibility Weighted Imaging to Differentiate Parkinson’s Disease From Atypical Parkinsonism: An In Vivo and Ex Vivo Pilot Study

Summary Background Previous case-control studies have suggested that the absence of a swallow-tail appearance in the substantia nigra on high-resolution SWI, representing nigrosome-1, has high accuracy to identify Parkinson’s disease (PD). The first goal of our study was to evaluate nigrosome-1 ex vivo using optimized high-resolution susceptibility sensitive MRI. Our second goal was to evaluate its diagnostic value in vivo using a clinical 3T SWI sequence to differentiate between PD and atypical parkinsonism (AP) in a cohort of patients with early-stage parkinsonism. Material/Methods Case-control pilot study to evaluate nigrosome-1 ex vivo (2 PD, 2 controls), using high-resolution susceptibility sensitive sequences at 11.7 T MRI. Next, evaluation of nigrosome-1 in vivo using a clinical 3 T SWI sequence in a prospective cohort of 60 patients with early-stage parkinsonism (39 PD, 21 AP). Moreover, 12 control subjects were scanned. The bilateral substantia nigra was evaluated by two neuroradiologists for the presence, absence or indecisive presence of nigrosome-1. The discriminative power was evaluated by Receiver-Operating Characteristic. Results We identified nigrosome-1 in ex vivo control subjects. Nigrosome-1 was not identified in the ex vivo PD cases. In our prospective clinical cohort study, the AUC for the swallow-tail sign to discriminate between PD and AP was 0.56 (0.41–0.71) for reader 1 and 0.68 (0.55–0.82) for reader 2. Conclusions The diagnostic accuracy of the swallow-tail sign was marginal to discriminate between PD and AP using our clinical 3 T SWI sequence.

Pulsatile Tinnitus: Differential Diagnosis and Radiological Work-Up

Purpose of ReviewIdentification of the underlying cause of pulsatile tinnitus is important for treatment decision making and for prognosis estimation. For this, an adequate diagnostic imaging strategy is crucial.Recent FindingsBoth CT and MRI can be useful, and in general, these modalities provide complementary diagnostic information. The scanning protocol can be optimized based on the estimated a priori chance for finding specific pathology, or the need to rule out more rare but clinical significant disease. In recent years, dynamic CTA, also referred to as 4D-CTA, has become available as a new technique that enables non-invasive evaluation of hemodynamics for the detection, classification, and follow-up of vascular malformations.SummaryThe value of different diagnostic imaging modalities in the work-up of pulsatile tinnitus is discussed in relation to the differential diagnosis. Furthermore, imaging findings of different diseases are presented, both for CT and MRI.

The diagnostic accuracy of non-imaging screening protocols for vestibular schwannoma in patients with asymmetrical hearing loss and/or unilateral audiovestibular dysfunction: a diagnostic review and meta-analysis

Currently, all patients presenting with asymmetrical sensorineural hearing loss and/or unilateral audiovestibular dysfunction (i.e. tinnitus, dizziness) undergo MRI, leading to a substantial amount of MRIs with negative findings as the incidence of vestibular schwannoma (VS) in this screening population varies between 1% and 4.7% (i.e. more than 95% of MRIs are negative for VS).

Magnetic resonance imaging of the carotid artery in long-term head and neck cancer survivors treated with radiotherapy

Abstract Background. In head and neck cancer (HNC) patients, long-term treatment-related complications include radiotherapy (RT)-induced carotid vasculopathy and stroke. The current study investigated the magnetic resonance imaging (MRI) characteristics of the carotid wall in long-term HNC survivors treated with RT. Methods. MRI of the carotid arteries was performed within a prospective cohort of 42 HNC patients on average 7 years after RT. Two independent radiologists assessed maximal vessel wall thickness of common and internal carotid arteries. In case of wall thickening (≥ 2 mm) the MRI signals as well as length of the thickened segment were assessed. Results. Mean (SD) age of the 42 patients at baseline was 53 (13) years and mean (SD) follow-up time after RT was 6.8 (1.3) years. In total 62% were men and 60% had one or more cerebrovascular risk factors. Mean (SD) dose of RT on the common carotid arteries and internal carotid arteries was 57 Gy (11) and 61 Gy (10), respectively. Wall thickening was observed in 58% of irradiated versus 27% of non-irradiated common carotid arteries and 24% of irradiated versus 6% of non-irradiated internal carotid arteries (p < 0.05). Mean (SD) thickness of the irradiated and non-irradiated common carotid arteries was 2.5 (0.9) and 2 (0.7) mm (p = 0.02). Mean thickness of the irradiated and non-irradiated internal carotid arteries was 1.8 (0.8) and 1.5 mm (0.3) (n.s.). Mean length of the thickened vessel wall was 48 mm versus 36 mm in the irradiated versus non-irradiated common carotid arteries (p = 0.03) and 20 mm versus 15 mm in the irradiated versus non-irradiated internal carotid arteries (n.s.). No significant differences were observed for signal intensities of the vessel walls. Conclusions. Our study showed significantly more vessel wall thickening in irradiated versus non-irradiated carotid arteries years after RT for HNC, while no differences in signal intensities were observed.

Brain CT perfusion improves intracranial vessel occlusion detection on CT angiography

BACKGROUND AND PURPOSE To evaluate whether brain CT perfusion (CTP) aids in the detection of intracranial vessel occlusion on CT angiography (CTA) in acute ischemic stroke. MATERIALS AND METHODS Medical-ethical committee approval of our hospital was obtained and informed consent was waived. Patients suspected of acute ischemic stroke who underwent non-contrast CT(NCCT), CTA and whole-brain CTP in our center in the year 2015 were included. Three observers with different levels of experience evaluated the imaging data of 110 patients for the presence or absence of intracranial arterial vessel occlusion with two strategies. In the first strategy, only NCCT and CTA were available. In the second strategy, CTP maps were provided in addition to NCCT and CTA. Receiver-operating-characteristic (ROC) analysis was used for the evaluation of diagnostic accuracy. RESULTS Overall, a brain perfusion deficit was scored present in 87-89% of the patients with an intracranial vessel occlusion, more frequently observed in the anterior than in the posterior circulation. Performance of intracranial vessel occlusion detection on CTA was significantly improved with the availability of CTP maps as compared to the first strategy (P=0.023), due to improved detection of distal and posterior circulation vessel occlusions (P-values of 0.032 and 0.003 respectively). No added value of CTP was found for intracranial proximal vessel occlusion detection, with already high accuracy based on NCCT and CTA alone. CONCLUSION The performance of intracranial vessel occlusion detection on CTA was improved with the availability of brain CT perfusion maps due to the improved detection of distal and posterior circulation vessel occlusions.

Potential savings in the diagnosis of vestibular schwannoma

Magnetic resonance imaging (MRI) is used to screen patients at risk for vestibular schwannoma (VS). These MRIs are costly and have an extremely low yield; only 3% of patients in the screening population has an actual VS. It might be worthwhile to develop a test to predict VS and refer only a subset of all patients for MRI.

An international comparison of the management of the neck in early oral squamous cell carcinoma in the Netherlands, UK, and USA.

BACKGROUND Early oral cavity squamous cell carcinoma (OCSCC) management appears to vary both within and between countries. Variation in practice can be an indicator of absence of evidence-based management and may negatively influence survival and morbidity. The exact variation and the relationship to differences in guidelines are unknown. This study aimed to report on these variations in the Netherlands, UK, and USA, and to evaluate them. METHODS Information regarding the variation in OCSCC management strategies was obtained from a questionnaire sent to representatives of head and neck cancer centers in the Netherlands, UK, and USA. Within-country and between-country variations were also assessed in light of the different guidelines. RESULTS In total, representatives of 45 centers completed the questionnaire; 10 from the Netherlands, 26 from the UK and 9 from the USA. Our results demonstrate a distinct variation in the diagnoses, treatment and follow-up of OCSCC, both within and between countries. Only a small amount of variation between countries could be linked to differences in guidelines. CONCLUSIONS There is high variation in the management of the neck in OCSCC. There seem to be a need for direct evidence about optimal management decisions to establish more evidence-based management and uniform practice.

Diagnostic accuracy of high-resolution T2-weighted MRI vs contrast-enhanced T1-weighted MRI to screen for cerebellopontine angle lesions in symptomatic patients

To evaluate diagnostic accuracy of high‐resolution T2‐weighted MRI (T2w) for detecting cerebellopontine angle (CPA) lesions compared to a combined protocol including gadolinium enhanced T1‐weighted MRI (GdT1w).