Left Ventricular Function and Iron Loading Status in a Tertiary Center Hemochromatosis Cohort-A Cardiac Magnetic Resonance Study.

Background: Haemochromatosis (HCH), a common genetic disorder with variable penetrance, results in progressive but understudied iron overload. We prospectively evaluated organ iron loading and cardiac function in a tertiary center HCH cohort. Methods: 42 HCH patients (47 ± 14 years) and 36 controls underwent laboratory workup and cardiac magnetic resonance (CMR), including T1 and T2* mapping. Results: Myocardial T2* (myoT2*), myocardial T1 (myoT1) and liver T2* (livT2*) were lower in patients compared to controls (33 ± 4 ms vs. 36 ± 3 ms [p = 0.004], 964 ± 33 ms vs. 979 ± 25 ms [p = 0.028] and 21 ± 10 ms vs. 30 ± 5 ms [p < 0.001], respectively). MyoT2* did not reach the threshold of clinically significant iron overload (<20 ms), in any of the patients. In 22 (52.4%) patients, at least one of the tissue parameters was reduced. Reduced myocardial T2* and/or T1 were found in 10 (23.8%) patients, including 4 pts with normal livT2*. LivT2* was reduced in 18 (42.9%) patients. MyoT1 and livT2* inversely correlated with ferritin (rs = −0.351 [p = 0.028] and rs = −0.602 [p < 0.001], respectively). LivT2* by a dedicated sequence and livT2* by cardiac T2* mapping showed good agreement (ICC = 0.876 p < 0.001). Conclusions: In contemporary hemochromatosis, significant myocardial iron overload is rare. Low myocardial T2* and/or T1 values may warrant closer follow-up for accelerated myocardial iron overload even in patients without overt liver overload. Cardiac T2* mapping sequence allows for liver screening at the time of CMR.

Reliability of diffusion tensor tractography of facial nerve in cerebello-pontine angle tumours.

AIM OF THE STUDY: This study aimed to verify the accuracy of preoperative visualisation of the facial nerve (FN) by magnetic resonance-based (MR) diffusion tensor imaging-fibre tracking (DTI-FT) with neuronavigation system integration in patients with cerebello-pontine angle (CPA) tumours. CLINICAL RATIONALE FOR THE STUDY: Complete excision with preservation of the FN remains the critical goal of today's vestibular schwannoma (VS) surgery. DTI-FT of the FN with neuronavigation is yet to be fully evaluated, and could make surgery safer. MATERIALS AND METHODS: This was a prospective cohort study in which 38 consecutive patients with a CPA tumour (32 VSs, five meningiomas and one epidermoid cyst) were operated on via the retrosigmoid route from 2013 to 2019. The course of the FN was simulated before surgery using StealthViz and the images were transferred to the Medtronic S7 neuronavigation system. The FN location reconstructed by DTI-FT was verified during the surgery. RESULTS: MR acquisition was inappropriate in three patients (7.9%). DTI-FT correctly predicted the course of the FN in 31 of the 38 patients; the discordance rate was 18.4%. The accuracy of DTI-FT was 81.6% (95% CI: 65.67-92.26), sensitivity 88.57% (95% CI: 73.26-96.80) and positive predictive value was 91.18% (95% CI: 90.17-92.09). The reliability of the neuronavigation-integrated visualisation of the FN did not depend on the tumour size (p = 0.85), but the method was more accurate when the nerve was compact in shape (p = 0.03, area under curve (AUC) 0.87, 95% CI: 0.60-1.00) and in females (p = 0.04, AUC 0.78, 95% CI: 0.56-1.00). Following surgery, 86.5% of the patients presented with useful facial function (House-Brackmann grades I-III). Correct simulation of the FN did not prevent postoperative facial palsy (p = 0.35). CONCLUSIONS: The accuracy of DTI-FT of the FN integrated with neuronavigation remains unsatisfactory. This method does not provide any clinical benefit over non-integrated DTI-FT in terms of nerve function preservation. CLINICAL IMPLICATIONS: Due to the low reliability of the predictions, further technical advances in predicting the course of the FN are awaited by clinicians. However, DTI-FT images in the operating theatre would make tumour excision more comfortable for the surgeon.

Computed tomography indicators of cerebral microperfusion improve long term after carotid stenting in symptomatic patients.

OBJECTIVES: We tested the hypothesis that computed tomography (CT) perfusion markers of cerebral microcirculation would improve 36 months after internal carotid artery stenting for symptomatic carotid stenosis while results obtained 6-8 weeks after the stenting procedure would yield a predictive value. METHODS: We recruited consecutive eligible patients with >70% symptomatic carotid stenosis with a complete circle of Willis and normal vertebral arteries to the observational cohort study. We detected changes in the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and permeability surface area-product (PS) before and after carotid stenting. We have also compared the absolute differences in the ipsilateral and contralateral CT perfusion markers before and after stenting. The search for regression models of "36 months after stenting" results was based on a stepwise analysis with bidirectional elimination method. RESULTS: A total of 34 patients completed the 36 months follow-up (15 females, mean age of 69.68±S.D. 7.61 years). At 36 months after stenting, the absolute values for CT perfusion markers had improved: CBF (ipsilateral: +7.76%, contralateral: +0.95%); CBV (ipsilateral: +5.13%, contralateral: +3.00%); MTT (ipsilateral: -12.90%; contralateral: -5.63%); TTP (ipsilateral: -2.10%, contralateral: -4.73%) and PS (ipsilateral: -35.21%, contralateral: -35.45%). MTT assessed 6-8 weeks after stenting predicted the MTT value 36 months after stenting (ipsilateral: R2=0.867, contralateral R2=0.688). CONCLUSIONS: We have demonstrated improvements in CT perfusion markers of cerebral microcirculation health that persist for at least 3 years after carotid artery stenting in symptomatic patients. MTT assessed 6-8 weeks after stenting yields a predictive value.

Diffusion tensor tractography imaging in pediatric epilepsy - A systematic review.

PURPOSE: Recent years brought several experimental and clinical reports applying diffusion tensor tractography imaging (DTI) of the brain in epilepsy. This study was aimed to evaluate current evidence for adding the DTI sequence to the standard diagnostic magnetic resonance imaging (MRI) protocol in pediatric epilepsy. MATERIAL AND METHODS: Rapid and qualitative systematic review (RAE, Rapid Evidence Assessment), aggregating relevant studies from the recent 7 years. The PubMed database was hand searched for records containing terms "tractography AND epilepsy." Only studies referring to children were included; studies were rated using "final quality of evidence." RESULTS: Out of 144 screened records, relevant 101 were aggregated and reviewed. The synthesis was based on 73 studies. Case-control clinical studies were the majority of the material and comprised 43.8% of the material. Low 'confirmability' and low 'applicability' referred to 18 and 17 articles (29.5% and 27.9%), respectively. The sufficient quality of evidence supported performing DTI in temporal lobe epilepsy, malformations of cortical development and prior to a neurosurgery of epilepsy. CONCLUSIONS: The qualitative RAE provides an interim estimate of the clinical relevance of quickly developing diagnostic methods. Based on the critical appraisal of current knowledge, adding the DTI sequence to the standard MRI protocol may be clinically beneficial in selected patient groups with childhood temporal lobe epilepsy or as a part of planning for an epilepsy surgery.