MyT3 18 - Neuro

Purpose:

To differentiate neoplastic from non-neoplastic brain lesions using conventional and advanced MR imaging techniques.

Methods and materials:

Contrast MRI and MRS were done on 50 patients with GE Optima 1.5 Tesla MRI-machine referred with clinically suspected space-occupying lesions (SOL) and patients with incidental/diagnosed ring-enhancing lesion by CT scan were enrolled in the study from June-18 to June-19. The data will be entered in MS EXCEL spreadsheet and analysis will be done using Statistical Package for Social Sciences (SPSS) VERSION 22.0.

Results:

Out of 50 cases, 22 are tuberculomas, 16 are NCC, 5 are abscess, 5 metastasis, 1 case of pilocytic astrocytoma and 1 tumefactive demyelination. Males were predominantly affected (31 cases - 62% of the cases) than females (19 cases - 38 %). 21-30 years is the most common age group involved (28% of the cases) and seizures are the most common presenting complaint (84%). The single lesion was noted in 34 % of patients whereas the rest 66% presented with multiple cases. Follow-up CT/MRI in 26 patients show resolution of the lesion and its associated perilesional oedema.

Conclusion:

MRI is non-invasive and non-radiating is an ideal imaging modality. MRS helps in the characterisation of various ring-enhancing lesions.

Limitations:

MRS could not be performed in four cases due to the presence of lesion close to the bone. MRS helps in the characterisation of various ring-enhancing lesions. However, no lesion can be diagnosed based on the findings of MRS as the sole criteria.

Ethics committee approval

After obtaining a written informed consent the patient was evaluated with Contrast MRI and MRS. The gold standard for diagnosis of brain mass is biopsy with histopathologic evaluation; however, most of the patients were followed up to correlate the findings with clinical imaging follow-up.

Funding:

No funding was received for this work.

Purpose:

Increasing evidence supports that Circle of Willis (CoW) variants predispose to cerebrovascular ischaemia. However, results on the factors determining CoW variants are sparse and conflicting. We aimed to determine whether CoW morphology and haemodynamics are associated with genetic or environmental factors in twins.

Methods and materials:

We investigated two separate twin populations: 1) 120 volunteer members of the Hungarian Twin Registry underwent time-of-flight magnetic resonance angiography (TOF-MRA) to record hypoplasia/aplasia in each CoW artery. 2) 64 volunteer members of the Italian Twin Registry were examined by transcranial colour-coded duplex sonography to investigate CoW haemodynamics. Concordance rates of CoW variants and raw heritability of haemodynamic traits were calculated. Cardiovascular risk factors were compared within twin pairs discordant for CoW morphology using paired t-test and Fisher’s exact test.

Results:

The average age was 52±21 and 43±23 years in the first and second twin group, respectively. Concordance rates were higher in dizygotic than in monozygotic twins regarding anterior (0.47 and 0.22, respectively) and posterior (0.85 and 0.69, respectively) CoW variants. Cardiovascular risk factors did not differ significantly within monozygotic twin pairs discordant for CoW morphology (p>0.05 for body-mass index, hypertension, hypercholesterolemia and smoking, respectively). Raw heritability of CoW haemodynamics was low to moderate (0.00-0.56).

Conclusion:

Our results support the dominance of environmental factors on both morphology and haemodynamics of the CoW. However, no cardiovascular risk factor was identified as a predictor of CoW variants. Consequently, our results stimulate further research aiming at specifying the environmental factors affecting CoW morphology.

Limitations:

Major limitations include small sample size, and low spatial resolution and flow-dependence of TOF-MRA.

Ethics committee approval

The regional ethical committees approved the study (approval number: 1046-260/2014; 189/2014, 2014/10/21). All participants signed informed consent.

Funding:

No funding was received for this work.

Purpose:

To study the neuroimaging in HIV-infected patients with different levels of СD4 cells, plasma HIV RNA, ART status.

Methods and materials:

The eligibility criteria: HIV+, performed brain MRI, an adult. Examination data of 410 patients included a history of HIV infection, opportunistic diseases, current CD4 count, plasma HIV RNA, pathogen identification in CSF. Statistic analysis included chi-square (with Yates correction), Fisher's, the Mann-Whitney, Wald criteria.

Results:

Regular ART was associated with a lower incidence of: large asymmetric lesions, caudate nuclei involvement, perilesional oedema, ring contrast enhancement. Duration of ART for more than five years reduces the incidence of brain involvement in HIV, contrast enhancement, white matter lesions, the involvement of the frontal lobes and basal nuclei. Lower current CD4 cells were associated with large asymmetric lesions, the involvement of the basal ganglia and posterior fossa, perilesional oedema and mass effect, blooming artefact on T2*, ring and nodular contrast enhancement. Plasma HIV RNA above 50 copies/ml was associated with diffuse white matter lesions, large asymmetric lesions, the involvement of the cerebellum, perilesional oedema. In major cases of CNS-IRIS we observed acute inflammatory demyelination, which was characterised by the appearance of new focal lesions, as well as the increase of old ones, atypical patterns of contrast enhancement: perivascular, peripheral, nodular, leptomeningeal.

Conclusion:

ART and dependent on its current СD4 cells, plasma HIV RNA had an influence on the severity of brain structural damage. With the disease progression, the most vulnerable regions were basal ganglia and cerebellum despite ART. The atypical PML were significantly more often visualised in CNS-IRIS.

Limitations:

This study was limited by its retrospective design, qualitative neuroradiological criteria, and several data were incomplete.

Ethics committee approval

The study approved by the ethics committee in accordance with the criteria ICH GCP. All patients have signed informed consent.

Funding:

No funding was received for this work.

Purpose:

We aimed to utilise a non-invasive in-vivo MR-based imaging modality and analysis framework to detect and characterise the laminar components of the human cerebral cortex in stroke and epilepsy patients compared with healthy controls (HC).

Methods and materials:

Using 3T-MRI we calculated T1-component probability maps and showed that the T1-signal of the cortex can be divided into 5-6 distinct Gaussian distributions centred at different values, which represent different cortical laminar classes. For the stroke patients, we explored in-vivo if in patients (n=20) with chronic lacunar infarct, involving the corticospinal-tracts (CST), the cortical layers of the connected primary motor cortex (M1) are differently affected. We performed tractography using the infarcts as the seed areas to reconstruct the CST and identified the connected M1. For epilepsy patients (focal cortical dysplasia (FCD) and periventricular nodular heterotopia (PNH); n=9 each) we determined the laminar composition of 78 cortical regions of interest of the automated anatomical labelling (AAL) atlas, which was divided into 1000 sub-areas with equal volume.

Results:

For stroke patients we showed focal cortical thinning in the connected M1 and specifically only in its deepest laminar portion as compared to the non-affected contralateral cortex (P<0.001), supporting the concept of secondary neurodegeneration. For epilepsy patients we found widespread cortical dyslamination compared to the HC, supporting evidences of epilepsy as a network disease with disrupted brain connectivity.

Conclusion:

Our findings provide a method to calculate and characterise the laminar architecture of the cortex, which was implemented to stroke and epilepsy patient groups. Our method may be used as a sensitive imaging biomarker, and could potentially elucidate pathophysiologic mechanisms and facilitate patient management towards developing individually tailored treatment.

Limitations:

Not applicable.

Ethics committee approval

Approved by institutional IRB.

Funding:

Not applicable.

Purpose:

Peripheral neuropathies are a group of disorders which affect the peripheral nervous system and have been conventionally diagnosed using electrodiagnostic studies. This study was carried out to assess the role of imaging in diagnosing peripheral neuropathy as exact anatomical localisation of the pathology is possible using high-resolution ultrasound (HRUS) and MR neurography, the modalities assessed in this study.

Methods and materials:

A prospective study was carried out in a resource-limited setting on 180 peripheral nerves in 131 patients with symptoms of peripheral neuropathy after taking IRB approval. Each patient underwent HRUS and MR neurography, findings of which were then compared and statistically analysed assuming electrodiagnostic findings as to the gold standard.

Results:

Overall, the diagnostic accuracy was highest for the proton density fat saturated (PDFS) MR sequence (93.89%) followed closely by HRUS (80%). The sensitivity was highest for PDFS sequence while the T1 MR sequence had the highest specificity. Combined diagnostic accuracy of both modalities was calculated to be 93.33% with a negative predictive value of 80%. HRUS and MRI equally detected the cases with nerve discontinuity, while neuromas were better identified on MRI.

Conclusion:

With the advent of higher frequency probes and improved MR field strength, imaging of peripheral nerves is possible with better accuracy. Imaging assessment of nerves allows anatomical delineation with the identification of the exact site of involvement. This comparative study demonstrates the role of imaging in diagnosing peripheral neuropathies with the accuracy of MRI as high as 93.89% which may serve as an imaging gold standard. HRUS, being quicker, cost-effective and a comparable accuracy of 80% can serve as a reliable screening tool.

Limitations:

Resource-limited setting and lack of newer sequences like DTI and DWI.

Ethics committee approval

The IRB approved.

Funding:

No funding was received for this work.

Purpose:

To investigate the effect of lumbar spinal stenosis (LSS) on objective parameters reflected on radiographs and to adapt existing radiographic indexes to the diagnosis of LSS.

Methods and materials:

LSS was determined by measuring the midline anteroposterior (AP) spinal canal diameter on axial T2-weighted images in lumbosacral MRI. Fifty patients with LSS and 50 patients without LSS were classified as. Lateral lumbosacral radiographs of the patients were evaluated retrospectively and on radiographs, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), L5 incidence (L5I), L5 slope (L5S), sacral table angle (STA), sagittal vertebral corpus height (SBH), sagittal vertebral corpus width(SBW), peduncular width(PW), foraminal width (FW), posterior pedicle margin (PPM) were measured, SBW/PW and SBW/PPM ratios were calculated.

Results:

In the LSS group, PI was significantly higher (p = 0.029). FW (p <0.001) and PW (p <0.005) values ​​were significantly lower in the LSS group for each level. In the LSS group, SBH levels were lower (p=0.041) at L4 level, SBW levels were higher at L2-5 levels (p <0.005) and PPM values ​​were lower at S1 level only (p <0.005). In the LSS group, the SBW / PW ratio for each level, the SBW / PPM ratio at L4 and L5 levels were significantly higher (p <0.005). In the ROC analysis of parameters with significant differences between LSS and control groups, the cut-off values of significant parameters and levels were calculated.

Conclusion:

The results of our study are useful for classifying patients with and without spinal narrow canals, but further studies are required.

Limitations:

Inclusion of patients with a single level of a narrow canal in the patient group, not classifying spinal stenosis as developmental or congenital.

Ethics committee approval

n/a

Funding:

No funding was recieved for this work.

Purpose:

To compare and correlate the diagnostic role of neurosonography with spectral Doppler and strain elastography in neonatal hypoxic-ischaemic encephalopathy with MRI as the gold standard. To assess the role of diffusion-weighted Imaging in early identification and extent of ischemic injury.

Methods and materials:

A prospective study was conducted on 50 patients under one month age with a clinical picture of neonatal encephalopathy, a history of perinatal asphyxia and low Apgar score. All patients were graded by Sarnat and Sarnat grading. Neurosonography with spectral Doppler of the anterior cerebral artery and strain elastography was done with 3-7 MHz probe on anterior fontanelle. Elastographic scores were assigned on a five-point colour scale.3 Tesla MRI was done with DWI (diffusion-weighted images). Ultrasound findings were correlated with MRI in various areas of the brain parenchyma and the role of DWI was evaluated by SPSS v.20.0.

Results:

The diagnostic accuracy, sensitivity and specificity of neurosonography compared to MRI were 82%, 82.6% and 75% respectively. DWI detected mild ischaemic changes when other MR sequences were negative. Neurosonography detected all cases of germinal matrix haemorrhage and showed better sensitivity for thalamic, basal ganglia and periventricular white matter lesions. Altered RI values of ACA were seen in 59% of moderate and severe cases. Diagnostic accuracy of Elastographic score was 76.67% with a specificity of 86.67% (95%CI;59.54%-98.34%) and sensitivity of 66.67% (95%CI;33.38%-88.18%).

Conclusion:

Neurosonography is an effective screening tool for detecting ischaemic encephalopathy. Raised elasticity of periventricular white matter in neonatal encephalopathy points towards its promising role in early diagnosis. DWI detects ischaemic changes earlier than conventional MRI which is important in initiating early management.

Limitations:

This study was limited by its small sample size.

Ethics committee approval

Approval was taken from the ethical committee of SMS Medical College.

Funding:

No funding was received for this work.

Purpose:

To investigate the correlation between childhood head injury and clinical-radiological features of Dyke-Davidoff-Masson Syndrome (DDMS).

Methods and materials:

A total of 33 patients with a diagnosis of cerebral hemiatrophy at our institution between January 2012 to July 2019 were retrospectively review. Patients of this study must fulfil the following criteria: (i) clinical presentation of seizure; (ii) radiological manifestations with ipsilateral sulcal enlargement, ipsilateral lateral ventricular dilatation, and ipsilateral calvarial thickening. The patients were distributed into two groups based on the present or absent of childhood head injury. Clinical and imaging characteristics were compared and analysed. Raw data are presented as frequencies and percentages for categories and mean for the age at presentation. Fisher’s exact test was used to assess the association between two categorical variables.

Results:

There are 14 patients (eight males, six females) aged 1 to 46 years (mean age±SD=20.7±13.8) were included. There are eight patients with childhood head injury and six patients without history of childhood head injury. Clinical features recognised in these two groups are hemiplegia (87.5% vs 66.7% respectively, p=0.539), mental retardation (87.5% vs 66.7%,p=0.539) and psychiatric disorders (37.5% vs 16.7%, p=0.580). Of these patients, radiological appearances of wallerian degeneration and hyperpneumatisation of paranasal sinus (75% vs 50%, p=0.580 ); elevation of orbital roof (75% vs 33.3%,p= 0.277); hperpneumatisation of the mastoid and elevation of petrous ridge (62.5% vs 16.7%, p=0.138) were found in these two groups. The formation of porencephaly and midline structural shift were identified among the patients (87.5% vs 16.7%, p=0.026).

Conclusion:

The clinical-radiological manifestations of DDMS vary widely. The patients with childhood head injury were more likely to have the formation of porencephaly and midline structural shifts.

Limitations:

This study was limited by a small number of patients and by the lack of detailed history and clinical information due to the retrospective nature of this study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To introduce AQuaPi, a fully-automated pipeline for PET/MRI to non-invasively determine the cerebral metabolic rate of glucose (CMRGlc) images.

Methods and materials:

The pipeline needs the following inputs: (1) PET list-mode data, (2) attenuation correction (AC) map, (3) MR angiography (MRA) images, (4) T1-w MRI and (5) MR navigators. The processing pipeline includes two main components: (i) an image-derived input function (IDIF) component and (ii) a quantification component (QC). The IC component calculates an IDIF by first determining a volume-of-interest through automated segmentation of the MRA, followed by MR navigator-based motion correction (MC) and an MR-based partial volume correction (PVC). The QC then uses the IDIF to generate CMRGlc images. To validate the pipeline, 10 healthy volunteers underwent [18F]FDG test-retest PET/MRI examinations in an integrated PET/MR. Arterial blood samples (AIF) were collected as a reference standard. Pseudo-CT images derived from T1-w MR were used for AC. Absolute percentage difference (APD) in regional MRGlc values (IDIF vs AIF) were determined in the following 6 brain regions: corpus callosum (CC), brainstem (BS), cerebellum (CB), thalamus (TH), anterior cingulate cortex (ACC) and the superior frontal cortex (SFC).

Results:

The APD between CMRGlc values obtained from AIF and IDIF were: (5.9 ±3.2%) for CC, (5.9 ±3.3%) for BS, (5.8 ±3.4%) for CB, (5.5 ±3.1%) for ACC, (5.8 ±3.14%) for TH and (5.9 ±3.3%) for the SFC.

Conclusion:

We have developed a fully-automated open-source processing pipeline which allows non-invasive determination of absolute CMRGlc values in a clinical setting.

Limitations:

Inter- and intra-variability of CMRGlc is high.

Ethics committee approval

Written informed consent was obtained from all the subjects along with ethics board approval.

Funding:

This work was supported by the Austrian Science Fund KLI482-B31.