Diffusion tensor imaging of the optic disc in idiopathic intracranial hypertension

Role of diffusion tensor imaging in the evaluation of white matter integrity in idiopathic intracranial hypertension

OBJECTIVES

To determine whether idiopathic intracranial hypertension (IIH) may affect white matter integrity and optic pathways by using diffusion tensor imaging (DTI) and to correlate the DTI metrics with intracranial pressure (ICP).

METHODS

This study is a retrospective case-control study. A total of 42 patients who underwent lumbar puncture and those with elevated ICP, meeting the diagnostic criteria for IIH, were included in the study. All patients had supportive magnetic resonance imaging findings for the diagnosis of IIH. The headache control group comprised 36 patients who presented to the Neurology Department with infrequent episodic tension-type headache, had a normal neurologic examination, and had clinical and radiological findings suggestive of normal ICP. For each patient with IIH, clinical findings and ophthalmological measurements were recorded. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) values were calculated using a region of interest-based method in different white matter tracts and optic pathways and compared.

RESULTS

A total of 42 patients diagnosed with IIH (three males, 39 females), with a mean (standard deviation [SD] age of 38.1 (8.9) years), and 36 headache controls (10 males, 26 females, mean [SD] age; 38.1 [9.4] years) were included in the study. The mean (SD) body mass index (BMI) of the patients with IIH was 25.2 (1.9) kg/m2, and the mean (SD) BMI of the headache controls was 23.3 (1.5) kg/m2 (p < 0.001). Decreased FA values and increased RD values in the cingulum were detected in patients with IIH compared to the headache controls (p = 0.003, Cohen's d = 0.681; p = 0.002 Cohen's d = -0.710). Decreased AD values in the left and right superior cerebellar peduncle and increased ADC values in the middle cerebellar peduncle were detected in patients with IIH compared to the headache controls (p < 0.001, Cohen's d = 0.961; p = 0.009, Cohen's d = 0.607; p = 0.015, Cohen's d = -0.564). Increased ADC and RD values and decreased FA values in optic nerve were detected in patients with IIH (p = 0.010, Cohen's d = -0.603; p = 0.004, Cohen's d = -0.676; p = 0.015 Cohen's d = 0.568). A positive correlation was found between the cerebrospinal fluid pressure and ADC values of the left and right superior and left inferior longitudinal fasciculus, genu of the corpus callosum, and right optic radiation (r = 0.43, p = 0.005; r = 0.31, p = 0.044; r = 0.39, p = 0.010; r = 0.35, p = 0.024; r = 0,41, p = 0.007). There was a positive correlation between the retinal nerve fiber layer thickness and the ADC values of the optic nerve (r = 0.32, p = 0.039).

CONCLUSIONS

Intracranial hypertension can be associated with deteriorated DTI values, which might be interpreted as a sign of impaired white matter microstructural integrity in many brain regions beyond the periventricular white matter. Pressure-induced edema and axonal degeneration may be the potential underlying mechanisms of this microstructural damage.

Diffusion tensor imaging of dorsal stream language areas in patients with post-stroke aphasia

Background

Aphasia complicating stroke occurs due to language deficits that decrease communication abilities and functional independence. Our study aims to assess fractional anisotropy (FA) and mean diffusivity (MD) parameters of diffusion tensor imaging (DTI) of the dorsal stream language areas in patients with post-stroke aphasia. It was conducted on 27 patients with post-stroke aphasia and 27 age- and sex-matched controls who underwent DTI of the brain. FA and MD values of Broca's area (BA), Wernick's area (WA), superior longitudinal fasciculus (SLF), and arcuate fasciculus (AF), and number of tract fibers (TF) of AF and SLF were calculated. Results were correlated with National Institutes of Health Stroke Scale (NIHSS), Arabic version of Comprehensive Aphasia Test (Arabic CAT), and Mansoura Arabic Screening Aphasia Test (MASAT).

Results

FA of AF and SLF in patients was significantly lower (P = 0.001) than controls. MD of AF and SLF in patients was significantly higher (P = 0.001) than controls. The mean volume TF of AF and SLF in patients was significantly (P = 0.001) lower than the mean volume in controls for AF and SLF. FA cutoff for AF was 0.34 and for SLF, it was 0.35 with sensitivity, specificity, and accuracy (85.2%, 62.1%, 73.2%) for AF, (74.1%, 69%, 71.4%) for SLF, respectively. MD cutoff value for AF was 0.87, and 0.84 for SLF with sensitivity, specificity, and accuracy (63%, 72.4%, 67.8%) for AF, (81.5%, 79.3%, 80.4%) for SLF, respectively. Cutoff TF of AF was 1728 and for SLF it was 601 with sensitivity, specificity, and accuracy (88.9%, 72.4%, 80.4%) for AF and (85.2%, 85.2%, 78.6%) for SLF, respectively.

Conclusions

DTI is a non-invasive promising method that can be used to assess language areas in patients with post-stroke aphasia.

Diffusion Tensor Imaging of Auditory Pathway in Patients With Crigler-Najjar Syndrome Type I: Correlation With Auditory Brainstem Response

AIM

To evaluate the role of diffusion tensor imaging of the auditory pathway in patients with Crigler Najjar syndrome type I and its relation to auditory brainstem response.

METHODS

Prospective study was done including 12 patients with Crigler Najjar syndrome type I and 10 age- and sex-matched controls that underwent diffusion tensor imaging of brain. Mean diffusivity and fractional anisotropy at 4 regions of the brain and brainstem on each side were measured and correlated with the results of auditory brainstem response for patients.

RESULTS

There was significantly higher mean diffusivity of cochlear nucleus, superior olivary nucleus, inferior colliculus, and auditory cortex of patients versus controls on both sides for all regions (P = .001). The fractional anisotropy of cochlear nucleus, superior olivary nucleus, inferior colliculus, and auditory cortex of patients versus controls was significantly lower, with P values of, respectively, .001, .001, .003, and .001 on the right side and .001, .001, .003, and .001 on left side, respectively. Also, a negative correlation was found between the maximum bilirubin level and fractional anisotropy of the left superior olivary nucleus and inferior colliculus of both sides. A positive correlation was found between the mean diffusivity and auditory brainstem response wave latency of the right inferior colliculus and left cochlear nucleus. The fractional anisotropy and auditory brainstem response wave latency of the right superior olivary nucleus, left cochlear nucleus, and inferior colliculus of both sides were negatively correlated.

CONCLUSION

Diffusion tensor imaging can detect microstructural changes in the auditory pathway in Crigler Najjar syndrome type I that can be correlated with auditory brainstem response.

Evaluation of 2D FLAIR hyperintensity of the optic nerve and optic nerve head and visual parameters in idiopathic intracranial hypertension

BACKGROUND AND PURPOSE

T2/FLAIR hyperintensity of the optic nerve/optic nerve head has been described as a sensitive finding in idiopathic intracranial hypertension using post-contrast 3D-T2/FLAIR imaging. The purpose of this study is to assess whether hyperintensity on non-enhanced 2D-T2/FLAIR imaging occurs more likely in diseased patients than controls and to evaluate the relationship between FLAIR signal and visual parameters MATERIALS AND METHODS: A retrospective case-control study was performed of patients with idiopathic intracranial hypertension and controls who underwent orbital MRI. Three neuroradiologists reviewed the FLAIR images, subjectively evaluating for hyperintense signal within the optic nerves/optic nerve heads using a 5-point Likert Scale. Quantitative assessment of optic nerve signal using regions of interests was performed. Clinical parameters were extracted. The diagnostic performance was evaluated, and Spearman correlation calculated to assess the relationship between FLAIR signal and visual outcomes.

RESULTS

The sensitivity of abnormal FLAIR signal within the optic nerves and optic nerve heads in patients with idiopathic intracranial hypertension ranged from 25-54% and 4-29%, respectively, with specificities ranging from 67-92% and 83-100%. Quantitative assessment revealed a significant difference in CNR between cases and controls in the left posterior optic nerve (p=.002). A positive linear relationship existed between abnormal optic nerve head signal and papilledema grade (OD: p=.02, OS: p=.008) but not with other visual parameters.

CONCLUSION

T2/FLAIR hyperintensity in the optic nerve/optic nerve head may support the diagnosis of idiopathic intracranial hypertension but its absence should not dissuade it. If present, abnormal signal in the optic nerve head correlates with papilledema.

The role of diffusion tensor imaging of the liver in children with autoimmune hepatitis

Purpose

To evaluate the role of diffusion tensor imaging (DTI) of the liver in children with autoimmune hepatitis (AIH).

Material and methods

A prospective study was done on 42 children with AIH (30 girls and 12 boys, with a mean age of 13 years) and 20 age- and sex-matched healthy control children. They underwent DTI of the liver and laboratory tests. Liver biopsy was done for the patients. The mean diffusivity (MD) and fractional anisotropy (FA) of the liver were calculated and correlated with the pathological results.

Results

The mean MD and FA of the liver in children with AIH were 1.42 ± 0.06 × 10^-3 mm²/s and 0.37 ± 0.11; and in the control children they were 1.55 ± 0.07 × 10^-3 mm²/s and 0.25 ± 0.03, respectively. The MD and FA were significantly different in the children with AIH compared to the control children (p = 0.001). The cutoff MD and FA used to differentiate patients from controls were 1.50 × 10^-3 mm²/s, 0.31 with AUC of 0.919 and 0.813, sensitivity of 97.6% and 66.7%, a specificity of 80% and 70%, an accuracy of 94.2% and 67.3%, PPV of 95.3 and 90.3, and NPV of 88.9 and 33.3, respectively. There was significantly lower MD and higher FA of the liver in children with AIH type I (n = 31) than type II (n = 11) (p = 0.001), and patients with (n = 9) and without (n = 33) overlap syndrome (p = 0.005).

Conclusions

We concluded that DTI parameters can help to diagnose AIH, detect its phenotyping, and give clues as to the presence of associated overlap syndrome.

Imaging Characteristics of Sigmoid Sinus Wall Anomalies, Idiopathic Intracranial Hypertension, and Spontaneous CSF Leaks

OBJECTIVE

To assess the frequency of radiographic features of elevated intracranial pressure (ICP) in patients with sigmoid sinus wall anomalies (SSWA) and compare to those in idiopathic intracranial hypertension (IIH) and spontaneous CSF (sCSF) leaks.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care center.

PATIENTS

110 patients - 62 SSWAs, 19 IIH, 29 sCSF leaks.

MAIN OUTCOME MEASURES

Demographics, comorbidities and radiographic features by diagnosis.

RESULTS

Imaging findings indicative of elevated ICP were similar across all three groups, as were body mass index, hyperlipidemia and diabetes. On univariate analysis, sCSF leak patients were significantly older than SSWA (60 vs. 41 years, p < 0.001) and IIH (60 vs. 40 years, p < 0.001) patients. They had a greater prevalence of arachnoid granulations than SSWA (75.8% vs. 37.1%, p < 0.01) and tegmen dehiscence than both SSWA and IIH (93.1% vs. 75.8% vs. 57.8%, p = 0.01), though a lower prevalence of empty sella than SSWA (44.8% vs. 72.5%, p < 0.001). SSWAs were present in roughly 44.3% of IIH and sCSF leak patients, and IIH in roughly 15.8% of SSWA and sCSF leak patients. Age (OR = 1.1, p = 0.001), hypertension (OR = 8.3, p = 0.01) and empty sella (OR = 0.1, p = 0.01) were predictive of sCSF leaks compared to SSWAs on multivariate analysis.

CONCLUSIONS

Many radiographic and clinical features of elevated ICP are found at similar rates among patients with SSWA, IIH and sCSF leaks, suggesting a common underlying process. SSWAs seem to present earlier along this spectrum of phenotypes, while sCSF leaks present later. Differences in age, metabolic syndrome and ICP may influence a patient's clinical presentation.

Diffusion tensor imaging of renal cortex in lupus nephritis

PURPOSE

To evaluate the diagnostic value of diffusion tensor imaging (DTI) of renal cortex in assessment of lupus nephritis (LN) and prediction of its pathological subtypes.

METHODS

Prospective study was performed upon 39 female patients with pathologically proven LN and 16 sex- and age-matched healthy controls. Patients and controls underwent DTI of kidney. Mean diffusivity (MD) and fractional anisotropy (FA) of renal cortex were calculated by two radiologists. LN patients were pathologically classified into either non-proliferative (n = 15) or proliferative (n = 24).

RESULTS

Mean MD of renal cortex in LN was significantly lower (p = 0.001) than that of controls with cut-off (2.16 and 2.2 X10^-3mm²/s), area under curve (AUC) of (0.92, 0.94) and accuracy of (91%, 89%) for both observers. Mean FA of renal cortex in LN was significantly higher (p = 0.001) than that of controls with cut-off (0.20, 0.21), AUC of (0.86, 0.82) and accuracy of (86%, 84%) for both observers. Renal cortex MD and FA in non-proliferative LN were significantly different (p = 0.001) from that of proliferative LN for both observers. There was excellent inter-observer agreement of MD and FA (ICC = 0.96 and 0.81).

CONCLUSION

MD and FA of renal cortex may help to assess renal affection in LN patients and predict its pathological subtypes.

Diffusion tensor imaging of vertebral bone marrow in children with Gaucher's disease type I and III: Pre- and post-therapy

PURPOSE

To assess diffusion tensor imaging (DTI) of the vertebral bone marrow (BM) in children with Gaucher's disease (GD) types I and III before and after therapy.

METHODS

Prospective study was conducted upon 25 children with GD type I (n = 17) and III (n = 8) and 13 age and sex-matched controls underwent DTI of vertebral BM. Mean diffusivity (MD) and fractional anisotropy (FA) of vertebral BM was calculated and correlated with genotyping, chitotriosidase, hemoglobin (HB) and, platelet count.

RESULTS

There was a statistically significant difference in MD and FA of BM between patients and controls (P = 0.001 and 0.02). The area under the curve (AUC) of MD and FA used to differentiate untreated patients from controls was 0.902 and 0.68 with sensitivity, specificity, and, accuracy 92%, 84.6%, and, 89.5% respectively. There was a significant difference in MD and FA of BM between untreated and treated patients (P = 0.001 and 0.02). AUC of MD and FA used to differentiate untreated from treated patients was 0.93 and 0.649 with sensitivity, specificity, and accuracy of 92%, 80%, and 86% respectively. There was a significant difference in MD and FA (P = 0.03, 0.001 respectively) of BM in GD with homozygous L444P mutation (n = 9) and other mutations (n = 14). Chiotriptase, HB and platelet count of patients was correlated with MD (r = -0.36, 0.42, -0.41) and FA (r = -0.47, -0.37, -0.46) respectively.

CONCLUSION

DTI of vertebral BM can help in diagnosis and monitoring patients with GD after therapy and correlated with genotyping, and hematological biomarkers of GD.

Olfactory bulb volume in patients with normal-pressure hydrocephalus: an MRI evaluation

AIM

To investigate changes in olfactory bulb (OB) volume in patients with idiopathic normal-pressure hydrocephalus (NPH).

MATERIALS AND METHODS

This multicentric retrospective study included a test group of 23 patients with NPH (10 male and 13 female patients) and a control group of 27 healthy participants without hydrocephalus. The OB volume in all participants had been measured using cranial magnetic resonance imaging (MRI). In the NPH group, positivity for disproportionately enlarged subarachnoid space hydrocephalus (DESH) was also evaluated.

RESULTS

The OB volumes of the NPH group (R 38.29 ± 9.34 mm³ and L37.52 ± 9.59 mm³) were significantly lower than those of the control group (R 45.87 ± 7.33 mm³ and L48.41 ± 7.62 mm³) bilaterally. There were no significant differences between right and left OB volumes in the NPH group. Nine of the 23 patients were DESH positive and 14 were DESH negative. There were no significant differences between OB volumes of the DESH positive and DESH vpatients in the NPH group. In both groups, there was a positive correlation between right and left OB volumes. There were no significant correlations between OB volumes and age or gender. In the NPH group, there were no significant correlations between DESH positivity and OB volumes.

CONCLUSION

OB volume decrease and olfactory problems should be taken into account in idiopathic NPH patients. When expanded ventricles and decreased OB volume are observed at cranial MRI, a diagnosis of idiopathic NPH should be considered.

Combined accuracy of optic nerve sheath diameter, strain ratio, and shear wave elastography of the optic nerve in patients with idiopathic intracranial hypertension

PURPOSE

This study assessed the combined accuracy of optic nerve sheath diameter (ONSD), strain ratio (SR), and shear wave elastography (SWE) of the optic nerve (ON) in patients with idiopathic intracranial hypertension (IIH).

METHODS

This prospective study was carried out on both ONs of 34 consecutive patients diagnosed with IIH and 16 age- and sex-matched healthy volunteers. All of the study participants were women. The ONSD, SR, and SWE of the ON were measured. The severity of papilledema of IIH patients was sub-classified into mild papilledema and moderate/severe papilledema.

RESULTS

The mean ONSD (5.6±1.1 mm), SR (0.7±0.1), and SWE (30.1±16.7 kPa) of the IIH patients were significantly different (P=0.001) from the ONSD (4.1±0.5 mm), SR (0.9±0.1), and SWE (8.2±3.4 kPa) of controls. The cutoff values of ONSD, SR, and SWE of the ON for differentiating IIH patients from controls were 5.45 mm, 0.8, and 10.3 kPa with areas under the curve (AUCs) of 0.91, 0.86, and 0.96 and accuracy values of 91%, 81%, and 93%, respectively. Combined SWE and ONSD and combined SWE, ONSD, and SR for differentiating IIH patients from controls revealed AUCs of 0.98 and 0.99 and accuracy values of 96% and 96%, respectively. ONSD, SR, and SWE showed significant differences between mild and moderate/severe papilledema (P=0.001). Papilledema was correlated with SWE (r=0.8, P=0.001), ONSD (r=0.4, P=0.001), and SR (r=-0.4, P=0.001).

CONCLUSION

The combination of ONSD, SR, and SWE may be helpful for diagnosing IIH, and a good indicator of the degree of papilledema.

Assessment of diffusion tensor imaging in differentiation between pyogenic and tuberculous spondylitis

PURPOSE

to assess diffusion tensor imaging (DTI); an emerging technique for differentiation between pyogenic and tuberculous spondylitis.

PATIENTS AND METHODS

The study was carried out on 33 patients with infective spondylitis performing conventional MRI and DTI. The mean diffusivity (MD) and fractional anisotropy (FA) of the affected vertebral body were calculated by two readers.

RESULTS

The MD of pyogenic spondylitis of both readers (1.48 ± 0.09 and 1.47 ± 0.08 × 10^-3 mm²/s) were significantly higher values (P = 0.001) than tuberculous spondylitis (1.11 ± 0.15 and 1.18 ± 0.08 × 10^-3 mm²/s). The FA of pyogenic spondylitis of both readers (0.18 ± 0.09 and 0.20 ± 0.08) were significantly lower values (P = 0.001) than tuberculous spondylitis (0.30 ± 0.05 and 0.32 ± 0.03). There was a strong inter-reader agreement between both readers using MD (K = 0.963) and FA (K = 0.858). The thresholds MD and FA used for differentiating pyogenic and tuberculous spondylitis of both readers were 1.37 and 1.33 × 10^-3 mm²/s and 0.21 and 0.25 with the area under the curve (AUC) of 0.927 and 0.831 respectively. Combined MD and FA revealed increased AUC to 0.97 and 0.98 of both readers respectively.

CONCLUSION

DTI with its parameters can be considered a noninvasive beneficial quantitative method that can help in differentiation between pyogenic and tuberculous spondylitis.

Imaging of vascular cognitive impairment

Vascular cognitive impairment (VCI) is a major health challenge and represents the second most common cause of dementia. We review the updated imaging classification and imaging findings of different subtypes of VCI. We will focus on the magnetic resonance imaging (MRI) markers of each subtype and highlight the role of advanced MR imaging sequences in the evaluation of these patients. Small vessel dementia appears as white matter hyperintensity, lacunae, microinfarcts, and microbleeds. Large vessel dementia includes strategic infarction and multi-infarction dementias. Hypoperfusion dementia can be seen as watershed infarcts and cortical laminar necrosis. Hemorrhagic dementia results from cerebral amyloid angiopathy and cortical superficial siderosis. Hereditary forms of VCI, caused by gene mutations such as CADASIL, should be suspected when dementia presents in young patients. Mixed dementia is seen in patients with Alzheimer's disease and the coexistence of cerebrovascular disease.

Imaging of congenital cranial dysinnervation disorders: What radiologist wants to know?

We aim to review the imaging features of congenital cranial dysinnervation disorders. Characteristic imaging findings can define subtypes of these disorders through assessment of cranial nerves, extraocular muscles, orbital, and brain abnormalities. Duane retraction syndrome shows absent or hypoplasic 6th cranial nerve and preserved extraocular muscles (EOM). Mobius syndrome shows absent 7th and 6th cranial nerves, absence of facial colliculus, flattening of the dorsal aspect of the pons, hypoplasia of the pons and medulla, and flattening of the 4th ventricular floor. Congenital fibrosis of the extraocular muscles reveals unilateral or bilateral hypoplasia or aplasia of the 3rd cranial nerve, atrophy of superior rectus and levator palpebrae superioris muscles, and atrophy of the brainstem and cerebellar hemispheres. Horizontal gaze palsy and progressive scoliosis show characteristic split pons sign, butterfly medulla, absent facial colliculi, and spinal scoliosis. HOXA1 Mutations show a bilateral absence of 6th cranial nerves with the underdeveloped inner ear. Pontine Cap Tegmental Dysplasia shows ventral pontine hypoplasia, dorsal tegmental projection into the 4th ventricle, and variable cranial nerve deficits.

Optic disc drusen: a systematic review : Up-to-date and future perspective

BACKGROUND

Optic disc drusen (ODD) are acellular deposits in the prelaminar optic nerve head. The most accredited theory is that they are secondary to abnormalities in axonal metabolism and degeneration, but the pathogenesis is not clear to date.

CLINICAL MANIFESTATION

Although ODD are often considered a benign condition, the great majority of patients with ODD show visual field defects and are at higher risk for developing anterior ischemic optic neuropathy. ODD are classified as superficial or buried, with the latter being often misdiagnosed as papilledema with optic nerve head swelling, leading to an unnecessary investigation for causes of increased intracranial pressure.

AIM

The recent technological improvements in OCT imaging which allowed an earlier and more certain diagnosis even of the smallest ODD, renovated the interest around this pathology. However, an updated systematic review is still missing. Therefore, the aim of this work is to provide a concise yet comprehensive overview of the current state of art, focusing on pathophysiology, clinical presentation, diagnostic methods, treatment modalities and potential future perspectives of this condition.

Pathogenesis and Evaluation of the Effects of Idiopathic Intracranial Hypertension on the Optic Nerves

Idiopathic intracranial hypertension (IIH) is a clinical syndrome of raised intracranial pressure of unknown aetiology. Although papilloedema and visual alterations are among the most important manifestations of the disease, their pathophysiological mechanisms are not fully understood. We aim to review the up-to-date evidence regarding how the optic nerves are affected, the possible pathophysiology and the methods of their assessment.

An Update on Imaging in Idiopathic Intracranial Hypertension

Neuroimaging plays an essential role in the diagnostic workup of idiopathic intracranial hypertension with the aims to exclude secondary causes of elevated intracranial pressure and to identify imaging signs that are commonly observed in this disorder. As a valuable expansion of brain imaging, the imaging of the retina using optical coherence tomography has been of increasing value. In particular, this is the case with the latest devices that allow a more accurate distinction between a reduction in retinal nerve fiber layer thickness due to an improvement of papilledema or due to a worsening caused by optic nerve atrophy. Although optical coherence tomography does not yet replace the other elements of the diagnostic workup, it is likely to play an increasing role in diagnosis and follow-up of idiopathic intracranial hypertension. The review focuses on the main findings in neuroimaging, including structural and vascular alterations as well as on the relevance of optical coherence tomography.

Diffusion Tensor Imaging of Microstructural Changes in the Gray and White Matter in Patients With Crigler-Najjar Syndrome Type I

PURPOSE

This study aimed to evaluate the role of diffusion tensor imaging of microstructural changes in gray and white matter in Crigler-Najjar syndrome type I.

PATIENT AND METHODS

A prospective study was conducted on 10 patients with Crigler-Najjar syndrome type I and 10 age- and sex-matched children who underwent diffusion tensor imaging of the brain. Mean diffusivity (MD) and fractional anisotropy (FA) of gray and white matter were measured.

RESULTS

There was a significantly higher MD of the gray matter regions including the globus pallidus, thalamus, caudate head, substantia nigra, and dentate nucleus in patients versus controls (P = 0.007, 0.001, 0.014, 0.003, and 0.002), respectively. The areas under the curve (AUC) of MD of the globus pallidus and thalamus used to differentiate patients from controls were 0.93 and 0.925, respectively. There was a significant difference in MD of the frontal white matter and posterior limb of the internal capsule in patients versus controls (P = 0.001 and 0.02), respectively. The AUCs of MD of these regions used to differentiate patients from controls were 0.82 and 0.8. There was a significant difference in FA of the frontal white matter and posterior limb of the internal capsule in patients versus controls (P = 0.006 and 0.006), respectively. The AUCs of FA of these regions were 0.83 and 0.85, respectively. The MD of the globus pallidus correlated with serum bilirubin (r = 0.87 and P = 0.001).

CONCLUSION

Diffusion tensor imaging can detect microstructural changes of deep gray matter and some regions of white matter in Crigler-Najjar syndrome type I.

Assessment of the optic nerve using strain and shear-wave elastography in patients with pseudotumour cerebri

AIM

To evaluate the optic nerve using strain elastography (SE) and shear-wave elastography (SWE) in idiopathic intracranial hypertension (IIH) patients in comparison to participants in the control group.

MATERIALS AND METHODS

Eighty eyes were evaluated in 40 cases consisting of 20 IIH patients and 20 participants in the control group. This study was conducted using SE and SWE in addition optic nerve sonography measurements of participants in the IIH patient group and the control group. SE patterns were categorised using three main types and two subtypes. Quantitative measurements of optic nerve stiffness with SWE were expressed in kilopascals.

RESULTS

In the IIH patient group, type 2 and type 1 elasticity patterns were primarily observed, followed by type 3 patterns. In the control group, type 3 elasticity patterns were most often observed, while type 2 elasticity patterns were seen less frequently. Statistically significance differences in the types of elasticity strain patterns were observed between the groups (p<0.01). Quantitative analysis was also performed, and the SWE moduli were obtained for the control group (10.1±0.28 kPa) and the IIH patient group (26.97±1 kPa). A statistically significant difference in the SWE modulus was found between the groups (p<0.01).

CONCLUSION

Biomechanical changes may have occurred in the optic nerve secondary to increased intracranial pressure in IIH patients. Strain and shear elastography may have potential as assistive diagnostic techniques for the detection and follow-up of these changes.

Imaging of Fulminant Demyelinating Disorders of the Central Nervous System

We aim to review the imaging appearance of fulminant demyelinating disorders of central nervous system that have different pathological features, clinical course, clinical features, and imaging findings different from classic multiple sclerosis. Routine magnetic resonance imaging (MRI) can help in accurate localization of the lesions, detection of associated lesions, and monitoring of these patients. Advanced MRI combined with routine MRI can aid in differentiation fulminant demyelinating lesions from simulating malignancy. Tumefactive demyelination lesions are located in supratentorial white matter mainly frontal and parietal regions with incomplete rim enhancement. Baló concentric sclerosis shows characteristic concentric onion skin appearance. Schilder disease is subacute or acute demyelinating disorders with one or more lesions commonly involving the centrum semiovale. Marburg disease is the most severe demyelinating disorder with diffuse infiltrative lesions and massive edema involving both the cerebral hemisphere and brain stem.

Visual evoked potentials follow-up in idiopathic intracranial hypertension

OBJECTIVE

To demonstrate the importance of visual evoked potential (VEP) in determining the severity and prognosis of the disease and in monitoring the clinical course in patients with idiopathic intracranial hypertension (IIH).

METHODS

This is a prospective cross-sectional study conducted covering the period between March 2014 and January 2015. The study included 32 patients recently diagnosed with IIH and 30 healthy volunteers. The initial VEP values of the IIH patients were compared to the VEP values of the healthy control group. Furthermore, the initial VEP values of the IIH patients were compared with their VEP values after one month of treatme RESULTS: The mean age of the IIH patients was 37.8+/-12.02 years. Of the IIH patients, 27 (84%) were females and 5 (16%) were males. There was a statistically significant association of the initial VEP values with the visual field findings (p=0.011) and visual acuity (p=0.040). Moreover, a statistically significant difference was found between the control group and IIH patients in terms of right (p less than 0.001) and left P100 values (p less than 0.001). While 18 (56%) of the initial VEPs of IIH patients were pathological, 14 (44%) of the second VEPs were pathological, and this difference was not statistically significant (p=0.125).

CONCLUSION

A relationship between the VEP P100 values and the severity of the disease was detected, while the importance of monitoring VEP values in the follow-up of IIH patients was not demonstrated.

Differences in Corticoreticulospinal Tract Injuries According to Whiplash in Mild Traumatic Brain Injury Patients

Background: This study investigated differences in postural control ability (PCA) and corticoreticulospinal tract (CRT) injury severity according to whiplash in patients with mild traumatic brain injury (mTBI).

Methods: Thirty-one patients with mTBI and 21 healthy control subjects were recruited for this study. The balance error scoring system (BESS) was used for PCA assessment. Based on their whiplash history, the patients were classified into two groups: group A—mTBI with whiplash injury; group B—mTBI without whiplash injury. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and tract volume (TV) values were estimated for the reconstructed CRTs in all subjects.

Results: Significant differences were observed among the total BESS scores of patient groups A and B and the control group (p < 0.05). The patient group A BESS score was significantly higher than that of patient group B, and that of the patient group B was significantly higher than that of the control group. No significant differences were detected among the FA and ADC values of the CRTs of the two patient groups and the control group (p > 0.05). However, the TV values of the CRT did reveal significant differences; the TV of patient group A was significantly lower than those of patient group B and the control group, and that of patient group B was significantly lower than that of the control group (p < 0.05).

Conclusions: We observed greater CRT injury severity and PCA impairment in mTBI patients with whiplash than in mTBI patients without whiplash. The results indicate that whiplash might lead to a greater level of severity in axonal injuries in mTBI patients.

Review of familial hemiplegic migraine, successful outcome in a pregnant patient

As the field of neurogenetics is expanding rapidly and variant classification criteria evolve, genetic variants in databases are re-evaluated overtime allowing updated classifications of pathogenicity predication. When caring for patients with genetic disorders, it is important to obtain the original genetic report and also consider an updated reanalysis.

Clinico-radiological correlation of magnetic resonance imaging findings in patients with idiopathic intracranial hypertension

PURPOSE

Although several studies have reported imaging findings associated with idiopathic intracranial hypertension (IIH), less is known about the correlation between imaging findings and IIH-related symptoms or signs. Our study aimed to determine if clinical features of IIH are correlated with magnetic resonance imaging (MRI) features.

METHODS

A retrospective chart review was conducted on consecutive patients presenting at the neuro-ophthalmology department over the last 15 years. All patients diagnosed with IIH were identified and those with available MRI were included in the final analysis. All MRI images were reviewed by a neuroradiologist blinded to the presenting symptoms and signs. Statistical analysis was performed to determine the correlation between the MRI findings with each clinical symptom or sign.

RESULTS

Thirty-one out of 88 patients with the initial diagnosis of IIH had MRI available and were included in the study. Significant correlations were observed between colour vision and amount of perineural fluid around the optic nerve on MRI (r = - 0.382; p = 0.004), disc assessment and intraocular optic nerve protrusion (r = 0.364; p = 0.004), disc assessment and perineural fluid around the optic nerve (r = 0.276; p = 0.033) and disc assessment and venous sinus stenosis (r = 0.351; p = 0.009).

CONCLUSION

Our study highlights correlations between imaging and clinical findings of IIH. MRI findings in IIH may be useful in ruling out ominous causes of intracranial pressure and risk stratifying ophthalmologic intervention and management of patients with headaches possibly due to IIH.

The benefits of radiological imaging for postoperative orthostatic headache: a case report

Background

Traditionally, the diagnosis of post-dural puncture headache (PDPH) relied upon the patient’s history regarding dural puncture and symptoms, such as orthostatic headache. However, such evidence may not always be reliable or specific. We report an unexpected diagnosis with spontaneous intracranial hypotension (SIH), which was confirmed upon examination of Magnetic Resonance (MR) images in a patient who was initially suspected to have PDPH because he had recently undergone a uncertain dural puncture.

Case presentation

A 45-year-old man had undergone a thoracic epidural catheter insertion for perioperative analgesia prior to general anesthesia induction. Due to intermittent dripping of fluid while the epidural needle was being advanced, a dural puncture was suspected. The patient complained of an orthostatic headache after recovery from surgery, therefore a PDPH was suspected. MR images revealed signs of SIH: dural sinus engorgement, contrast enhancement along the neural sleeves of the left C6–7, bilateral C7-T1, T1–2, T2–3, T3–4, T4–5, and T5–6. Computed tomography-guided epidural blood patching (EBP) was performed the following day, with the patient experiencing immediate relief of the headache.

Conclusion

The benefits of radiological imaging in this case included confirming the correct diagnosis, guiding the accurate level and proper approach of EBP, distinguishing the epidural space from the intrathecal space, and ultimately increasing the likelihood of successful EBP.

Diffusion tensor imaging parameters in differentiation recurrent breast cancer from post-operative changes in patients with breast-conserving surgery

AIM OF THE WORK

To investigate mean diffusivity (MD) and fractional anisotropy (FA) measured by diffusion tensor imaging (DTI) as complementary tools to differentiate recurrent breast cancer from post-operative changes in patients with breast-conserving surgery (BCS).

PATIENTS AND METHODS

Prospective study was conducted upon 30 patients with BCS that underwent DTI and dynamic contrast MR imaging. DTI was performed using an axial two-dimensional spin-echo echo-planar imaging sequence. The MD and FA of the lesions were calculated by 2 observers. A single pixel seed isotropic region of interest was placed in the solid part of the tumor on the axial color FA map guided by an enhanced part of the tumor. The final diagnosis was done by biopsy for all patients.

RESULTS

/s) used for differentiation between entities revealed sensitivity (76.9%, 92.3%), specificity (82.4%, 64.7%) and accuracy (80%, 76.7%) of both observers respectively. At ROC curve analysis of FA, the AUC was 0.82 and 0.75 by both observers. The threshold FA (0.82, 0.75) was used for differentiation between entities revealed sensitivity (92.3%, 76.9%), specificity (70.6%, 70.6%) and accuracy of (80.0%, 73.3%) of both observers respectively. There was a strong positive correlation of MD (r = 0.86) and FA (r = 0.73) of both observers. Combined analysis of FA and MD used for differentiation between entities had AUC (0.90, 0.88) revealed sensitivity (92.3%, 92.3%), specificity (82.4%, 70.6%) and accuracy of (86.7%, 80.0%) for both observers respectively.

CONCLUSIONS

Combined analysis of MD and FA of DTI may play an important role as a non-invasive method for differentiation recurrent breast cancer from post-operative changes in patients with BCS.

Differentiation of Primary Central Nervous System Lymphoma From Glioblastoma: Quantitative Analysis Using Arterial Spin Labeling and Diffusion Tensor Imaging

OBJECTIVE

Differentiation of primary central nervous system lymphoma (PCNSL) from glioblastoma using arterial spin labeling perfusion and diffusion tensor imaging (DTI).

METHODS

We performed a prospective study of 31 patients with a provisional diagnosis of PCNSL and glioblastoma who underwent conventional magnetic resonance imaging, DTI, and arterial spin labeling of the brain. The tumor blood flow (TBF), mean diffusivity (MD) plus fractional anisotropy (FA) of the mass were measured. The final diagnosis was confirmed by pathological examination.

RESULTS

The TBF of PCNSL (26.41 ± 4.03 mL/100 g/minute) was significantly lower than that of glioblastoma (51.08 ± 3.9 mL/100 g/minute; P = 0.001). The TBF cutoff (35.73 mL/100 g/minute) used for differentiation showed area under the curve (AUC) of 0.93, accuracy of 95.2%, sensitivity of 91.7%, and specificity of 100%. The MD of PCNSL (0.87 ± 0.2X 10^-3 mm²/second) was significantly lower than that of glioblastoma (0.87 ± 0.2 × 10^-3 mm²/second; P = 0.01). The MD cutoff (0.935 × 10^-3 mm²/second) used for differentiation showed an AUC of 0.73 and accuracy of 66.7% and a sensitivity of 75% and specificity of 55.6%. The FA of PCNSL (0.253 ± 0.05) was significantly greater than that of glioblastoma (0.135 ± 0.06; P = 0.001). The FA cutoff (0.185) used for differentiation revealed an AUC of 0.944 and accuracy of 85.7% and a sensitivity of 83.3% and specificity of 88.9%. The combined TBF, MD, and FA cutoffs revealed an AUC of 0.96 and accuracy of 95.5% and a sensitivity of 83.3% and specificity of 100%.

CONCLUSION

The noninvasive imaging parameters using TBF and DTI might help in differentiating PCNSL from glioblastoma.

Apparent diffusion coefficient as an effective index for the therapeutic efficiency of brain chemoradiotherapy for brain metastases from lung cancer

BACKGROUND

The potential of apparent diffusion coefficient (ADC) value alteration before and after chemoradiotherapy as a potential monitor for therapeutic efficiency of treatment for brain metastases from lung cancer were discussed.

METHOD

Thirty lung cancer patients with brain metastases, conventional magnetic resonance imaging (MRI) examination and diffusion weighted imaging (DWI) were performed one week before chemoradiotherapy and after one treatment cycle and two treatment cycles. 43 tumor lesions were divided into effective group and invalid group according to the changes of the tumor size. The differences in ADC values at different time points before and after treatment in each treatment group were analyzed.

RESULT

The maximum diameter of the tumor was no difference after one treatment cycle, but decreased after two treatment cycles. ADC values significantly increased after both one and two treatment cycles. In effective group, the ADC values were significantly increased after one and two treatment cycles. While, there are no difference in invalid group after one treatment cycle but decreased after two treatment cycles. ΔADC values in effective group after one and two treatment cycles were both significantly higher than those in the invalid group. ROC curve analysis then revealed that the area under the curve (AUC) of ΔADC after one treatment was 0.872.

CONCLUSION

ADC values in brain metastases from lung cancer can help monitor and dynamically observe the therapeutic efficiency of whole brain chemoradiotherapy.