1. |
- Agerskov, Simon, et al.
(author)
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Absence of Disproportionately Enlarged Subarachnoid Space Hydrocephalus, a Sharp Callosal Angle, or Other Morphologic MRI Markers Should Not Be Used to Exclude Patients with Idiopathic Normal Pressure Hydrocephalus from Shunt Surgery
- 2019
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In: American Journal of Neuroradiology. - 0195-6108. ; 40:1, s. 74-79
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: Several studies have evaluated the use of MR imaging markers for the prediction of outcome after shunt surgery in idiopathic normal pressure hydrocephalus with conflicting results. Our aim was to investigate the predictive value of a number of earlier proposed morphologic MR imaging markers in a large group of patients with idiopathic normal pressure hydrocephalus. MATERIALS AND METHODS: One hundred sixty-eight patients (mean age, 70 +/- 9.3 years) with idiopathic normal pressure hydrocephalus, subjected to standardized quantification of clinical symptoms before and after shunt surgery, were included in the study. Outcome was calculated using a composite score. Preoperative T1, FLAIR, and flow-sensitive images were analyzed regarding the presence of 13 different morphologic MR imaging markers. RESULTS: The median Evans index was 0.41 (interquartile range, 0.37-0.44). All patients had an aqueductal flow void sign present and white matter hyperintensities. The median callosal angle was 68.8 degrees (interquartile range, 57.7 degrees-80.8 degrees). Dilated Sylvian fissures were found in 69%; focally dilated sulci, in 25%; and widening of the interhemispheric fissure, in 55%. Obliteration of the sulci at the convexity was found in 36%, and 36% of patients were characterized as having disproportionately enlarged subarachnoid space hydrocephalus. Sixty-eight percent of patients improved after surgery. None of the investigated MR imaging markers were significant predictors of improvement after shunt surgery. CONCLUSIONS: Disproportionately enlarged subarachnoid space hydrocephalus, a small callosal angle, and the other MR imaging markers evaluated in this study should not be used to exclude patients from shunt surgery. These markers, though they may be indicative of idiopathic normal pressure hydrocephalus, do not seem to be a part of the mechanisms connected to the reversibility of the syndrome.
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2. |
- Agerskov, Simon, et al.
(author)
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MRI diffusion and perfusion alterations in the mesencephalon and pons as markers of disease and symptom reversibility in idiopathic normal pressure hydrocephalus
- 2020
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In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:10
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Journal article (peer-reviewed)abstract
- Introduction Core symptomatology in idiopathic normal pressure hydrocephalus (iNPH) points at dysfunction in the mesencephalon and pons indicating pathological changes in these regions, but only a few studies have addressed the issue. The aim of this study was to investigate diffusion (ADC) and perfusion patterns pre- and postoperatively in these areas in iNPH. Methods Twenty iNPH patients and 15 healthy controls were included. Patients underwent a clinical examination and brain MRI pre- and 3-6 months postoperatively. The MRI-scan included diffusion and dynamic susceptibility contrast perfusion weighted sequences. Regions of interest in the mesencephalon and pons were drawn on a FLAIR sequence and co-registered to ADC maps and perfusion data. Results There were no significant differences in pre or postoperative ADC compared to the control group, however postoperative ADC increased by 10% (p = 0.026) in the mesencephalon and 6% (p = 0.016) in the pons in all patients and also in the subgroup of shunt responders by 11% (p = 0.021) and 4% (p = 0.020), respectively. Preoperative relative cerebral blood flow (rCBF) was similar in iNPH patients and controls. Postoperatively, rCBF increased in shunt responders by 6% (p = 0.02) in the mesencephalon and 11% (p = 0.004) in the pons. This increase correlated with the degree of clinical improvement (r(s)= 0.80, p = 0.031 and r(s)= 0.66, p = 0.021, respectively). Conclusion The postoperative increase in ADC and the correlation between postoperative increase in rCBF and clinical improvement in the mesencephalon and pons shown in this study point at an involvement of these areas in the core pathophysiology and its reversibility in iNPH.
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3. |
- Anckarsäter, Henrik, 1966, et al.
(author)
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Persistent regional frontotemporal hypoactivity in violent offenders at follow-up.
- 2007
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In: Psychiatry research. - : Elsevier BV. - 0165-1781 .- 0925-4927 .- 1872-7123. ; 156:1, s. 87-90
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Journal article (peer-reviewed)abstract
- Since cross-sectional brain-imaging studies demonstrating frontotemporal cerebral hypoactivity in violent offenders have generally been carried out around the time of trial and sentencing, the findings might be influenced by the stressful situation of the subjects. It seems that no group of offenders with this finding has yet been followed longitudinally. We have re-examined nine offenders convicted of lethal or near-lethal violence in whom single photon emission tomography (SPECT) previously had demonstrated frontotemporal hypoperfusion. The mean interval between the initial and the follow-up examination was 4 years. The initially observed hypoactivity was found to have remained virtually unchanged at follow-up: no mean change in the group exceeded 5% in 12 assessed regions of interest. Although preliminary due to the small sample size, this study suggests that frontotemporal brain hypoactivity is a trait rather than a state in perpetrators of severe violent crimes.
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4. |
- Arvidsson, Jonathan, et al.
(author)
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Effects of bolus injection duration on perfusion estimates in dynamic CT and dynamic susceptibility contrast MRI
- 2023
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In: Magnetic Resonance Materials in Physics, Biology and Medicine. - : Springer Science and Business Media LLC. - 0968-5243 .- 1352-8661. ; 36:1, s. 95-106
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Journal article (peer-reviewed)abstract
- Estimates of cerebral blood flow (CBF) and tissue mean transit time (MTT) have been shown to differ between dynamic CT perfusion (CTP) and dynamic susceptibility contrast MRI (DSC-MRI). This study investigates whether these discrepancies regarding CBF and MTT between CTP and DSC-MRI can be attributed to the different injection durations of these techniques. Five subjects were scanned using CTP and DSC-MRI. Region-wise estimates of CBF, MTT, and cerebral blood volume (CBV) were derived based on oscillatory index regularized singular value decomposition. A parametric model that reproduced the shape of measured time curves and characteristics of resulting perfusion parameter estimates was developed and used to simulate data with injection durations typical for CTP and DSC-MRI for a clinically relevant set of perfusion scenarios and noise levels. In simulations, estimates of CBF/MTT showed larger negative/positive bias and increasing variability for CTP when compared to DSC-MRI, especially for high CBF levels. While noise also affected estimates, at clinically relevant levels, the injection duration effect was larger. There are several methodological differences between CTP and DSC-MRI. The results of this study suggest that the injection duration is among those that can explain differences in estimates of CBF and MTT between these bolus tracking techniques.
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5. |
- Constantinescu, Clara, 1995, et al.
(author)
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Prevalence of Possible Idiopathic Normal Pressure Hydrocephalus in Sweden: A Population-Based MRI Study in 791 70-Year-Old Participants.
- 2024
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In: Neurology. - 1526-632X. ; 102:2
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Journal article (peer-reviewed)abstract
- Very divergent prevalence rates for idiopathic normal pressure hydrocephalus (iNPH) are reported, probably due to differences in study sample selection and diagnostic criteria. This MRI-based study aimed to determine the prevalence of iNPH and iNPH-specific radiologic changes and their association with clinical symptoms in a large, 70-year-old population-based cohort (Gothenburg H70).In this cross-sectional study, disturbances in gait and balance, cognition, and urinary continence were assessed using clinical examination and self-report. MRI was evaluated for iNPH-specific imaging markers. iNPH was diagnosed according to International Guidelines (I.G.). Based on radiologic findings, participants were allocated to 1 of 4 groups: (A) Evans index (EI) ≤0.3 (reference), (B) EI >0.3 without other iNPH-typical radiologic findings, (C) radiologically probable iNPH according to I.G., and (D) radiologically holistically probable (h-probable) iNPH fulfilling radiologic criteria according to I.G. plus highly iNPH-specific changes according to an experienced neuroradiologist.The Gothenburg H70 Studies include 791 individuals (377 men, 414 women) born in 1944 who underwent brain MRI. The prevalence of iNPH was 1.5% (2.1% for men, 0.96% for women) according to I.G. Ninety participants (11%) had EI >0.3 without other iNPH-typical radiologic findings, 29 (3.7%) fulfilled the I.G. radiologic probable iNPH criteria alone, and 11 (1.4%) were classified as radiologically h-probable iNPH. Forty participants (5.1%) had I.G. radiologic features of iNPH (70% men vs 30% women, p = 0.005). Gait disturbances were more common in participants with EI >0.3 without other radiologic iNPH features (B) (33%) compared with the reference group (A) (19%) (p = 0.006). All clinical symptoms were more common in participants with I.G. radiologic features of iNPH (C + D) than they were in the reference group (A) (p < 0.03).The iNPH prevalence of 1.5% among 70-year-olds, which is considerably higher than earlier reported in this age group, suggests that iNPH may be more common than previously assumed. This is supported by the 5.1% total prevalence of imaging signs of iNPH. Ventriculomegaly without other iNPH-typical radiologic findings may be an early sign of developing iNPH in some patients.
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6. |
- Edsbagge, Mikael, et al.
(author)
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Spinal cerebrospinal fluid volume in healthy elderly individuals.
- 2011
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In: Clinical anatomy (New York, N.Y.). - : Wiley. - 1098-2353 .- 0897-3806. ; 24:6, s. 733-40
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Journal article (peer-reviewed)abstract
- The amount of spinal cerebrospinal fluid (CSF) could be of importance for the understanding of CSF dynamics, CSF biomarker analyses as well as for the amount and effect of anaesthesia using intrathecally administered drugs. However, knowledge of spinal CSF volumes is scarce. The main purpose of this article is to present data on spinal CSF volumes. In total, 22 healthy individuals aged between 64 and 76 years underwent MR imaging with a 3D balanced turbo field echo pulse sequence, which provided high contrast between spinal cord, CSF and the extradural surroundings. The entire spinal CSF volume, the cervical, thoracic, and lumbosacral CSF volumes and the spinal cord volume were calculated. The total spinal CSF volume was 81 ± 13 ml (range 52-103 ml). The amount of CSF in the cervical region was 19 ± 4 ml, in the thoracic region 38 ± 8 and in the lumbosacral region 25 ± 7 ml. There was no difference between genders nor was there any correlation with height. The volume of the spinal cord was 20 ± 3 ml. The results present new magnetic resonance imaging-based data on the spinal CSF volume in healthy elderly individuals. Clin. Anat. 24:733-740, 2011. © 2011 Wiley-Liss, Inc.
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7. |
- Farahmand, Dan, et al.
(author)
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Endoscopic versus open microsurgery for colloid cysts of the third ventricle
- 2023
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In: British Journal of Neurosurgery. - : Informa UK Limited. - 0268-8697 .- 1360-046X. ; 37:1, s. 59-62
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Journal article (peer-reviewed)abstract
- Purpose The surgical approach for colloid cysts of the third ventricle mainly consists of endoscopic or microscopic approach but few studies compare the neurologic outcomes and complications related to the different approaches. We retrospectively reviewed our results after resection of colloid cysts of the third ventricle using endoscopic surgery (ES) compared to open microsurgery (OS). Methods Fifty-one patients were included in the study of which 17 patients underwent ES. Colloid cyst size and Evans' index were evaluated on CT or MRI scans. Presenting symptoms, neurologic outcomes and complications were compared between the two groups and analysed using Fisher's exact test. Operative time and days of hospital stay were compared between the two groups, using independent sample t-test. The median follow-up time was 96 days and did not differ significantly between the groups. Results Shorter mean operative time (p = 0.04) and fewer days of hospital stay (p < 0.01) were found in the endoscopic group compared to the open microsurgical group. Presenting symptoms, neurological outcomes and postoperative complications were similar in the two groups. Conclusions ES showed similar neurologic outcomes and complications compared to OS for colloid cysts of the third ventricle. ES showed significantly shorter operative times and hospital stays compared to OS.
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8. |
- Lindberg, K., et al.
(author)
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Three-Dimensional Volumetric Segmentation of Pituitary Tumors: Assessment of Inter-rater Agreement and Comparison with Conventional Geometric Equations
- 2018
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In: Journal of Neurological Surgery Part B-Skull Base. - : Georg Thieme Verlag KG. - 2193-6331 .- 2193-634X. ; 79:5, s. 475-481
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Journal article (peer-reviewed)abstract
- Background The assessment of pituitary tumor (PT) volume is important in the treatment and follow-up of patients with PT. Previously, PT volume estimation has been performed by conventional geometric equations (CGE) such as abc/2 (simplified ellipsoid volume equation) and 4 pi r(3)/3 (sphere), both presuming a symmetric tumor shape, which occurs uncommonly in patients with PT. In contrast, three-dimensional (3D) voxel-based software segmentation takes the irregular and asymmetric shapes that PTs often possess into account and might be a more accurate method for PT volume segmentation. The purpose of this study is twofold. (1) To compare 3D segmentation with CGE for PT volume estimation. (2) To assess inter-rater reliability in 3D segmentation of PTs. Methods Nineteen high-resolution (1mm slice thickness) T1-weighted MRI examinations of patients with PT were independently analyzed and manually segmented, using the software ITK-SNAP, by two certified neuroradiologists. Concurrently, the volumes of the PTs were estimated with abc/2 and 4 pi r(3)/3 by a clinician, and the results were compared with the corresponding segmented volumes. Results There was a significant decrease in PT volume attained from the segmentations compared with the calculations made with abc/2 (p < 0.001, mean volume 18% higher than segmentation) and 4 pi r(3)/3 (p < 0.001, mean volume 28% higher than segmentation). The intraclass correlation coefficient (ICC) for the two sets of segmented PTs was 0.99. Conclusion CGE (abc/2 and 4 pi r(3)/3) significantly overestimates PT volume compared with 3D volumetric segmentation. The inter-rater agreement on manual 3D volumetric software segmentation is excellent.
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9. |
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10. |
- Molinder, Anna, et al.
(author)
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Validity and reliability of the medial temporal lobe atrophy scale in a memory clinic population
- 2021
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In: BMC Neurology. - : Springer Science and Business Media LLC. - 1471-2377. ; 21:1
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Journal article (peer-reviewed)abstract
- Background Visual rating of medial temporal lobe atrophy (MTA) is often performed in conjunction with dementia workup. Most prior studies involved patients with known or probable Alzheimer's disease (AD). This study investigated the validity and reliability of MTA in a memory clinic population. Methods MTA was rated in 752 MRI examinations, of which 105 were performed in cognitively healthy participants (CH), 184 in participants with subjective cognitive impairment, 249 in subjects with mild cognitive impairment, and 214 in patients with dementia, including AD, subcortical vascular dementia and mixed dementia. Hippocampal volumes, measured manually or using FreeSurfer, were available in the majority of cases. Intra- and interrater reliability was tested using Cohen's weighted kappa. Correlation between MTA and quantitative hippocampal measurements was ascertained with Spearman's rank correlation coefficient. Moreover, diagnostic ability of MTA was assessed with receiver operating characteristic (ROC) analysis and suitable, age-dependent MTA thresholds were determined. Results Rater agreement was moderate to substantial. MTA correlation with quantitative volumetric methods ranged from -0.20 (p< 0.05) to -0.68 (p < 0.001) depending on the quantitative method used. Both MTA and FreeSurfer are able to distinguish dementia subgroups from CH. Suggested age-dependent MTA thresholds are 1 for the age group below 75 years and 1.5 for the age group 75 years and older. Conclusions MTA can be considered a valid marker of medial temporal lobe atrophy and may thus be valuable in the assessment of patients with cognitive impairment, even in a heterogeneous patient population.
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11. |
- Neikter, J, et al.
(author)
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Ventricular Volume Is More Strongly Associated with Clinical Improvement Than the Evans Index after Shunting in Idiopathic Normal Pressure Hydrocephalus
- 2020
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In: American Journal of Neuroradiology. - 0195-6108. ; 41:7, s. 1187-1192
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: Ventricular enlargement in idiopathic normal pressure hydrocephalus is often estimated using the Evans index. However, the sensitivity of the Evans index to estimate changes in ventricular size postoperatively has been questioned. Here, we evaluated the postoperative change in ventricle size in relation to shunt response in patients with idiopathic normal pressure hydrocephalus, by comparing ventricular volume and the Evans index. MATERIALS AND METHODS: Fifty-seven patients with idiopathic normal pressure hydrocephalus underwent high-resolution MR imaging preoperatively and 6 months after shunt insertion. Clinical symptoms of gait, balance, cognition, and continence were assessed according to the idiopathic normal pressure hydrocephalus scale. The ventricular volume of the lateral and third ventricles and the Evans index were measured using ITK-SNAP software. Semiautomatic volumetric analysis was performed, and postoperative changes in ventricular volume and the Evans index and their relationships to postoperative clinical improvement were compared. RESULTS: The median postoperative ventricular volume decrease was 25 mL (P < .001). The proportional decrease in ventricular volume was greater than that in the Evans index (P < .001). The postoperative decrease in ventricular volume was associated with a postoperative increase in the idiopathic normal pressure hydrocephalus scale score (P = .004). Shunt responders (75%) demonstrated a greater ventricular volume decrease than nonresponders (P = .002). CONCLUSIONS: Clinical improvement after shunt surgery in idiopathic normal pressure hydrocephalus is associated with a reduction of ventricular size. Ventricular volume is a more sensitive estimate than the Evans index and, therefore, constitutes a more precise method to evaluate change in ventricle size after shunt treatment in idiopathic normal pressure hydrocephalus.
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12. |
- Tullberg, Mats, 1965, et al.
(author)
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White matter diffusion is higher in Binswanger disease than in idiopathic normal pressure hydrocephalus.
- 2009
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In: Acta neurologica Scandinavica. - : Hindawi Limited. - 1600-0404 .- 0001-6314. ; 120:4, s. 226-34
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To explore diagnostic differences in periventricular white matter (PWM) and deep white matter (DWM) diffusion patterns in patients diagnosed with Binswanger disease (BD) and in patients diagnosed with probable idiopathic normal pressure hydrocephalus (INPH) using diffusion-weighted imaging (DWI). MATERIALS AND METHODS: Apparent diffusion coefficient (ADC) values were calculated in the PWM and DWM in patients with INPH (n = 14) and BD (n = 9) and in controls (n = 10) using an spin echo echo planar imaging single-shot diffusion sequence and region of interest (ROI) analysis. RESULTS: Patients with BD had higher ADC values than patients with INPH in the PWM and DWM in the frontal and occipital regions (P < 0.05) and higher values than controls in the frontal PWM and DWM (P < 0.01). After shunt surgery, ADC values were reduced in the frontal PWM in patients with INPH (P < 0.05). CONCLUSIONS: Increased diffusion in the PWM and DWM in patients with BD may reflect irreversible breakdown of axonal integrity caused by the subcortical ischaemic vascular disease. By contrast, the normal white matter diffusion in patients with INPH indicates structurally intact axons, compatible with the reversibility of this disorder. DWI may be an important non-invasive diagnostic tool for differentiating between INPH and BD and identifying shunt responders and reversible brain damage in patients with INPH. However, the overlap between patients with INPH and BD in this study restricts the predictive value of the method.
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13. |
- Ziegelitz, Doerthe, et al.
(author)
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Absolute quantification of cerebral blood flow in neurologically normal volunteers: dynamic-susceptibility contrast MRI-perfusion compared with computed tomography (CT)-perfusion.
- 2009
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In: Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine. - : Wiley. - 1522-2594 .- 0740-3194. ; 62:1, s. 56-65
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Journal article (peer-reviewed)abstract
- To improve the reproducibility of arterial input function (AIF) registration and absolute cerebral blood flow (CBF) quantification in dynamic-susceptibility MRI-perfusion (MRP) at 1.5T, we rescaled the AIF by use of a venous output function (VOF). We compared CBF estimates of 20 healthy, elderly volunteers, obtained by computed tomography (CT)-perfusion (CTP) and MRP on two consecutive days. MRP, calculated without the AIF correction, did not result in any significant correlation with CTP. The rescaled MRP showed fair to moderate correlation with CTP for the central gray matter (GM) and the whole brain. Our results indicate that the method used for correction of partial volume effects (PVEs) improves MRP experiments by reducing AIF-introduced variance at 1.5T.
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14. |
- Ziegelitz, Doerthe
(author)
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Cerebral CT - and MRI perfusion: Techniques and clinical application in iNPH
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Idiopathic normal pressure hydrocephalus (iNPH) is a disorder of the elderly, defined by slowly progressive impairment of gait and balance, cognitive decline, and incontinence. Disturbance of the cerebrospinal fluid (CSF) dynamics results in ventriculomegaly without intracranial pressure increase. Treatment by CSF diversion is successful in about 80% of the cases. Better preoperative identification of non-responders is required. The pathophysiology of iNPH is obscure, but linked to cortical and especially subcortical cerebral blood flow (CBF) reductions. The association between perfusion and the severity of the clinical features is not clearly established and a predictive perfusion pattern has not been identified. CT-perfusion (CTP) and Dynamic susceptibility contrast MRI perfusion (DSC MRI) offer advantages compared to traditional perfusion techniques, but are so far not of significant use in iNPH. The aim of this thesis was to compare CTP and DSC MRI in iNPH and to study their potential role as investigational techniques by exploring the pre-and postoperative CBF changes, how these correlate to the severity of the symptoms and, subsequently, the prognostic value of CBF. Fifty-one patients with suspected iNPH and 24 age-matched healthy individuals (HI) were recruited. At baseline all subjects had CTP and DSC MRI on 2 consecutive days. Patients repeated the perfusion measurements 3 months after shunting. Probable iNPH was diagnosed corresponding to the European-American iNPH guidelines and clinical performance was scored according to a recently published scale. After drop-outs, omission secondary to unsuccessful imaging and exclusion of non iNPH patients, 20 HI and 21 patients with complete preoperative imaging remained. One patient died prior to shunting. Postoperative DSC MRI was successful in all 20 cases and CTP in 17. Deconvolution generated absolute CBF estimates that eventually were normalized against an internal reference. Region of interest analysis was used for evaluation. Seventy-five percent of the patients were shunt responders. Correction of partial volume effects (PVE) of the arterial input function increased the accuracy of DSC MRI in HI. Despite PVE correction the linear relationship on the group level and the agreement between the modalities was limited. In iNPH, preoperative global and regional perfusion deficits, most pronounced in the periventricular white matter (PVWM), were measured by DSC MRI and, in spite of a limited spatial coverage, also by CTP. After shunting, DSC MRI and CTP demonstrated CBF restoration in responders in all anatomical regions and remaining hypoperfusion in the PVWM of non-responders. Postoperative metallic valve artefacts restricted the DSC MRI evaluation to one hemisphere, but were no issue in CTP. A valid prognostic CBF threshold was not identified. Regional and global CBF correlated with the severity of symptoms of iNPH. Patients with higher preoperative perfusion performed better in clinical tests and a lower preoperative perfusion resulted in a more marked postoperative improvement. Although the agreement of CTP and DSC MRI is limited, both methods contain perfusion information. The good general consistency of the results of CTP and DSC MRI measurements in the same material indicates reliability of both methods. DSC MRI and CTP might be used as investigational tools in iNPH.
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15. |
- Ziegelitz, Doerthe, et al.
(author)
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Cerebral perfusion measured by dynamic susceptibility contrast MRI is reduced in patients with idiopathic normal pressure hydrocephalus.
- 2014
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In: Journal of magnetic resonance imaging : JMRI. - : Wiley. - 1522-2586 .- 1053-1807. ; 39:6, s. 1533-1542
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Journal article (peer-reviewed)abstract
- Purpose To demonstrate in idiopathic normal pressure hydrocephalus (iNPH) patients by dynamic susceptibility contrast MRI a reduced preoperative cerebral blood flow (CBF) which correlates with the severity of clinical symptoms and predicts shunt outcome. Materials and Methods In cortical, subcortical, periventricular regions and along peri-and paraventricular profiles absolute perfusion values were estimated by multi-slice DSC MRI in 21 iNPH patients and 16 age-matched healthy individuals (HI). Relative CBF (rCBF), calculated with the occipital cortex as internal reference, was used for comparison between groups and for correlation analysis between regional rCBF and symptoms or outcome. Results iNPH patients showed significantly decreased rCBF in the basal medial frontal cortex, hippocampus, lentiform nucleus, periventricular white matter (PVWM), central grey matter and the global parenchyma as compared to HI. iNPH patients with higher preoperative rCBF in the PVWM performed better in clinical tests. A lower overall preoperative function resulted in a more obvious recovery after shunt insertion. Shunt-responders had higher rCBF values in the basal medial frontal cortex than non-responders. Conclusion DSC MRI perfusion is a potentially useful diagnostic tool in iNPH and perfusion based criteria might be possible predictors of shunt response. J. Magn. Reson. Imaging 2014;39:1533-1542. (c) 2013 Wiley Periodicals, Inc.
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16. |
- Ziegelitz, Doerthe, et al.
(author)
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Evaluation of a Fully Automated Method for Ventricular Volume Segmentation Before and After Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus
- 2024
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In: World Neurosurgery. - 1878-8750 .- 1878-8769. ; 181
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Journal article (peer-reviewed)abstract
- Background: Determination of the ventricle size in idiopathic normal pressure hydrocephalus (iNPH) is essential for diagnosis and follow-up of shunt results. Fully automated segmentation methods are anticipated to optimize the accuracy and time efficiency of ventricular volume measurements. We evaluated the accuracy of preoperative and postoperative ventricular volume measurements in iNPH by a magnetic resonance imaging (MRI)-based licensed software for fully automated quantitative assessment. Methods: Forty-eight patients diagnosed with iNPH were retrospectively analyzed. All patients received a ventriculoperitoneal shunt and had symptom grading and routine MRI preoperatively and 3–6 months postoperatively. Ventricular volumes, generated by fully automated T1-weighted imaging volume sequence segmentation, were compared with semiautomatic measurements and routine radiologic reports. The relation of postoperative ventricular size change to clinical response was evaluated. Results: Fully automated segmentation was achieved in 95% of the MRIs, but showed various rates of 8 minor segmentation errors. The correlation between both segmentation methods was very strong (r >0.9) and the agreement very good using Bland-Altman analyses. The ventricular volumes differed significantly between semiautomated and fully automated segmentations and between preoperative and postoperative MRI. The fully automated method systematically overestimated the ventricles by a median 15 mL preoperatively and 14 mL postoperatively; hence, the magnitudes of volume changes were equivalent. Routine radiologic reports of ventricular size changes were inaccurate in 51% and lacked association with treatment response. Objectively measured ventricular volume changes correlated moderately with postoperative clinical improvement. Conclusions: A fully automated volumetric method permits reliable evaluation of preoperative ventriculomegaly and postoperative ventricular volume change in idiopathic normal pressure hydrocephalus.
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17. |
- Ziegelitz, Doerthe, et al.
(author)
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In Patients With Idiopathic Normal Pressure Hydrocephalus Postoperative Cerebral Perfusion Changes Measured by Dynamic Susceptibility Contrast Magnetic Resonance Imaging Correlate With Clinical Improvement
- 2015
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In: Journal of Computer Assisted Tomography. - : Ovid Technologies (Wolters Kluwer Health). - 0363-8715. ; 39:4, s. 531-540
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Journal article (peer-reviewed)abstract
- Objective To explore relationships between clinical improvement and relative cerebral blood flow (rCBF) changes after shunt-insertion in idiopathic normal pressure hydrocephalus (iNPH) as measured by dynamic susceptibility contrast magnetic resonance imaging. In 20 idiopathic normal pressure hydrocephalus patients rCBF was measured preoperatively and 3 months postoperatively. Because of shunt-induced right-sided artefacts, evaluation was restricted to 12 left-sided cortical, subcortical, and periventricular regions of interest. Correlations between rCBF and clinical symptoms were analyzed in shunt responders. In responders, the postoperative regions of interest-based rCBF increase of 2% to 9% was significant in the parenchyma, the hippocampus, and the anterior periventricular white matter. Perfusion improvement in the cingulus, caudate head, and thalamus correlated with decreased disturbance in one or more of the domains neuropsychology, gait, balance, and total performance. Apparently, dynamic susceptibility contrast magnetic resonance imaging can measure postoperative perfusion changes in responders. Postoperatively, perfusion increase in some grey matter structures seems to determine the degree of clinical improvement.
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18. |
- Ziegelitz, Doerthe, et al.
(author)
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Pre-and postoperative cerebral blood flow changes in patients with idiopathic normal pressure hydrocephalus measured by computed tomography (CT)-perfusion.
- 2016
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In: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 36:10, s. 1755-1766
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Journal article (peer-reviewed)abstract
- In idiopathic normal pressure hydrocephalus (iNPH), the cerebral blood flow (CBF) is of pathophysiological interest and a potential biomarker. Computed tomography perfusion (CTP), an established technique with high spatial resolution and quantitative measurements, has not yet been used in the iNPH context. If CTP were sensitive to the CBF levels and changes in iNPH, this technique might provide diagnostic and prognostic absolute perfusion thresholds. The aim of this work was to determine the applicability of CTP to iNPH. CBF measurements of 18 patients pre- and 17 three months postoperatively, and six healthy individuals (HI) were evaluated in 12 cortical and subcortical regions of interest. Correlations between CBF and symptomatology were analyzed in shunt-responders. Compared to HI, the preoperative CBF in iNPH was significantly reduced in normal appearing and periventricular white matter (PVWM), the lentiform nucleus and the global parenchyma. No CBF differences were shown between responders and non-responders. In responders, the CBF recovered postoperatively by 2.5-32% to approximately the level of HI, but remained significantly decreased in the PVWM of non-responders. The pre- and postoperative CBF of cortical and subcortical regions correlated with the intensity of symptoms. In spite of limited spatial coverage, CTP can measure CBF changes in iNPH.
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