Multidisciplinary and standardized management of patients with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

BACKGROUND: The appropriate management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) remains uncertain. We aimed to evaluate the effect of implementing a standardized protocol for detection and management of DCI after aSAH on cerebral infarction and functional outcome. METHODS: We studied two cohorts of aSAH patients, one before (pre-implementation cohort: January 2012 to August 2014) and one after (post-implementation cohort: January 2016 to July 2018) implementation of a multidisciplinary approach, with standardized neurological and radiological assessment and risk-based medical treatment of DCI. We assessed the presence of new hypodensities on CT within 6 weeks after aSAH and categorized cerebral infarction into overall and DCI-related infarctions (hypodensities not within 48 h after IA repair and not attributable to aneurysm occlusion or intraparenchymal hematoma). Functional outcome was assessed at 3 months using the extended Glasgow outcome scale (eGOS), dichotomized into unfavorable (eGOS: 1-5) and favorable (eGOS: 6-8). We calculated odds ratios (OR) with corresponding 95% confidence intervals (CI's), and adjusted for age, WFNS grade, Fisher score, and treatment modality (aOR). RESULTS: In the post-implementation (n = 158) versus the pre-implementation (n = 143) cohort the rates for overall cerebral infarction were 29.1% vs 46.9% (aOR: 0.41 [0.24-0.69]), for DCI-related cerebral infarction 17.7% vs. 31.5% (aOR: 0.41 [0.23-0.76]), and for unfavorable functional outcome at 3 months 37.3% vs. 53.8% (aOR: 0.30 [0.17-0.54]). For patients with DCI, the rates for unfavorable functional outcomes at 3 months in the post-implementation versus the pre-implementation cohort were 42.3% vs. 77.8% (aOR: 0.1 [0.03-0.27]). CONCLUSIONS: A multidisciplinary approach with more frequent and standardized neurological assessment, standardized CT and CT perfusion monitoring, as well as tailored application of induced hypertension and invasive rescue therapy strategies, is associated with a significant reduction of cerebral infarction and unfavorable functional outcome after aneurysmal aSAH.

Open-Label Phase II Evaluation of Imatinib in Primary Inoperable or Incompletely Resected and Recurrent Glioblastoma.

PURPOSE: Preclinical studies indicated that imatinib may have single-agent activity in glioblastoma through inhibition of tyrosine kinase activity and also that it might enhance the efficacy of radiotherapy. We therefore sought to investigate clinical efficacy in patients with newly diagnosed and recurrent glioblastoma in combination with radiotherapy. METHODS: We conducted a nonrandomized, 2-arm, open-label phase II trial including patients aged 18 years or older with an ECOG performance status of 0-2 that were either newly diagnosed (arm A) with a measurable tumor (i.e., after incomplete resection or biopsy) or that were diagnosed with progression of a glioblastoma after initial therapy (arm B). Patients in arm A received 600 mg/day imatinib in combination with hypofractionated radiotherapy (2.5 Gy per fraction, 22 fractions). Patients in arm B received 600 mg/day imatinib alone or in combination with re-irradiation at various doses. In case tumor progression occurred, CCNU was added (2 cycles, 100 mg/m2) to imatinib. The primary end point was progression-free survival (PFS). The secondary end point was safety, defined as per Common Terminology Criteria for Adverse Events (version 2.0). Overall survival (OS) was analyzed as an exploratory end point. RESULTS: Fifty-one patients were enrolled, of which 19 were included in arm A and 32 in arm B. The median follow-up was 4 (0.5-30) months in arm A and 6.5 (0.3-51.5) months in arm B. The median PFS was 2.8 months (95% CI 0-8.7) in arm A and 2.1 months (95% CI 0-11.8) in arm B. The median OS was 5.0 (0.8-30) months (95% CI 0-24.1) in arm A and 6.5 (0.3-51.5) months (95% CI 0-32.5) in arm B. The major grade 3 events were seizure (present in 17 patients), pneumonia (11 patients), and vigilance decrease (7 patients). CONCLUSIONS: Imatinib showed no measurable activity in patients with newly diagnosed or recurrent glioblastoma.

Longitudinal MRI findings in patients with newly diagnosed glioblastoma after intraoperative radiotherapy.

BACKGROUND AND PURPOSE: Post-radiation treatment effects (pseudoprogression/radionecrosis) may bias MRI-based tumor response evaluation. To understand these changes specifically after high doses of radiotherapy, we analyzed MRIs of patients enrolled in the INTRAGO study (NCT02104882), a phase I/II dose-escalation trial of intraoperative radiotherapy (20-40 Gy) in glioblastoma. METHODS: INTRAGO patients were evaluated and compared to control patients who received standard therapy with focus on contrast enhancement patterns/volume, T2 lesion volume, and mean rCBV. RESULTS: Overall, 11/15 (73.3%) INTRAGO patients (median age 60 years) were included. Distant failure was observed in 7/11 (63.6%) patients, local tumor recurrence in one patient (9.1%). On the first follow-up MRI all but one patient demonstrated enhancement of varying patterns around the resection cavity which were: in 2/11 (18.2%) patients thin and linear, in 7/11 (63.6%) combined linear and nodular, and in 1/11 (9.1%) voluminous, indistinct, and mesh-like. In the course of treatment, most patients developed the latter two patterns (8/11 [72.7%]). INTRAGO patients demonstrated more often combined linear and nodular and/or voluminous, indistinct, mesh-like components (8/11 [72.7%]) in comparison to control patients (3/12 [25%], P = 0.02). INTRAGO patients demonstrated significantly increasing enhancing lesion (P = 0.001) and T2 lesion volumes (P < 0.001) in the longitudinal non-parametric analysis in comparison to the control group. rCBV showed no significant differences between both groups. CONCLUSIONS: High doses of radiotherapy to the tumor cavity result in more pronounced enhancement patterns/volumes and T2 lesion volumes. These results will be useful for the response evaluation of patients exposed to high doses of radiotherapy in future studies.

Gadolinium Leakage in Ocular Structures Is Common in Lacunar Infarction.

Background and Purpose- We investigated the frequency and pattern of blood-brain barrier, as well as blood-retina barrier, impairment in acute lacunar infarction as demonstrated by hyperintense acute reperfusion marker and gadolinium leakage in ocular structures (GLOS), respectively, on fluid-attenuated inversion recovery images. Methods- Acute lacunar infarction patients who underwent repeated magnetic resonance imaging after intravenous contrast agent administration were identified and the presence of GLOS in the anterior chamber and vitreous body and hyperintense acute reperfusion marker noted on fluid-attenuated inversion recovery. Results- Overall, 24 acute lacunar infarction patients (median age 64.5 years; interquartile range, 54-78 years) were included. On contrast-enhanced fluid-attenuated inversion recovery, GLOS was observed in 11 (45.8%) patients: in 4 (16.7%) in the anterior chamber only and in 7 (29.2%) in the anterior chamber and vitreous body. In all patients, GLOS was bilateral and symmetrical. In patients with GLOS in the anterior chamber only, the time between initial and follow-up magnetic resonance imaging was significantly shorter (7.5 [interquartile range, 4.25-11.5] hours) compared with patients with GLOS in the anterior chamber and vitreous body (28 [interquartile range, 10-43] hours; P=0.047). Hyperintense acute reperfusion marker could not be demonstrated in any of the patients. Conclusions- In acute lacunar infarction patients, unlike hyperintense acute reperfusion marker, GLOS is a frequent finding and shows a similar temporal evolution like in larger ischemic stroke.

Contrast-enhanced fat-suppressed FLAIR for the characterization of leptomeningeal inflammation in optic neuritis.

BACKGROUND: Leptomeningeal contrast enhancement on fluid-attenuated inversion recovery (FLAIR) images has been reported in patients with multiple sclerosis and interpreted as a biomarker of inflammation. In this study, we sought to evaluate this phenomenon in patients with optic neuritis (ON). METHODS: A total of 42 patients with suspected ON were included in this prospective study and underwent a dedicated study magnetic resonance imaging (MRI) protocol including native and contrast-enhanced fat-suppressed thin-section axial and coronal FLAIR images on an 1.5 T magnetic resonance (MR) system. RESULTS: After diagnostic workup, 34 patients with final diagnosis of ON were analyzed in detail. On contrast-enhanced fat-suppressed FLAIR images, 25 (73.5%) patients with ON demonstrated perioptic leptomeningeal enhancement, and in 3 (8.8%) patients, this was even the only pathological MRI finding. In comparison, patients with perioptic leptomeningeal enhancement on contrast-enhanced fat-suppressed FLAIR images had a higher prevalence of additional hyperintense brain lesions ( p = 0.022) as well as cerebrospinal fluid (CSF)-specific oligoclonal bands ( p = 0.013) than patients without. CONCLUSION: Perioptic leptomeningeal contrast enhancement on fat-suppressed FLAIR images is a novel marker in ON and possibly reflects a leptomeningeal inflammatory process preceding or accompanying ON. Thin-section contrast-enhanced fat-suppressed FLAIR images might be a useful addition in MRI protocols for patients with suspected ON.

Heterogeneity of glioblastoma with gliomatosis cerebri growth pattern on diffusion and perfusion MRI.

BACKGROUND AND PURPOSE: Gliomatosis cerebri (GC) is a rare growth pattern of glioblastoma whose diffuse nature is reflected by unspecific, relatively uniform findings on conventional MRI. In the present study we sought to evaluate the additional value of diffusion (DWI) and perfusion weighted (PWI) MRI for a more detailed characterization. METHODS: We analyzed the MRI findings in patients with histologically proven glioblastoma with GC growth pattern with a specific emphasis on T2 lesion pattern, volume, relative apparent diffusion coefficient (rACD), and relative cerebral blood volume (rCBV) and compared these to age-/gender-matched patients with localized glioblastoma. RESULTS: Overall, 16 patients (median age 59.5 years, 4 male) were included in the study. Of these, 8 patients had a glioblastoma with GC growth pattern, and 8 a classical localized growth pattern. While the median rADC (1.27 [IQR 1.12-1.41]) within the T2 lesion was significant lower in glioblastoma with GC growth pattern compared to localized glioblastoma (1.74 [IQR 1.45-1.96]; p = 0.003), the median T2 lesion volume and rCBV within the T2 lesion did not differ significantly. Furthermore, six patients with glioblastoma with GC growth pattern showed focal areas with significantly reduced rADC (p = 0.043), and/or increased rCBV (p = 0.028). CONCLUSIONS: Lower rADC in glioblastoma with GC growth pattern might reflect the diffuse tumor cell infiltration whereas focal areas with decreased rADC and/or increased rCBV probably indicate high tumor cell density and/or abnormal tumor vessels which may be useful for biopsy guidance.

Assessment of collateral blood flow in patients with distal branch occlusion of the middle cerebral artery.

PURPOSE: Aim of this study was to evaluate the collateral blood flow between more distal branches of the middle cerebral artery (MCA) in the case of peripheral MCA branch occlusion on dynamic 4D angiograms. We sought to individually predict the finally resulting infarction volume with regard to the extent of collateral blood flow. METHODS: Overall, 35 acute ischemic stroke patients with peripheral MCA branch occlusion were included. Volumes of the ischemic infarctions and perfusion deficits were measured on diffusion-weighted images DWI and time-to-peak TTP (> 4 s). Collateral flow on 4D MR angiograms were classified as previously specified. RESULTS: On DWI, the ischemic lesions had a mean volume of 3.4 ± 15.1 mL while the mean volume on TTP (> 4 s) was significantly larger 22.0 ± 18.1 mL (P < 0.001). On dynamic 4D angiograms we observed grade 1 in 8 (22.9%), grade 2 in 4 (11.4%), grade 3 in 10 (28.6%), and grade 4 in 13 (37.1%) patients. In comparison to patients with better collateralization (grade 3-4) patients with less sufficient collateralization (grade 0-2) demonstrated larger infarction volumes on initial (11.1 mL (IQR 2.9-35.5) vs. 2.1 mL (IQR 0.5-4.5), P = 0.03) and follow-up DWI (15.5 mL (IQR 12.6-23.3) vs. 1.9 mL (IQR 0.5-4.5), P = 0.03) with prominent infarction growth (7.4 mL (IQR 2.6-10.1) vs. 0.9 mL (IQR 0.2-2.6), P = 0.08). CONCLUSIONS: In the majority of cases with distal MCA branch occlusion a good collateral blood flow has been observed. Nevertheless, in approximately one quarter of patients an insufficient collateral blood flow has been detected that was associated with substantial infarction growth.

Incidence, Locations, and Longitudinal Course of Cerebral Microbleeds in European Moyamoya.

BACKGROUND AND PURPOSE: Cerebral microbleeds (cMBs) have previously been linked with especially high incidence in Asian patients with moyamoya together with high tendency to bleed. This, presumably, is characteristic of patients with moyamoya. Herein, we, therefore, investigate retrospectively the frequency, location, and longitudinal course of cMBs in a large German cohort. METHODS: We included all patients with moyamoya who underwent standard magnetic resonance imaging, including T2*-weighted images, in our department between 1998 and 2015. Two independent readers evaluated magnetic resonance imaging scans to determine the occurrence of cMBs according to the Brain Observer Microbleed Scale. Demographics, initial symptoms leading to hospitalization, and associated diseases were obtained by chart review. RESULTS: Overall, there was a total of 242 T2* studies of 101 included moyamoya patients available with a strong female predominance (69.3%). Eight patients (7.9%) were ≤18 years of age. We detected 25 cMBs within 13 patients (12.9%). One patient <18 of age was presented with a cMB; 2 of 3 patients with an intracranial hemorrhage as initial event demonstrated cMB(s). In 72 of 101 cases, there were 1719 person months of follow-up, with 3 adult patients showing 3 de novo cMBs in the course. The majority of cMBs (64.0%) were located at the cortex/gray-white junction. CONCLUSIONS: Although the frequency of cMBs herein is much higher than the expected age-specific incidence, it is still much lower compared with previous reports on cMBs in moyamoya patients of Asian descent. These results might reflect another ethnic-specific difference in patients diagnosed with moyamoya.

Late-onset major depression is associated with age-related white matter lesions in the brainstem.

OBJECTIVE: Age-related white matter lesions (ARWMLs) have been identified in various clinical conditions such as reduced gait speed, cognitive impairment, urogenital dysfunction, and mood disturbances. Previous studies indicated an association between ARWML and late-onset major depression. However, most of these focused on the extent of supratentorial ARWML and neglected presence and degree of infratentorial lesions. METHODS: In 45 patients (mean age 73.7 ± 6.3 years, 17 (37.8%) men, 28 (62.2%) women) with late-onset major depression, MRI findings (3.0-T MR system, Magnetom Trio, Siemens Medical Systems, Erlangen, Germany) were analyzed with emphasis on the extent of supratentorial and infratentorial, as well as brainstem ARWMLs, and compared with control subjects. ARWMLs were determined by semiquantitative rating scales (modified Fazekas rating scale, Scheltens' rating scale), as well as a semiautomatic volumetric assessment, using a specific software (MRIcron). Supratentorial and infratentorial, as well as brainstem ARWMLs, were assessed both on fluid attenuated inversion recovery and T2-weighted images. RESULTS: Patients with late-onset major depression had significantly higher infratentorial ARWML rating scores (5 (5-7) vs 4.5 (3-6), p = 0.003) on T2-weighted images and volumes (1.58 ± 1.35 mL vs 1.05 ± 0.81 mL, p = 0.03) on T2-weighted images, as well as fluid attenuated inversion recovery images (2.07 ± 1.35 mL vs 1.52 ± 1.10 mL, p = 0.04), than normal controls. In more detail, in particular, the pontine ARWML rating subscore was significantly higher in patients with late-onset major depression (1 (1-2) vs 1 (1-1), p = 0.004). CONCLUSIONS: The extent and localization of brainstem ARWML might be of importance for the pathophysiology of late-onset major depression. In particular, this may hold true for pontine ARWML. Copyright © 2016 John Wiley & Sons, Ltd.

GREAT-a randomized aneurysm trial. Design of a randomized controlled multicenter study comparing HydroSoft/HydroFrame and bare platinum coils for endovascular aneurysm treatment.

The effectiveness of a hybrid hydrogel platinum detachable coil (HydroCoil; MicroVention Inc., Tustin, CA) for endovascular aneurysm treatment has been proven in a recently published RCT. Due to technical restrictions (coil stiffness, time restriction for placement), the HydroSoft coil as well as a corresponding 3D framing coil, the HydroFrame coil (MicroVention Inc., Tustin, CA), a class of new softer coils containing less hydrogel and swelling more slowly than the HydroCoil, have been developed and brought to clinical practice. The present study aims to compare the effectiveness of endovascular aneurysm treatment with coil embolization between patients allocated HydroSoft/HydroFrame versus bare platinum coiling. GREAT is a randomized, controlled, multicentre trial in patients bearing cerebral aneurysms to be treated by coil embolization. Eligible patients were randomized to either coil embolization with HydroSoft/HydroFrame coils (>50 % of administered coil length), or bare platinum coils. Inclusion criteria were as follows: age 18-75, ruptured aneurysm (WFNS 1-3) and unruptured aneurysm with a diameter between 4 and 12 mm. Anatomy such that endovascular coil occlusion deemed possible and willingness of the neurointerventionalist to use either HydroSoft/HydroFrame or bare platinum coils. Exclusion criteria were as follows: aneurysms previously treated by coiling or clipping. Primary endpoint is a composite of major aneurysm recurrence on follow-up angiography and poor clinical outcome (modified Rankin scale 3 or higher), both assessed at 18 months post treatment. Risk differences for poor outcomes will be estimated in a modified intention-to-treat analysis stratified by rupture status (DRKS-ID: DRKS00003132).

Missing relationship of moyamoya and persistent primitive artery in Europeans. Another distinctive feature or artifact?

PURPOSE: Previous studies found higher incidence of persistent primitive arteries in Asian moyamoya (MM) patients than in the general population, which was thought to be a characteristic trait of the MM entity in general. We analyzed incidence of persistent primitive arteries and demographics of patients with European MM treated in one single center. First, we compared our large dataset to existing literature and second, we raised the question whether European MM demonstrates similar high prevalence of persistent primitive arteries as it was previously presented within Asian MM. METHODS: All European MM on whom revascularization surgery was performed from 1999 to 2013 were included. Demographics and associated diseases were obtained by retrospective chart review. Two independent readers evaluated 122 MM angiograms to determine the occurrence of persistent primitive arteries as well as the Suzuki score. RESULTS: We identified 112 cases with MM disease, 10 with MM syndrome. Mean age at time of diagnosis was 38.2 (range 6-64 years); a peak incidence in early childhood was not observed. Ninety (73.8%) were women, associated systemic diseases were found in four patients. Seven cases (5.7%) presented with unilaterally affected vessels. The majority of patients (71; 58.2%) were graded Suzuki Score 3. One 14-year-old boy with moyamoya presented with a primitive trigeminal artery (0.89%). CONCLUSIONS: We did not find a bimodal age distribution, but only a second peak during adulthood. Unlike previous studies on Asian moyamoya patients, our collective does not exhibit a higher prevalence of persistent primitive arteries than the normal population.

Morphology and function: MR pineal volume and melatonin level in human saliva are correlated.

PURPOSE: To investigate the relation between circadian saliva melatonin levels and pineal volume as determined by MRI. Plasma melatonin levels follow a circadian rhythm with a high interindividual variability. MATERIALS AND METHODS: In 103 healthy individuals saliva melatonin levels were determined at four time points within 24 h and MRI was performed once (3.0 Tesla, including three-dimensional T2 turbo spin echo [3D-T2-TSE], susceptibility-weighted imaging [SWI]). Pineal volume as well as cyst volume were assessed from multiplanar reconstructed 3D-T2-TSE images. Pineal calcification volume tissue was determined on SWI. To correct for hormonal inactive pineal tissue, cystic and calcified areas were excluded. Sleep quality was assessed with the Landeck Inventory for sleep quality disturbance. RESULTS: Solid and uncalcified pineal volume correlated to melatonin maximum (r = 0.28; P < 0.05) and area under the curve (r = 0.29; P < 0.05). Of interest, solid and uncalcified pineal volume correlated negatively with the sleep rhythm disturbances subscore (r = -0.17; P < 0.05) despite a very homogenous population. CONCLUSION: Uncalcified solid pineal tissue measured by 3D-T2-TSE and SWI is related to human saliva melatonin levels. The analysis of the sleep quality and pineal volume suggests a linkage between better sleep quality and hormonal active pineal tissue.

Perfusion patterns in migraine with aura.

OBJECTIVES: Migraine with aura is a common neurological disorder, and differentiation from transient ischemic attack or stroke based on clinical symptoms may be difficult. METHODS: From an MRI report database we identified 33 patients with migraine with aura and compared these to 33 age-matched ischemic stroke patients regarding perfusion patterns on perfusion-weighted imaging (PWI)-derived maps: time to peak (TTP), mean transit time (MTT), and cerebral blood flow and volume (CBF, CBV). RESULTS: In 18/33 (54.5%) patients with migraine with aura, TTP showed areas of hypoperfusion, most of these not limited to the territory of a specific artery but affecting two or more vascular territories. In patients with migraine with aura, TTP (1.09 ± 0.05 vs. 1.47 ± 0.40, p < 0.001) and MTT ratios (1.01 ± 0.10 vs. 1.19 ± 0.21, p = 0.003) were significantly lower compared to patients with ischemic stroke. In contrast to this, CBF and CBV ratios did not differ significantly between both groups. CONCLUSIONS: Migraine aura is usually associated with a perfusion deficit not limited to a specific vascular territory, and only a moderate increase of TTP. Thus, hypoperfusion restricted to a single vascular territory in combination with a marked increase of TTP or MTT may be regarded as atypical for migraine aura and suggestive of acute ischemic stroke.

FLAIR vascular hyperintensities and dynamic 4D angiograms for the estimation of collateral blood flow in posterior circulation occlusion.

INTRODUCTION: The objectives of this paper are to assess collateral blood flow in posterior circulation occlusion by MRI-based approaches (fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs), collateralization on dynamic 4D angiograms) and investigate its relation to ischemic lesion size and growth. METHODS: In 28 patients with posterior cerebral artery (PCA) and 10 patients with basilar artery (BA) occlusion, MRI findings were analyzed, with emphasis on distal FVH and collateralization on dynamic 4D angiograms. RESULTS: In PCA occlusion, distal FVH was observed in 18/29 (62.1%), in BA occlusion, in 8/10 (80%) cases. Collateralization on dynamic 4D angiograms was graded 1 in 8 (27.6%) patients, 2 in 1 (3.4%) patient, 3 in 12 (41.4%) patients, and 4 in 8 (27.6%) patients with PCA occlusion and 0 in 1 (10%) patient, 2 in 3 (30%) patients, 3 in 1 (10%) patient, and 4 in 5 (50%) patients with BA occlusion. FVH grade showed neither correlation with initial or follow-up diffusion-weighted image (DWI) lesion size nor DWI-perfusion-weighted imaging (PWI) mismatch ratio. Collateralization on dynamic 4D angiograms correlated inversely with initial DWI lesion size and moderately with the DWI-(PWI) mismatch ratio. The combination of distal FVH and collateralization grade on dynamic 4D angiograms correlated inversely with initial as well as follow-up DWI lesion size and highly with the DWI-PWI mismatch ratio. CONCLUSIONS: In posterior circulation occlusion, FVH is a frequent finding, but its prognostic value is limited. Dynamic 4D angiograms are advantageous to examine and graduate collateral blood flow. The combination of both parameters results in an improved characterization of collateral blood flow and might have prognostic relevance.

Photon Counting Computed Tomography for Accurate Cribriform Plate (Lamina Cribrosa) Imaging in Adult Patients.

Detailed visualization of the cribriform plate is challenging due to its intricate structure. This study investigates how computed tomography (CT) with a novel photon counting (PC) detector enhance cribriform plate visualization compared to traditionally used energy-integrated detectors in patients. A total of 40 patients were included in a retrospective analysis, with half of them undergoing PC CT (Naeotom Alpha Siemens Healthineers, Forchheim, Germany) and the other half undergoing CT scans using an energy-integrated detector (Somatom Sensation 64, Siemens, Forchheim, Germany) in which the cribriform plate was visualized with a temporal bone protocol. Both groups of scans were evaluated for signal-to-noise ratio, radiation dose, the imaging quality of the whole scan overall, and, separately, the cribriform plate and the clarity of volume rendering reconstructions. Two independent observers conducted a qualitative analysis using a Likert scale. The results consistently demonstrated excellent imaging of the cribriform plate with the PC CT scanner, surpassing traditional technology. The visualization provided by PC CT allowed for precise anatomical assessment of the cribriform plate on multiplanar reconstructions and volume rendering imaging with reduced radiation dose (by approximately 50% per slice) and higher signal-to-noise ratio (by approximately 75%). In conclusion, photon-counting technology provides the possibility of better imaging of the cribriform plate in adult patients. This enhanced imaging could be utilized in skull base-associated pathologies, such as cerebrospinal fluid leaks, to visualize them more reliably for precise treatment.

Three-Dimensional Visualization of Shunt Valves with Photon Counting CT and Comparison to Traditional X-ray in a Simple Phantom Model.

This study introduces an application of innovative medical technology, Photon Counting Computer Tomography (PC CT) with novel detectors, for the assessment of shunt valves. PC CT technology offers enhanced visualization capabilities, especially for small structures, and opens up new possibilities for detailed three-dimensional imaging. Shunt valves are implanted under the skin and redirect excess cerebrospinal fluid, for example, to the abdominal cavity through a catheter. They play a vital role in regulating cerebrospinal fluid drainage in various pathologies, which can lead to hydrocephalus. Accurate imaging of shunt valves is essential to assess the rate of drainage, as their precise adjustment is a requirement for optimal patient care. This study focused on two adjustable shunt valves, the proGAV 2.0® and M. blue® (manufactured by Miethke, Potsdam, Germany). A comprehensive comparative analysis of PC CT and traditional X-ray techniques was conducted to explore this cutting-edge technology and it demonstrated that routine PC CT can efficiently assess shunt valves' adjustments. This technology shows promise in enhancing the accurate management of shunt valves used in settings where head scans are already frequently required, such as in the treatment of hydrocephalus.

Cranial Computer Tomography with Photon Counting and Energy-Integrated Detectors: Objective Comparison in the Same Patients.

This study provides an objective comparison of cranial computed tomography (CT) imaging quality and radiation dose between photon counting detectors (PCCTs) and energy-integrated detectors (EIDs). We retrospectively analyzed 158 CT scans from 76 patients, employing both detector types on the same individuals to ensure a consistent comparison. Our analysis focused on the Computed Tomography Dose Index and the Dose-Length Product together with the contrast-to-noise ratio and the signal-to-noise ratio for brain gray and white matter. We utilized standardized imaging protocols and consistent patient positioning to minimize variables. PCCT showed a potential for higher image quality and lower radiation doses, as highlighted by this study, thus achieving diagnostic clarity with reduced radiation exposure, underlining its significance in patient care, particularly for patients requiring multiple scans. The results demonstrated that while both systems were effective, PCCT offered enhanced imaging and patient safety in neuroradiological evaluations.

Advanced Imaging of Shunt Valves in Cranial CT Scans with Photon-Counting Scanner.

This brief report aimed to show the utility of photon-counting technology alongside standard cranial imaging protocols for visualizing shunt valves in a patient's cranial computed tomography scan. Photon-counting CT scans with cranial protocols were retrospectively surveyed and four types of shunt valves were encountered: proGAV 2.0®, M.blue®, Codman Certas®, and proSA®. These scans were compared with those obtained from non-photon-counting scanners at different time points for the same patients. The analysis of these findings demonstrated the usefulness of photon-counting technology for the clear and precise visualization of shunt valves without any additional radiation or special reconstruction patterns. The enhanced utility of photon-counting is highlighted by providing superior spatial resolution compared to other CT detectors. This technology facilitates a more accurate characterization of shunt valves and may support the detection of subtle abnormalities and a precise assessment of shunt valves.