Detection of Global Brain Injury Using Point-of-Care Neonatal MRI Scanner.

BACKGROUND: Conventional magnetic resonance imaging (MRI) neuroimaging of infants is complicated by the need to transport infants outside the neonatal intensive care unit (NICU), often to distant areas of the hospital. PRIMARY OBJECTIVE: The main aim of this study was to evaluate and compare scoring of images from a novel 1T MRI, which enables neuroimaging within the NICU, with those from a conventional MRI. SECONDARY OBJECTIVE: The second aim of this study was to document improved expediency, and thereby greater patient safety, as reflected by decreased transport time. MATERIALS AND METHODS: Thirty premature infants (mean gestational age: 28.8 ± 2.1 weeks) were scanned consecutively on the novel 1T and 1.5T conventional scanners at term-equivalent age. Orthogonal T1- and T2-weighted images were acquired and reviewed. A global brain abnormality score (Kidokoro) was assigned independently to all images by two radiologists. Interrater agreement was evaluated using the kappa statistic and interscanner agreement was evaluated by Bland-Altman analysis. Transport time to and from both scanners was monitored and compared. RESULTS: Weighted kappas were 0.77 (standard error of measurement [SEM] 0.08; confidence interval [CI]: 0.62-0.92) and 0.86 (SEM: 0.07; CI: 0.73-1), for the 1T and 1.5T scanners, respectively, reflecting substantial interrater agreement. Bland-Altman analysis showed excellent agreement between the two scanners.Transport time was 8 ± 6 minutes for the 1T MRI versus 46 ± 21 minutes for the conventional MRI (p < 0.00001). No adverse events were recorded during transport. Standard transport times will vary from institution to institution. CONCLUSION: Kidokoro scores are similar when comparing images obtained from a 1T MRI with those of a conventional 1.5T MRI, reflecting comparable image quality. Transport time was significantly decreased using the 1T neonatal MRI.

Utility of MRI in surgical planning for parasagittal meningiomas.

BACKGROUND: Surgical resection is the standard treatment for parasagittal meningioma (PSM), but complete resection may be challenging due to superior sagittal sinus (SSS) involvement. The SSS may be partially or completely obstructed, and collateral veins are commonly present. Thus, knowing the status of the SSS in PSM cases prior to treatment is essential to a successful outcome. MRI is utilized prior to surgery in order to determine SSS status and to check for presence of collateral veins. The objective of this study is to evaluate the reliability of MRI in predicting both SSS involvement and presence of collateral veins in subsequent comparison to actual intra-operative findings, and to report on complications and outcomes. METHODS: 27 patients were retrospectively analyzed for this study. A blinded radiologist reviewed all pre-operative images, noting SSS status and collateral vein presence. Intraoperative findings were obtained from hospital records to similarly categorize SSS status and collateral vein presence. RESULTS: Sensitivity of the MRI to SSS status was found to be 100% and specificity was 93%. However, sensitivity and specificity of MRI to collateral vein presence was only 40% and 78.6%, respectively. Complications were experienced by 22% of patients, the majority neurologic in nature. CONCLUSION: MRI accurately predicted SSS occlusion status, but was less consistent in identification of collateral veins. These findings suggest MRI should be used with caution prior to PSM resection surgery particularly with regards to the presence of collateral veins which may complicate resection.

Mildly Elevated Bilirubin Levels are Associated with Increased Magnetic Resonance Imaging Signal Intensity in the Basal Ganglia of Preterm Neonates.

OBJECTIVE: This study aimed to test whether mildly elevated bilirubin levels in preterm infants are associated with increased signal intensity (SI) on magnetic resonance imaging (MRI) of the basal ganglia (BG). STUDY DESIGN: MRI was performed at term equivalent age in 55 postpreterm infants using a neonatal MRI 1-T scanner. SI of the BG was correlated with mild hyperbilirubinemia. RESULTS: BG MRI SI was significantly increased in infants with mild hyperbilirubinemia on T1-weighted image (T1; p = 0.0393) and T2-weighted image (T2; p = 0.0309). We found no effect of gestational age or sepsis on BG MRI intensity; however, there was a significant effect of acidosis on T1 (p = 0.0223) but not on T2 (p = 0.2316). Infants with combined hyperbilirubinemia and acidosis had the most significant increase in SI on both T1 and T2 respectively (p = 0.0072 and 0.0195, respectively). CONCLUSION: We found a positive association between increased BG MRI SI and mildly elevated bilirubin levels. The effect was greatly strengthened when hyperbilirubinemia was associated with acidosis. KEY POINTS: · Excessive bilirubin is neurotoxic to the neonatal brain. It is deposited in the BG.. · BG MRI SI is increased with bilirubin deposition.. · The premature brain is more vulnerable to bilirubin associated MRI changes..

Characterization and Evaluation of Injectable Biodegradable Polymer Multimodality Radiologic Markers in an In Vivo Murine Model.

Biodegradable polymer clips as multidimensional soft tissue biopsy markers were developed with better biocompatibility and imaging features. Unlike the commercially available metallic biopsy markers, the developed polymer clips are temporary implants with similar efficacies as metal markers in imaging and detection and get absorbed within the body with time. Herein, we evaluate the degradation rate of three resorbable polymer-based marker compounds in an in vivo murine model. Three polymers, abbreviated as Polymer A (PLGA poly(lactic-co-glycolic acid)50:50), Polymer B (PLGA (poly(lactic-co-glycolic acid)) 75:25), and Polymer C (polycaprolactone (PCL)), mixed with 20% lipiodol and 0.2% iron oxide and a control polymer were implanted into nine mice, followed by CT and MRI imaging. Images were evaluated for conspicuity. Specimens were examined for tissue analysis of iodine and iron contents. Significant differences in polymer resorption and visualization on CT were noted, particularly at 8 weeks (p < 0.027). Polymers A, B, and C were visible by CT at 4, 6, and 8 weeks, respectively. All marker locations were detected on MRI (T1 and SWI) after 24 weeks, with tattooing of the surrounding soft tissue by iron deposits. CT and MR visible polymer markers can be constructed to possess variable resorption, with stability ranging between 4 and 14 weeks post placement, making this approach suitable for distinct clinical scenarios with varying time points.

Traumatic cerebral dural sinus vein thrombosis/stenosis in pediatric patients-is anticoagulation necessary?

INTRODUCTION: Cerebral dural vein thrombosis/stenosis (CDVT/S) is a condition that affects the venous drainage of the brain. Risk factors and causes associated with CDVT/S include systemic risk factors that cause hypercoagulability, or local factors such as head trauma. While consensus is that non-traumatic sinus vein thrombosis should be treated with anticoagulation therapy, treatment of patients with TBI-induced CDVT is not yet established. METHODS: Retrospective review of clinical data of pediatric patients presented to our medical center from July 2017 to August 2020. Inclusion criteria were age, birth to 18 years, admission due to head trauma, head CT scan with positive traumatic findings, and follow-up in our clinic. Exclusion criteria were a normal head CT on admission and failure to follow-up. Data regarding demographics, clinical presentation, imaging findings, treatment, and status on follow-up were recorded. Study protocol was approved by our institutional ethics committee. RESULTS: One hundred sixty-two patients were enrolled. Falling accident occurred in 90.1%, a minority suffered from direct head trauma or gunshot wound. Of the patients, 95.1% suffered from mild TBI. Forty-two percent suffered from an associated intracranial injury. Fourteen cases with CDVT were included in the cohort. Linear fractures were significantly correlated with CDVT. Additionally, occipital/suboccipital fractures, associated intracranial injury, and proximity of injury to the sinus were correlated with CDVT. From this group, 12 were treated conservatively; one patient was treated surgically due to EDH. All patients with CDVT were neurologically intact at discharge. Only one patient was treated with therapeutic dose of LMWH. A total of 86.7% of patients with CDVT who were treated conservatively had full recanalization on follow-up imaging. Four patients had CDVS; all were neurologically intact at admission and discharge, and all were treated conservatively and had full recanalization on follow-up. DISCUSSION: Treatment with ACT is established in pediatric CDVT but not in the sub-group of TBI. While ACT prevents progression of thrombosis, it might cause worsening of extra-axial hemorrhage. In our study, no clinical deterioration was noted with expectant management; thus, we present an algorithm for diagnosis and treatment of trauma-induced CDVT/S in children with frequent clinical and radiologic imaging while avoiding anticoagulation. CONCLUSION: In most cases, anticoagulation therapy is not necessary in traumatic CDVT/S. Initial expectant management in children is safe. However, each case should be evaluated individually and further studies should be performed.

Optimization and characterization of a novel internally-cooled radiofrequency ablation system with optimized pulsing algorithm in an ex-vivo bovine liver.

Purpose: To prospectively characterize and optimize radiofrequency energy deposition to determine ideal parameters for achieving large ablation zones. Materials and methods: An internally-cooled RF system was used to perform 214 ablations in 72 ex-vivo bovine livers. Tip exposure (1-5 cm), electrode current (400-2500 mA), and application duration (3-15 min) were systematically varied. A pulsing algorithm optimized efficiency of RF deposition, including initial automatic ramping followed by adjustment in current, in response to changes in tissue impedance. Following the procedure ablation diameter and length were measured, sphericity calculated, and correlated with parameters of energy deposition and tissue temperatures. Results: Increasing electrode exposure from 1-5 cm produced linear increases in ablation diameter from 1.4 ± 0.1 to 5.3 ± 0.1 cm (y = 1.1x-0.5; R2 = 0.93), and length (y = 1.18x + 0.34; R2 = 0.92). A sphericity index >0.85 was noted at optimal energy setting for electrode exposures of 1-4 cm. Maximum temperatures post-ablation increased with active tip length from 68.5 ± 4.9 °C to 91.3 ± 1.5 °C in a logarithmic (y = 0.94ln(x)-2.75; R2 = 0.90) or power relationship between temperature and the resultant ablation diameter (y = 0.27e0.0295x; R2 = 0.76). A tight exponential relationship (y = 0.28x0.38; R2 = 0.97) was also observed between total energy deposition and ablation diameter. Finally, a multifactor relationship of the diameter of ablation to electrode tip exposure and the time to first impedance rise was successfully modeled, with a root mean squared error of 1.9 mm and R2 = 0.95. Conclusion: Large, reproducible, and spherical ablation areas can be achieved with the novel system described, with efficient delivery of RF energy deposited into tissue. These findings may have important clinical relevance in regards to the clinical utility of RF ablation compared to other competitive forms of thermal tumor ablation.

Sensitivity of the Mount Fuji Sign After Evacuation of Chronic Subdural Hematoma in Nonagenarians.

BACKGROUND: The Mount Fuji sign (MFS) is a radiological sign on computed tomographic scans depicting air between the frontal lobes. Air in this location indicates tension pneumocephalus (TP), considered a neurosurgical emergency.We evaluate the correlation between the MFS and perioperative mortality attributed to TP in nonagenarians who have undergone evacuation of chronic subdural hemorrhage (cSDH). MATERIALS AND METHODS: We retrospectively reviewed the records of nonagenarians who had cSDH evacuation between 2006 and 2015. Postoperative computed tomographic images were evaluated for findings consistent with the MFS. RESULTS: Of 45 patients, 15 patients (33%) had radiological MFS, and 3 patients (20%) with MFS required reoperation because of new blood collection. No patient required reoperation because of TP. Perioperative (30-day) mortality in patients demonstrating the MFS was 6.67% caused by cardiac arrhythmia versus 13.33% mortality in patients with no evidence of the MFS. CONCLUSION: Mount Fuji sign in nonagenarians after cSDH evacuation is not a specific sign of TP.

Evaluation of a CT-Guided Robotic System for Precise Percutaneous Needle Insertion.

PURPOSE: To assess overall targeting accuracy for CT-guided needle insertion using prototype robotic system for common target sites. MATERIALS AND METHODS: Using CT guidance, metallic (2 × 1 mm) targets were embedded in retroperitoneum (n = 8), kidneys (n = 8), and liver (n = 14) of 8 Yorkshire pigs (55-65 kg). Bronchial bifurcations were targeted in the lung (n = 13). CT datasets were obtained for planning and controlled needle placement of commercially available 17- to 19-gauge needles (length 15-20 cm) using a small, patient-mounted, CT-guided robotic system with 5° of motion. Mean distance to target was 92.9 mm ± 19.7 (range, 64-146 mm). Planning included selection of target, skin entry point, and 4.6 ± 1.3 predetermined checkpoints (range, 2-9) where additional CT imaging was performed to permit stepwise correction of needle trajectory path as needed. Scanning and needle advancement were coordinated with breath motion using respiratory gating. Accuracy was assessed as distance from needle tip to predefined target. RESULTS: Of 45 needle insertions performed, 2 were unsuccessful owing to technical issues. Accuracy of targeting was 1.2-1.4 mm ± 0.6 for kidney, retroperitoneum, and lung (P = .51), with 2.9 mm ± 1.9 accuracy for liver (P = .0003). This was achieved in 39 cases (91%) using a single insertion. Intraprocedural target movement was detected (3.5 mm ± 2.1 in retroperitoneum and 6.4 mm ± 3.9 in liver); the system compensated for 52.9% ± 30.3 of this movement. One pneumothorax was the only complication (8%). CONCLUSIONS: Accurate needle insertion (< 3 mm error) can be achieved in common target sites when using a CT-guided robotic system. Stepwise checks with corrective angulation can potentially overcome issues of target movement during a procedure from organ deformity and other causes.

Optimizing Irreversible Electroporation Ablation with a Bipolar Electrode.

PURPOSE: To optimize single-insertion bipolar irreversible electroporation (IRE) by characterizing effects of electric parameters and controlling tissue electric properties in a porcine model. MATERIALS AND METHODS: Single-insertion electrode bipolar IRE was performed in 28 in vivo pig livers (78 ablations). First, effects of voltage (2,700-3,000 V), number of pulses, repeated cycles (1-6 cycles), and pulse width (70-100 µs) were studied. Next, electric conductivity was altered by instillation of hypertonic and hypotonic fluids. Finally, effects of thermal stabilization were assessed using internal electrode cooling. Treatment effect was evaluated 2-3 hours after IRE. Dimensions were compared and subjected to statistical analysis. RESULTS: Delivering 3,000 V at 70 µs for a single 90-pulse cycle yielded 3.8 cm ± 0.4 × 2.0 cm ± 0.3 of ablation. Applying 6 cycles of energy increased ablation to 4.5 cm ± 0.4 × 2.6 cm ± 0.3 (P < .001). Further increasing pulse lengths to 100 µs (6 cycles) increased ablation to 5.0 cm ± 0.4 × 2.9 cm ± 0.3 (P < .001) but resulted in electric spikes and system crashes in 40%-50% of cases. Increasing tissue electric conductivity via hypertonic solution instillation in surrounding tissues increased frequency of generator crashes, whereas continuous instillation of distilled water eliminated this arcing phenomenon but reduced ablation to 2.3 cm ± 0.1. Controlled instillation of distilled water when electric arcing was suspected from audible popping produced ablations of 5.3 cm ± 0.6 × 3.1 cm ±0.3 without crashes. Finally, 3.1 cm ± 0.1 short-axis ablation was achieved without system crashes with internal electrode perfusion at 37°C versus 2.3 cm ± 0.1 with 4°C-10°C perfusion (P < .001). CONCLUSIONS: Bipolar IRE ablation zones can be increased with repetitive high voltage and greater pulse widths accompanied by either judicious instillation of hypotonic fluids or internal electrode perfusion to minimize unwanted electric arcing.

Semiquantitative and Quantitative Analyses of Dynamic Contrast-Enhanced Magnetic Resonance Imaging of Thyroid Nodules.

OBJECTIVE: This study was aimed to determine the utility of quantitative dynamic contrast-enhanced magnetic resonance imaging (MRI) in differentiating benign and malignant lesions in patients with known thyroid gland lesions scheduled for resection. METHODS: Patients scheduled for resection of a thyroid mass were prospectively enrolled. Dynamic contrast-enhanced MRI scans of the neck were performed before surgery. After resection, patients were divided into benign and malignant groups. Quantitative and semiquantitative MRI kinetic measurements of benign and malignant lesions were compared and analyzed. RESULTS: Twelve benign and 9 malignant lesions were identified in 19 patients. Mean Ktrans, Ve, and Kep for benign lesions were 1.69 ± 1.59 min, 0.44 ± 0.21 min, and 4.51 ± 2.96 min, respectively; for the malignant lesions, 0.96 ± 0.57 min, 0.45 ± 0.19 min, and 3.57 ± 3.53 min, respectively (P = 0.1886, 0.8036, and 0.3028, respectively). Tpeak, ERmax, slopemax, and iAUGC60 for benign lesions were 7.00 ± 8.09 seconds, 293.27 ± 141.25 seconds, 76.45 ± 65.80 seconds, and 63.46 ± 46.84, respectively; for malignant lesions, 8.11 ± 8.55 seconds, 227.6 ± 113.37 seconds, 81.17 ± 109.71 seconds, and 43.69 ± 26.19, respectively (P = 0.7525, 0.4941, 0.4474, and 0.3028, respectively). CONCLUSIONS: Dynamic contrast-enhanced MRI pattern of kinetics was not significantly different for benign and malignant lesions of the thyroid using quantitative or semiquantitative methods.

Influence of common fixed retainers on the diagnostic quality of cranial magnetic resonance images.

INTRODUCTION: Orthodontists are often asked to remove fixed retainers before magnetic resonance imaging (MRI). This study was undertaken to assess the effects of 2 commonly used fixed retainers on MRI distortion and whether they should be removed. METHODS: MRI scans were performed on a dry skull with Twistflex (Dentaurum, Ispringen, Germany) and Ortho Flex Tech (Reliance Orthodontic Products, Itasca, Ill) retainers. Two neuroradiologists independently ranked the distortions. The influence of the fixed retainers' alloys, their distance to the area of diagnosis, location, strength of the magnetic field, and the spin-echo sequence were examined. Statistical analysis included kappa and Pearson chi-square tests. RESULTS: Ortho Flex Tech retainers caused no distortion. Twistflex retainers caused distortion in 46% of the tests in areas close to the retainer (tongue and jaws). Maxillary fixed retainers and the combination of maxillary and mandibular fixed retainers further increased the distortion. Greater distortion was observed with 3-T magnetic fields and T1-weighted spin-echo sequences. CONCLUSIONS: Removal of the Ortho Flex Tech retainer is unnecessary before MRI. Removal of the Twistflex should be considered if the MRI scans are performed to diagnose areas close to the fixed retainers, when 3-T magnetic fields and T1-weighted sequences are used, and when both maxillary and mandibular fixed retainers are present.

Irreversible electroporation ablation: creation of large-volume ablation zones in in vivo porcine liver with four-electrode arrays.

PURPOSE: To prospectively determine optimal parameters with which to achieve defined large target zones of coagulation by using irreversible electroporation (IRE) with four-electrode arrays and the time needed to achieve this treatment effect in an in vivo animal model. MATERIALS AND METHODS: This study was approved by the animal care and use committee. Ultrasonography (US)-guided IRE ablation (n = 90) was performed in vivo in 69 pig livers with an array of four electrodes (18 gauge) and an electroporation generator. Cardiac-gated 100-µsec IRE pulses were applied sequentially between the six sets of electrode pairs at 2250-3000 V. Multiple algorithms of energy deposition and electrode configuration were studied, including interelectrode spacing (1.5-2.5 cm), number of IRE pulses applied consecutively to each electrode pair (10, 20, 50, and 100), and number of times per cycle each electrode pair was activated (one to 10). Resultant zones of treatment were measured with US 1.5-3 hours after IRE and confirmed at gross and histopathologic examination. Data and ablation times were compared to determine the optimal algorithms with which to achieve 4-7-cm areas of treatment effect in the shortest time possible. In addition, the IRE current applied was correlated with ablation size. Data were analyzed by using analysis of variance with multiple comparisons, t tests, or nonparametric statistics. RESULTS: For 2.5-cm spacing, ablation diameter was increased by increasing either the overall time of energy application or the number of cycles of 20 pulses (P < .01 for both). IRE application of less than four cycles (or continuous IRE application of 100 pulses) did not result in contiguous ablation. However, sequentially increasing the number of cycles of IRE from four to 10 increased both the electrical current applied (from 14.4 A ± 0.4 to 17.6 A ± 0.7, P = .0004) and ablation diameter (from 5.6 cm ± 0.3 to 6.6 cm ± 0.3, P = .001). Although division of application into cycles did not alter coagulation at 2.0- and 1.5-cm spacing, application of energy to diagonal electrode pairs increased coagulation. Thus, one 100-pulse cycle (11.0 minutes ± 1.4) produced 4.8 cm ± 0.3 of ablation for 2.0-cm spacing with diagonal pairs but only 4.1 cm ± 0.3 of ablation without diagonal pairs (7.5 minutes ± 1.0, P < .03 for both). CONCLUSION: With four-electrode arrays, IRE can create large contiguous zones of treatment effect in clinically acceptable ablation times; parameters can be tailored to achieve a wide range of ablation sizes. Cyclical deposition of IRE application is beneficial, particularly for larger interprobe spacing, most likely owing to alterations of electrical conductivity that occur after successive applications of IRE energy.

Irreversible electroporation ablation: is all the damage nonthermal?

PURPOSE: To determine whether high-dose irreversible electroporation (IRE) ablation induces thermal effects in normal liver tissue. MATERIALS AND METHODS: Animal care and use committee approval was obtained prior to the experiments. IRE ablation (n = 78) was performed by a single four-person team in vivo in 22 porcine livers by applying electric current to two 1.3-cm-diameter circular flat-plate electrodes spaced 1 cm apart. Cardiac-gated IRE pulses (n = 40-360) were systematically applied at varying voltages (1500-2900 V). End temperatures at the ablation zone center were measured and were correlated with ablation time, energy parameters, and resultant treatment effect as determined at gross pathologic and histopathologic examination. Temperatures were then monitored at the center and periphery of four ablations created by using a four-electrode IRE array (3000 V, 90 pulses per electrode pair). Data were analyzed by using multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis, as appropriate. RESULTS: Temperature rose above the 34°C baseline after IRE in all flat-plate experiments and correlated linearly (R(2) = 0.39) with IRE "energy dose" (product of voltage and number of pulses) and more tightly in univariate analysis with both voltage and number of pulses. Thus, mean temperatures as high as 86°C ± 3 (standard deviation) were seen for 2500 V and 270 pulses. Ablations of 90 pulses or more at 2500 V produced temperatures of 50°C or greater and classic gross and histopathologic findings of thermal coagulation (pyknotic nuclei and streaming cytoplasm). For lower IRE doses (ie, 2100 V, 90 pulses), temperatures remained below 45°C, and only IRE-associated pathologic findings (ie, swollen sinusoids, dehydrated cells, and hemorrhagic infiltrate) were seen. For the four-electrode arrays, temperatures measured 54.2°C ± 6.1 at the electrode surfaces and 38.6°C ± 3.2 at the ablation zone margin. CONCLUSION: In some conditions of high intensity, IRE can produce sufficient heating to induce "white zone" thermal coagulation. While this can be useful in some settings to increase tumor destruction, further characterization of the thermal profile created with clinical electrodes and energy parameters is therefore needed to better understand the best ways to avoid unintended damage when ablating near thermally sensitive critical structures.

Irreversible electroporation: treatment effect is susceptible to local environment and tissue properties.

PURPOSE: To study the effects of the surrounding electrical microenvironment and local tissue parameters on the electrical parameters and outcome of irreversible electroporation (IRE) ablation in porcine muscle, kidney, and liver tissue. MATERIALS AND METHODS: Animal Care and Use Committee approval was obtained, and National Institutes of Health guidelines were followed. IRE ablation (n = 90) was applied in muscle (n = 44), kidney (n = 28), and liver (n = 18) tissue in 18 pigs. Two electrodes with tip exposure of 1.5-2 cm were used at varying voltages (1500-3000 V), pulse repetitions (n = 70-100), pulse length (70-100 µsec), and electrode spacing (1.5-2 cm). In muscle tissue, electrodes were placed exactly parallel, in plane, or perpendicular to paraspinal muscle fibers; in kidney tissue, in the cortex or adjacent to the renal medulla; and in liver tissue, with and without metallic or plastic plates placed 1-2 cm from electrodes. Ablation zones were determined at gross pathologic (90-120 minutes after IRE) and immunohistopathologic examination (6 hours after) for apoptosis and heat-shock protein markers. Multivariate analysis of variance with multiple comparisons and/or paired t tests and regression analysis were used for analysis. RESULTS: Mean (± standard deviation) ablation zones in muscle were 6.2 cm ± 0.3 × 4.2 cm ± 0.3 for parallel electrodes and 4.2 cm ± 0.8 × 3.0 cm ± 0.5 for in-plane application. Perpendicular orientation resulted in a cross-shaped zone. Orientation significantly affected IRE current applied (28.5-31.7A for parallel, 29.5-39.7A for perpendicular; P = .003). For kidney cortex, ovoid zones of 1.5 cm ± 0.1 × 0.5 cm ± 0.0 to 2.5 cm ± 0.1 × 1.3 cm ± 0.1 were seen. Placement of electrodes less than 5 mm from the medullary pyramids resulted in treatment effect arcing into the collecting system. For liver tissue, symmetric 2.7 cm ± 0.2 × 1.4 cm ± 0.3 coagulation areas were seen without the metallic plate but asymmetric coagulation was seen with the metallic plate. CONCLUSION: IRE treatment zones are sensitive to varying electrical conductivity in tissues. Electrode location, orientation, and heterogeneities in local environment must be considered in planning ablation treatment. Online supplemental material is available for this article.

Simultaneous Multifocal Intracranial Haemorrhages Associated with Staphylococcus Aureus Endocarditis: A Plausible Role for Diclofenac Administration.

Introduction: Intracranial haemorrhage may complicate infective endocarditis, caused by ruptured mycotic aneurysms or haemorrhagic transformation of brain septic emboli. The risk of intracranial bleeding may increase with the use of non-steroidal anti-inflammatory agent (NSAIDs). Case description: We report on a 53-year-old male patient with a past history of intravenous drug abuse, who was treated with diclofenac (75 mg IM) for a few hours of preceding fever and arthralgia. Seven hours later he was hospitalised with impaired consciousness and hemiparesis. Evaluation revealed multiple intracranial haemorrhages, at least one originating from a mycotic aneurysm. Repeated blood cultures grew methicillin-resistant Staphylococcus aureus (MRSA), and echocardiography revealed a vegetation on the mitral valve, establishing the diagnosis of bacterial endocarditis. Conclusion: The abrupt simultaneous multifocal intracranial bleeds shortly following the administration of NSAIDs for a few hours of febrile disease, one clearly originating from a mycotic aneurism, are exceptional. This raises a possibility of a role for diclofenac the intracranial bleeding diathesis in this unique clinical presentation. Intracranial haemorrhage in the set-up of undiagnosed infective endocarditis (IE) might be added to the long list of potential adverse outcomes of NSAID administration, and the possibility of IE should be considered before their administration for febrile disease of undetermined cause. LEARNING POINTS: Intracranial haemorrhage in the set-up of undiagnosed infective endocarditis might be added to the long list of potential adverse outcomes of NSAID administration.The possibility of infective endocarditis should be considered before the administration of NSAIDs for febrile disease of an undetermined cause.

Non-invasive assessment of normal and impaired iron homeostasis in the brain.

Strict iron regulation is essential for normal brain function. The iron homeostasis, determined by the milieu of available iron compounds, is impaired in aging, neurodegenerative diseases and cancer. However, non-invasive assessment of different molecular iron environments implicating brain tissue's iron homeostasis remains a challenge. We present a magnetic resonance imaging (MRI) technology sensitive to the iron homeostasis of the living brain (the r1-r2* relaxivity). In vitro, our MRI approach reveals the distinct paramagnetic properties of ferritin, transferrin and ferrous iron ions. In the in vivo human brain, we validate our approach against ex vivo iron compounds quantification and gene expression. Our approach varies with the iron mobilization capacity across brain regions and in aging. It reveals brain tumors' iron homeostasis, and enhances the distinction between tumor tissue and non-pathological tissue without contrast agents. Therefore, our approach may allow for non-invasive research and diagnosis of iron homeostasis in living human brains.