Early Postoperative Magnetic Resonance Imaging Research Articles

The Predictive Role of Early Postoperative Magnetic Resonance Imaging After Endoscopic Third Ventriculostomy

ObjectiveEndoscopic third ventriculostomy (ETV) is a treatment option for obstructive hydrocephalus; reported success rates vary. We investigated immediate postoperative magnetic resonance imaging (MRI) to evaluate the role of imaging parameters associated with outcomes. MethodsRetrospective chart review was performed patients undergoing initial ETV between 2005 -2019. Patients with pre- and postoperative MRI with follow-up >one year were included. The following were noted: changes in subarachnoid CSF, third ventricle diameter (TV), bowing of the TV floor, and postoperative flow void. Kaplan-Meier survival methods were used to assess ETV success, Univariable and multivariable Cox proportional-hazards models were fitted to assess factors contributing to ETV success. ResultsFifty-eight subjects were included. Nineteen (32.8%) experienced failure within one year, individually, no single imaging parameter predicted success. However, all cases with failure had no identifiable flow void. Any postoperative radiological change was not consistently associated with decreased odds of failure. Obstructive hydrocephalus treated with ETV demonstrated significantly better ETV success than patients treated for non-obstructive hydrocephalus Inter-observer reliability was moderate for two of the radiological variables and substantial for one of the radiological variables. ConclusionsIndividually none of the qualitative radiologic parameters measured in our study predicted ETV success. Absence of a flow void predicted ETV failure, but additional studies are needed to determine its true negative predictive value. Inability to clarify which specific parameter predicts success, reflects the limited role of immediate postoperative imaging in influencing clinical management.

Clinic and treatment of intramedullary ependymomas

Objective — to improve the results of treatment of patients with intramedullary ependymomas. Materials and methods. The results of treatment of 29 patients (14 men and 15 women aged 18 to 64 years) with intramedullary ependymomas operated on at the Romodanov Institute of Neurosurgery of the National Academy of Medical Sciences of Ukraine were analysed. All patients who were scheduled for surgery underwent magnetic resonance imaging (MRI) with paramagnetic contrast agent. The preoperative and postoperative neurological status was assessed using the modified McCormick scale. Results. Microsurgical technique for removal of spinal cord tumors was used in all 29 observations. According to the volume of tumor removal, operations with total (12 observations), subtotal (9 observations) and partial (8 observations) removal were distinguished. Removal of at least 95 % of the tumor volume, which was confirmed by visualization with a microscope during surgery and early postoperative MRI, was considered total. At the time of discharge from the hospital, in 11 patients (37.9 %) the neurological condition improved compared to the preoperative period, in 13 (44.8 %) it remained unchanged, and in 5 (17.2 %) there was an increase in neurological symptoms. 12 patients were examined 12—36 months after the operation. Improvement compared to the preoperative period was found in 10 patients, and no changes in 2. There were no cases of worsening of neurological symptoms during this period. MRI performed before discharge from the hospital showed almost normal spinal cord diameter in the area of surgical procedures, and MRI performed ≥ 3 months after total tumour removal showed atrophic changes in the spinal cord with ependymoma localisation at the thoracic level. Conclusions. Intramedullary ependymomas can be totally removed, and surgical intervention must be carried out immediately after the diagnosis before the appearance of signs of increasing neurological deficit. Thanks to the use of microsurgical techniques and an intraoperative microscope, it is possible to achieve positive functional results during the total removal of intramedullary tumors.

NIMG-04. PRE-RADIATION PROGRESSION PREDICTION IN GLIOBLASTOMA PATIENTS

Abstract Pre-Radiation Progression (PRP) has been identified as an increase ( > 25%) in the size of the residual brain tumor or interval development of a new tumor after surgical resection but prior to radiation therapy. Glioblastoma (GB) patients with PRP have worse survival outcome compared to patients without PRP (non-PRP).The standardized approach to identify PRP in GB patients is to manually compare early post-operative MRI to radiation planning MRI. In this study, we investigate the efficacy of traditional radiomics and sophisticated multi-resolution fractal texture features to differentiate PRP from non-PRP. Radiation-planning T1C magnetic resonance imaging (MRI) of 13 PRP and 13 non-PRP patients is analyzed to develop the classification method. For each patient, around 600 conventional radiomics and fractal texture features are obtained from tumor tissue and entire brain areas. We propose a two-step feature selection process followed by ensemble classification. In the first step of feature selection, we apply a beta-mixture based graphical model to identify correlations between the extracted features. The features are the nodes of the graph and the edges of the graph denote the correlations among the features and adjacency to PRP node. After the first step feature selection, the 21 selected features are used in the second step feature selection based on accuracy, similarity, and stability of each feature to yield the final 12 features. Lastly, we utilize the final 12 selected features for ensemble classification of PRP from non-PRP. With leave-one-out cross validation, the predictive model has an area under curve (AUC) of 0.79 and accuracy of 80% which indicates the discriminatory function of imaging features to differentiate PRP patients from non-PRP. The experimental results show the diagnostic ability of radiation planning imaging features to predict PRP from non-PRP.

The Río Hortega University Hospital Glioblastoma dataset: A comprehensive collection of preoperative, early postoperative and recurrence MRI scans (RHUH-GBM).

Glioblastoma, a highly aggressive primary brain tumor, is associated with poor patient outcomes. Although magnetic resonance imaging (MRI) plays a critical role in diagnosing, characterizing, and forecasting glioblastoma progression, public MRI repositories present significant drawbacks, including insufficient postoperative and follow-up studies as well as expert tumor segmentations. To address these issues, we present the "Río Hortega University Hospital Glioblastoma Dataset (RHUH-GBM)," a collection of multiparametric MRI images, volumetric assessments, molecular data, and survival details for glioblastoma patients who underwent total or near-total enhancing tumor resection. The dataset features expert-corrected segmentations of tumor subregions, offering valuable ground truth data for developing algorithms for postoperative and follow-up MRI scans.

P19.03.B IMPLEMENTATION OF RESECT CATEGORIES FOR EXTENT OF RESECTION STRESS THE LONG-TERM CLINICAL BENEFIT OF SUPRAMAXIMAL CONTRAST ENHANCING RESECTION IN A RETROSPECTIVE COHORT OF NEWLY DIAGNOSED IDH WT GLIOBLASTOMA PATIENTS

Abstract BACKGROUND to assess the long-term benefit associated with supramarginal CE resection and to apply ReSECT criteria for extent of resection in patients with primary glioblastoma IDH wild-type. MATERIAL AND METHODS We performed a retrospective search in the institutional of Livorno Hospital for adult patients with primary GBM IDH wild-type. We assess residual tumor volumetry in the early post-operative magnetic resonance imaging by the 3dslicer software. We attributed EOR classes according to ReSECT criteria based on residual contrast and non-contrast enhancing tumor volumes. We performed multivariate analysis by Cox regression including main known prognostic factors and MGMT promoter status assessed by pyrosequencing. IDH wild-type status was defined on both IDH1 and IDH2 genes. RESULTS We identified 173 patients who underwent surgery for confirmed primary glioblastoma IDH wild-type in our institutions from 2016 and 2022. Male/female ratio was 1.6, median age at diagnosis 68 years old (yo) (range 30-83), median KPS before surgery was 80 (range 30-100) with no significant variation at the post-operative stage. Forty out of 173 (23%) patients received a supramarginal CE resection (class 1) in the whole cohort; prevalence of class 1 resection was the highest in the subgroup of patients aged ≤ 65 yo (27%) than the subgroup of >65 ≤ 75 yo (22%) and the subgroup of >75 yo (14%). The rate of class 1 resection was not different between patients with tumors located in the right and in left hemisphere (24% and 23% respectively). We analysed survival in patients treated with adjuvant RT-TMZ and found a significant longer OS in patients operated with resection class 1 (16.7 months) than other classes (p<0.0001). Long term benefit resulted the strongest in the subgroup of patients aged ≤ 65 yo (median OS 23.8 months). Multivariate analysis confirmed EOR according to the ReSECT criteria as the strongest independent predictor factor of OS (HR 0.6, p=0.004). CONCLUSION We efficiently implemented ReSECT criteria for EOR in our retrospective cohort of patients with primary GBM IDH wild-type. Supramarginal CE resection defined as no residual CE and ≤ 5 cm of nCE on the post-operative imaging emerged as the strongest predictive factor of survival.

Significance of Early Postoperative Magnetic Resonance Imaging following Intracranial Meningioma Resection.

The significance of early postoperative magnetic resonance imaging (MRI) for meningioma resection has not yet been evaluated. We retrospectively reviewed patients with intracranial meningiomas resected at our institute between 2011 and 2021. Early postoperative MRI with contrast enhancement was routinely performed within 48 h after surgery while first follow-up MRI was performed approximately after 6 months. MRI findings were reviewed, and the risk factors for postoperative infarction and early recurrence were analyzed. Among the 245 resections performed, early postoperative MRI was performed in 200 cases. Postoperative radiological and symptomatic infarctions occurred in 54 (27%) and 17 patients (9%), respectively. Diameter > 5 cm (p = 0.015) and skull base location (p = 0.010) were independent risk factors for radiological infarctions. Follow-up postoperative MRI performed in 180 patients (90%) detected early recurrence in 24 patients (13%). Non-gross total resection was an independent risk factor for early recurrence (p < 0.0001). Additionally, early recurrence after gross total resection occurred significantly more frequently in meningiomas with dural sinus involvement than in those without (8.3% vs. 0%, p = 0.018). Thus, early postoperative MRI may enable the timely assessment of postoperative neurological deficits, especially after large skull base meningioma resections along with accurate detection of early recurrence, which is critical for meningiomas with dural sinus involvement.

Early Postoperative Magnetic Resonance Imaging Findings Related to Electrocauterization for Cerebellar Reduction During Chiari Decompression Surgery.

Cerebellar tonsillar reduction or resection can be performed as part of the surgical management of Chiari type 1 malformation when it is accompanied by symptomatic brainstem compression or syringomyelia. The purpose of this study is to characterize the early postoperative magnetic resonance imaging (MRI) findings in patients with Chiari type 1 malformations who undergo cerebellar tonsillar reduction via electrocautery. The extent of cytotoxic edema and microhemorrhages demonstrated on MRI scans obtained within 9 days following surgery was assessed and correlated with neurological symptoms. Cytotoxic edema was found on all postoperative MRI examinations included in this series, with superimposed hemorrhage in 12 of 16 patients (75%) and was primarily located along the margins of the cauterized inferior cerebellum. Cytotoxic edema was present beyond the margins of the cauterized cerebellar tonsils in 5 of 16 patients (31%) and was associated with new focal neurological deficits in 4 of 5 patients (80%). Cytotoxic edema and hemorrhages along the cerebellar tonsil cautery margins can be expected findings in early postoperative MRI in patients who undergo Chiari decompression accompanied by tonsillar reduction. However, the presence of cytotoxic edema beyond these regions can be associated with new focal neurological symptoms.

Comparison of EPI DWI and STEAM DWI in Early Postoperative MRI Controls After Resection of Tumors of the Central Nervous System

PurposeDiffusion-weighted imaging (DWI) is important for differentiating residual tumor and subacute infarctions in early postoperative magnetic resonance imaging (MRI) of central nervous system (CNS) tumors. In cases of pneumocephalus and especially in the presence of intraventricular trapped air, conventional echo-planar imaging (EPI) DWI is distorted by susceptibility artifacts. The performance and robustness of a newly developed DWI sequence using the stimulated echo acquisition mode (STEAM) was evaluated in patients after neurosurgical operations with early postoperative MRI.MethodsWe compared EPI and STEAM DWI of 43 patients who received 3‑Tesla MRI within 72 h after a neurosurgical operation between 1 October 2019 and 30 September 2021. We analyzed susceptibility artifacts originating from air and blood and whether these artifacts compromised the detection of ischemic changes after surgery. The DWI sequences were (i) visually rated and (ii) volumetrically analyzed.ResultsIn 28 of 43 patients, we found severe and diagnostically relevant artifacts in EPI DWI, but none in STEAM DWI. In these cases, in which artifacts were caused by intracranial air, they led to a worse detection of ischemic lesions and thus to a possible failed diagnosis or lack of judgment using EPI DWI. Additionally, volumetric analysis demonstrated a 14% smaller infarct volume detected with EPI DWI. No significant differences in visual rating and volumetric analysis were detected among the patients without severe artifacts.ConclusionThe newly developed version of STEAM DWI with highly undersampled radial encodings is superior to EPI DWI in patients with postoperative pneumocephalus.

The Fate of Fat Graft in Extended Endoscopic Transtuberculum-Transplanum Approaches.

To analyze the long-term fate of autologous fat graft in skull base reconstruction after an extended endoscopic transtuberculum-transplanum approach. Data from 98 consecutive patients undergoing a transtuberculum-transplanum approach and skull base reconstruction using the 3F technique between June 2017 and January 2022 were retrospectively analyzed. Fat graft volume was measured on postoperative day 1 computed tomography scan and early (≤15 days), 3-month, and 1-year magnetic resonance imaging scans. Fat graft volumes and resorption rate were calculated in patients with a complete radiological follow-up and correlated to demographic, pathological, and surgical features. Fat volumes and resorption rate were calculated in 55 patients. Mean volume of fat on postoperative day 1 computed tomography scan was 3.58 ± 1.89 cm3 and on early, 3-month, and 1-year postoperative magnetic resonance imaging scans was 2.45 ± 1.57 cm3, 1.40 ± 0.76 cm3, and 0.92 ± 0.56 cm3, respectively. Resorption rate was 44% after 3 months and 67% after 1 year. Resorption rate did not significantly correlate with demographic, pathological, and surgical features. Cerebrospinal fluid leak requiring redo surgery occurred in 1 patient (1/98, 1.2%). There were 6 cases of visual worsening (6/98, 6.1%); no cases correlated to fat overpacking. No delayed complications at the donor site or at the grafting site were noted. Autologous fat graft in skull base reconstruction is observed to shrink significantly over time, reaching 67% in 1 year. Its use is associated with excellent outcomes, making it a favored material for skull base reconstruction.

Remodeling of Epidural Fluid Hematoma after Uniportal Lumbar Endoscopic Unilateral Laminotomy with Bilateral Decompression: Comparative Clinical and Radiological Outcomes with a Minimum Follow-up of 2 Years.

Retrospective cohort study. To evaluate the clinical and radiological effects of epidural fluid hematoma in the medium term after lumbar endoscopic decompression. There is limited literature comparing the effect of postoperative epidural fluid hematoma after uniportal endoscopic decompression. Magnetic resonance imaging (MRI) and clinical evaluation were performed for patients with single-level uniportal endoscopic lumbar decompression with a minimum follow-up of 2 years. A total of 126 patients were recruited with a minimum follow-up of 26 months. The incidence of epidural fluid hematoma was 27%. Postoperative MRI revealed a significant improvement in the postoperative dura sac area at postoperative day 1 and at the upper endplate at 6 months in the hematoma cohort (39.69±15.72 and 26.89±16.58 mm2) as compared with the nonhematoma cohort (48.92±21.36 and 35.1±20.44 mm2), respectively (p <0.05); and at the lower endplate on postoperative 1 day in the hematoma cohort (51.18±24.69 mm2) compared to the nonhematoma cohort (63.91±27.92 mm2) (p <0.05). No significant difference was observed in the dura sac area at postoperative 1 year in both cohorts. The hematoma cohort had statistically significant higher postoperative 1-week Visual Analog Scale (VAS; 3.32±0.68) pain and Oswestry Disability Index (ODI; 32.65±5.56) scores than the nonhematoma cohort (2.99±0.50 and 30.02±4.84, respectively; p <0.05). No significant difference was found at the final follow-up VAS, ODI, and MRI dura sac area. Epidural fluid hematoma is a common early postoperative MRI finding in lumbar endoscopic unilateral laminotomy with bilateral decompression. Conservative management is the preferred treatment option for patients who do not have a neurological deficit. Symptoms last only a few days and are self-limiting. A common endpoint is a remodeled fluid hematoma and the subsequent expansion of the dura sac area.

Second-look surgery after pediatric brain tumor resection – Single center analysis of morbidity and volumetric efficacy

IntroductionPostoperative residual tumor can occur for intentional or unintentional reasons. Decision-making regarding second-look surgery has to weigh molecular biology, probability of total resection and prognostic relevance against potential additional morbidity. In interdisciplinary tumor boards the neurosurgeon has to estimate risk and efficacy of second-look surgery in individual cases, based on precise data. Research questionAim of this study was to provide such data by analyzing morbidity and volumetric efficacy of second-look surgery at a designated pediatric neuro-oncology unit. Material and methodsChildren who received second-look surgery in 2007–2018 after incomplete resections were analyzed retrospectively. Measurements were performed on early postoperative magnetic resonance imaging, comparing axial diameter-based measurement as well as computer-assisted volumetric analysis. Results59 patients (37% of the overall cohort; 21 female; mean age: 8 ​± ​5 years) received a subtotal (n ​= ​35) or near total (n ​= ​24) resection. After interdisciplinary case review, 12 of these patients received second-look surgery mainly for residual ependymoma. This led to further tumor volume reduction in all cases (new degrees of resection: subtotal ​= ​2, near total ​= ​6, gross total ​= ​4). No new permanent morbidity or perioperative mortality was observed. Discussion and conclusionSecond-look surgery did not increase mortality and permanent morbidity, had an 8% rate of transient morbidity and achieved tumor volume reduction above 95% in 75% of selected cases, with 4 additional gross total resections. Second-look surgery is safe and effective with regard to volumetric outcome parameters even in cases with good initial resections, although the role of second-look surgery regarding oncological outcome has to be further investigated in times of personalized molecular medicine.

Management of Spinal Dumbbell Tumors via a Minimally Invasive Posterolateral Approach and Carbon Fiber–Reinforced Polyether Ether Ketone Instrumentation: Technical Note and Surgical Case Series

Stand-alone minimally invasive approaches for the surgical management of spinal dumbbell tumors carry the risk of incomplete resections and impaired hemostasis. More-extensive approaches require subsequent instrumentation with metal artifacts impairing follow-up imaging. Here, we present a technical note on percutaneous instrumentation using carbon fiber-reinforced polyether ether ketone (CFR-PEEK) hardware combined with a minimally invasive posterolateral approach for tumor resection. We present a Technical Note and according case series of 7 patients with dumbbell tumors in the lumbar and thoracolumbar spine operated on between 2017 and 2020. CFR-PEEK pedicle screws and rods were inserted percutaneously. Afterwards, a dedicated self-standing retractor for posterolateral approaches was connected to the screws. Following a unilateral facetectomy, the tumor was resected in a microsurgical fashion. Clinical data are reported with respect to the Preferred Reporting Of CasE Series in Surgery (PROCESS) guidelines. Four patients presented with de novo tumors. Three patients were treated for residual tumor mass after previous surgeries. Gross total resection was achieved in all 7 cases, as demonstrated by early postoperative magnetic resonance imaging. Histopathology demonstrated 5 World Health Organization grade I schwannomas, 1 grade II hemangiopericytoma, and 1 cavernous hemangioma. No postoperative complications were observed. CFR-PEEK hardware allowed unambiguous visualization of the resection cavity on follow-up imaging. Resection of dumbbell tumors via a minimally invasive posterolateral approach and instrumentation with CFR-PEEK hardware allows maximal and safe resection. Due to lack of major metal artifacts, carbon fiber hardware improves the interpretation of follow-up imaging as well as planning of radiation if required for tumor recurrence.

Intraoperative Ultrasound-Assisted Extent of Resection Assessment in Pediatric Neurosurgical Oncology

Central nervous system tumors represent the most frequent solid malignancy in the pediatric population. Maximal safe surgical resection is a mainstay of treatment, with significant prognostic impact for the majority of histotypes. Intraoperative ultrasound (ioUS) is a widely available tool in neurosurgery to assist in intracerebral disease resection. Despite technical caveats, preliminary experiences suggest a satisfactory predictive ability, when compared to magnetic resonance imaging (MRI) studies. Most of the available evidence on ioUS applications in brain tumors derive from adult series, a scenario that might not be representative of the pediatric population. We present our preliminary experience comparing ioUS-assisted resection assessment to early post-operative MRI findings in 154 consecutive brain tumor resections at our pediatric neurosurgical unit. A high concordance was observed between ioUS and post-operative MRI. Overall ioUS demonstrated a positive predictive value of 98%, a negative predictive value of 92% in assessing the presence of tumor residue compared to postoperative MRI. Overall, sensibility and specificity were 86% and 99%, respectively. On a multivariate analysis, the only variable significantly associated to unexpected tumor residue on postoperative MRI was histology. Tumor location, patient positioning during surgery, age and initial tumor volume were not significantly associated with ioUS predictive ability. Our data suggest a very good predictive value of ioUS in brain tumor resective procedures in children. Low-grade glioma, high-grade glioma and craniopharyngioma might represent a setting deserving specific endeavours in order to improve intraoperative extent of resection assessment ability.

Early Postoperative Magnetic Resonance in the Diagnosis of Persistent Juvenile Angiofibroma.

Despite improvements in the treatment of juvenile angiofibroma (JA), the rate of persistence (pJA) is still not negligible. In the present study, we assessed the value of early postoperative magnetic resonance imaging (MRI) in depicting unintentional pJAs and designed a MRI-driven decisional flow-chart for pJA management and follow-up. Observational study. Patients undergoing early postoperative MRI after endoscopic resection of JA in the Unit of Otorhinolaryngology - ASST Spedali Civili, University of Brescia from 2007 to 2017 were enrolled. MRI was defined as negative or positive based on defined radiological criteria. The diagnostic performance of MRI was evaluated. The analysis included 26 patients, with a mean age of 16.5 years (range, 11-25). Early MRI was negative for pJA in 21 (80.8%) patients and positive in five (19.2%). No patient with a negative finding was found positive at subsequent follow-up MRIs. The accuracy of a positive finding was confirmed by pathologic examination (three cases) or follow-up MRIs (two cases). The diagnostic performance of MRI was excellent with sensitivity and specificity of 100%. An MRI-driven flow-chart for pJA management and follow-up was designed. Early postoperative MRI demonstrated a high diagnostic accuracy in the detection of unintentional pJA. Our MRI-driven strategy and decisional flow-chart could aid in the decision-making process in the management of pJA and definition of postoperative surveillance. 4 Laryngoscope, 131:E2436-E2441, 2021.

Osteochondral Allograft Transplant of the Patella Using Femoral Condylar Allografts: Magnetic Resonance Imaging and Clinical Outcomes at Minimum 2-Year Follow-up

Background:Fresh osteochondral allograft transplant (OCA) has good outcomes in the knee. However, donor tissue for patellar OCA is limited. Outcomes after nonorthotopic OCA of the patella using more readily available femoral condylar allograft (FCA) tissue have not been previously reported.Purpose:To assess short-term magnetic resonance imaging (MRI) and minimum 2-year clinical outcomes of nonorthotopic patellar OCA using an FCA donor.Study Design:Case series; Level of evidence, 4.Methods:A prospective institutional cartilage registry was reviewed to identify patients treated with patellar OCA using an FCA donor between August 2009 and June 2016. OCA plugs were obtained from the FCA at its trochlear-condylar junction and implanted into the recipient patellar lesion. Early postoperative MRI scans were graded by a blinded musculoskeletal radiologist using the Osteochondral Allograft MRI Scoring System (OCAMRISS). International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), Knee Outcomes Survey–Activities of Daily Living (KOS-ADL), and pain visual analog scale (VAS) scores were collected preoperatively and at minimum 2 years postoperatively, and outcomes were compared using the paired t test.Results:A total of 25 patients were included for clinical outcome analysis and 20 patients for MRI analysis. MRI scans obtained at a mean of 11.4 months (range, 6-22 months) postoperatively showed a mean total OCAMRISS score of 9.0 (range, 7-11); mean bone, cartilage, and ancillary subscores were 2.6, 3.7, and 2.6, respectively. At the latest follow-up (mean, 46.5 months; range, 24-85 months), postoperative improvements were noted in IKDC (from 45.0 to 66.2; P = .0002), KOS-ADL (from 64.3 to 80.4; P = .0012), and VAS (from 5.1 to 3.4; P = .001) scores, with IKDC and KOS-ADL scores above the corresponding previously reported minimal clinically important difference.Conclusion:In this study, patellar OCA using nonorthotopic FCA led to significant short-term improvements in pain and patient-reported outcomes. The majority of nonorthotopic patellar grafts demonstrated full osseous incorporation and good restoration of the articular surface on MRI at short-term follow-up.

Frequency and Evolution of New Postoperative Enhancement on 3 Tesla Intraoperative and Early Postoperative Magnetic Resonance Imaging.

Intraoperative magnetic resonance imaging (IO-MRI) provides real-time assessment of extent of resection of brain tumor. Development of new enhancement during IO-MRI can confound interpretation of residual enhancing tumor, although the incidence of this finding is unknown. To determine the frequency of new enhancement during brain tumor resection on intraoperative 3 Tesla (3T) MRI. To optimize the postoperative imaging window after brain tumor resection using 1.5 and 3T MRI. We retrospectively evaluated 64 IO-MRI performed for patients with enhancing brain lesions referred for biopsy or resection as well as a subset with an early postoperative MRI (EP-MRI) within 72 h of surgery (N=42), and a subset with a late postoperative MRI (LP-MRI) performed between 120 h and 8 wk postsurgery (N=34). Three radiologists assessed for new enhancement on IO-MRI, and change in enhancement on available EP-MRI and LP-MRI. Consensus was determined by majority response. Inter-rater agreement was assessed using percentage agreement. A total of 10 out of 64 (16%) of the IO-MRI demonstrated new enhancement. Seven of 10 patients with available EP-MRI demonstrated decreased/resolved enhancement. One out of 42 (2%) of the EP-MRI demonstrated new enhancement, which decreased on LP-MRI. Agreement was 74% for the assessment of new enhancement on IO-MRI and 81% for the assessment of new enhancement on the EP-MRI. New enhancement occurs in intraoperative 3T MRI in 16% of patients after brain tumor resection, which decreases or resolves on subsequent MRI within 72 h of surgery. Our findings indicate the opportunity for further study to optimize the postoperative imaging window.

Impact of Multifidus Muscle Swelling on C5 Palsy After Cervical Laminoplasty.

Retrospective radiological analysis OBJECTIVE.: The aim of this study was to identify the effects of posterior cervical muscle swelling on C5 palsy (C5P) by evaluating early postoperative magnetic resonance (MR) images. Cervical laminoplasty is an established technique, but the risk of C5P after surgery has not been fully resolved. Studies have reported that lateral stretching and postoperative swelling of the multifidus muscle may cause stretching of the medial branches and cervical nerves. A total of 214 C5 nerves of 107 consecutive patients who underwent laminoplasty were examined. We reviewed their demographic and surgical data and radiographic and MR images as parameters, including the axial cross-sectional area (CSA) of the posterior muscles. The patients and C5 nerves were divided into C5P and non-C5P groups. The parameters and changes were compared between the two groups to examine correlations with C5P. In demographic data, age, sex, history of smoking, diabetes mellitus, and preoperative Japanese Orthopedic Association scores were not significantly different between the groups. Only body mass index (BMI) was significantly higher in the C5P group. Regarding the surgical and imaging data, the number of laminoplasty, operative time, decompression trough width, cervical sagittal alignment, preoperative spinal cord rotation, and posterior shift of the spinal cord were not significantly different, but the multifidus CSA change ratio was significantly higher in the C5P group. Multiple logistic regression analyses revealed that the multifidus CSA change ratio and BMI were significant independent factors. Multifidus swelling is associated with C5P, possibly through traction of the C5 nerve via the medial branches of the cervical dorsal rami. The medial branch is the shortest of the dorsal rami and may have the largest effect by traction force. Therefore, a gentle maneuver of the deep posterior muscles during surgery is a potential countermeasure to prevent C5P. 3.

Effect of Autogenous Bone Marrow Aspirate Treatment on Magnetic Resonance Imaging Integration of Osteochondral Allografts in the Knee: A Matched Comparative Imaging Analysis

To accurately evaluate the effects of bone marrow aspirate (BMA) augmentation on osteochondral allograft (OCA) integration on early postoperative magnetic resonance imaging (MRI) using the comprehensive Osteochondral Allograft MRI Scoring System (OCAMRISS). This imaging study compared patients who underwent OCA transplantation with and without BMA augmentation for the treatment of focal osteochondral defects in the knee performed by a single surgeon between July 2013 and July 2017. Patients were excluded if they underwent implantation of premade plugs, had an overlapping OCA configuration ("snowman" technique), or did not undergo MRI at 6months postoperatively. Patients were matched by lesion location, lesion size, age, and body mass index, as well as whether they underwent previous surgical procedures. Data were analyzed using descriptive statistics, Spearman correlation, the independent t test, the Mann-Whitney U test, and the χ2 test. A total of 58 patients (29 per group) were included in this study, with an average age of 36.4 ± 10.1years and mean body mass index of 28.6 ± 5.1. The mean size of the analyzed OCA plugs was 3.3 ± 1cm2. At an average imaging follow-up of 5.6 ± 1months, 86.2% of the grafts had achieved osseous integration at the graft-host junction and 75.9% did not show any cystic changes in the subchondral bone. No difference in any OCAMRISS subscale was seen comparing OCAs with and without BMA augmentation (P>.05). Specifically, osseous integration and subchondral cyst formation were comparable between groups (P= .128 and P= .539, respectively). OCAs showed excellent osseous integration at the graft-host junction on 6-month postoperative MRI. The treatment of OCAs with autogenous BMA did not result in superior imaging outcomes when analyzed using the OCAMRISS. Level III, case-control study.

Extension Pathways of Pituitary Adenomas with Cavernous Sinus Involvement and Its Surgical Approaches

Resection and remission rates are low in pituitary adenomas that invade the cavernous sinus (CS) because of the complexity of the region. In this study, the authors describe the invasion patterns and surgical approaches for these corridors. Endoscopic transsphenoidal surgery was performed in 1849 patients between August 1997 and 2017; 381 of these patients were included in the study because of the presence of CS invasion. CS invasion pathways and CS compartments were defined, and these patients were divided into 3 groups according to their invasion corridors. The cases were also categorized according to the Knosp classification. A total of 381 patients were included, 199 of whom were men. The mean follow-up duration was 34 months. In preoperative magnetic resonance imaging measurements, 2 of 381 patients had microadenoma, 350 of 381 had macroadenoma, and 29 of 381 had giant adenoma. When the early postoperative magnetic resonance images were compared with the preoperative images, 91 of 381 (23.9%) patients had subtotal tumor resection, 83 of 381 (21.8%) had near-total tumor resection, and 207 of 381 (54.3%) had gross total tumor resection. Considering the invasion classification with endoscopic confirmation, there were 168 of 381 (44.1%) cases of isolated medial corridor involvement, 74 of 381 (19.4%) cases of isolated lateral corridor involvement, and 139 of 381 (36.5%) cases of total involvement cases. Medial wall defect has no importance in the invasion. Similarly, seeing the existence of pitholes is not an invasion criterion. Pituitary adenomas invade 4 compartments: the superior, anteroinferior, posterior, and lateral compartments of the CS via 2 corridors. Increased experience, novel approaches, and endoscopic developments have contributed immensely to this field.

Multiple Burr-Hole Surgery for the Treatment of Moyamoya Disease and Quasi-Moyamoya Disease in Children: Preliminary Surgical and Imaging Results

Moyamoya disease (MMD) is characterized by a progressive spontaneous occlusion of distal internal carotid arteries and its main branches. It is necessary to promptly diagnose and treat this condition, especially in children, because of the high risk of stroke and consequent severe disability. In this study, we examine the role of multiple burr-hole surgery (MBHS) in the treatment of pediatric patients with MMD and quasi-MMD and the role of perfusion magnetic resonance imaging (MRI) in the surgical indication and during follow-up. We reviewed preoperative, early postoperative, and late postoperative MRI perfusion and digital subtraction angiography images together with clinical and surgical outcomes in 10 children with MMD treated by MBHS. Fourteen MBHS procedures (6 unilateral, 2 bilateral, and 2 single-setting bilateral) were performed in 10 children. Clinical and radiologic follow-up for all patients ranges from 16 months to 7 years. No ischemic events (transient ischemic attacks or stroke) occurred during the follow-up period. Postoperative digital subtraction angiography showed good revascularization around the burr-hole sites in all patients. The functional efficacy of the surgery was confirmed by dynamic susceptibility contrast perfusion MRI studies in 8 patients. Our data underline the good rate of success of MBHS in pediatric MMD and quasi-MMD. This technique results in good collateral revascularization, improved cerebral perfusion and excellent short and long-term symptoms control, with low perioperative risk. Postoperative changes of perfusion parameters and ivy sign MRI finding seem to show a positive correlation and mainly occur in posterior middle cerebral artery territory.