Publications by authors named "John K Hald"

Article Synopsis
  • The study examines the timing and failure rates of ventriculoperitoneal (VP) shunts in adults after brain tumor surgeries.
  • It found that out of 4,774 craniotomies, only 85 patients (1.8%) developed VP shunt dependency, with most patients needing a shunt about 1.9 months post-surgery.
  • The research highlights that 20% of patients experienced shunt failure within 90 days, although factors like age and tumor type did not significantly influence this early failure rate.
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In a blind, dual-center, multi-observer setting, we here identify the pre-treatment radiologic features by Magnetic Resonance Imaging (MRI) associated with subsequent treatment options in patients with glioma. Study included 220 previously untreated adult patients from two institutions (94 + 126 patients) with a histopathologically confirmed diagnosis of glioma after surgery. Using a blind, cross-institutional and randomized setup, four expert neuroradiologists recorded radiologic features, suggested glioma grade and corresponding confidence.

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Purpose: According to the revised World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS) of 2016, oligodendrogliomas are now defined primarily by a specific molecular signature (presence of IDH mutation and 1p19q codeletion). The purpose of our study was to assess the value of dynamic susceptibility contrast MR imaging (DSC-MRI) and diffusion-weighted imaging (DWI) to characterize oligodendrogliomas and to distinguish them from astrocytomas.

Methods: Seventy-one adult patients with untreated WHO grade II and grade III diffuse infiltrating gliomas and known 1p/19q codeletion status were retrospectively identified and analyzed using relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) maps based on whole-tumor volume histograms.

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The efficacy of tumor removal via craniotomies on preoperative hydrocephalus (HC) in adult patients with intracranial tumors is largely unknown. Therefore, we sought to evaluate the effect of tumor resection in patients with preoperative HC and identify the incidence and risk factors for postoperative VP shunt dependency. All craniotomies for intracranial tumors at Oslo University Hospital in patients ≥ 18 years old during a 10-year period (2004-2013) were reviewed.

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Objective: According to the new World Health Organization 2016 classification for tumors of the central nervous system, 1p/19q codeletion defines the genetic hallmark that differentiates oligodendrogliomas from diffuse astrocytomas. The aim of our study was to evaluate whether relative cerebral blood volume (rCBV) and apparent diffusion coefficient (ADC) histogram analysis can stratify survival in adult patients with genetic defined diffuse glioma grades II and III.

Methods: Sixty-seven patients with untreated diffuse gliomas World Health Organization grades II and III and known 1p/19q codeletion status were included retrospectively and analyzed using ADC and rCBV maps based on whole-tumor volume histograms.

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The risk of developing a de novo shunt-dependent hydrocephalus (HC) after undergoing a craniotomy for brain tumor in adult patients is largely unknown. All craniotomies for intracranial tumors at Oslo University Hospital in adult patients ≥18 years of age during a 10-year period (2004-2013) were included. None were lost to follow-up.

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Neurologic complications are common after hematopoietic stem cell transplantation (HSCT) and solid organ transplantation (SOT) and affect 30-60% of transplant recipients. The aim of this article is to provide a practical imaging approach based on the timeline and etiology of CNS abnormalities, and neurologic complications related to transplantation of specific organs. The lesions will be classified based upon the interval from HSCT procedure: pre-engraftment period <30 days, early post-engraftment period 30-100 days, late post-engraftment period >100 days, and the interval from SOT procedure: postoperative phase 1-4 weeks, early posttransplant syndromes 1-6 months, late posttransplant syndromes >6 months.

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Background And Study Object: We report an unusual case of a benign lateral sphenoid wing meningioma that presented with, and was masked by, an acute intracerebral hemorrhage.

Case Report: A 68-year-old woman was admitted after sudden onset of coma. Computed tomography (CT) revealed an intracerebral hemorrhage, without any underlying vascular pathology on CT angiography.

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Article Synopsis
  • A study developed a support vector machine (SVM) model using MR imaging data to predict survival in preoperative glioma patients.
  • The research involved 235 adult patients and used historical data to train the SVM model on blood volume distribution, with the effectiveness tested on independent patient data from another institution.
  • Results showed the SVM model outperformed expert assessments in predicting survival rates, indicating it's a reliable tool for early prognosis in aggressive gliomas.
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Purpose: To retrospectively evaluate the performance of an automatic support vector machine (SVM) routine in combination with perfusion-based dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) for preoperative survival associations in patients with gliomas and compare our results to traditional MRI.

Materials And Methods: The study was approved by the Ethics Committee and informed consent was signed. Structural, diffusion- and perfusion-weighted MRI was performed at 1.

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Aims: To evaluate metastatic lesions within the radiation field using repeated magnetic resonance imaging (MRI) and to compare the imaging findings with pain response following radiotherapy (RT) in patients with spinal metastases (SM) from breast cancer.

Material And Methods: 32 Patients with SM from breast cancer admitted for fractionated RT were included in this study. MRI examinations of the spine were scored for the extent of bone metastases, epidural disease and the presence and severity of vertebral fractures.

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Background: Magnetic resonance imaging (MRI) criteria play an important role in making an earlier diagnosis of multiple sclerosis (MS) in patients presenting with clinically isolated syndrome.

Objective: The objective of this paper is to determine whether MRI criteria may be used to distinguish MS from primary and secondary central nervous system (CNS) vasculitis, lupus, and Sjogren's syndrome.

Methods: MRI criteria were applied retrospectively to images for patients with clinically definite MS (CDMS), primary CNS vasculitis, secondary CNS vasculitis, and autoimmune disorders including systemic lupus erythematosus (SLE) and Sjogren's syndrome.

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Purpose: The objectives of this study were to establish the prevalence of pulmonary artery dilatation in Marfan syndrome using modern radiological methods and to correlate the diameter of the vessel with aortic disease.

Methods: Magnetic resonance or computed tomography imaging of the pulmonary artery and aorta was performed in 87 patients with proven Marfan syndrome. Diameters of the root and trunk of the pulmonary artery and of the aortic root were measured perpendicular to the long axes of the vessels.

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Background: A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking.

Purpose: To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients.

Material And Methods: T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired.

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Introduction: Change detection is a crucial factor in monitoring of slowly evolving pathologies. The objective of the study was to test a semi-automatic method applied on longitudinal MRI monitoring of volume change in pituitary macroadenomas.

Methods: The proposed method is based on a visual comparison of geometrically corrected, co-registered, intensity-normalized contrast-enhanced (CE) 3D GRE T1-weighted images.

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Context: Appropriate cell-to-cell adhesion is fundamental for the epithelial phenotype of pituitary cells. Loss of the adhesion protein E-cadherin has been associated with invasiveness, metastasis, and poor prognosis in cancers of epithelial origin. In somatotroph adenomas, a variable and reduced expression of E-cadherin has been demonstrated.

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Purpose: To assess whether glioma volumes from knowledge-based fuzzy c-means (FCM) clustering of multiple MR image classes can provide similar diagnostic efficacy values as manually defined tumor volumes when characterizing gliomas from dynamic susceptibility contrast (DSC) imaging.

Materials And Methods: Fifty patients with newly diagnosed gliomas were imaged using DSC MR imaging at 1.5 Tesla.

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Article Synopsis
  • The presence of large blood vessels in tumor regions can complicate MR-based evaluations of gliomas, making accurate grading challenging.
  • A new vessel segmentation technique, using clustering of multiple dynamic contrast-enhanced imaging parameters, aims to help differentiate between these blood vessels and the actual tumor blood volume.
  • Analysis of 77 glioma patients showed that using this vessel segmentation method alongside mean transit time masks significantly improved diagnostic accuracy in grading the tumors.
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The advantages of predictive modeling in glioma grading from MR perfusion images have not yet been explored. The aim of the current study was to implement a predictive model based on support vector machines (SVM) for glioma grading using tumor blood volume histogram signatures derived from MR perfusion images and to assess the diagnostic accuracy of the model and the sensitivity to sample size. A total of 86 patients with histologically-confirmed gliomas were imaged using dynamic susceptibility contrast (DSC) MRI at 1.

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Context: Surgery is the primary treatment of acromegaly. However, it often fails to cure the patient. New strategies that improve surgical outcome are needed.

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Purpose: To retrospectively compare the diagnostic accuracy of an alternative method used to grade gliomas that is based on histogram analysis of normalized cerebral blood volume (CBV) values from the entire tumor volume (obtained with the histogram method) with that of the hot-spot method, with histologic analysis as the reference standard.

Materials And Methods: The medical ethics committee approved this study, and all patients provided informed consent. Fifty-three patients (24 female, 29 male; mean age, 48 years; age range, 14-76 years) with histologically confirmed gliomas were examined with dynamic contrast material-enhanced 1.

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Context: Excessive GH production by pituitary tumors causes acromegaly. Medical treatment of acromegaly with somatostatin analogs (SMSs), like octreotide, is well established, but the clinical effect is variable. One mechanism for octreotide effect is inhibition of the MAPK signaling pathway after binding to the G protein-coupled somatostatin receptor.

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Article Synopsis
  • The study aimed to investigate the relationship between somatostatin receptor subtype 2 (SSTR2) protein expression and the effectiveness of octreotide treatment in patients with acromegaly, particularly focusing on adenomas with Gsalpha mutations.
  • Seventy-one patients with acromegaly participated, undergoing analysis of SSTR2a expression through immunohistochemistry and Western blot, alongside assessments of their octreotide response.
  • Results indicated that better octreotide responses were linked to higher SSTR2a positivity in immunohistochemical staining, while SSTR2a levels measured by Western blot did not predict treatment success, suggesting SSTR2a may be down-regulated during octre
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Objective: Although uncommon, residual effects from contrast agents used more than 2 decades ago are possible. This case report is to alert clinicians to the implications of residual oil-based ionic contrast agents in the intrathecal space.

Case Report: A 70-year-old female with evidence of degenerative disc disease underwent a series of lumbar epidural steroid injections.

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