Interpretation Of Postoperative Imaging Research Articles

343 Influence of Duraplasty on Clinical, Radiological, and Surgical Factors Associated with Syrinx Location in Children Treated for Chiari Malformation Type I and Syringomyelia: A Park-Reeves Syringomyelia Research Consortium Study

INTRODUCTION: Analyses of factors associated with syrinx location in Chiari malformation type I (CM-I) and syringomyelia (SM) are limited by the low individual incidences of syringes in certain spinal cord segments but could have important clinical implications on surgical planning, interpretation of postoperative imaging, and outcomes. METHODS: The Park-Reeves Syringomyelia Research Consortium database of pediatric patients with CM-I with SM was queried for patients who underwent first-time operation for posterior fossa decompression with (PFDD) or without (PFD) duraplasty. Clinical, radiological, and surgical data were compared among patients with cervical, thoracic, cervicothoracic, and holocord syringes. RESULTS: 390 patients (90 cervical, 41 thoracic, 149 cervicothoracic, and 110 holocord) were analyzed. PFDD enhanced the magnitude of change on postoperative imaging in patients with cervical syringes. Patients with cervical or cervicothoracic syringes who underwent PFDD were less likely to develop postsurgical headaches, nausea and vomiting, or infections. However, PFDD was associated with more complications less than 6 months after surgery in patients with thoracic syringes and more complications overall in patients with cervicothoracic and holocord syringes. CONCLUSIONS: In the largest multi-institutional analysis of the effects of syrinx location in CM-I with SM, patients with cervicothoracic and holocord syringes experienced the greatest magnitude of change on postoperative imaging parameters while those with thoracic syringes experienced the fewest and smallest magnitude of postoperative radiological changes. PFDD-associated enhancement of postoperative radiological changes in cervical, thoracic, and holocord syringes did not necessarily translate into improvements in clinical symptoms or complication rates following surgery. PFDD is associated with greater clinical benefit for patients with cervical or cervicothoracic syringes but is less appropriate for patients with thoracic syringes based on outcomes and complication profiles.

Photon-Counting Detector CT Virtual Monoengergetic Images for Cochlear Implant Visualization-A Head to Head Comparison to Energy-Integrating Detector CT.

Cochlear implants (CIs) are the primary treatment method in patients with profound sensorineural hearing loss. Interpretation of postoperative imaging with conventional energy-integrating detector computed tomography (EID-CT) following CI surgery remains challenging due to metal artifacts. Still, the photon-counting detector (PCD-CT) is a new emerging technology with the potential to eliminate these problems. This study evaluated the performance of virtual monoenergetic (VME) EID-CT images versus PCD-CT in CI imaging. In this cadaveric study, two temporal bone specimens with implanted CIs were scanned with EID-CT and PCD-CT. The images were assessed according to the visibility of interelectrode wire, size of electrode contact, and diameter of halo artifacts. The visibility of interelectrode wire sections was significantly higher when reviewing PCD-CT images. The difference in diameter measurements for electrode contacts between the two CT scanner modalities showed that the PCD-CT technology generally led to significantly larger diameter readings. The larger measurements were closer to the manufacturer’s specifications for the CI electrode. The size of halo artifacts surrounding the electrode contacts did not differ significantly between the two imaging modalities. PCT-CT imaging is a promising technology for CI imaging with improved spatial resolution and better visibility of small structures than conventional EID-CT.

MRI appearance of adjunct surgical material used in spine surgery

BACKGROUND CONTEXTEarly postoperative MR images are frequently necessary after spine surgery. The appearance of commonly used adjunct hemostatic agents and dural sealants in MR images has not been systematically evaluated. PURPOSEThe purpose of this experimental study was to systematically analyze and describe the characteristics of the most commonly applied hemostatic agents and dural sealants in spine surgery on early postoperative MR images. STUDY DESIGNCadaver Study METHODSFour commonly applied dural sealants (Duraseal, Bioglue, Tachosil, Tisseel) and five commonly used hemostatic agents (Surgiflo, Bonewax, , Spongostan, Gelfoam, Avitene) were investigated. The experimental setting involved a human cadaver where a standard left-sided laminotomy was performed on nine levels of the thoracolumbar spine, and the materials were separately applied and mixed with fresh blood or water for hemostatic and dural sealants, respectively. The cadaver model was scanned at a 3 Tesla MRI and the imaging findings for all materials were compared to the surrounding tissue and systematically reported. RESULTSAll investigated dural sealants and hemostatic agents were distinguishable from the surrounding tissue on MR images with different appearances on the MR sequences. A detailed atlas for the identification of the materials in postoperative spine MRI was established. CONCLUSIONCommonly used hemostatic agents and dural sealants can be successfully identified on early postoperative spine MRI. CLINICAL SIGNIFICANCEKnowledge about MRI appearances of commonly used adjunct surgical materials helps in interpretation of postoperative imaging and supports clinical decision making.

Postoperative Imaging of Complications Following Cranial Implants

A wide range of neurosurgical implants, cranioplasty materials and catheters have been developed to treat a variety of intracranial disorders. Interpretation of postoperative imaging can be challenging and confounded by postoperative changes and implant-related complications. Review of recent literature suggested that there is a paucity of data on postoperative cranial implant-related complications.If not addressed appropriately in a timely manner, these complications may cause a delay in the patient’s treatment with subsequent prolongation of hospital stay. It is therefore paramount for clinicians and radiologists to be aware of the appearance of these implant-related complications on imaging during postoperative surveillance.

The Postoperative Meniscus: Anatomical, Operative, and Imaging Considerations.

Meniscal surgery is commonplace. Patients who have had prior surgery may return for additional imaging for continued or new pain, limited range of motion, or interval injury. Accurate interpretation of postoperative imaging requires a clear understanding of the normal meniscal anatomy and biomechanics. Surgical goals and current surgical techniques impact the imaging appearance. These techniques are reviewed in the context of the various meniscal tear patterns. Multiple imaging modalities may be used in patient assessment with magnetic resonance (MR) imaging providing key information regarding the integrity of the meniscal repair. Imagers need to be aware of the key findings for a normal versus pathologic appearance to the postoperative meniscus as well as other potential MR findings that may account for patient presentation.

Imaging of post-surgical treatment and of related complications in spinal trauma.

Spinal trauma is a devastating event with a high morbidity and mortality. The rationale of imaging is to diagnose the traumatic abnormalities and characterize the type of injury, to estimate the severity of the lesions, to evaluate the potential spinal instability. In case of spinal instability, the goals of operative treatment are decompression of the spinal cord canal and stabilization of the disrupted vertebral column. Particularly, diagnostic imaging, mainly by CT and MR, has a main role in the post-treatment evaluation. The neuroradiological evaluation of the postoperative spine requires a general knowledge of the surgical approach to each spinal region and of the normal temporal evolution of expected postoperative changes. The neuroradiologist should evaluate the devices implanted, their related complications and promptly alert the surgeon of acute complications, mainly vascular and infective. During the follow-up, it is mandatory to know and search chronic complications as pseudomeningocele, accelerated degenerative disease, arachnoiditis, peridural fibrosis. Knowledge of specific complications relating to each surgical approach will assist the neuroradiologist in interpretation of postoperative images.

Simple closure following transsphenoidal surgery

The most common nonendocrine complication after transsphenoidal surgery is cerebrospinal fluid (CSF) leak. Many neurosurgeons have advocated the routine reconstruction of the floor of the sella turcica using autologous fat, muscle, fascia, and either cartilage or bone after transsphenoidal surgery to prevent postoperative CSF fistulas. However, the use of autologous grafting requires a second incision, prolongs operative time, and adds to the patient's postoperative discomfort. In addition, the presence of sellar packing may interfere with the interpretation of postoperative images. To avoid these disadvantages, the authors suggest that routine sellar reconstruction or closure after transsphenoidal surgery is unnecessary unless an intraoperative CSF leak is encountered. The incidence of postoperative CSF leakage in the patients reported on in this series is no higher than that reported by others, and no other complications such as pneumatocele have been encountered in approximately 2700 patients in whom no intraoperative CSF leak was encountered. The authors conclude that routine closure of the floor of the sella turcica or sphenoid is unnecessary in the absence of intraoperative CSF leak.