Evaluating Surgical Cervical Arthrodesis With a Novel MRI Grading Score.

STUDY DESIGN: This was a single-institution retrospective study. OBJECTIVE: Evaluate a magnetic resonance imaging (MRI)-scoring system to differentiate arthrodesis from pseudoarthrosis following anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA: Diagnostic workup following fusion surgery often includes MRI to evaluate neural structures and computed tomography (CT) and/or dynamic x-rays to evaluate instrumentation and arthrodesis. The use of MRI alone for these evaluations would protect patients from harmful CT and x-ray ionizing radiation. METHODS: Neurosurgical attending evaluated CTs for arthrodesis or pseudoarthrosis. Blinded neuroradiology attending and neurosurgery senior resident evaluated independent T1 and T2 region of interest (ROI) signal intensity over instrumented disk space. Cerebral spinal fluid (CSF) at the cisterna magnum and distal adjacent uninstrumented vertebral body (VB) were also calculated. ROI interspace /ROI CSF and ROI interspace /ROI VB quotients were used to create T1- and T2-interspace interbody scores (IIS). RESULTS: Study population (n=64 patients, 50% female) with a mean age of 51.72 years and 109 instrumented levels with 45 fused levels (41.3%) were included. T1-weighted MRI, median T1-IIS CSF for arthrodesis was 176.20 versus 130.92 for pseudoarthrosis ( P <0.0001), T1-IIS VB for arthrodesis was 68.52 and pseudoarthrosis was 52.71 ( P <0.0001). T2-weighted MRI, median T2-IIS CSF for arthrodesis was 27.72 and 14.21 for pseudoarthrosis ( P <0.0001), while T2-IIS VB for arthrodesis was 67.90 and 41.02 for pseudoarthrosis ( P <0.0001). The greatest univariable discriminative capability for arthrodesis via AUROC was T1-IIS VB (0.7743). CONCLUSION: We describe a novel MRI scoring system that may help determine arthrodesis versus pseudoarthrosis following anterior cervical discectomy and fusion. Postoperative symptomatic patients may only require MRI, which would protect patients from ionizing radiation. LEVEL OF EVIDENCE: Level IV.

Early postoperative MRI findings following anterior cervical discectomy and fusion: What to expect when the unexpected happens.

Background: Magnetic resonance imaging (MRI) is not routinely ordered following spinal fusion. Some literature suggests MRIs are unhelpful due to postoperative changes that obscure interpretation. We aim to describe findings of acute postoperative MRI following anterior cervical discectomy and fusion (ACDF). Methods: The authors retrospectively analyzed adult MRIs completed within 30 days of ACDF (from 2005-2022). T1 and T2 signal intensity in the interbody space dorsal to the graft, mass effect on the dura/spinal cord, intrinsic spinal cord T2 signal, and interpretability were reviewed. Results: In 38 patients there were 58 ACDF levels (1, 2, and 3 levels; 23, 10, and 5, respectively). MRIs were completed on mean postoperative day 8.37 (range; 0-30 days). T1-weighted imaging was described as isointense, hyperintense, heterogenous, and hypointense in 48 (82.8%), 5 (8.6%), 3 (5.2%), and 2 levels (3.4%), respectively. T2-weighted imaging was described as hyperintense, heterogenous, isointense, and hypointense in 41 (70.7%), 12 (20.7%), 3 (5.2%), and 2 levels (3.4%), respectively. There was no mass effect in 27 levels (46.6%), 14 (24.1%) had thecal sac compression, and 17 (29.3%) had cord compression. Conclusions: The majority of MRIs exhibited readily compression and intrinsic spinal cord signal even with various types of fusion constructs. Early MRI after lumbar surgery can be difficult to interpret. However, our results support the use of early MRI to investigate neurological complaints following ACDF. Our findings do not support the idea that epidural blood products and mass effect on the cord are seen in most postoperative MRIs after ACDF.

Possible association of trichorhinophalangeal syndrome I and intracranial subependymoma.

Trichorhinophalangeal syndromes (TRPSs) are rare hereditary syndromes with autosomal dominant inheritance. Patients exhibit abnormalities including bulbous pear-shaped nose, broad columella, and long and flat philtrum, fine, sparse, brittle, slow-growing scalp hair, skeletal abnormalities, and short stature. Three families; age at subependymoma surgery, pathogenic TRPS1(NM_014112.5) variant, and subependymoma number are described.

Rare Case of Pediatric Disseminated Choroid Plexus Papilloma: Literature Review and Call for Reclassification.

INTRODUCTION: Choroid plexus tumors are rare neuroectodermal tumors that arise from the choroid plexus. Choroid plexus papillomas (CPPs) represent the lowest grade of these types of tumors and have a WHO grade I designation. Despite their typical low grade, some CPPs can exhibit aggressive behaviors including parenchymal invasion and dissemination throughout the neuro-axis. Due to their association with the choroid plexus, patients with CPP commonly present with signs and symptoms of hydrocephalus and increased intracranial pressure. CASE PRESENTATION: A 2-year-old male presented in extremis with acute hydrocephalus and seizure. He was found to have a large left intraventricular mass with innumerable intraparenchymal and extra-axial cysts throughout his neuro-axis. A literature review revealed five similar disseminated CPP cases with innumerable lesions. This is the youngest reported patient with disseminated CPP and the first with multiple compressive lesions. Following cranial resection and thoracic decompression, the patient's lesions have remained stable (2 years of follow-up). A literature search of the PubMed/Medline databases was performed using the search terms ["disseminated choroid plexus papilloma" OR "choroid plexus papilloma" OR "metastatic choroid plexus papilloma"] up to March 2021. Articles were then screened for similar patient radiographic presentation and histological diagnosis. To mitigate publication bias, referenced articles were utilized to identify other case reports and case series. DISCUSSION/CONCLUSION: We describe a rare case of a lateral ventricle CPP with widespread leptomeningeal dissemination causing acute obstructive hydrocephalus and compressive myelopathy requiring cerebrospinal fluid diversion and intracranial resection followed by thoracic spine decompression. This case report serves to broaden knowledge of disseminated CPP and to encourage complete neuro-axis imaging for choroid plexus tumors. Additionally, we propose a naming paradigm refinement that includes radiographic characteristics.

Neurological emergency from rare spinal metalloma: Case report and literature review.

Metallosis is a rare and poorly understood long-term complication of instrumented surgery that can result in an inflammatory pseudotumor termed metalloma. We describe a particularly unique case and compare it to 6 analogous cases identified by PubMed and/or Medline search through July 2020. A 79-year-old male with multiple prior spinal lumbar fusion procedures presented with progressive weakness and pain. Imaging revealed a large mass surrounding the right-sided paraspinal rod with extension into the spinal canal, neural foramina, extraforaminal spaces, psoas muscle, marrow spaces, and right sided pedicles. The case presented is a unique example of a unilateral metalloma with mixed-metal instrumentation that created a progressive neurologic deficit without infection, pseudoarthrosis, or hardware failure. This case highlights the lack of understanding regarding the pathophysiology of metallosis and metalloma in spinal instrumentation. We highlight the imaging findings of metalloma to encourage early identification for removal and decompression.

Prevalence and Clinical Significance of Incidental Vertebral Marrow Signal Abnormality in Thoracolumbar Spine MRI.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: This study investigates the prevalence of incidental vertebral marrow signal abnormality (VMSA) in thoracolumbar spine magnetic resonance imaging (MRI) ordered for the evaluation of back and/or leg pain and assess the clinical work-up for VMSAs. SUMMARY OF BACKGROUND DATA: Patients presenting with back pain are often referred for spine MRI for diagnostic evaluation. VMSA is most frequently found in the lumbar spine and is of clinical concern because it can represent malignancy. Standardized procedures for reporting and managing VMSAs do not exist. METHODS: The radiology database at the Oregon Health & Science University health system was queried to identify patients with thoracolumbar spine MRI scans performed between January 2014 and June 2016. Patients 16 years or older with MRIs ordered by providers at a multidisciplinary spine specialty clinic for the diagnostic evaluation of back and/or leg pain were included. Radiology reports were searched for keywords pertaining to VMSAs, such as "malignancy." Medical records of these patients were further reviewed for the clinical work-up and final diagnoses pertaining to the VMSA. RESULTS: The study sample included 1503 individual patients, of whom 65 (4%) had MRI radiology reports that described a VMSA. Thirty-one (48%) of the 65 patients with VMSAs had further evaluation recommended by radiology. Ten (32%) of these 31 patients were followed clinically without further diagnostic testing for the VMSA. Of the 65 patients with VMSAs, only one was diagnosed with malignancy (multiple myeloma). CONCLUSION: While VMSAs are not frequently found on thoracolumbar MRIs ordered to evaluate back and/or leg pain, there is a large amount of heterogeneity in how these abnormalities are documented and managed. This may indicate the need for clinical guidelines for the reporting and management of VMSAs detected on spine MRI and for improvement in communication between radiologists and ordering providers. LEVEL OF EVIDENCE: 3.

Combined iron oxide nanoparticle ferumoxytol and gadolinium contrast enhanced MRI define glioblastoma pseudoprogression.

BACKGROUND: Noninvasively differentiating therapy-induced pseudoprogression from recurrent disease in patients with glioblastoma is prospectively difficult due to the current lack of a biologically specific imaging metric. Ferumoxytol iron oxide nanoparticle MRI contrast characterizes innate immunity mediated neuroinflammation; therefore, we hypothesized that combined ferumoxytol and gadolinium enhanced MRI could serve as a biomarker of glioblastoma pseudoprogression. METHODS: In this institutional review board-approved, retrospective study, we analyzed ferumoxytol and gadolinium contrast enhanced T1-weighted 3T MRI in 45 patients with glioblastoma over multiple clinical timepoints. Isocitrate dehydrogenase 1 (IDH-1) mutational status was characterized by exome sequencing. Sum of products diameter measurements were calculated according to Response Assessment in Neuro-Oncology criteria from both gadolinium and ferumoxytol enhanced sequences. Enhancement mismatch was calculated as the natural log of the ferumoxytol to gadolinium sum of products diameter ratio. Analysis of variance and Student's t-test assessed differences in mismatch ratios. P-value <0.05 indicated statistical significance. RESULTS: With the development of pseudoprogression we observed a significantly elevated mismatch ratio compared with disease recurrence (P < 0.01) within IDH-1 wild type patients. Patients with IDH-1 mutation demonstrated significantly reduced mismatch ratio with the development of pseudoprogression compared with disease recurrence (P < 0.01). Receiver operator curve analysis demonstrated 100% sensitivity and specificity for the use of mismatch ratios as a diagnostic biomarker of pseudoprogression. CONCLUSION: Our study suggests that ferumoxytol to gadolinium contrast mismatch ratios are an MRI biomarker for the diagnosis of pseudoprogression in patients with glioblastoma. This may be due to the unique characterization of therapy-induced neuroinflammation.

Diagnostic accuracy and clinical outcomes associated with prenatal diagnosis of fetal absent cavum septi pellucidi.

BACKGROUND: Absence of the cavum septi pellucidi (CSP) on prenatal imaging is historically associated with additional anomalies; however, recent cases of isolated absent CSP have also been identified. This study seeks to assess the accuracy of prenatal imaging in evaluating isolated absent CSP and to describe the spectrum of clinical outcomes. METHODS: This is a retrospective observational study of all prenatally diagnosed absent CSP cases between 2011 and 2016 at our institution. Cases with additional structural parenchymal abnormalities were excluded. Clinical outcomes were abstracted from available records. RESULTS: We identified 15 cases of prenatally diagnosed isolated absent CSP. All patients were initially diagnosed on ultrasound (US) and 11/15 patients had fetal magnetic resonance imaging (MRI) confirming the diagnosis. Prenatal US and MRI were concordant in all cases. Of the continuing pregnancies, 2 neonatal deaths occurred related to extreme prematurity. Two cases of septo-optic dysplasia were identified in our cohort. DISCUSSION: In this study, fetal MRI and US had a high degree of accuracy with concordant postnatal imaging. Our study is similar to other case series suggesting that a range of clinical outcomes is possible with isolated absent CSP, but long-term patient follow up is necessary.

Radiological appearances of corpus luteum cysts and their imaging mimics.

PURPOSE: To review the radiological appearances of corpus luteum cysts and their imaging mimics. CONCLUSION: Corpus luteum cysts are normal post-ovulatory structures seen in the ovaries through the second half of the menstrual cycle and the first trimester of pregnancy. The typical appearance, across all modalities, is of a 1- to 3-cm cyst with a thick crenulated vascularized wall. Occasionally, similar imaging findings may be seen with endometrioma, ectopic pregnancy, tuboovarian abscess, red degeneration of a fibroid, and ovarian neoplasia. In most cases, imaging findings are distinctive and allow for a confident and accurate diagnosis that provides reassurance for patients and referring physicians and avoids costly unnecessary follow-up.

Prostate cancer with a pseudocapsule at MR imaging: a marker of high grade and stage disease?

Clinicopathological correlates of prostate cancer associated with a pseudocapsule at T2-weighted magnetic resonance (MR) imaging are presented in a retrospective series of 15 patients. Of 15 tumors, 14 involved the peripheral zone. Extracapsular extension was seen in 14 cases. Tumor Gleason score was 8 or above in 12 of 15 cases, and ductal type adenocarcinoma was identified in 4 cases. Step section histopathological correlation (n=5) demonstrated that the pseudocapsule corresponded with dense compressive or reactive peritumoral fibrosis. A pseudocapsule around prostate cancer at T2-weighted MR imaging is a rare finding that appears to be associated with high grade and stage disease.

Endorectal multiparametric MRI of the prostate: incremental effect of perfusion imaging on biopsy target identification.

PURPOSE: To evaluate the incremental effect of perfusion imaging on biopsy target identification at endorectal multiparametric prostate magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively 52 patients who underwent endorectal multiparametric prostate MRI for suspected or untreated prostate cancer. Two readers independently identified biopsy targets without and with perfusion images. RESULTS: Reader 1 identified 36 targets without and 39 targets with perfusion imaging (P>.05). The corresponding numbers for reader 2 were 38 and 38, respectively (P=.5). CONCLUSION: Perfusion imaging does not significantly increase the number of biopsy targets identified at endorectal multiparametric prostate MRI.

Direct MRI-guided biopsy of the prostate: use of post-biopsy needle track imaging to confirm targeting.

PURPOSE: To report the observation that in-plane post-biopsy T2-weighted MRI often demonstrates the needle track as a transient visible linear tissue distortion during direct MRI-guided biopsy. MATERIALS AND METHODS: We retrospectively identified 11 prostatic lesions in 9 men that underwent direct MRI-guided biopsy and in which post-biopsy images were obtained in the plane of the biopsy needle. RESULTS: In 9 of 11 targets, a post-biopsy needle track was visible as a linear tissue distortion on in-plane T2-weighted images obtained at a mean interval of 6 min (range 3-15). In these nine cases, the needle track traversed the intended target, and the biopsy was positive for malignancy in six. Biopsy was positive in one of two cases where the needle track was not visible. In five targets, one or more delayed series were obtained after a mean interval of 21 min (range 8-33), showing the track was no longer visible (n = 3) or was of progressively decreased conspicuity (n = 2). CONCLUSION: Accurate targeting during direct MRI-guided biopsy of the prostate can be confirmed by obtaining post-biopsy in-plane images, since the needle track is usually visible as a transient linear tissue distortion.

Size-appropriate radiation doses in pediatric body CT: a study of regional community adoption in the United States.

BACKGROUND: During the last decade, there has been a movement in the United States toward utilizing size-appropriate radiation doses for pediatric body CT, with smaller doses given to smaller patients. OBJECTIVE: This study assesses community adoption of size-appropriate pediatric CT techniques. Size-specific dose estimates (SSDE) in pediatric body scans are compared between community facilities and a university children's hospital that tailors CT protocols to patient size as advocated by Image Gently. MATERIALS AND METHODS: We compared 164 pediatric body scans done at community facilities (group X) with 466 children's hospital scans. Children's hospital scans were divided into two groups: A, 250 performed with established pediatric weight-based protocols and filtered back projection; B, 216 performed with addition of iterative reconstruction technique and a 60% reduction in volume CT dose index (CTDIvol). SSDE was calculated and differences among groups were compared by regression analysis. RESULTS: Mean SSDE was 1.6 and 3.9 times higher in group X than in groups A and B and 2.5 times higher for group A than group B. A model adjusting for confounders confirmed significant differences between group pairs. CONCLUSIONS: Regional community hospitals and imaging centers have not universally adopted child-sized pediatric CT practices. More education and accountability may be necessary to achieve widespread implementation. Since even lower radiation doses are possible with iterative reconstruction technique than with filtered back projection alone, further exploration of the former is encouraged.