Intracranial causes of ophthalmoplegia: the visual reflex pathways.

The gathering of visual information is a complex process that relies on concerted movements of the eyes, and cranial nerves II-VIII are at least partially involved in the visual system. The cranial nerves do not function in isolation, however, and there are multiple higher-order cortical centers that have input into the cranial nerves to coordinate eye movement. Among the functions of the cortical reflex pathways are (a) controlling vertical and horizontal gaze in response to vestibular input to keep the eyes focused on an object as the head moves through space, and (b) controlling rapid, coordinated eye movement to a new visual target (saccades). There are also reflex pathways connecting the cranial nerves involved in vision that produce consensual blinking of the eyes in response to corneal stimulation of one eye and consensual pupillary constriction in response to light input on one pupil. A variety of intracranial pathologic conditions, including benign and malignant neoplasms, infection, trauma, autoimmune diseases, vascular anomalies, degenerative diseases, and inherited-congenital disorders, can disrupt the cranial nerves and visual reflex pathways. This disruption can manifest in myriad ways-for example, as extraocular muscle paresis, afferent pupillary defect, oculosympathetic paresis (Horner syndrome), internuclear ophthalmoplegia, dorsal midbrain (Parinaud) syndrome, or loss of the corneal reflex. Knowledge of the function and anatomy of the cranial nerves and visual reflex pathways, coupled with selection of the proper magnetic resonance pulse sequence, will allow the radiologist to order appropriate imaging of the involved cranial nerve or visual reflex pathway based on the patient's symptoms and thereby play an essential role in establishing the diagnosis and planning appropriate therapy.

Neoadjuvant presurgical PD-1 inhibition in oral cavity squamous cell carcinoma.

Oral cavity squamous cell carcinoma (OCSCC) is a prevalent surgically treated subset of head and neck cancer with frequent recurrence and poor survival. Immunotherapy has demonstrated efficacy in recurrent/metastatic head and neck cancer. However, whether antitumor responses could be fostered by neoadjuvant presurgical immunotherapy remains unclear. Using a Simon's two-stage design, we present results of a single-arm phase-II trial where 12 patients with stage II-IVA OCSCC received 3 to 4 biweekly doses of 3 mg/kg nivolumab followed by definitive surgical resection with curative intent. Presurgical nivolumab therapy in this cohort shows an overall response rate of 33% (n = 4 patients; 95% CI: 12%-53%). With a median follow up of 2.23 years, 10 out of 12 treated patients remain alive. Neoadjuvant nivolumab is safe, well-tolerated, and is not associated with delays in definitive surgical treatment in this study. This work demonstrates feasibility and safety for incorporation of nivolumab in the neoadjuvant setting for OCSCC (ClinicalTrials.gov: NCT03021993).

Predictive value of computed tomography in identifying extranodal extension in human papillomavirus-positive versus human papillomavirus-negative head and neck cancer.

Pathologic extranodal extension (pENE) impacts treatment planning and is an important prognostic indicator for patients with head and neck squamous cell carcinoma (HNSCC). Computed tomography (CT) is a commonly used modality for assessment of radiographic ENE (rENE). To determine the predictive value of CT-identified rENE in predicting pENE, we performed a systematic review through a search of 4 databases (PubMed, Scopus, Cochrane, and OVID). Meta-analysis of diagnostic performance based on human papillomavirus (HPV) status was conducted. For HPV-negative HNSCC, pooled sensitivity, specificity, and accuracy were 60.6%, 93.3%, and 82.6%, respectively. Overall positive predictive value (PPV) was 82.7%. For HPV-positive HNSCC, pooled sensitivity, specificity, and accuracy were 77.7%, 72.2%, and 63.8%, respectively. Overall PPV was 68.6%. Significant differences were observed in diagnostic performance parameters between the two cohorts. The radiographic characteristics of HPV-positive and HPV-negative nodal metastases in HNSCC differ and radiographic evaluation of ENE in HPV-positive nodes is challenging. Development of refined imaging characteristics of HPV-positive nodes is needed to improve diagnostic performance.

Optimizing the Learning and Working Environment for Radiology Residents.

RATIONALE AND OBJECTIVES: In the newest revision of the Accreditation Council for Graduate Medical Education Common Program Requirements, substantial changes were made to section VI now entitled "The Learning and Working Environment." The Accreditation Council for Graduate Medical Education expanded section VI to include patient safety, quality improvement, supervision, accountability, well-being, and fatigue mitigation realizing work hours represent only one part of the work environment. MATERIALS AND METHODS: These new requirements prompted us to evaluate our current curriculum, including our current tools for meeting program requirements such as the didactic lecture series and tracking resident progress in our Clinical Competency Committee, and identified areas of our curriculum that were lacking or could be improved upon. RESULTS: This assessment leads to incorporation of innovative and novel strategies to not only satisfy the requirements but also to engage our trainees throughout the process. CONCLUSION: Our model can be used as an example for other residency programs looking for ways to fulfill these new requirements.

Sulcal FLAIR hyperintensity after CSF removal in two patients with intracranial hypertension.

Sulcal hyperintensity on fluid-attenuated inversion recovery (FLAIR) sequence is a frequently encountered finding that could be due to an abnormality of cerebrospinal fluid, a secondary finding related to an intracranial pathologic process, or be artifactual or iatrogenic. Here we present two cases of sulcal FLAIR hyperintensity in the setting of intracranial hypotension after CSF removal for intracranial hypertension.

RADIATION DOSE AND IMAGE QUALITY IN PEDIATRIC HEAD CT.

Our goal was to define a pediatric head CT protocol able to provide images of diagnostic quality, using the least amount of radiation, in children <10 years of age, while using a filtered back projection reconstruction algorithm. Image quality of 119 pediatric head CTs was assessed using a 5-point scoring system. Exams with scores ≥2.5 were considered of sufficient diagnostic quality. The contrast-to-noise ratio (CNR) was also measured. For children <1 year and 1-9 years, all studies performed with CTDIvol ≥ 20.1 mGy (range: 9-46 mGy) and CTDIvol ≥ 27.5 mGy (range: 15-60 mGy) yielded images of diagnostic quality. All diagnostic studies had a minimum CNR of 1.4. These CTDIvol values represent a good balance between image quality and radiation burden. This information can be helpful in designing pediatric head CT protocols with further dose-reduction, namely, iterative reconstruction algorithms and automated exposure control.

Image Sharing in Radiology-A Primer.

By virtue of its information technology-oriented infrastructure, the specialty of radiology is uniquely positioned to be at the forefront of efforts to promote data sharing across the healthcare enterprise, including particularly image sharing. The potential benefits of image sharing for clinical, research, and educational applications in radiology are immense. In this work, our group-the Association of University Radiologists (AUR) Radiology Research Alliance Task Force on Image Sharing-reviews the benefits of implementing image sharing capability, introduces current image sharing platforms and details their unique requirements, and presents emerging platforms that may see greater adoption in the future. By understanding this complex ecosystem of image sharing solutions, radiologists can become important advocates for the successful implementation of these powerful image sharing resources.

Influence of needle-tip position on the incidence of immediate complications in 2,217 selective lumbar nerve root blocks.

BACKGROUND CONTEXT: Selective lumbar nerve blocks (SLNBs) are a popular, minimally invasive treatment and diagnostic tool for lumbar radiculopathy. It is therefore relevant to determine the complication rate for SLNBs, as well as examine the association between needle-tip position and complication rates in order to improve safety. PURPOSE: The purposes of the present study are to determine the overall rate of immediate, postprocedural complications in a large cohort of patients who received SLNBs and determine if certain needle-tip positions are less likely to cause complications. To our knowledge, this is the first paper to examine the relationship between needle-tip position and complications. STUDY DESIGN: A large retrospective cohort was assembled from patients who had undergone a SLNB. We determined the overall immediate complication rate for all injections. In addition, all patients who received only a single injection were compiled into another cohort, and needle-tip position was determined. The complication rate was determined for each needle-tip position. PATIENT SAMPLE: All adult patients who underwent a SLNB in a single radiology department from April 1, 1997 to May 31, 2002. OUTCOME MEASURES: Patients were observed for 15-30 minutes after their procedure, then interviewed about any self-reported weakness, light-headedness, increase in pain from the preprocedural levels, or development of new pain. Their postprocedural pain was then rated on the Visual Analogue Scale. The radiologic notes from each examination were reviewed for incidence of these, or any other, complications. METHODS: SLNBs were performed as they would be in the normal course of care, using fluoroscopic guidance and methodology established by a single radiologist overseeing the procedures. The radiologist's record of each visit was examined for note of immediate, postprocedural complications. The radiographs from the patients who received a single injection during their visit were examined to determine the position of the needle tip during the procedure. The needle-tip positions from the "Complications" and "No Complications" single injection cohorts were compared to determine if certain needle-tip positions cause less complications than others. RESULTS: Minor complications were encountered in 98 of the 1,777 total patient visits, for an overall complication rate of 5.5%. All complications were transient, and no patient suffered lasting harm. There were 1,232 procedures in which the patient received a single injection, and a minor complication was encountered in 62 of these visits. The complication rate approached 5% for all needle-tip positions, which is not statistically different from the overall complication rate. However, there was an increased likelihood of complications in patients undergoing a multiple injection procedure vs. those who had only one injection. CONCLUSIONS: Our results suggest that SLNBs performed with fluoroscopic guidance have a low incidence of complications. All of our complications were minor. The specific needle-tip position within or adjacent to the lumbar neural foramen does not appear to be associated with the incidence of complications.

Atypical accessory intraparietal sutures mimicking complex fractures in a neonate.

Partial or complete division of the parietal bones resulting in anomalous cranial sutures is a rare entity and may raise concern for fracture and potential abuse when identified on radiological examination in young children. We present a case of a 4-week-old male found to have anomalous intraparietal sutures originally interpreted as fractures during a comprehensive evaluation for nonaccidental trauma. Our goal is to raise awareness of a complex branching pattern of accessory intraparietal sutures, which has not been previously described. Additionally, we will review the characteristics that aid in the radiologic differentiation of accessory cranial sutures and fractures.

Characterization of intracranial atherosclerotic stenosis using high-resolution MRI study--rationale and design.

BACKGROUND: Intracranial atherosclerosis is a leading cause of stroke, but little is known about the composition of the intracranial atherosclerotic lesion and how intracranial plaque morphology is related to the risk of stroke. High-resolution magnetic resonance imaging (HR MRI) has been used in patients with extracranial carotid atherosclerosis as an in vivo tool to identify, with high-interrater agreement, histologically defined plaque components (i.e., intraplaque hemorrhage, fibrous cap, and lipid core), which have been shown to be predictors of recurrent stroke. With careful imaging the components of atherosclerotic plaque can be visualized in the intracranial arteries using HR MRI, but there are no reports of reproducibility or interrater reliability. METHODS/STUDY DESIGN: The Characterization of intracranial atherosclerotic stenosis using high-resolution MRI (CHIASM) study is a single-center NIH-funded prospective observational study, to (1) demonstrate high -interrater agreement for identifying intracranial plaque components on HR MRI, (2) determine the frequency of these components in symptomatic versus asymptomatic plaques, and (3) estimate the 1-year rate of stroke in the territory of high-risk plaque components. CHIASM will recruit 90 patients with 50-99% intracranial atherosclerosis to undergo HRMRI of the intracranial artery plaque at enrollment and 1-year follow-up. Both symptomatic and asymptomatic subjects will be recruited. CONCLUSION: Determination of good interrater reliability is an important first step in the development of HR MRI as a tool to predict risk in patients with intracranial atherosclerosis. This study will inform the design of future multicenter studies to determine the prevalence and prognosis of intracranial atherosclerotic plaque components. Such studies could lead to new understanding of the pathophysiological mechanisms of cerebral ischemia in patients with atherosclerotic intracranial stenosis, improvements in risk stratification, and potentially to new treatments of this common and serious disease.