Nafi Aygun

The role of imaging in the management of progressive glioblastoma: A systematic review and evidence-based clinical practice guideline

QuestionWhich imaging techniques most accurately differentiate true tumor progression from pseudo-progression or treatment related changes in patients with previously diagnosed glioblastoma?Target populationThese recommendations apply to adults with previously diagnosed glioblastoma who are suspected of experiencing progression of the neoplastic process.RecommendationsLevel IIMagnetic resonance imaging with and without gadolinium enhancement is recommended as the imaging surveillance method to detect the progression of previously diagnosed glioblastoma.Level IIMagnetic resonance spectroscopy is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma.Level IIIThe routine use of positron emission tomography to identify progression of glioblastoma is not recommended.Level IIISingle-photon emission computed tomography imaging is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma.

Temporal bone fractures

Temporal bone injury is frequently associated with severe brain injury which limits the clinical evaluation and detracts from the clinical signs of temporal bone fracture such as sensorineural hearing loss, conductive hearing loss, and facial nerve paralysis. Radiologists are often the first to note the presence of temporal bone fractures and should be familiar with common types of injuries and their clinical implications. We review the traditional classification systems of temporal bone fractures with respect to clinical findings and management and suggest that radiologists should be familiar with the classification systems and, more importantly, focus their attention to identifying all critical temporal bone structures and describing their status of involvement to better the individual care.

Cochlear coiling pattern and orientation differences in cochlear implant candidates.

Background: Detailed studies of cochlear morphology can guide our approach to cochleostomy and electrode insertion to optimize neuronal and hair cell preservation and ultimate electrode location. Methods: Normal developed cochleae from 124 cochlear implant candidates were studied. We performed morphometric analysis of the right cochleae in all subjects based on computed tomographic data. The length and width of the cochlear base, the angle between the first and second turn of the cochlea, and the cochlear orientation within the cranial base were measured and compared across age groups. In cochlear implant candidates with underdeveloped cochleae (n = 7), we performed similar measurements and assessed the modiolar inlet area on 3D volume rendered images. Results: The birth to 1 year and 1- to 2-year age groups showed insignificant differences in the lengths and widths of the cochlear base, although variability was considerable, and a significantly wider angle (from the midsagittal line) than that of the older age groupings (p < 0.05). For underdeveloped cochleae, the length and width of the cochlear base were significantly smaller and angled between the first and second turn differed from the normal developed group. The modiolar inlet also was significantly smaller in the underdeveloped cochleae compared with normal cochleae. Conclusion: We observed that perspective 3D-volume rendering of the cochlea enables the determination of key features of cochlear morphology and orientation that may escape detection with routine computed tomographic scanning. Infants and young toddler candidates demonstrate greater variability in the dimensions of the cochlear base and in the orientation of the cochlea within the cranium. As evolving surgical techniques and device design enhance the ability of the surgeon to avoid cochlear damage and optimize electrode location, refined morphometric information may assist the surgeon in tailoring strategies of scala tympani implantation.

Radiologic Evaluation of Larynx Cancer

The authors present the value of imaging for preoperative evaluation of structures that are not assessed or incompletely assessed on physical and endoscopic examination. Discussed are CT, MRI, and positron emission tomography-CT and the appropriate selection of each method to provide information, including the presence or absence of extent of disease to the pre-epiglottic and paraglottic spaces and the subglottis, cartilage invasion, extralaryngeal spread of disease, nodal metastasis, and tumor volume.

Imaging findings of bisphosphonate-related osteonecrosis of the jaw with emphasis on early magnetic resonance imaging findings.

Purpose: To describe the imaging findings of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with emphasis on early magnetic resonance imaging (MRI) findings. Materials and Methods: The medical records and computed tomography, MRI, and bone scintigraphy images of 5 female and 1male patients (n = 6) between the ages of 49 and 79 years (mean age, 70 years) who had a diagnosis of BRONJ were retrospectively reviewed, and temporal changes in imaging features were noted. Results: The earliest MRI finding was the loss of the normal T1 hyperintensity of fatty marrow in the mandible and maxilla. The MRI findings of more advanced BRONJ included bone destruction, soft tissue edema and enhancement, inferior alveolar nerve thickening, and pterygoid muscle swelling and enhancement. On computed tomography, sclerosis and subtle lucencies (widening) of the periodontal ligament and cortex and around the apices of the teeth in the early stage, and osteolytic bone lesions, cortical disruption, and frank bone fragmentation in the later stages were observed. Bone scintigraphy showed increased uptake early in the disease. Conclusions: Osteonecrosis of the mandible and maxilla occurs as a complication of bisphosphonate treatment of bone metastasis and osteoporosis and typically manifests after a dental procedure. Magnetic resonance imaging and bone scintigraphy findings may precede clinical symptoms and mimic metastatic disease.

Medulloblastoma: atypical CT and MRI findings in children

Posterior fossa mass lesions in children usually present a diagnostic challenge despite their high frequency and the limited number of differential diagnostic possibilities. Consideration of medulloblastoma within the differential diagnosis of such lesions mandates an aggressive surgical approach as residual tumor is a known risk factor for poor prognosis. Preoperative imaging of the entire neuroaxis is critical given the high propensity of drop metastases. In this pictorial presentation, we review and demonstrate less common features of medulloblastomas to facilitate diagnosis in challenging cases.

Imaging of the Paranasal Sinuses and In-Office CT

Since the introduction of functional endoscopic sinus surgery (FESS) in the United States in 1985, the information gained from imaging has proved imperative in understanding regional morphology and guidance of surgical procedures. More than 20 years later, the importance of imaging continues to be the anatomic detail afforded by this technology, the roadmap it provides in planning the surgery, and the morphologic detail it provides in recurrent disease. The latest development in CT technology, cone beam CT instrumentation, may change the way imaging of the nasal cavity and paranasal sinuses is performed in the future. These topics are discussed in this article.

High-Resolution CISS MR Imaging With and Without Contrast for Evaluation of the Upper Cranial Nerves: Segmental Anatomy and Selected Pathologic Conditions of the Cisternal Through Extraforaminal Segments

The authors review the course and appearance of the major segments of the upper cranial nerves from their apparent origin at the brainstem through the proximal extraforaminal region, focusing on the imaging and anatomic features of particular relevance to high-resolution magnetic resonance imaging evaluation. Selected pathologic entities are included in the discussion of the corresponding cranial nerve segments for illustrative purposes.

The many faces of fungal disease of the paranasal sinuses: CT and MRI findings.

The prevalence of fungal rhinosinusitis has increased worldwide over the last two decades. Fungal rhinosinusitis includes a wide variety of infections, from relatively innocent to rapidly fatal processes. Fungal infection may be one of the most challenging forms of sinonasal pathology to manage, especially the invasive forms, which have high mortality rates. Therefore, it is essential to correctly diagnose and classify fungal disease of paranasal sinuses in order to accurately predict prognosis and implement effective therapy. This essay describes the different manifestations of fungal sinusitis on computed tomography and magnetic resonance imaging to optimize differentiation, and includes correlation with the pathologic classifications.

Retrospective Review of Positron Emission Tomography With Contrast-Enhanced Computed Tomography in the Posttreatment Setting in Human Papillomavirus–Associated Oropharyngeal Carcinoma

OBJECTIVE To determine the value of positron emission tomography (PET) with contrast-enhanced computed tomography (CT) in assessing the need for neck dissection by retrospectively reviewing the pathology reports of patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC). DESIGN Retrospective cohort study. SETTING Tertiary medical center. PATIENTS Seventy-seven patients with HPV-related SCC. MAIN OUTCOME MEASURES Seventy-seven consecutive patients with a diagnosis of HPV-related SCC who were treated with radiotherapy as the primary treatment between August 2007 and October 2010 were retrospectively evaluated for radiologic and pathologic rate of persistence of nodal metastasis after completion of definitive radiotherapy. Pretreatment and posttreatment imaging included contrast-enhanced CT and PET. Response to treatment was measured on CT, PET at standardized uptake value (SUV) thresholds of 2 and 2.5, and PET/CT by a neuroradiologist in a blinded fashion. Then, the pathology report of the patients who underwent neck dissections was reviewed for nodal status after resection and correlated with the imaging findings. RESULTS Of the 77 patients, 67 met the study criteria, with an average follow-up PET/CT scan at 90.5 days after completion of radiotherapy. Ten patients did not undergo follow-up PET/CT imaging. Twenty patients underwent neck dissections after completion of radiation therapy. Of these 20 patients, 4 had persistent tumor and 16 did not have viable tumor. Using the final pathology report to correlate with imaging responses, CT had a negative predictive value (NPV) of 85.7% (95% CI, 48.7%-97.4%), PET with SUV thresholds of 2 had an NPV of 91.7% (95% CI, 64.6%-98.5%), PET with a cutoff SUV of 2.5 had an NPV of 85.7% (95% CI, 60.1%-96.0%), PET/CT with an SUV of 2 had an NPV of 100% (95% CI, 59.8%-100.0%), and PET/CT with an SUV of 2.5 had an NPV of 85.7% (95% CI, 48.7%-97.4%). The 47 patients who did not undergo neck dissection had a median follow-up of 26 months without an isolated neck failure. Analysis of all 67 patients in the cohort revealed the following values: CT had an NPV of 95.7% (95% CI, 85.8%-98.8%), PET with an SUV of 2 had an NPV of 98.2% (95% CI, 90.4%-99.7%), PET with an SUV of 2.5 had an NPV of 95.0% (95% CI, 86.3%-98.3%), PET/CT with an SUV of 2 had an NPV of 100.0% (95% CI, 92.0%-100.0%), and PET/CT with an SUV of 2.5 had an NPV of 95.7% (95% CI, 85.8%-98.8%). CONCLUSIONS Positron emission tomography combined with contrast-enhanced CT has a better NPV than either imaging modality alone in patients with HPV-associated oropharyngeal SCC. Furthermore, PET/CT with an SUV threshold of 2 used in patients with HPV-related SCC offers an imaging modality with a high NPV that may obviate the need for unnecessary neck dissections.