Tarek A. Hijaz

Imaging of Head Trauma

This article reviews the fundamental concepts related to the imaging of head trauma, and it is vital for radiologists to have a thorough understanding of the principal imaging findings in this setting and of the underlying mechanisms which are involved. There is a large and continually expanding body of literature on this subject, and imaging technologies and techniques continue to evolve. Radiologists continue to play an integral role in the assessment and care of patients with head trauma, and in order to maintain and strengthen this role, it is incumbent upon them to stay abreast of these developments.

Pearls & Oy-sters: Bilateral thalamic involvement in West Nile virus encephalitis

Bilateral thalamic inflammation in the presence of a clinical picture suggestive of viral encephalitis should raise concern for West Nile virus infection.

Pacemakers in MRI for the Neuroradiologist

The authors review the relevant cardiac implantable electronic devices encountered in practice today, the background physics/technical factors related to scanning these devices, the multidisciplinary screening protocol used at their institution for scanning patients with implantable cardiac devices, and their experience in safely performing these examinations since 2010. SUMMARY: Cardiac implantable electronic devices are frequently encountered in clinical practice in patients being screened for MR imaging examinations. Traditionally, the presence of these devices has been considered a contraindication to undergoing MR imaging. Growing evidence suggests that most of these patients can safely undergo an MR imaging examination if certain conditions are met. This document will review the relevant cardiac implantable electronic devices encountered in practice today, the background physics/technical factors related to scanning these devices, the multidisciplinary screening protocol used at our institution for scanning patients with implantable cardiac devices, and our experience in safely performing these examinations since 2010.

An unusual appearance of discitis due to gas-forming Escherichia coli with associated pneumocephalus.

Study Design. Case report. Objective. To report on an unusual case of isolated septic discitis, meningitis, pneumocephalus, and solid organ abscesses associated with urosepsis from gas-producing Escherichia coli. Summary of Background Data. Isolated septic discitis, or disc infection without involvement of adjacent vertebrae, following E. coli urosepsis is an unusual finding in the adult population and to our knowledge has not been reported previously. Methods. The clinical manifestations and imaging findings of a patient with a history of back pain are described. The significance of the reported case is discussed. Results. Laboratory finding and imaging studies revealed a Gram-negative sepsis associated with meningitis, discitis, pneumocephalus, and solid organ abscesses. Due to widespread involvement of multiple organs, the infection remained refractory to treatment, and the patient died. Conclusion. Our report adds to the literature by describing an unusual appearance of spine infection in an adult. Furthermore, it emphasizes the importance of a systematic approach to the diagnosis and treatment of low back pain.

Isolated Reversible Thalamic Vasogenic Edema Following a Generalized Seizure

Transient MR imaging signal-intensity changes in the thalamus, usually accompanied by signal-intensity changes elsewhere in the brain, have been previously reported in the setting of seizures.[1][1]–[3][2] We report a case in which an MR image obtained shortly after a seizure episode demonstrated

Can loss of the swallow tail sign help distinguish between Parkinson Disease and the Parkinson-Plus syndromes?

PURPOSE To determine if loss of the swallow tail sign (STS) can distinguish Parkinson Disease (PD) from the Parkinson-Plus syndromes. METHODS Twenty-five patients with PD, 21 with Parkinson-Plus syndromes, and 14 control patients were included. Presence of the STS was assessed. RESULTS The STS was present in 79% of controls, statistically greater than the PD/Parkinson-Plus patients. There was no difference in the presence of the STS between the PD/Parkinson-Plus subgroups or when scanning at 1.5 T or 3 T. CONCLUSIONS Loss of the STS could not distinguish between PD and Parkinson-Plus patients. The STS can be identified at both 1.5 T and 3 T.

CT findings in a patient with bilateral metachronous carotidynia.

Carotidynia is a self-limiting, idiopathic clinical syndrome characterized by acute unilateral neck pain and tenderness of the carotid artery. We describe a unique case of bilateral carotidynia that occurred metachronously, with each incident resolving without long-term sequelae. Knowledge of this entity is important to properly interpret the imaging findings and to not mistake this finding as an ill-defined tumor, thus avoiding unnecessary biopsy.

Radiologic appearance of chronic parapharyngeal Teflon granuloma.

Although Teflon has been used for almost 5 decades to provide tissue augmentation in various surgical indications, including head and neck surgery, its use has significantly declined in the last 2 decades, primarily because of its implication in granuloma formation. Teflon granulomas have been shown to cause false positives on positron emission tomography imaging and have been reported to have a characteristic magnetic resonance imaging (MRI) appearance. We report a patient with a large chronic Teflon granuloma of the parapharyngeal space that caused significant bony erosion of the atlas vertebra. The lesions MRI signal characteristics were indistinguishable from those of surrounding tissues, while it showed characteristic hyperdensity on computed tomography due to the presence of fluorine atoms within Teflon. As MRI may supersede or replace computed tomography for a number of indications, and as Teflon has been used in large numbers of patients whose records may not always be available, knowledge of these findings has clinical relevance.

Percutaneous Transosseous Translaminar Approach for Thecal Sac Access in Advanced Ankylosing Spondylitis with Instrumented Posterior Spinal Fusion

SUMMARY: A novel transosseous approach for percutaneous access of the lumbar subarachnoid space is described in a patient with advanced ankylosing spondylitis (AS) and instrumented spinal fusion who presented for myelography. Use of a coaxial threaded bone biopsy system to provide transosseous access to the thecal sac, imaging findings, and outcome are discussed. This technique provided access to an otherwise inaccessible subarachnoid space and is an alternative approach in the setting of advanced AS or posterior spinal fusion.

Combined galactography and stereotactic core needle breast biopsy for diagnosis of intraductal lesions

The diagnosis of intraductal breast lesions detected during galactography performed for spontaneous nipple discharge traditionally has been obtained by performing subsequent needle localization and surgical excision. Galactography followed by stereotactic core needle breast biopsy offers a less invasive alternative for arriving at a diagnosis in many patients. This article describes our technique for combined galactography and stereotactic core needle breast biopsy. We also discuss the use of stereotactic core needle breast biopsy versus needle localization with surgical excision and the advantages and applications of our use of combined galactography and stereotactic core needle breast biopsy. In most cases, no mammographic abnormalities, other than the occasional dilated duct or segmental microcalcifications, are present in patients with spontaneous nipple discharge. Galactography, or ductography, usually is performed to evaluate the various causes of nipple discharge.1 Galactography is used to determine whether there is an intraductal lesion causing the nipple discharge, and to identify the location of the intraductal filling defect for surgical planning. Nipple discharge from multiple ducts is seen more often in the setting of duct ectasia or fibrocystic change. These entities usually present with bilateral cloudy yellow or greenish discharge that must be expressed from the nipple1 (Table 1). Intraductal papillomas most commonly present with spontaneous, unilateral nipple discharge that is bloody, serous, or clear, from a single duct. However, because some breast cancers also can present in this fashion,1 further evaluation of this type of spontaneous, uniorificial nipple discharge is indicated. The indication for galactography is the presence of a spontaneous, serous, serosanguineous, or bloody nipple discharge. Typically, such discharge is uniorificial and unilateral. However, these more suspicious types of discharge occasionally may occur simultaneously with a more benign, multiorificial, bilateral nipple discharge.