High-Resolution CT Imaging of the Temporal Bone: A Cadaveric Specimen Study.

Objective Super-high and ultra-high spatial resolution computed tomography (CT) imaging can be advantageous for detecting temporal bone pathology and guiding treatment strategies. Methods Six temporal bone cadaveric specimens were used to evaluate the temporal bone microanatomic structures utilizing the following CT reconstruction modes: normal resolution (NR, 0.5-mm slice thickness, 512 2 matrix), high resolution (HR, 0.5-mm slice thickness, 1,024 2 matrix), super-high resolution (SHR, 0.25-mm slice thickness, 1,024 2 matrix), and ultra-high resolution (UHR, 0.25-mm slice thickness, 2,048 2 matrix). Noise and signal-to-noise ratio (SNR) for bone and air were measured at each reconstruction mode. Two observers assessed visualization of seven small anatomic structures using a 4-point scale at each reconstruction mode. Results Noise was significantly higher and SNR significantly lower with increases in spatial resolution (NR, HR, and SHR). There was no statistical difference between SHR and UHR imaging with regard to noise and SNR. There was significantly improved visibility of all temporal bone osseous structures of interest with SHR and UHR imaging relative to NR imaging ( p < 0.001) and most of the temporal bone osseous structures relative to HR imaging. There was no statistical difference in the subjective image quality between SHR and UHR imaging of the temporal bone ( p ≥ 0.085). Conclusion Super-high-resolution and ultra-high-resolution CT imaging results in significant improvement in image quality compared with normal-resolution and high-resolution CT imaging of the temporal bone. This preliminary study also demonstrates equivalency between super-high and ultra-high spatial resolution temporal bone CT imaging protocols for clinical use.

Hemangioma of the Cavernous Sinus: A Case Series.

Introduction Cavernous sinus hemangiomas (CSHs) are rare, vascular, extra-axial tumors that are diagnosed with a combination of imaging and biopsy. We describe the clinical presentations, imaging findings, and management of two male patients with CSHs. Case Report Case 1 describes a 57-year-old man who presented with vision changes and cranial nerve palsies. Initial imaging and surgical biopsy were nondiagnostic. Follow-up Tc-99m tagged red blood cell (RBC) imaging supported CSH diagnosis. He was treated with surgical resection and radiotherapy. Case 2 describes a 57-year-old man who presented with chronic headache. Imaging findings were suggestive of CSH. He underwent endoscopic endonasal surgical resection and a final diagnosis of CSH was made via biopsy. Discussion CSHs often present with headache, vision changes, and cranial nerve palsies. Characteristic findings of a T2 hyperintense lesion with homogeneous contrast enhancement has been described in the literature. There is also a role for tagged RBC imaging studies in the setting of nondiagnostic imaging and biopsy. Surgical resection can be difficult due to tumor vascularity and encasement of internal carotid arteries. Stereotactic radiosurgery and adjuvant radiotherapy can play a role in the treatment of patients who have inoperable lesions or subtotal resections.

Chronic Hematic Cyst of the Right Maxillary Sinus and Orbit Presenting as Proptosis.

A 28-year-old man presented to the emergency room complaining of right proptosis. He also manifested eye pain and facial fullness and redness in this side. Seven years ago, he had right hemifacial gunshot trauma treated with surgical reconstruction. The CT scan showed expansion of the right maxillary sinus due to a hypodense nonenhancing lesion extending to the nasal cavity, masticatory space, and extraconal space of the orbit. MRI was performed showing high signal intensity of the lesion on T2-weighted images indicating a cystic nature. T1-weighted images also demonstrated high signal intensity of the lesion suggesting hemorrhage. At endoscopic maxillary antrostomy, the diagnosis of a chronic hematic cyst was confirmed. Chronic hematic cysts of the orbit should be included in the differential diagnosis of proptosis, especially if there is clinical history of past trauma. Due to the fact that physical examination is nonspecific, radiologic evaluation is useful to confirm the diagnosis and for presurgical planning.

Contrast-enhanced T2-FLAIR MR imaging in patients with uveitis.

To report MRI findings which reflect a pathological inflammatory condition of the uveal tract. This study includes single-center retrospective case series of five patients with clinical diagnosis of uveitis. There were 1 male (20 %) and 4 female patients (80 %). The average age was 29.6 years (range 25-38 years). Patients and 50 age-range-matched control subjects were scanned using a 1.5 T scanner. Ten additional control subjects scanned at 3 T were evaluated to have reference images at that high field. All patients (n = 5, 100 %) presented uveal tract enhancement on post-contrast T2-FLAIR fat-suppressed images and only 2 (40 %) had enhancement on T1-weighted images. The enhancement was anterior in 2 (40 %), pan-uveal in 2 (40 %), and posterior in 1 patient (20 %). Two patients (40 %) had unilateral increased vitreous signal on T2-FLAIR. One patient (20 %) had bilateral retrobulbar fat enhancement in both post-contrast T2-FLAIR and T1-weighted images. Post-contrast T2-FLAIR images can reveal abnormal enhancement of the uveal tract and retrobulbar fat as well as increased vitreous signal in patients with uveitis. In our small series, the sensitivity of post-contrast T2-FLAIR was higher than the conventional post-contrast T1-weighted images. Nonetheless, when bilateral uveal tract enhancement is present, there should be discretion before calling uveitis because the finding has been reported in different eye conditions as well as in a small percentage of healthy subjects at 1.5 T. In addition, it should be noted that post-contrast T2-FLAIR enhancement of the uveal tract is a normal finding at 3 T imaging.

Basic Imaging of Skull Base Trauma.

Skull base fractures extend through the floor of the anterior, middle, or posterior cranial fossa. They are frequently associated with complex facial fractures and serious complications such as cranial nerve or vascular injury, cerebrospinal fluid leak, or meningitis. Several distinct patterns of skull base fractures have been recognized, each of them associated with different complications. Recognition of, often subtle, skull base fracture is essential to prevent or allow early treatment of these serious complications.

Imaging Characteristics of Olfactory Neuroblastoma (Esthesioneuroblastoma).

This presentation outlines the clinical and imaging characteristics of esthesioneuroblastoma.

Intracranial Aneurysms in Children: The Role of Stenting and Flow-Diversion.

OBJECTIVE: To report a single-center experience in the endovascular management of cerebral aneurysms in children with stenting and flow-diversion techniques. METHODS: During a 7-year period, 5 male patients with six intracranial aneurysms (IA) were treated by endovascular therapy with stenting or flow-diversion. The average age was 11 years (range 6-18 years). RESULTS: The etiology of the aneurysms was vasculopathic in 3 cases (50%), traumatic in 2 patients (33.3%), and idiopathic in 1 case (16.7%). Two-thirds of the aneurysms were giant in size. The aneurysms were most frequently located in the anterior circulation (66.7%). Fifty percent of the aneurysms were treated with stenting and coiling, and 50% were treated with flow-diversion stents alone. After treatment, occlusion was graded as: partial in five aneurysms (88.3%) and complete in 1 case (16.7%). Most cases (83.3%) had a good outcome after the procedure. During follow-up, most aneurysms had progressive occlusion (80%), while the rest were unchanged (20%). Most stents and flow-diverter devices remained patent (80%). However, one Pipeline flow-diverter device in the Anterior cerebral artery (ACA) A2 segment had an asymptomatic occlusion. CONCLUSIONS: In this series, device-assisted endovascular techniques were a relatively safe and effective method of treatment of pediatric aneurysms. However, continued follow-up is required after treatment, because there are unsolved issues regarding the durability of flow-diverters and stents.

Combined Balloon Test Occlusion and SPECT Analysis for Carotid Sacrifice: Angiographic Predictors for Success or Failure?

Objectives To evaluate angiographic patterns that may predict the success or failure of carotid artery balloon test occlusion (BTO) and single-photon emission computed tomography (SPECT) analysis for carotid sacrifice. Study Design This is a retrospective nonrandomized study. Study Setting Conducted at the University of California Davis Medical Center, Sacramento, California. Patients A total of 31 patients, ranging from 24 to 83 years of age, with a mean age of 61 years (22 men, 9 women) with head and neck cancer (26 patients), malignant glomus tumor (1 patient) or giant carotid aneurysms (4 patients) as possible candidates for surgical carotid artery sacrifice were evaluated from September 2005 to September 2012. Methods All patients underwent unilateral internal carotid artery balloon test occlusion with SPECT analysis (20 mCi technetium 99m-hexamethyl propyleneamine oxime [HMPAO]) imaging before and during carotid occlusion. Carotid angiography with carotid cross-compression (manual compression of the cervical artery contralateral to the side of contrast injection) was used to analyze filling through the anterior communicating artery to the contralateral hemisphere. Intervention The balloon occlusion was terminated in two patients because of deterioration of the neurologic exam. Main Outcome Measures All patients who passed the neurologic examination during BTO and also passed the SPECT occlusive study underwent successful carotid sacrifice without neurologic sequelae. Patients failing the occlusive neurologic examination and/or the SPECT study elected chemoradiation, with the exception of one patient who underwent a successful carotid bypass graft and carotid resection. Results The success of carotid sacrifice in patients passing both the occlusive test and the SPECT analysis for carotid sacrifice was 100%. Three patients failed both the BTO and the SPECT, with two demonstrating no anterior circulation cross-fill, but one showed some cross-fill. Six additional patients passed the BTO but failed the SPECT, with poor cross-fill in five patients. In addition, three patients who had excellent cross-fill through the anterior communicating artery to the contralateral hemisphere failed the SPECT examination in two cases and failed both tests in another case.

Congenital and Acquired Conditions of the Mesial Temporal Lobe: A Pictorial Essay.

PURPOSE: Our goal is to pictorially review a wide spectrum of congenital and acquired conditions affecting the medial aspect of the temporal lobe. CONCLUSION: After completing this article, the reader will have knowledge of the imaging appearance of diverse developmental, malformative, and acquired lesions of the mesial temporal lobe, which will be useful when evaluating pathology in this location.

Lateral pterygoid plate fractures associated with mandible fractures.

IMPORTANCE: Classically, pterygoid plate fractures have been associated with fractures of the mid-face and skull base. When isolated pterygoid plate fractures are identified on imaging that only extends to the level of the skull base, other related facial fractures may be missed. We sought to evaluate isolated lateral pterygoid plate fractures on computed tomography (CT) scans in conjunction with mandible fractures and to propose a mechanism of fracture unrelated to the classic dissociating mid-face Le Fort fractures. OBSERVATIONS: In this retrospective case series, 7 patients who sustained facial trauma from 2006 to 2012 were found to have isolated lateral pterygoid plate fractures. All patients had an ipsilateral subcondylar fracture, 2 had symphyseal fracture, 2 had body fracture, and 1 had coronoid fracture. CONCLUSIONS AND RELEVANCE: On the basis of these cases, isolated lateral pterygoid fractures noted on CT of the head may be suggestive of an unappreciated mandibular fracture. The suspected mechanism is due to force transduction through the medial and lateral pterygoid muscles when acute displacing force is placed on the mandible. In patients with identified isolated pterygoid plate factures, a dedicated CT of the mandible may be indicated to assess for associated mandibular fracture, even in patients whose clinical examinations have had negative results.

The value of cervical magnetic resonance imaging in the evaluation of the obtunded or comatose patient with cervical trauma, no other abnormal neurological findings, and a normal cervical computed tomography.

BACKGROUND: The value of magnetic resonance imaging (MRI) in the evaluation of the obtunded or comatose patient with a potential neck injury is a controversial subject. Some authors have suggested that MRI of the cervical spine adds no value in the evaluation of patients with a normal computed tomography (CT) of the neck. However, others have suggested that MRI is the gold standard for clearing the cervical spine in a clinically suspicious or unevaluatable blunt trauma patient. The purpose of this study is to evaluate our data in regard to these conflicting hypotheses. METHODS: Five consecutive years of data from 17,000 patients seen at our Level I trauma center yielded 512 individuals who underwent both CT and MRI of the cervical spine. Of the latter group, 150 individuals met three strict inclusion criteria for this study: (1) obtundation (Glasgow Coma Scale ≤13, with 94 of this group comatose [Glasgow Coma Scale ≤8]); (2) no obvious neurologic deficits; and (3) a normal cervical CT. The effect of MRI on the clinical management of these patients was evaluated. RESULTS: Among the 150 obtunded or comatose patients with a negative CT, the majority (51%) had a normal MRI. Among the patients with a positive MRI, the most common MRI-positive findings were ligamentous and soft tissue injury (81%). However, no MRI findings were deemed unstable, and no surgical intervention or change in the clinical management aside from collar immobilization of these individuals occurred after MRI. CONCLUSIONS: The addition of a cervical MRI to the evaluation protocol of obtunded or comatose patients with an otherwise normal neurologic examination and a normal cervical CT did not provide any additional useful information to change the management of these patients.

Validating the RTOG-endorsed brachial plexus contouring atlas: an evaluation of reproducibility among patients treated by intensity-modulated radiotherapy for head-and-neck cancer.

PURPOSE: To evaluate interobserver variability for contouring the brachial plexus as an organ-at-risk (OAR) and to analyze its potential dosimetric consequences in patients treated with intensity-modulated radiotherapy (IMRT) for head-and-neck cancer. METHODS AND MATERIALS: Using the Radiation Therapy Oncology Group (RTOG)-endorsed brachial plexus contouring atlas, three radiation oncologists independently delineated the OAR on treatment planning computed-tomography (CT) axial scans from 5 representative patients undergoing IMRT to a prescribed dose of 70 Gy for head-and-neck cancer. Dose-volume histograms for the brachial plexus were calculated, and interobserver differences were quantified by comparing various dosimetric statistics. Qualitative analysis was performed by visually assessing the overlapping contours on a single beam's eye view. RESULTS: Brachial plexus volumes for the 5 patients across observers were 26 cc (18-35 cc), 25 cc (21-30 cc), 29 cc (28-32 cc), 29 cc (23-38 cc), and 29 cc (23-34 cc). On qualitative analysis, minimal variability existed except at the inferolateral portion of the OAR, where slight discrepancies were noted among the physicians. Maximum doses to the brachial plexus ranged from 71.6 to 72.6 Gy, 75.2 to 75.8 Gy, 69.1 to 71.0 Gy, 76.4 to 76.9 Gy, and 70.6 to 71.4 Gy. Respective volumes receiving doses greater than 60 Gy (V60) were 8.6 to 10.9 cc, 6.2 to 8.1 cc, 8.2 to 11.6 cc, 8.3 to 10.5 cc, and 5.6 to 9.8 cc. CONCLUSION: The RTOG-endorsed brachial plexus atlas provides a consistent set of guidelines for contouring this OAR with essentially no learning curve. Adoption of these contouring guidelines in the clinical setting is encouraged.

Endovascular treatment of penetrating traumatic injuries of the extracranial carotid artery.

PURPOSE: To describe the clinical and angiographic results of endovascular therapy for traumatic injuries of the extracranial carotid artery. MATERIALS AND METHODS: The clinical and angiographic features of 36 traumatic injuries of the carotid artery during a 12-year period were reviewed. There were 35 male patients (97.2%) and 1 female patient (2.8%) with an average age of 28.8 years (range 13-60 years). Of the 36 lesions of the carotid artery, 29 (80.6%) were the result of gunshot injury, and 7 (19.4%) were secondary to stab wounds. In 24 (66.7%) instances, the injury resulted in a pseudoaneurysm; in 7 (19.4%), in an arteriovenous fistula (AVF); in 4 (11.1%), in a dissection; and in 1 (2.8%), in inactive bleeding. All patients were treated with an endovascular approach using different techniques (balloon occlusion, embolization, or stent deployment). RESULTS: Endovascular therapy resulted in documented lesion occlusion in 34 (94.4%) patients. Two patients declined any follow-up postprocedural imaging; however, they have remained asymptomatic. Clinical improvement was documented in 35 (97.2%) patients, and there was one procedure-related complication with fatal consequences. CONCLUSIONS: In this series, endovascular techniques were an effective method of treatment. It was possible to use different endovascular reconstructive techniques or parent artery occlusion depending on the degree of vessel damage, with resolution of clinical symptoms and avoidance of surgery in most cases.

Traumatic carotid-cavernous fistula with pontomesencephalic and cervical cord venous drainage presenting as tetraparesis.

A 27-year-old male presented with progressive ascending myelopathy leading to tetraparesis. Magnetic resonance imaging of the cervical spine showed dilated perimedullary veins and spinal cord edema. Catheter angiography demonstrated a direct carotid-cavernous fistula (CCF) with prominent pontomesencephalic and perimedullary venous drainage. Successful coil embolization of the fistula was performed with improvement of the patient's symptoms. To our knowledge, no case of a direct CCF with perimedullary drainage has been previously reported.

Pediatric lipoblastoma in the head and neck: a systematic review of 48 reported cases.

BACKGROUND: Lipoblastoma is an exceedingly rare cause of pediatric head and neck masses. There have been 47 cases previously reported in the English literature. We present an additional case and review of the available literature on this rare neoplasm. OBJECTIVE: To review and assess the current published literature regarding the efficacy of preserving neurovascular structures in the surgical management of pediatric lipoblastoma. METHODS: Literature analysis of case reports was performed. MEDLINE was searched for the terms "neonatal lipoblastoma", "lipoblastomatosis", and "benign lipoblastoma". Results in the English literature were mined for relevant clinical data when available. The citations of case reviews found were searched to find additional cases. RESULTS: Including our new case, a total of 48 cases of head and neck lipoblastoma have been reported in the English literature within 23 manuscripts. Four manuscripts presented cases series (Evidence Based Medicine Level 4) and 19 were case reports (Level 5). The median sample size was 1 (range 1-4). For those 14 articles (N=23 cases) reporting follow-up, the median follow-up duration was 22 months. Male to female ratio was 2.1:1 with an average age at presentation of 2.1 years (range: newborn to 12 years). Lesions ranged from 3 to 12 cm in longest diameter. Recurrence was seen in 27% of patients in which there was at least 1-year follow-up. The most common presenting symptoms were painless enlarging neck mass (53%, 17/32) and respiratory distress (12%, 4/32). An exact binomial sign test indicated that most authors recommend conservative complete excision with preservation of vital structures with 10 of 11 authors giving a stance supporting conservative surgical resection, p=.012. CONCLUSIONS: Our findings suggest that although total excision is ideal and curative, subtotal resection may be a viable treatment alternative for lipoblastoma of the head and neck. This tumor presents a clinical challenge and should be considered in infants presenting with a cervical mass. It is difficult to differentiate from the much more common lymphangioma on clinical and radiological examination. Additionally, the potential for rapid growth and adhesion to neurovascular tissue makes surgical resection arduous. Nonetheless, recurrence rates for head and neck lipoblastomas are similar to those rates observed elsewhere in the body.

Delayed complication after embolotherapy of a vertebral arteriovenous fistula: spinal cord ischemia.

Previous reports suggest a generally successful experience with embolotherapy of vertebral arteriovenous fistulas of the neck. However, potential complications do exist, as shown by this report documenting spinal cord ischemia secondary to compromise of a dominant spinal artery arising from the proximal aspect of the right vertebral artery.

Dermoid cyst of the orbit and frontal sinus: a case report.

We describe a case of a dermoid cyst involving the orbit and frontal sinus of an adult treated at our tertiary referral center, and we review the literature on dermoid cysts of the orbit and frontal sinus. A 28-year-old Caucasian man presented with right-sided supraorbital swelling resulting in diplopia and reduced visual acuity. Computed tomography and magnetic resonance imaging scans were preformed. Although a definitive diagnosis was unclear, the imaging findings were consistent with a dermoid cyst. The lesion was excised through an upper-lid incision. Postoperatively, the patient had a patent frontal sinus and his visual symptoms resolved. Dermoid cysts of the orbit are uncommon lesions that occur primarily in the pediatric population. Lesions extending into the frontal sinus have not been reported before in the literature. In adults, orbital dermoids are more likely to present with bone erosion, and therefore they should be considered in the differential diagnosis for orbital and frontal bone lesions extending into the frontal sinus.

Leptomeningeal cyst of the orbital roof in an adult: case report and literature review.

OBJECTIVE: To present the case of a leptomeningeal cyst involving the orbital roof in an adult. DESIGN: Case report and literature review. SETTING: Tertiary referral center. SUMMARY: A 47-year-old female with a remote history of a skull fracture at 3 years of age presented with increasing headaches and retro-orbital pain. A computed tomogram and magnetic resonance image revealed a leptomeningeal cyst of the orbital roof. RESULTS: Only one previous leptomeningeal cyst of the orbital roof has been reported in an adult. Surgical excision of the lesion was performed and follow-up imaging 18 months after the operation revealed no evidence of recurrence. CONCLUSION: Although extremely rare, adult patients can develop growing skull fractures or leptomeningeal cysts of the orbital roof. Such lesions should be included in the differential diagnosis when a patient presents with orbital pain or exophthalmos and a history of head trauma as a child.