Greater Palatine Canal: Computed Tomography-Based Anatomic Analysis And Clinical Significance for the Sinus and Skull Base Surgeon.

OBJECTIVE: Our aim is to describe the location and course of the greater palatine canal (GPC) by analyzing its relationship with anatomical landmarks that can be used during endoscopic sinus surgery. This information might help prevent injury to the neurovascular bundle. METHODS: A retrospective evaluation of paranasal sinus CT scans of 100 consecutive random patients, 200 sides, was performed. Five measurements related to the course of the GPC were conducted, from cranial to caudal. The anatomical landmarks were the inferior bony border of the sphenopalatine foramen to the cranial entrance of the GPC, the distance from the most dorsal, and inferior bony insertion of the middle turbinate and the inferior turbinate bones to the anterior margin of the GPC. The angle between the horizontal palatine bone and the GPC, its length, and the prevalence of osteophytes in GPC was also assessed. RESULTS: The mean distance of the inferior border of the sphenopalatine foramen to the cranial entrance of the GPC was 9.39 ± 1.72 mm. The mean distance of the dorsal insertion of the middle turbinate to the anterior margin of the GPC was 3.89 ± 0.93 mm. The distance of the dorsal insertion of the inferior turbinate to the anterior margin of the GPC was 3.16 ± 0.81 mm. The mean angle between the horizontal palatine bone and the GPC was 114.33 ± 10.92º and the mean length of the GPC was 30.23 ± 3.74 mm. None of the measurements showed a significant difference between the two sides. CONCLUSIONS: The landmarks used are easy to locate and assess on CT scans. These findings may help to make dissection safer in pathologies related to the pterygopalatine fossa, lateral sphenoid sinus or adjacent skull base.

Patterns of Perineural Skull Base Tumor Extension from Extracranial Tumors.

Perineural extension is an increasingly recognized pathway of extension of cutaneous, mucosal, and salivary gland neoplasms associated with a severe adverse prognosis. Imaging identification is feasible by MR imaging 3-dimensional contrast-enhanced submillimetric sequences. The trigeminal nerve branches and facial nerve are the most commonly involved. PET with computed tomography may aid in the identification of the primary tumor location or recognition of recurrence, but only in conjunction with MR imaging does it achieve similar detection rates for perineural extension. Computed tomography scanning is an adjunct to MR imaging to increase specificity and for surgical treatment planning.

The Role of Non-Echoplanar Diffusion-Weighted Magnetic Resonance Imaging in Diagnosis of Primary Cholesteatoma and Cholesteatoma Recidivism as an Adjunct to Clinical Evaluation.

INTRODUCTION:: The aim of this study was to analyze the sensitivity and specificity of non-echoplanar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) for the detection of cholesteatoma, with a focus on its value as an adjunct to clinical examination. METHODS:: In a prospective cohort study, 92 cases were divided into 2 groups: "clinically cholesteatoma" ( n = 79) and "clinically no cholesteatoma" ( n = 13). Non-EPI DW MRI was performed preoperatively in all cases. The presence of a cholesteatoma was assessed by clinicians otoscopically, by neuroradiologists on non-EPI DW MRI, by the surgeon intraoperatively, and finally by the pathologist postoperatively. Data analysis was performed for specificity, sensitivity, positive predictive value, negative predictive value, and interrater variability. RESULTS:: The sensitivity and specificity were 89.3% and 75%, respectively, in the "clinically cholesteatoma" group and 0% and 100% in the "clinically no cholesteatoma" group. Non-EPI DW MRI had a positive predictive value of 98.5% when cholesteatoma was suspected clinically and a negative predictive value of 84.6% when cholesteatoma was not suspected clinically. CONCLUSION:: If cholesteatoma is suspected clinically, non-EPI DW MRI is not necessary. If there is no clinical suspicion of cholesteatoma in second-look situations, sensitivity is low and serial follow-up MRI with long intervals is advised.

Durable Control of Metastatic AKT1-Mutant WHO Grade 1 Meningothelial Meningioma by the AKT Inhibitor, AZD5363.

High-throughput analyses have revealed the presence of activating mutations in the AKT1 gene in a subpopulation of meningiomas. We report a female patient with multiple intracranial tumor manifestations and histologically verified meningotheliomatous meningioma in the lung. The tumor was continuously growing at multiple sites despite six surgical resections, radiotherapy, and two lines of systemic therapy. Following detection of an AKT1E17K mutation in three independent tumor samples by sequencing, treatment with AZD5363, a selective AKT inhibitor, was initiated. Ex vivo cultured meningioma cells exhibited sensitivity to the drug as shown by pAKT accumulation on immunoblots. Treatment with AZD5363 resulted, for the first time, in stable disease and minor radiographic response. The patient has been on that treatment for more than one year with ongoing clinical and radiographic response. This is the first report of an AKT1-mutant meningioma responding to AKT inhibition, suggesting that molecular screening may result in clinical benefit.

[Thrombosis of the external jugular vein. Case report of a rare cause for pain in the lateral neck]. / Thrombose der vena jugularis externa. Fallbericht einer ungewöhnliche Ursache für Schmerzen im seitlichen Halsbereich.

Dental practitioners are sometimes confronted with patients complaining about pain in the neck area. Especially if an induration in the region of the big vessels is present, one must keep in mind the differential diagnosis of a spontaneous thrombosis of the external jugular vein. This diagnosis needs consequent treatment but also consequent search for an underlying pathology. This case report presents such a situation in an exemplary way. Despite risk factors, the reason for thrombosis stays in the dark. However, all possible causes were cleared and are shown to the reader. Especially malignancies are responsible for thrombosis of the jugular vein in many cases.

Spinal magnetic resonance imaging with reduced specific absorption rate in patients harbouring a spinal cord stimulation device - A single-centre prospective study analysing safety, tolerability and image quality.

BACKGROUND: Spinal cord stimulation (SCS) is an accepted treatment in patients with failed back surgery (FBS), complex regional pain syndrome (CRPS) and persistent radicular pain following surgery. In order to avoid patient hazards or device malfunction manufacturers advise to abstain from magnetic resonance imaging (MRI) in patients with implanted electrodes or pulse generators. METHODS: In a prospective study, 13 patients harbouring an implanted Medtronic Spinal Cord Stimulation (SCS) device underwent MRI (1.5 T) of the lumbar (n=13), the cervical (n=2) or the thoracic spine (n=1) following the development of new spinal symptoms. An adapted MRI protocol was used limiting the transmitted energy and specific absorption rate. Tolerability and safety were assessed by means of a standardized patient evaluation form documenting pain on a visual analogue scale (0-10), neurologic deficit, and discomfort during the scan. In addition, overall satisfaction with the examination procedure was rated on a Likert scale (1-5). Image quality was rated independently and blinded to the presence of a SCS device by the radiologist and the surgeon as equivalent, superior or inferior compared to the standard spine MRI examination. RESULTS: None of the 13 patients investigated by the modified spinal MRI protocol experienced new neurological deficits, worsening of symptoms or a defect/malfunction of the implant device. Three patients (23.1 %) reported transient warm sensation in the location of the electrode and in one case intermittent slight tingling in the lower extremities. Overall satisfaction with the examination was 1.13 ± 0.34 according to Likert scale (1-5). The image quality was rated - not statistically significant - slightly inferior to standard lumbar spine imaging (0.82 ± 0.54) with a kappa value of 0.68 between the two investigators. MRI examinations detected relevant and new lesions in 9 (69.2 %) patients which affected treatment in 8 (61.5 %) individuals. CONCLUSION: Using a protocol with a reduced specific energy absorption rate, spinal MRI examinations in patients with SCS can be considered safe. The current view that neurostimulators are a general contraindication to MR examinations has to be reconsidered in patients with new or progressive spinal symptoms.

De novo development and progression of endolymphatic sac tumour in von hippel-lindau disease: an observational study and literature review.

Endolymphatic sac tumors (ELST) are rare invasive lesions of the temporal bone that are commonly associated with von Hippel-Lindau disease. This report describes serial magnetic resonance imaging (MRI) and computed tomography (CT) findings over a period of 6 years in a 12-year-old patient who developed an ELST after 3.5 years surveillance for a cerebellar hemangioblastoma. A 1.5 × 8 mm tumor was identified on MRI within the endolymphatic duct when the patient presented with audiovestibular symptoms due to intralabyrinthine hemorrhage. The tumor demonstrated subsequent growth over 25 months until the patient agreed to undergo surgical resection by subtotal petrosectomy. De novo development and the natural history have been described only in six previous cases. MRI is regarded to be unreliable with respect to the ability to demonstrate an ELST in the presence of intralabyrinthine hemorrhage, with only two out of four previously reported patients demonstrating positive MRI findings. Little is known about the precise origin (endolymphatic duct versus sac), growth, and symptom correlation. This case highlights that new audiovestibular symptoms are a potential clinical clue and intralabyrinthine hemorrhage is a neuroimaging indicator for the presence of an ELST, which based on high-resolution MRI appears to originate in the endolymphatic duct rather than sac.

Initial staging of the neck in head and neck squamous cell carcinoma: a comparison of CT, PET/CT, and ultrasound-guided fine-needle aspiration cytology.

BACKGROUND: The aim of this study was to compare imaging modalities for staging the neck in a prospective cohort of patients evaluated by CT, ultrasound with fine-needle aspiration cytology (FNAC), and [(18)F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT with the histologic evaluation of the neck dissection as the standard of reference. METHODS: In all, 76 consecutive patients were prospectively enrolled. RESULTS: Ultrasound-guided FNAC showed the highest level of agreement with histology for exact N classification. Ultrasound-guided FNAC showed the smallest percentage of overstaged patients, 7%, versus 16% with PET/CT, 13% with CT, and 13% with ultrasound. The rate of understaged patients was comparable between the imaging modalities. With regard to the endpoint N0 versus N+ there were no statistically significant differences to be found. CONCLUSIONS: Ultrasound-guided FNAC seems to correlate best with histologic staging compared with PET/CT and CT. None of the modality is reliable enough to replace elective neck treatment in cN0 necks.

Comparison of two resorbable membrane systems in bone regeneration after removal of wisdom teeth: a randomized-controlled clinical pilot study.

OBJECTIVES: To compare the performance and safety of Inion GTR(TM) Biodegradable Membrane System and Geistlich resorbable bilayer Bio-Gide((R)) membrane in human bone regeneration. MATERIAL AND METHODS: In a multicenter, split blind, comparative, randomized, prospective, pilot study 15 patients have been randomized at surgery whether to be treated either with Inion GTR(TM) Biodegradable Membrane System on one and Geistlich resorbable bilayer Bio-Gide((R)) membrane on the other side or vice versa after surgical removal of both fully impacted wisdom teeth. During the follow-up visits at week 1, 2 and 6 and at months 3 and 6 the general state, the wound, eventual adverse events and the medication of the patients were assessed. Computed Tomography (CT) scans were performed immediately and 3 months after the surgery, before biopsy collection. Semi-quantitative histological evaluation and histomorphometric analyses were performed according to the ISO 10993-6 standard. New bone formation and membrane integration were evaluated by CT scan measurements. Tissue healing was evaluated clinically and by photographs between the time on teeth extraction and during follow ups. RESULTS: Five patients were smokers, none drank alcohol. Mild adverse events like wound infection, haematoma or late swelling of the gums occurred in three patients. The trephine bur harvest of bone biopsies under local anaesthesia was uneventful. Whereas specimens from the sites treated with the Inion membrane yielded 17.0% (SD 24%), the Bio-Gide membrane sites yielded 13.5% (SD 15%) of bone tissue density. In sites treated with the Inion membrane, 9.5% of old bone density and 7.5% of newly formed bone could be found, whereas the Bio-Gide((R)) membrane sites showed 3.8% of old bone density and 9.8% of newly formed bone. There were no statistically significant differences between the two groups with respect to the two variables. The osteoid rim was more extended with the Bio-Gide((R)) (6.6 mm) than with the Inion membrane (5.1 mm) but the difference between the two treatments did not reach statistical significance. Highly significant reductions in the area of the defect with both membranes were detected with significant increases in CT density at the immediate inferio-buccal adjacent bone and in the surgical defect area with both membranes. However, there was neither significant change in CT density in the immediate inferior-lingual adjacent bone of the two membranes, nor significant difference between the membranes on any of the four measurements (area of defect: P=0.1354; CT density immediate inferio-buccal adjacent bone: P=0.7615; CT density surgical defect area: P=0.1876; CT density immediate inferio-lingual adjacent bone: P=0.4212). CONCLUSION: The overall clinical outcome was satisfying and the majority of the patients showed an uneventful healing phase. Both membranes presented similar capacities regarding their barrier function and were associated with analogous bone regeneration. No statistically valid evidence about the superiority of one particular membrane was obtained. For the patient the only difference is that one product is animal derived and the other synthetic.

Cholesteatoma triggering squamous cell carcinoma: case report and literature review of a rare tumor.

BACKGROUND: The aim of this study was to report a case of squamous cell carcinoma of the petrous part of the temporal bone associated with a long history of secondary acquired cholesteatoma in a 71-year-old man. PATIENTS AND METHODS: We present the case of a 71-year-old man diagnosed with secondary acquired cholesteatoma in 1950. Treatments consisted of repetitive surgery owing to several relapses. In 2004, he presented with progressive fetid otorrhea. Clinical and computed tomography findings were indicative for relapsing cholesteatoma and a subtotal petrosectomy was performed. RESULTS: Histologic work-up demonstrated a moderately differentiated squamous cell carcinoma. The staging revealed stadium pT3 cN0 cM0. Postoperative treatment consisted of local radiation therapy with intensity-modulated beam geometry with a total of 64.2 Gy in 30 fractions using a simultaneous integrated boost. CONCLUSION: Middle ear carcinoma can arise from acquired cholesteatoma. The pathogenesis of squamous cell carcinoma associated with cholesteatoma has not been elucidated satisfactorily. Due to the complex anatomic features, intensity-modulated radiation therapy is the technique of choice for postoperative radiotherapy.

Positron emission tomography/computed tomography for staging and restaging of head and neck cancer: comparison with positron emission tomography read together with contrast-enhanced computed tomography.

This retrospective study aimed to describe the differences between image readings done with combined positron emission tomography/computed tomography (PET/CT) and PET read together with contrast-enhanced CT (ceCT) in patients with squamous cell carcinoma of the head and neck. In 46 patients, no differences were found between the two readings for assessing infiltration of adjacent structures (P=.63), transgression of the midline (P=.67), lymph node involvement (P=.32), and T- and N stage. PET/CT and PET read together with ceCT have comparable diagnostic yield.

Lipoma on the corpus callosum in a patient with schizophrenia-like episode: is there a causal relationship?

Disturbed interhemispheric communication has been proposed as responsible for schizophrenia. We present a case of a schizophrenia-like episode with no neurologic or other psychiatric symptoms. However, magnetic resonance imaging revealed a lipoma on the splenium of the corpus callosum. Neuropsychologic examination revealed normal interhemispheric transfer, but a slight dysfunction associated with right-hemispheric anterior regions. Rather than supporting the hypothesis of a causal relationship between callosal abnormality and schizophrenia-like symptoms, our findings argue against a direct causal relationship between lesion site and psychotic episode. We conclude that cerebral abnormality per se may represent a risk factor for neuropsychiatric symptoms.

Seizure outcome after resection of cavernous malformations is better when surrounding hemosiderin-stained brain also is removed.

PURPOSE: Considering the epileptogenic effect of cavernoma-surrounding hemosiderin, assumptions are made that resection only of the cavernoma itself may not be sufficient as treatment of symptomatic epilepsy in patients with cavernous malformations. The purpose of this study was to test the hypothesis whether seizure outcome after removal of cavernous malformations may be related to the extent of resection of surrounding hemosiderin-stained brain tissue. METHODS: In this retrospective study, 31 consecutive patients with pharmacotherapy-refractory epilepsy due to a cavernous malformation were included. In all patients, cavernomas were resected, and all patients underwent pre- and postoperative magnetic resonance imaging (MRI). We grouped patients according to MRI findings (hemosiderin completely removed versus not/partially removed) and compared seizure outcome (as assessed by the Engel Outcome Classification score) between the two groups. RESULTS: Three years after resection of cavernomas, patients in whom hemosiderin-stained brain tissue had been removed completely had a better chance for a favorable long-term seizure outcome compared with those with detectable postoperative hemosiderin (p=0.037). CONCLUSIONS: Our study suggests that complete removal of cavernoma-surrounding hemosiderin-stained brain tissue may improve epileptic outcome after resection of cavernous malformations.

In-line (18)F-fluorodeoxyglucose positron emission tomography with computed tomography (PET/CT) in patients with carcinoma of the sinus/nasal area and orbit.

BACKGROUND: Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are the standard imaging techniques to evaluate patients with carcinoma in the sinus/nasal area and orbit. The use of positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) in such patients is as yet less well established. PURPOSE: The aim of this study was to assess the clinical impact of PET co-registered with CT (PET/CT). PATIENTS: Evaluation of 21 consecutive patients. METHODS: A retrospective analysis of the whole body PET/CT studies was done. Images were assessed visually without knowing the results of the other imaging technique. Histology and clinical follow-up served to verify lesions. The clinical impact on therapy was assessed together with the physician in charge. RESULTS: All patients underwent PET/CT and CT or MRI for staging (n=9 scans) and restaging (n=17 scans) without treatment between the examinations. PET/CT changed the treatment protocol in 2 patients at staging and in 7 at re-staging. Distant metastases were found in 5 and a secondary tumour in 1 patient. CONCLUSIONS: Whole body PET/CT adds clinically important information to CT or MRI, thus, influencing treatment.

Bone invasion in patients with oral cavity cancer: comparison of conventional CT with PET/CT and SPECT/CT.

PURPOSE: To prospectively compare the accuracy of helical contrast material-enhanced computed tomography (CT) with that of CT and positron emission tomography (PET) combined and CT and single photon emission CT (SPECT) combined in the detection of bone invasion in patients scheduled to undergo surgery for clinically suspected oral cavity carcinoma with possible bone invasion, with surgical results as the reference standard. MATERIALS AND METHODS: This study had local ethical committee approval, and all patients gave written informed consent. Thirty-four consecutive patients (17 men, 17 women; mean age, 64.2 years; age range, 46.0-84.6 years) who were clinically suspected of having bone invasion from oral cavity carcinoma prospectively underwent helical contrast-enhanced CT, coregistered PET/CT, and coregistered SPECT/CT. Two radiologists assessed the contrast-enhanced CT images and two nuclear medicine physicians separately assessed the PET/CT and SPECT/CT images in consensus and without knowledge of the results of other imaging tests. The presence of bone involvement as suggested with an imaging modality was compared with histologic findings in the surgical specimen. RESULTS: With histologic findings as the standard of reference, the accuracy of SPECT/CT (88% [30 of 34 patients]) was lower than that of PET/CT and contrast-enhanced CT (94% [32 of 34 patients] and 97% [33 of 34 patients], respectively). Sensitivity was highest with PET/CT (100% [12 of 12 patients]), and specificity was highest with contrast-enhanced CT (100% [22 of 22 patients]). Fluorine 18 fluorodeoxyglucose (FDG) uptake seen on two sides of the same cortical bone was not a helpful imaging pattern for better identifying bone invasion in patients without evident cortical erosion on CT scans. CONCLUSION: The assessment of cortical erosion with contrast-enhanced CT and the CT information from PET/CT are the most reliable methods for detecting bone invasion in patients with oral cavity carcinoma. FDG uptake seen on PET/CT images does not improve identification of bone infiltration.

Osteomyelitis of the mandible.

Before application of any cross-sectional imaging modality, the orthopanoramic view is indispensable in assessing the status of dentition, in recognizing direct radiographic signs of osteomyelitis, or in determining the presence of predisposing conditions such as a fracture or systemic bone disease. The orthopanoramic view is the procedure of choice in follow-up examinations in patients who have osteomyelitis. In acute osteomyelitis, the higher sensitivity of MR imaging for detection of intramedullary inflammation advocates this imaging modality for confirmation of the clinical diagnosis. If surgical treatment is planned, high-resolution CT is required to specify the degree of cortical destruction, the presence of sequestra in particular, and to define the extent of osseous removal required. In chronic osteomyelitis, the higher sensitivity of MR imaging to detect periosteal inflammation and soft tissue involvement advocates this modality to reveal the presence, location, and extent of chronic inflammation. The assessment of persistence or recurrence of chronic inflammation after surgical treatment is by high-resolution CT for the first 6 months following surgery. Finally, scintigraphy is recommended when multi-focal systemic disease is suspected, such as in CRMO and SAPHO syndrome.

Evaluation of paragangliomas presenting as a cervical mass on color-coded Doppler sonography.

OBJECTIVES: To assess the potential of color Doppler sonography to identify cervical mass lesions as paragangliomas. STUDY DESIGN: Prospective evaluation. METHODS: Fifteen patients with 18 paragangliomas (13 carotid body tumors, 3 vagal and 2 temporal) presenting as a mass in the neck were investigated using color Doppler sonography. RESULTS: All paragangliomas presented in B-mode sonography as solid, well-defined, and hypoechoic tumors. Color Doppler imaging revealed hypervascularity in 15 (82%) tumors. No flow signal was detected in 3 carotid body tumors at standard velocity encoding (30 cm/s). Only carotid body tumors could be assessed in their full extent. Temporal and vagal paragangliomas were only partially visible. Carotid body tumors showed a splaying of the carotid bifurcation with displacement of the external carotid anteriorly and both the internal carotid and the internal jugular vein posteriorly. Anterior displacement of both carotid arteries and posterior displacement of the internal jugular vein was found in the 3 vagal paragangliomas. The caudal tumor extension of the 2 temporal paragangliomas was recognized within the expanded lumen of the internal jugular vein. According to the direction of tumor growth and vascular supply, the intratumoral flow signal was predominantly directed upward in carotid body tumors and downward in vagal and temporal paragangliomas. CONCLUSIONS: Based on the appearance in the B-mode, the hypervascularity, the relationship toward the carotid arteries and the internal jugular vein, and the intratumoral flow direction, color Doppler sonography was able to establish the diagnosis and type of a paraganglioma.