Ultra-low-dose CBCT: new cornerstone of paranasal sinus imaging.

BACKGROUND: This study evaluates the clinical image quality (IQ) and usability of a sinonasal ultra-low-dose (ULD) cone-beam computed tomography (CBCT) scan. The results are compared to those of a high resolution (HR) CBCT scan to identify the strengths and weaknesses of a ULD CBCT protocol. METHODOLOGY: Sixty-six anatomical sites in 33 subjects were imaged twice using two imaging modalities: HR CBCT (Scanora 3Dx scanner; Soredex, Tuusula, Finland) and ULD CBCT (Promax 3D Mid scanner; Plandent, Helsinki, Finland). IQ, opacification and obstruction, structural features and operative usability were assessed. RESULTS: The overall IQ in subjects with 'no or minor opacification' was excellent: 100% (HR CBCT) and 99% (ULD CBCT) of ratings were evaluated as sufficient for every structure. Increased opacification reduced the quality of both imaging modalities, resulting conchtoethmoidectomy, frontal sinusotomy, sphenotomy and posterior ethmoidectomy in cases with greater opacification. CONCLUSIONS: IQ of paranasal ULD CBCT is sufficient for clinical diagnostics and should be considered for surgical planning. We recommend it as the primary imaging protocol for all patients who meet imaging criteria due to recurrent or chronic nasal symptoms. Additional or conventional imaging might be needed for patients with extensive chronic rhinosinusitis and/or indications of frontal sinus involvement.

Spatio-temporal dynamics of face perception.

The temporal and spatial neural processing of faces has been investigated rigorously, but few studies have unified these dimensions to reveal the spatio-temporal dynamics postulated by the models of face processing. We used support vector machine decoding and representational similarity analysis to combine information from different locations (fMRI), time windows (EEG), and theoretical models. By correlating representational dissimilarity matrices (RDMs) derived from multiple pairwise classifications of neural responses to different facial expressions (neutral, happy, fearful, angry), we found early EEG time windows (starting around 130 â€‹ms) to match fMRI data from primary visual cortex (V1), and later time windows (starting around 190 â€‹ms) to match data from lateral occipital, fusiform face complex, and temporal-parietal-occipital junction (TPOJ). According to model comparisons, the EEG classification results were based more on low-level visual features than expression intensities or categories. In fMRI, the model comparisons revealed change along the processing hierarchy, from low-level visual feature coding in V1 to coding of intensity of expressions in the right TPOJ. The results highlight the importance of a multimodal approach for understanding the functional roles of different brain regions in face processing.

A prospective, randomized clinical study comparing drug eluting stent therapy and intranasal corticoid steroid therapy in the treatment of patients with chronic rhinosinusitis.

OBJECTIVES: To conduct the first prospective, randomized controlled clinical trial comparing the efficacy of a drug-eluting stent (DES) (the Relieva StratusTM MicroFlow Spacer) and topical intranasal corticosteroid therapy in patients with chronic rhinosinusitis (CRS). METHODS: Sixty-three adult patients with ethmoiditis were randomized into either the DES group (n=34) or nasal spray group (n=29). The main outcome variable was the Sinonasal Outcome Test 22, Visual Analogue Scale, nasal endoscopy, rhinometric measurements were performed at the beginning of the study, after three months and six months of follow-up. RESULTS: Both treatments significantly improved quality of the life with no significant difference being found between the two groups. The VAS score decreased in both groups: improvements were significant at three and six months in the nasal spray group, but in the DES group a significant difference was noted only at three months. There was a statistically significant increase in total nasal cavity volumes in the corticosteroid spray group, but not in the DES group. CONCLUSION: We found that patients benefitted from DES and the corticosteroid nasal spray. We could not find any significant difference between the treatments, except the greater increase in the total nasal cavity volumes favouring the nasal spray group. Because of the very good results for the nasal spray and the much higher material and operating room costs associated with DES, we cannot recommend the use of DES over nasal spray as a monotherapeutic treatment for CRS.

Pleomorphic adenoma in the nasal cavity: a clinicopathological study of ten cases in Finland.

The objective of the study was to investigate the nationwide occurrence of sinonasal pleomorphic adenoma in Finland. A retrospective study was conducted at The Departments of Otorhinolaryngology-Head and Neck Surgery, and Pathology at the five university hospitals in Finland. Data were obtained by searching for sinonasal pleomorphic adenoma cases in the clinical and histopathological registries at these institutions for the past two to four decades. All patients who had had a histologically proven pleomorphic adenoma in the sinonasal area were included as participants. Ten cases with pleomorphic adenoma of the nasal cavity were found. The majority of these tumours originated in the septum, and there were no malignant transformations. Pleomorphic adenomas of the nasal cavity were found to be extremely rare in this nationwide investigation.

Decrease of nasal airway resistance and alleviations of symptoms after balloon sinuplasty in patients with isolated chronic rhinosinusitis: a prospective, randomised clinical study.

OBJECTIVES: The aim of this study was to evaluate and compare the clinical outcome of balloon sinuplasty and uncinectomy for patients suffering from isolated chronic rhinosinusitis of the maxillary sinus. DESIGN: A prospective, randomised, non-blinded, controlled trial was conducted. SETTING: The study was carried out at the Department of Otolaryngology, Tampere University Hospital, Finland. PARTICIPANTS: Adult patients with symptomatic isolated chronic or recurrent rhinosinusitis without severe findings in the sinuses, as documented in the sinus' Computer Tomography scan and clinical examination, were randomised into two groups: uncinectomy and balloon sinuplasty. MAIN OUTCOME MEASURES: The variables in our study are the Sinonasal Outcome Test-22 (SNOT 22), acoustic rhinometry and rhinomanometry. These parameters were analysed preoperatively and postoperatively (after 3 and 6 months). RESULTS: The preliminary results of our study have been previously published. Both balloon sinuplasty and uncinectomy significantly improved almost all the parameters of SNOT22 (P < 0.05), with no significant difference being found between these two groups (P > 0.05). Based on rhinomanometry results, airway resistance decreased after treatment. Regarding adverse effects, balloon sinuplasty was significantly associated with a lesser risk of synechia. CONCLUSIONS: Both balloon sinuplasty and uncinectomy improved the quality of life and decreased upper airway resistance of patients with mild, isolated chronic or recurrent rhinosinusitis. The smaller risk of postoperative synechiae with balloon sinuplasty combined with its promising efficiency could partially compensate for its high material cost.

Quality of life after endoscopic sinus surgery or balloon sinuplasty: a randomized clinical study.

OBJECTIVES: To conduct the first prospective randomized controlled trial that evaluates and compares the clinical outcome and impact of ballonsinuplasty and endoscopic sinus surgery (ESS) on the quality of life of patients suffering from chronic or recurrent rhinosinusitis (CRS) of the maxillary sinus. METHODS: Adult patients with symptomatic chronic or recurrent rhinosinusitis without severe findings in the sinuses, as documented in the sinus' Computer Tomography scan and clinical exam, were randomized in 2 groups: ESS and Balloon Sinuplasty.The main variable in our study is the Sinonasal Outcome Test-22 (SNOT 22) and its parameters. These parameters were analysed preoperatively and at 3 months, postoperatively. RESULTS: There was a subjective improvement in symptoms after surgery. We also noticed an objective improvement in the quality of life of our patients seen as a decrease in the total SNOT 22 score. Both balloon sinuplasty and ESS significantly improved almost all the parameters of SNOT22, with no significant difference being found between these two groups. CONCLUSION: Both balloon sinuplasty and endoscopic sinus surgery improved the quality of life of patients with mild chronic or recurrent rhinosinusitis. However, the remarkably higher material cost of balloon sinuplasty compared to ESS sets limits on its broad use. There is an obvious need for further study to find out if, as an office procedure, balloon sinuplasty could deliver cost-savings high enough to cover the higher material cost of balloon sinuplasty. Our study was, however, too small to enable firm conclusions to be drawn.

Assessing Cut-off Points of Eosinophils, Nasal Polyp, and Lund-Mackay Scores to Predict Surgery in Nasal Polyposis: A Real-World Study.

BACKGROUND: Developing tools to identify chronic rhinosinusitis with nasal polyps (CRSwNP) patients requiring surgical treatment would help clinicians treat patients more effectively. The aim of this retrospective cross-sectional study was to identify cut-off values ​​for eosinophil percentage, nasal polyps (NP), and Lund-Mackay (LM) scores that may predict the need for surgical treatment in Finnish CRSwNP patients. METHODS: Data of CRSwNP patients (N = 378) undergoing consultation for ESS in 2001-19 were used. Data was collected from patient records and Lund-Mackay scores were determined from sinus computed tomography scans. The percentage of eosinophils was microscopically evaluated from the polyp samples available (n = 81). Associations were analyzed by Mann Whitney U test, and cut-off values by the area under the receiver operating characteristic curve (AUROC). RESULTS: ESS was performed to 293 (77.5%) of patients. Polyp eosinophilia was associated significantly with ESS (p = 0.001), whereas peripheral blood eosinophil count, LM- score and endoscopic NP- score were not (p > 0.05). AUROC values (95% CI) for detecting those needing ESS were for polyp eosinophilia 0.71 (0.60-0.83), p = 0.001, for LM score 0.59 (0.50-0.67), p = 0.054; for NP score 0.56 (0.48-0.64), p = 0.17, and for blood eosinophil count 0.68 (0.46-0.90), p = 0.08. With the threshold value of polyp eosinophilia (>25%), the sensitivity and specificity were optimal for detecting the group needing ESS from the group not undergoing ESS. The cut-off value of blood eosinophil count (>0.26 × 109/L) had relatively good, yet statistically insignificant (underpowered), predictive potential. Moderate cut-off values were found for endoscopic LM score (≥14/24) and NP score (≥4/8). CONCLUSIONS: Polyp eosinophilia (>25%) predicted ESS among Finnish hospital-level CRSwNP patients. A future challenge would be to find less invasive and cost-effective clinical factors predicting uncontrolled CRSwNP.

Diagnostic Accuracy of Symptoms, Endoscopy, and Imaging Signs of Chronic Rhinosinusitis Without Nasal Polyps Compared to Allergic Rhinitis.

Objectives The diagnosis of chronic rhinosinusitis without nasal polyps (CRSsNP) and distinguishing it from allergic rhinitis is difficult. Yet, early detection of CRSsNP is important to prevent progressive and severe chronic rhinosinusitis. Our aim was to compare diagnostic accuracy of symptoms, endoscopy, and imaging signs of CRSsNP and allergic rhinitis -only phenotypes. Setting Prospective controlled follow-up study. Participants Forty-two nonsmoking patients visiting tertiary care due to CRSsNP and 19 nonsmoking volunteer controls with allergic rhinitis filled a symptoms questionnaire and underwent nasal endoscopy off-seasonally. All CRSsNP patients underwent computed tomography scans of paranasal sinuses. All the allergic rhinitis control subjects and 14 of the CRSsNP patients underwent sinus magnetic resonance imaging. Results Radiologic Lund-Mackay score, duration of symptoms, visual analogue scale scores of symptoms, and Sinonasal Outcome Test 22 were significantly higher in the CRSsNP group compared to allergic rhinitis control group. These factors also correlated in part with each other. Endoscopic score did not correlate with other factors, nor did it differ between CRSsNP and allergic rhinitis groups. The highest area under curve value was demonstrated for visual analogue scale score of facial pain/pressure (0.93) and score ≥4/10 showed 60% sensitivity and 95% specificity for detecting CRSsNP group ( P < .001). Radiologic sign of obstructed osteomeatal complex showed 100% specificity and 38% sensitivity for detecting CRSsNP group ( P < .001). Conclusions CRSsNP phenotype could be primarily distinguished from allergic rhinitis by higher facial pain/pressure score and secondarily by radiologic sings of obstructed ostiomeatal complex and higher Lund-Mackay score. Endoscopic score has limited value in distinguishing CRSsNP from allergic rhinitis.

Risk factors for secondary post-tonsillectomy haemorrhage following tonsillectomy with bipolar scissors: four-year retrospective cohort study.

OBJECTIVE: To analyse risk factors associated with secondary post-operative bleeding when only one technique, namely bipolar scissors, is used. METHODS: The medical records of all consecutive patients aged six years or older who underwent tonsillectomy or adenotonsillectomy between 1 December 2010 and 30 November 2014 were retrospectively analysed. RESULTS: A total of 1734 patients were included in the study. A secondary haemorrhage occurred in 208 patients (12 per cent). Patients aged 15 years or older were 4.5 times (95 per cent confidence interval = 2.6-7.9; p < 0.001) more likely to experience secondary haemorrhage. In cases of acute quinsy, patients aged 15 years or older had an 8.1-fold (95 per cent confidence interval = 1.1-59.6; p = 0.02) increased likelihood of experiencing secondary haemorrhage. CONCLUSION: Patients aged 15 years or older have a higher risk for bleeding regardless of the primary indication for the tonsillectomy. The risk for secondary haemorrhage does not seem to depend on the primary indication itself.

The effect of adenoidectomy on occlusal development and nasal cavity volume in children with recurrent middle ear infection.

OBJECTIVES: The aim of the study was to examine the effect of adenoidectomy on occlusal/dentoalveolar development and nasal cavity volume in children who underwent tympanostomy tube insertion with or without adenoidectomy due to recurrent episodes of middle ear infection. METHODS: This prospective controlled study consisted of two randomly allocated treatment groups of children, younger than 2 years, who had underwent more than 3-5 events of middle ear infection during the last 6 months or 4-6 events during the last year. At the mean age of 17 months tympanostomy tube placement without adenoidectomy (Group I, n=63) tympanostomy tube placement with adenoidectomy (Group II, n=74) was performed. At the age of 5 years 41 children of the original Group I (14 females, 27 males, mean age 5.2 yrs, SD 0.17) and 59 children of the original Group II (17 females, 42 males, mean age 5.2 yrs, SD 0.18) participated in the re-examination, which included clinical orthodontic examination defining morphological and functional craniofacial status and occlusal bite index to measure upper dental arch dimensions. Acoustic rhinometry and anterior rhinomanometry was made by otorhinolaryngologist at the same day. RESULTS: No statistically significant differences were found between the groups in the frequencies of morphological or functional characteristics or upper dental arch measurements or in the minimal cross-sectional areas or inspiratory nasal airway resistance measurements. CONCLUSION: Combining adenoidectomy with tympanostomy tube insertion in the treatment of recurrent middle ear infection at an early age (under the age of 2 years) does not seem to make any difference in occlusal development in primary dentition at the age of 5 years as compared to tympanostomy tube insertion only. Since adenoid size was not evaluated, the findings do not allow interpretation that hypertrophic adenoids should not be removed in children with continuous mouth breathing or sleep disordered breathing.

Differential effects of overt, covert and replayed speech on vowel-evoked responses of the human auditory cortex.

Recent magnetoencephalographic studies showed that speaking dampens voice-evoked activity in the human auditory cortex. To further characterize this audio-vocal interaction, neuromagnetic responses to short tape-recorded probe vowels were measured while subjects were vocalizing long (8 s) 'background' vowels either aloud or silently, or while both probe and background vowels were replayed from tape. Auditory cortex responses peaking at 100 ms (M100) were delayed and dampened bilaterally relative to a background-free control during both overtly spoken and replayed long vowels, identifying auditory interference as the main cause for these modifications. During covert speech M100 peaked later for matching than non-matching probe/background vowels in the speech-dominant left hemisphere. Thus, voiceless 'inner' speaking is sufficient to modify utterance-specific processing in the human auditory cortex.

Subject's own speech reduces reactivity of the human auditory cortex.

Previous studies on monkeys have shown that uttering-related cortical areas exert an inhibitory effect on the auditory cortex, and cerebral blood-flow analyses on humans have revealed modulation of the activity of the auditory cortex during own speech. To study this modulation on a millisecond time scale, we recorded neuromagnetic evoked responses to short 1-kHz tones while the subjects were reading silently and aloud. The 100-ms response (M100) of the auditory cortex was delayed by 10-21 ms and its amplitude was dampened by 44-71% during reading aloud compared with reading silently. This effect was more prominent in responses to ipsilateral than contralateral tones, possibly due to a sum effect of diminished ipsilateral input to the cortex and decreased transcallosal excitation.

Reliability of acoustic rhinometry.

In recent years increasing evidence has been provided on frequent simultaneous coexistence of inflammatory diseases and allergies in upper and lower airways. To achieve a good standard of measurement of upper airways, an objective method should be used. A total of 48 nasal cavities with nasal stuffiness associated with chronic sinusitis were measured with acoustic rhinometry (AR) and High-resolution computer tomography volumetry (HRCTV). Comparison of volumes and minimum cross-sectional areas measured with these methods was performed. The volumes measured from the nostril with both methods were the anterior (0-10 mm), middle (11-40 mm) and posterior (41-70 mm) volumes. The AR cross-sectional area curve was analysed based on two minimal notches corresponding to local minimal areas. A series of 1-mm coronal CT images without intervening gaps were made and analysed based on two minimal voxel values, which were later converted to cross-sectional areas corresponding to local, minimum cross-sectional areas (MCA). Furthermore, the distances of these 2 MCAs from the nostril were also measured. Strong statistically significant (P < 0.05) correlations were found between AR and computer tomography volumetry (CTV) volumes in the anterior (r = 0.83) and middle (r = 0.77) parts of the nasal cavity. In the posterior part of the nasal cavity a statistically significant (P < 0.05) correlation was also found (r = 0.62). Good agreements between the AR and CTV volumes in the anterior and middle parts of the nasal cavities were confirmed with Bland-Altman plots. Correlations among the MCAs were weaker (r = 0.59 and r = 0.55). Our results suggest that the reliability of AR appears sufficient for clinical and scientific use in the nasal cavities. Reliability is very good in the anterior and middle parts of the nasal cavities, while strong conclusions based on evaluation of the posterior part should be avoided due to decreasing accuracy.

Transformation of multichannel magnetocardiographic signals to standard grid form.

Multichannel magnetocardiographic (MCG) recordings with fixed sensor arrays are not directly comparable with single-channel measurements carried out at standard grid locations. In addition, comparison of data obtained with different types of magnetometers is difficult. We present a method for transforming multichannel measurements to the standard-grid format. The minimum-norm estimate (MNE) of the source current distribution in the body is calculated, and the desired field components in standard grid points are then computed from the MNE. We measured three subjects with both a 24-channel and a single-channel instrument. The signals extrapolated from the multichannel measurements corresponded quite well to the single-channel data registered at the standard grid locations, especially in those grid points that were covered by the 24-channel device. The signal-amplitude-weighted correlations between the extrapolated and directly measured signals were 0.73-0.87. In simulations with ideal measurement geometry but with a realistic amount of random noise in the signals, we obtained a 0.99 correlation. It was also found that the method is relatively tolerant to errors in the location and orientation of the multichannel magnetometer. For example, a simulated 20-mm displacement in the location of the sensor array caused only a 3% decrease in the correlation, and when it was rotated and tilted by 10 degrees C, the correlation decreased by 5%. The basic advantage of our extrapolation method is its physiologic nature: the method is based on the mathematical modeling of the source current distribution, rather than on direct constraints applied to the magnetic field.

Perceiving and naming actions and objects.

Neuropsychological studies have suggested differences in the cortical representations of verbs and nouns. Assessment of word-class specific deficits often relies on picture naming with different sets of images used for action and object naming. Such a setup may be problematic in neuroimaging studies, as the perception of the image and the actual differences in retrieving verbs or nouns become intertwined. To address this issue, we investigated how different sets of images affect the pattern of activation in action and object naming. In the present fMRI experiment, healthy volunteers silently performed both action and object naming from action images, and object naming from object-only images. A similar network of cortical areas was activated in all three conditions, including bilateral occipitotemporal and parietal regions, and left frontal cortex. With action images, noun retrieval enhanced activation in bilateral parietal and right frontal cortex, areas previously associated with visual search and attention. Increased activation in the left posterior parietal cortex during this condition also suggests that naming an object in the context of action emphasizes motor-based properties of objects. Action images, regardless of whether verbs or nouns were named, evoked stronger activation than object-only images in the posterior middle temporal cortex bilaterally, the left temporo-parietal junction, and the left frontal cortex, a network previously identified in processing of action knowledge. The strong influence of perceptual input on neural activation associated with noun vs. verb naming can in part explain discrepancies in previous lesion and functional neuroimaging studies on the processing of nouns and verbs.

Distributions and sources of magnetoencephalographic K-complexes.

Whole-head magnetoencephalographic (MEG) and midline electroencephalographic (EEG) signals were simultaneously recorded from 6 subjects during drowsiness and sleep to define the topography and source distribution of K-complexes. In light sleep, K-complexes were also triggered by infrequent tones. Distributions of spontaneous and triggered magnetic K-complexes did not differ systematically, nor did those evoked by right- and left-ear stimuli, but there were large intra- and interindividual differences. Minimum-norm estimates and current dipoles were used to characterize the source currents. Current direction and distribution varied remarkably between the K-complexes appearing in similar situations. In one subject, most K-complexes were adequately modelled with two current dipoles which were situated in the left and right inferior parietal lobes. In other subjects, the current distributions were more complex, suggesting several brain regions to be active during one K-complex; the dominant foci were in frontal and parietal lobes. Our results suggest that the K-complex is not a stereotyped response of the cortex to internal or external stimuli, comparable to evoked responses, but a diffuse and variable cortical reaction during which large areas of cortex may be active.

Speaking modifies voice-evoked activity in the human auditory cortex.

The voice we most often hear is our own, and proper interaction between speaking and hearing is essential for both acquisition and performance of spoken language. Disturbed audiovocal interactions have been implicated in aphasia, stuttering, and schizophrenic voice hallucinations, but paradigms for a noninvasive assessment of auditory self-monitoring of speaking and its possible dysfunctions are rare. Using magnetoencephalograpy we show here that self-uttered syllables transiently activate the speaker's auditory cortex around 100 ms after voice onset. These phasic responses were delayed by 11 ms in the speech-dominant left hemisphere relative to the right, whereas during listening to a replay of the same utterances the response latencies were symmetric. Moreover, the auditory cortices did not react to rare vowel changes interspersed randomly within a series of repetitively spoken vowels, in contrast to regular change-related responses evoked 100-200 ms after replayed rare vowels. Thus, speaking primes the human auditory cortex at a millisecond time scale, dampening and delaying reactions to self-produced "expected" sounds, more prominently in the speech-dominant hemisphere. Such motor-to-sensory priming of early auditory cortex responses during voicing constitutes one element of speech self-monitoring that could be compromised in central speech disorders.

Semi-automatic segmentation of computed tomographic images in volumetric estimation of nasal airway.

The objective of this study was to determine nasal cavity volumes and cross-sectional profiles from segmented coronal high-resolution computed tomography (HRCT) images. Pathological mucosal changes and congenital sinonasal variants were quantitated and three-dimensional (3D) images for determining sinonasal airway diseases evaluated by using the new semiautomatic segmentation software, Anatomatic. Anterior to posterior cross-sectional profiles of the sinonasal airway were obtained from acoustic rhinometry and segmented coronal HRCT images and compared in five patients having complaints of nasal obstruction and chronic sinusitis. Results showed that accurate volumes of air spaces in the nasal cavity and paranasal sinuses were obtained. When compared, the cross-sectional profiles of the nasal cavities obtained from acoustic rhinometry and the segmentation technique were similar in the anterior portion, but differed in the posterior portion. The results obtained by coronal HRCT and segmentation were more reliable than those produced with acoustic rhinometry. 3D images acquired from segmented images were found to help make a good pre-operative assessment of the whole sinonasal compartment. Segmentation and volumetric analysis using the Anatomatic technique also proved to be well suited to the evaluation of the nasal cavity and paranasal sinus geometry in patients with sinonasal diseases.

Dorsal penile nerve stimulation elicits left-hemisphere dominant activation in the second somatosensory cortex.

Activation of peripheral mixed and cutaneous nerves activates a distributed cortical network including the second somatosensory cortex (SII) in the parietal operculum. SII activation has not been previously reported in the stimulation of the dorsal penile nerve (DPN). We recorded somatosensory evoked fields (SEFs) to DPN stimulation from 7 healthy adults with a 122-channel whole-scalp neuromagnetometer. Electrical pulses were applied once every 0.5 or 1.5 sec to the left and right DPN. For comparison, left and right median and tibial nerves were stimulated alternatingly at 1.5-sec intervals. DPN stimuli elicited weak, early responses in the vicinity of responses to tibial nerve stimulation in the primary somatosensory cortex. Strong later responses, peaking at 107-126 msec were evoked in the SII cortices of both hemispheres, with left-hemisphere dominance. In addition to tactile processing, SII could also contribute to mediating emotional effects of DPN stimuli.