Diagnostic imaging modalities in head and neck disease

Comparison of 96-kV and 120-kV cone-beam CT for the assessment of cochlear implants

BACKGROUND

To compare the diagnostic value of 120-kV with conventional 96-kV Cone-Beam CT (CBCT) of the temporal bone after cochlear implant (CI) surgery.

METHODS

This retrospective study included CBCT scans after CI surgery between 06/17 and 01/18. CBCT allowed examinations with 96-kV or 120-kV; other parameters were the same. Two radiologists independently evaluated following criteria on 5-point Likert scales: osseous spiral lamina, inner and outer cochlear wall, semi-circular canals, mastoid trabecular structure, overall image quality, metal and motion artefacts, depiction of intracochlear electrode position and visualisation of single electrode contacts. Effective radiation dose was assessed.

RESULTS

Seventy-five patients (females, n = 39 [52.0%], mean age, 55.8 ± 16.5 years) were scanned with 96-kV (n = 32, 42.7%) and 120-kV (n = 43, 57.3%) protocols including CI models from three vendors (vendor A n = 7; vendor B n = 43; vendor C n = 25). Overall image quality, depiction of anatomical structures, and electrode position were rated significantly better in 120-kV images compared to 96-kV (all p < = 0.018). Anatomical structures and electrode position were rated significantly better in 120-kV CBCT for CI models from vendor A and C, while 120-kV did not provide improved image quality in CI models from vendor B. Radiation doses were significantly higher for 120-kV scans compared to 96-kV (0.15 vs. 0.08 mSv, p < 0.001).

CONCLUSIONS

120-kV and 96-kV CBCT provide good diagnostic images for the postoperative CI evaluation. While 120-kV showed improved depiction of temporal bone and CI electrode position compared to 96-kV in most CI models, the 120-kV protocol should be chosen wisely due to a substantially higher radiation exposure.

Learning Head and Neck Anatomy Through a Radiological Imaging Platform

INTRODUCTION

Head and neck anatomy is complex for students to learn and educators to teach. Instructing students on anatomy using radiological imaging can aid comprehension and prepare them for future clinical practice. Computer-aided anatomy instruction is accessible to diverse learners and avoids barriers identified with face-to-face teaching.

METHODS

We designed a self-guided PowerPoint tutorial with multiple medical imaging modalities, clinical correlations, and self-review questions incorporated throughout. The tutorial was evaluated with a group of 178 Australian preclinical medical students who had prior teaching related to head and neck anatomy. Student participants were divided into experimental and control groups. Participants completed two knowledge assessments: experimental group before and after tutorial engagement and control group before tutorial engagement. All participants were invited to provide feedback on their experiences with the tutorial via questionnaires.

RESULTS

Engagement with the tutorial improved overall head and neck anatomy knowledge (p < .001). Knowledge outcomes were maintained across question group type (e.g., multiple-choice questions, identification, and short-answer questions; p < .05), with participants reporting 96% overall positive feedback related to the tutorial experience.

DISCUSSION

Given the improved outcomes following tutorial exposure, our results suggest that this tutorial is efficacious when used in concert with existing anatomy curricula. Participants' perceived value of the tutorial additionally suggests that it would be taken up well by medical students and is an effective addition to the existing tutorial series. Further research is needed to assess the tutorial's use as a stand-alone addition to the anatomy curriculum.

Clinical, CT scan, and laboratory changes of abscess patients with odontogenic origin admitted to Shiraz acute surgical care center, Iran

Introduction

Rapid diagnosis of maxillofacial abscess with the odontogenic origin is effective in the treatment of patients. This study aimed to check the clinical evaluation, head, and neck computed tomography (CT) scan, and microbial sensitivity of hospitalized patients diagnosed with maxillofacial abscess admitted to the Maxillofacial Surgery Ward Shaheed Rajaie Surgical Acute Care Center of Shiraz, Iran from 2019-2021.

Method

A cross-sectional study was conducted. The sample included patients diagnosed with the abscess of odontogenic origin. Data collection tools included personal profile registration form, chief complainant and clinical evaluation, laboratory test results, pus culture, antibiogram results, and head and neck CT scan changes form. Data was reported with descriptive statistics by SPSS-16 software.

Results

The majority of patients were male; infection duration was 10 days; maximum mouth opening size was less than 20 mm in more than half of patients. The scan revealed 41.8% abscess, 36.4% cellulite, and 21.8% mixed abscess and cellulitis. There was 29.1% involvement of salivary glands. The majority of abscesses were unifocal involved in the submandibular space, and the least involvement was in peri mandibular space and carotid sheath. The most common organism causing was staphylococcal abscess coagulase-negative.

Conclusion

In patients with maxillofacial abscess requiring hospitalization, the most common clinical features were trismus, toxic appearance, and dysphagia, and the most common source of abscess in scanning patients with mandibular molars was the most involved submandibular space and pterygomandibular space. Vancomycin, cotrimoxazole, and cefazolin had the greatest effect in the treatment of odontogenic infections in terms of antibiogram results and microbial culture.

Detection of inaccessible head and neck lesions using human saliva and fluorescence spectroscopy

Head and neck cancer detection using fluorescence spectroscopy from human saliva is reported here. This study has been conducted on squamous cell carcinoma (SCC), and dysplastic (precancer) and control (normal) groups using an in-house developed compact set-up. Fluorescence set-up consists of a 375-nm laser diode and optical components. Spectral bands of flavin adenine dinucleotide (FAD), porphyrins, and Raman are observed in the spectral range of 400 to 800 nm. Presence of FAD and porphyrin bands in human saliva is confirmed by the liquid phantoms of FAD and porphyrin. Significant differences in fluorescence intensities among all the three groups are observed. Three spectral ranges from 455 to 600, 605 to 770, and 400 to 800 nm are selected for each group and area values under each spectral range are computed. To differentiate among the groups, receiver operating characteristic (ROC) analysis is employed on the area values. ROC differentiates among the groups with accuracies of 98%, 92.85%, and 81.13% respectively in the spectral ranges of 400 to 800 nm. However, in other two spectral ranges (455 to 600 and 605 to 770 nm), low accuracy values are found. Obtained accuracy values indicate that selection of human saliva for head and neck cancer detection may be a good alternative.

Radiomics Nomograms Based on Multi-Parametric MRI for Preoperative Differential Diagnosis of Malignant and Benign Sinonasal Tumors: A Two-Centre Study

Objectives

To investigate the efficacy of multi-parametric MRI-based radiomics nomograms for preoperative distinction between benign and malignant sinonasal tumors.

Methods

Data of 244 patients with sinonasal tumor (training set, n=192; test set, n=52) who had undergone pre-contrast MRI, and 101 patients who underwent post-contrast MRI (training set, n=74; test set, n=27) were retrospectively analyzed. Independent predictors of malignancy were identified and their performance were evaluated. Seven radiomics signatures (RSs) using maximum relevance minimum redundancy (mRMR), and the least absolute shrinkage selection operator (LASSO) algorithm were established. The radiomics nomograms, comprising the clinical model and the RS algorithms were built: one based on pre-contrast MRI (RNWOC); the other based on pre-contrast and post-contrast MRI (RNWC). The performances of the models were evaluated with area under the curve (AUC), calibration, and decision curve analysis (DCA) respectively.

Results

The efficacy of the clinical model (AUC=0.81) of RNWC was higher than that of the model (AUC=0.76) of RNWOC in the test set. There was no significant difference in the AUC of radiomic algorithms in the test set. The RS-T1T2 (AUC=0.74) and RS-T1T2T1C (RSWC, AUC=0.81) achieved a good distinction efficacy in the test set. The RNWC and the RNWOC showed excellent distinction (AUC=0.89 and 0.82 respectively) in the test set. The DCA of the nomograms showed better clinical usefulness than the clinical models and radiomics signatures.

Conclusions

The radiomics nomograms combining the clinical model and RS can be accurately, safely and efficiently used to distinguish between benign and malignant sinonasal tumors.

Comparison of image quality of head and neck lesions between 3D gradient echo sequences with compressed sensing and the multi-slice spin echo sequence

Background

Although magnetic resonance imaging (MRI) provides excellent soft-tissue contrast, long acquisition times are major disadvantages.

Purpose

To evaluate the usefulness of compressed sensing (CS) for contrast-enhanced oral and maxillofacial MRI by comparing the 3D T1 turbo field echo with compressed SENSE (CS-3D-T1TFE) sequence with the multi-slice spin echo (MS-SE) sequence as the reference standard.

Material and Methods

Thirty patients with orofacial lesions participated in this study. The scan times for MS-SE and CS-3D-T1TFE were 5 min 56 s and 1 min 43 s, respectively. The signal-to-noise ratio (SNR) was calculated for quantitative analysis and seven parameters (degree of lesion conspicuity, motion artifacts, metal artifacts, pulsation artifacts, quality of fat suppression, homogeneity of blood vessel signal intensity, and overall image quality) were evaluated using a 5-point scale (5 = excellent, 1 = unacceptable) by two observers for qualitative analysis. For comparisons between MS-SE and CS-3D-T1TFE, the paired t-test was used.

Results

The SNR of CS-3D-T1TFE was higher than or equal to that of MS-SE. The CS-3D-T1TFE scores for motion artifacts, pulsation artifacts, and homogeneity of blood vessel signal intensity were higher than the corresponding MS-SE scores in assessments by both observers. The MS-SE scores for fat suppression were higher than or equal to the CS-3D-T1TFE scores. There were no significant differences in lesion conspicuity, metal artifacts, and overall image quality between the two sequences.

Conclusion

CS-3D-T1TFE imaging, less than 30% of the scan time for MS-SE, showed no image degradation while retaining equal or higher SNR and image quality.

Diagnostic Capabilities of MRI Versus 18F FDG PET-CT in Postoperative Patients with Thyroglobulin Positive, 131I-negative Local Recurrent or Metastatic Thyroid Cancer

BACKGROUND

The detection of recurrence or metastasis might be challenging in patients, who underwent total thyroidectomy and radioactive iodine therapy for Differentiated Thyroid Carcinoma (DTC), with increased serum Thyroglobulin (Tg) levels and negative 131I whole body scan (131I-WBS) results.

AIMS

The purpose of this study was to compare the ability of Magnetic Resonance Imaging (MRI) and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET-CT) to detect recurrence or cervical and upper mediastinal metastases in postoperative DTC patients who had negative 131I-WBS despite elevated serum Tg levels.

STUDY DESIGN

This study has a retrospective study design.

METHODS

We evaluated cervical and upper mediastinal MRI and 18F FDG PET-CT of 32 postoperative patients with DTC (26 patients with papillary thyroid carcinoma and 6 patients with follicular thyroid carcinoma).

RESULTS

We evaluated 44 lesions in 32 patients. For all lesions, the Positive Predictive Value, (PPV) Negative Predictive Value (NPV), sensitivity, specificity, and accuracy of MRI were 81.4%, 76.4%, 84.6%, 72.2%, and 79.5% respectively. The PPV, NPV, sensitivity, specificity, and accuracy of 18F FDG PET-CT were 100.0%, 85.7%, 88.4%, 100.0%, and 93.1%, respectively.

CONCLUSION

Although we could not replace 18F FDG PET-CT, MRI might be used as an adjunct to 18F FDG PET-CT for the evaluation of recurrent or cervical and upper mediastinal metastatic thyroid cancers; however, MRI is inadequate for the detection of metastases in small lymph nodes.

[Low-dose helical CT-dacryocystography in nasolacrimal duct obstruction-a prospective study]

BACKGROUND

In addition to basic ophthalmologic diagnostic workup, different radiologic procedures can be performed for assessment of nasolacrimal duct obstruction. However, no gold standard imaging technique has yet been established. Using the results of the present study, the advantages of helical CT-dacryocystography (CT-DCG) are demonstrated, particularly when performed before endonasal endoscopic dacryocystorhinostomy.

MATERIALS AND METHODS

In 21 patients with uni- or bilateral epiphora, 24 low-dose helical CT-DCGs were performed with non-ionic iodine-containing contrast medium and including three-dimensional reconstruction. For 8 patients, digital subtraction angiography (DSA)-DCG results were available for comparison with CT-DCG.

RESULTS

Using low-dose helical CT-DCG, either the location of nasolacrimal duct pathology could be exactly identified (n = 19; stenosis presaccal n = 3, intrasaccal n = 11, postsaccal n = 5) or nasolacrimal system block could be definitively excluded as the cause of epiphora (n = 5). For imaging of the perilacrimal and periorbital bony structures, CT-DCG is significantly better than DSA-DCG.

CONCLUSION

Low-dose helical CT-DCG with reconstruction of the coronal and sagittal planes represents an ideal imaging technique with low exposure for detection of nasolacrimal duct obstruction. By demonstrating all relevant anatomic landmarks for endoscopic dacryocystorhinostomy, helical CT-DCG enables head and neck surgeons to plan surgery optimally.

EUS of the neck: A comprehensive anatomical reference for the staging of head and neck cancer (with videos)

The use of EUS has application in the nodal staging of head and neck cancer. The technique and the anatomy of head and neck region using EUS have not been described. EUS from three stations in thoracic esophagus, cervical esophagus, and hypopharynx can allow imaging of head and neck. In this article we describe the normal structures from the three stations. The EUS imaging of head and neck can give relevant and additional information in malignancies of head and neck.

[Diagnostics and treatment of lacrimal duct diseases : A structured patient-centred care concept]

BACKGROUND

The cardinal symptom of lacrimal stenosis is epiphora and a subjective high level of discomfort due to continuous dacryorrhea.

OBJECTIVE

The aim of the current paper is to present a structured review of common diagnostic and therapeutic strategies for lacrimal stenosis.

MATERIALS AND METHODS

The most important diagnostic and therapeutic approaches are analysed using the existing literature and by reporting the authors' own experiences.

RESULTS

A detailed patient history is crucial for diagnosis of lacrimal disorders. Precise inspection and palpation of the lacrimal and lid region may confirm lacrimal stenosis. Examinations of tear production, tear quality and the properties of the ocular surface are helpful. The most important diagnostic tool is lacrimal duct probing and syringing. Therapy is guided by underlying pathologies. Treatment of congenital lacrimal stenosis follows a staged concept. Epiphora in adults without signs of dacryocystitis should be treated with dacryoendoscopy. Dacryoendoscopy is also a therapeutic option for chronic dacryocystitis, but dacryocystorhinostomy may also be required. Lacrimal trauma should be reconstructed rapidly after the incident by lacrimal intubation. Neoplasia of the lacrimal excretory system requires histological classification to enable multidisciplinary management.

CONCLUSION

Basic ophthalmologic diagnostics are complemented by special symptom-based examinations. Due to ongoing improvement of available diagnostic and therapeutic options, patients' care is becoming increasingly individualised.

[Standardization and modeling of surgical processes]

BACKGROUND

Due to the technological developments around the operating room, surgery in the twenty-first century is undergoing a paradigm shift.

OBJECTIVE

Which technologies have already been integrated into the surgical routine? How can a favorable cost-benefit balance be achieved by the implementation of new software-based assistance systems?

METHODS

This article presents the state of the art technology as exemplified by a semi-automated operation system for otorhinolaryngology surgery. The main focus is on systems for implementation of digital handbooks and navigational functions in situ.

RESULTS

On the basis of continuous development in digital imaging, decisions may by facilitated by individual patient models thus allowing procedures to be optimized. The ongoing digitization and linking of all relevant information enable a high level of standardization in terms of operating procedures. This may be used by assistance systems as a basis for complete documentation and high process reliability.

CONCLUSION

Automation of processes in the operating room results in an increase in quality, precision and standardization so that the effectiveness and efficiency of treatment can be improved; however, care must be taken that detrimental consequences, such as loss of skills and placing too much faith in technology must be avoided by adapted training concepts.

Evaluation of symptomatic maxillary sinus pathologies using panoramic radiography and cone beam computed tomography-influence of professional training

Background

A comparison of panoramic radiography (PAN) alone and PAN together with small field of view cone beam computed tomography (sFOV-CBCT) for diagnosis of symptomatic pathologies of the maxillary sinus was carried out by clinicians of different experience.

Methods

Corresponding radiographic images (PAN/sFOV-CBCT) of 28 patients with symptomatic maxillary sinus pathologies were chosen and analyzed by two general practitioners (GP), two junior maxillofacial surgeons (MS1), and three senior maxillofacial surgeons (MS2) via questionnaire.

Results

Visibility of maxillary pathologies in PAN was significantly different between the groups (GP 39%, MS1 48%, MS2 61%; p < 0.05). The number of incidental findings varied within examiner groups in PAN with a significant increase in MS2 (p = 0.027). The majority of examiners rated an additional sFOV-CBCT as “reasonable”/“required” with a significant influence of the examining groups (GP 98.2%, MS1 94.6%, MS2 80.9%; p = 0.008). In 58% of cases, an additional sFOV-CBCT was seen as “affecting therapy” with significant differences between the groups (GP 68%, MS1 50%, MS2 55%; p < 0.001).

Conclusions

PAN alone is not sufficient for the evaluation of pathologies of the maxillary sinus. But, depending on the examiners’ clinical experience, it remains a useful diagnostic tool. Along with the observers’ training, significant benefits of an additional sFOV-CBCT for evaluation of symptomatic maxillary sinus pathologies were detected.

[Modern imaging of the temporal bone]

This article describes the current significance of computed tomography (CT), magnetic resonance imaging (MRI), cone beam CT, digital subtraction angiography (DSA), and special X‑rays in the diagnostics of temporal bone diseases. The latter is obsolete for diagnostic intentions. Possibilities and limitations in terms of detection and/or depiction of the extent of inflammatory, traumatic, tumorous, and postoperative pathologies are discussed. A concrete question and conveyance of clinical findings influence the choice of the method to be applied in the individual case. Malformations of the middle ear can only be detected noninvasively by CT or cone beam CT. These are also the methods that may support the diagnosis of otosclerosis in clinically unclear cases. MRI is the method of choice for pathologies of the inner ear and internal auditory canal, including inner ear malformations. At present, only in few institutions is a successful visualization of endolymphatic hydrops in Menière's disease realized.

Impact of combined FDG-PET/CT and MRI on the detection of local recurrence and nodal metastases in thyroid cancer

Background

Suspected recurrence of thyroid carcinoma is a diagnostic challenge when findings of both a radio iodine whole body scan and ultrasound are negative. PET/CT and MRI have shown to be feasible for detection of recurrent disease. However, the added value of a consensus reading by the radiologist and the nuclear medicine physician, which has been deemed to be helpful in clinical routines, has not been investigated. This study aimed to investigate the impact of combined FDG-PET/ldCT and MRI on detection of locally recurrent TC and nodal metastases in high-risk patients with special focus on the value of the multidisciplinary consensus reading.

Materials and methods

Forty-six patients with suspected locally recurrent thyroid cancer or nodal metastases after thyroidectomy and radio-iodine therapy were retrospectively selected for analysis. Inclusion criteria comprised elevated thyroglobulin blood levels, a negative ultrasound, negative iodine whole body scan, as well as combined FDG-PET/ldCT and MRI examinations.

Neck compartments in FDG-PET/ldCT and MRI examinations were independently analyzed by two blinded observers for local recurrence and nodal metastases of thyroid cancer. Consecutively, the scans were read in consensus. To explore a possible synergistic effect, FDG-PET/ldCT and MRI results were combined. Histopathology or long-term follow-up served as a gold standard.

For method comparison, sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated.

Results

FDG-PET/ldCT was substantially more sensitive and more specific than MRI in detection of both local recurrence and nodal metastases. Inter-observer agreement was substantial both for local recurrence (κ = 0.71) and nodal metastasis (κ = 0.63) detection in FDG-PET/ldCT. For MRI, inter-observer agreement was substantial for local recurrence (κ = 0.69) and moderate for nodal metastasis (κ = 0.55) detection. In contrast, FDG-PET/ldCT and MRI showed only slight agreement (κ = 0.21). However, both imaging modalities identified different true positive results. Thus, the combination created a synergistic effect. The multidisciplinary consensus reading further increased sensitivity, specificity, and diagnostic accuracy.

Conclusions

FDG-PET/ldCT and MRI are complementary imaging modalities and should be combined to improve detection of local recurrence and nodal metastases of thyroid cancer in high-risk patients. The multidisciplinary consensus reading is a key element in the diagnostic approach.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0096-y) contains supplementary material, which is available to authorized users.

Presurgical evaluation of bony implant sites using panoramic radiography and cone beam computed tomography-influence of medical education

OBJECTIVES

The aim of this study was to compare the subjective quality rating of panoramic radiography (PAN) and CBCT in the planning of dental implant procedures by clinicians with different educational backgrounds.

METHODS

Radiographic images (PAN and CBCT) of 42 patients were examined as follows: the maxillary (MX) anterior region of patients, the MX posterior region of 16 patients and the mandibular (MD) posterior region of 16 patients. These sites were used for planning of dental implant insertion. Data sets were analyzed by examiners with different training backgrounds: three general practitioners (GP), three oral surgeons (OS) and three maxillofacial surgeons (MS). A standardized questionnaire in a standardized setting was answered by participants.

RESULTS

The majority of participants rated an additional CBCT as "required" (14.0%) or "reasonable" (56.1%). These ratings depended strongly on the area of interest (MX anterior region: 31.1 and 58.9%; MX posterior region: 14.6 and 62.5%; and MD posterior region: 2.8% and 47.9%). MS classified CBCT as required more often than GP and OS (23.8 vs 10.3 and 7.9%; p < 0.001). With the additional information of CBCT, "therapy affecting" ratings were stated high in all groups.

CONCLUSIONS

Especially in the anterior and posterior MX, significant subjective benefits for an additional CBCT were seen for planning of dental implant procedures. Participants with fundamental medical education asked for CBCT more often. The results indicate that an improved education in three-dimensional dental radiology is necessary.

Mesenchymal Stem Cells Enhance Nerve Regeneration in a Rat Sciatic Nerve Repair and Hindlimb Transplant Model

This study investigates the efficacy of local and intravenous mesenchymal stem cell (MSC) administration to augment neuroregeneration in both a sciatic nerve cut-and-repair and rat hindlimb transplant model. Bone marrow-derived MSCs were harvested and purified from Brown-Norway (BN) rats. Sciatic nerve transections and repairs were performed in three groups of Lewis (LEW) rats: negative controls (n = 4), local MSCs (epineural) injection (n = 4), and systemic MSCs (intravenous) injection (n = 4). Syngeneic (LEW-LEW) (n = 4) and allogeneic (BN-LEW) (n = 4) hindlimb transplants were performed and assessed for neuroregeneration after local or systemic MSC treatment. Rats undergoing sciatic nerve cut-and-repair and treated with either local or systemic injection of MSCs had significant improvement in the speed of recovery of compound muscle action potential amplitudes and axon counts when compared with negative controls. Similarly, rats undergoing allogeneic hindlimb transplants treated with local injection of MSCs exhibited significantly increased axon counts. Similarly, systemic MSC treatment resulted in improved nerve regeneration following allogeneic hindlimb transplants. Systemic administration had a more pronounced effect on electromotor recovery while local injection was more effective at increasing fiber counts, suggesting different targets of action. Local and systemic MSC injections significantly improve the pace and degree of nerve regeneration after nerve injury and hindlimb transplantation.

Imaging of spaces of neck and mediastinum by endoscopic ultrasound

Endoscopic ultrasound (EUS) of the mediastinum was pioneered by gastroenterologists, and it was taken up by pulmonologists when the smaller-diameter endobronchial ultrasound (EBUS) scope was designed after a few years. The pulmonologists’ approach remained largely confined to entry from the trachea, but they soon realized that the esophagus was an alternative route of entry by the EBUS scope. The new generations of interventionists are facing the challenge of learning two techniques (EUS and EBUS) from two routes (esophagus and trachea). The International Association for the Study of Lung Cancer (IASLC) proposed a classification of mediastinal lymph nodes at different stations that lie within the boundaries of specific spaces. These interventionists need clear definitions of landmarks and clear techniques to identify the spaces. There are enough descriptions of spaces of the neck and the mediastinum in the literature, yet the topic mentioned above has never been discussed separately. The anatomical structures, landmarks, and boundaries of spaces will be important to interventionists in the near future during performances of endosonography. This article combines the baseline anatomy of the spaces with the actual imaging during EUS.

Laryngeal lipoma: a rare cause of acute intermittent airway obstruction

We present a case of a 62-year-old man with a lipoma in the exceedingly rare location of the larynx, causing intermittent airway obstruction and dysphagia. The lipoma was excised endoscopically with complete resolution of symptoms. Lipomas are relatively common, accounting for 4-5% of all benign tumours in the body. They traditionally occur in areas of large depositions of subcutaneous fat, most frequently the trunk and limbs. They are recognised to occur in the head and neck but these only represent 13-15% of all lipomas. Lipomas are typically asymptomatic unless their impingement of nearby structures causes symptoms.

Optimized imaging of the midface and orbits

A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.

Advanced Modeled Iterative Reconstruction in Low-Tube-Voltage Contrast-Enhanced Neck CT: Evaluation of Objective and Subjective Image Quality

BACKGROUND AND PURPOSE

Dose-saving techniques in neck CT cause increased image noise that can be counteracted by iterative reconstruction. Our aim was to evaluate the image quality of advanced modeled iterative reconstruction (ADMIRE) in contrast-enhanced low-tube-voltage neck CT.

MATERIALS AND METHODS

Sixty-one patients underwent 90-kV(peak) neck CT by using third-generation 192-section dual-source CT. Image series were reconstructed with standard filtered back-projection and ADMIRE strength levels 1, 3, and 5. Attenuation and noise of the sternocleidomastoid muscle, internal jugular vein, submandibular gland, tongue, subscapularis muscle, and cervical fat were measured. Signal-to-noise and contrast-to-noise ratios were calculated. Two radiologists assessed image noise, image contrast, delineation of smaller structures, and overall diagnostic acceptability. Interobserver agreement was calculated.

RESULTS

Image noise was significantly reduced by using ADMIRE compared with filtered back-projection with the lowest noise observed in ADMIRE 5 (filtered back-projection, 9.4 ± 2.4 Hounsfield units [HU]; ADMIRE 1, 8.3 ± 2.8 HU; ADMIRE 3, 6.7 ± 2.0 HU; ADMIRE 5, 5.4 ± 1.7 HU; all, P < .001). Sternocleidomastoid SNR and internal jugular vein-sternocleidomastoid contrast-to-noise ratios were significantly higher for ADMIRE with the best results in ADMIRE 5 (all, P < .001). Subjective image quality and image contrast of ADMIRE 3 and 5 were consistently rated better than those for filtered back-projection and ADMIRE 1 (all, P < .001). Image noise was rated highest for ADMIRE 5 (all, P < .005). Delineation of smaller structures was voted higher in all ADMIRE strength levels compared with filtered back-projection (P < .001). Global interobserver agreement was good (0.75).

CONCLUSIONS

Contrast-enhanced 90-kVp neck CT is feasible, and ADMIRE 5 shows superior objective image quality compared with filtered back-projection. ADMIRE 3 and 5 show the best subjective image quality.

Prognostic value of MRI-derived masticator space involvement in IMRT-treated nasopharyngeal carcinoma patients

Objectives

This retrospective study reassessed nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiation therapy (IMRT), to determine the significance how magnetic resonance imaging (MRI)-derived masticator space involvement (MSI) affected patients’ prognosis.

Methods

One thousand one hundred ninety seven NPC patients who had complete set of MRI and medical records were enrolled. Basing on their MRI findings, the T-categories of tumors were identified according to the seventh edition of American Joint Committee on Cancer staging system, which considers MSI a prognostic indicator for NPCs. Rates of overall survival (OS), local relapse-free survival (LRFS), regional relapse-free survival (RRFS) and distant metastasis-free survival (DMFS) were analyzed by the Kaplan-Meier method, and the Log-Rank test compared their differences. Cox regression analysis was employed to evaluate various prognostic factors systematically. Statistical analyses were conducted with SPSS 18.0 software, P value < 0.05 was considered statistically significant.

Results

Medial pterygoid muscle (MPM) was involved in 283 (23.64 %) cases, of which lateral pterygoid muscle (LPM) was concurrently affected in 181 (15.12 %) and infratemporal fossa (ITF) in 19 (1.59 %). Generally, MSI correlated with an OS, LRFS, and DMFS consistent with a T4-stage diagnosis (P > 0.05). Although different degrees of MSI presented a similar OS and DMFS (P > 0.1), tumors involving LPM had a relatively poorer LRFS than those affected the MPM only (P = 0.027), even for subgroup of patients composed of T3 and T4 classifications (P = 0.035). A tumor involving MPM brought an LRFS consistent with a T2 or T3-stage disease (P > 0.1). If the tumor affected LPM or ITF concurrently, the survival outcomes were more consistent with a T4-stage disease (P > 0.1). Nevertheless, compared to tumor infiltrating MPM, those invading LPM or ITF more frequently spread into other concurrent sites that earned higher T-staging categories. Moreover, multivariate analyses indicated the degree of MSI was a significant prognostic factor for the OS of NPCs (P = 0.036).

Conclusions

Degree of MSI is a significant prognosticator for the OS of IMRT-treated NPCs, and the prognosis of patients with lateral MSI extension (LPM and ITF) were shown to be significantly worse than those affected only MPM or the T3-stage disease. Thus, it is highly recommended that lateral MSI extension be a higher T-staging category.

Diagnostic yield of MRI for pediatric hearing loss: a systematic review

OBJECTIVE

To perform a systematic review to analyze the diagnostic yield of magnetic resonance imaging (MRI) for pediatric hearing loss, including comparison to computed tomography (CT) and subgroup evaluation according to impairment severity and specific diagnostic findings (cochlear anomalies, enlarged vestibular aqueduct, cochlear nerve abnormalities, and brain findings).

DATA SOURCES

Pubmed, EMBASE, and the Cochrane library were assessed from their inception through December 2013. Manual searches were also performed, and topic experts were contacted.

REVIEW METHODS

Data from studies describing the use of MRI with or without comparison to CT in the diagnostic evaluation of pediatric patients with hearing loss were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I(2) statistic.

RESULTS

There were 29 studies that evaluated 2434 patients with MRIs and 1451 patients with CTs that met inclusion/exclusion criteria. There was a wide range of diagnostic yield from MRI. Heterogeneity among studies was substantial but improved with subgroup analysis. Meta-analysis of yield differences demonstrated that CT had a greater yield than MRI for enlarged vestibular aqueduct (yield difference 16.7% [95% CI, 9.1%-24.4%]) and a borderline advantage for cochlear anomalies (4.7% [95% CI, 0.1%-9.5%]). Studies were more likely to report brain findings with MRI.

CONCLUSIONS

These data may be utilized in concert with that from studies of risks of MRI and risk/yield of CT to inform the choice of diagnostic testing.