Ultrasonographic evaluation of calcification patterns in costal cartilage: implications for rib graft harvesting.

IMPORTANCE: Complex augmentation rhinoplasty often requires the use of cartilaginous grafts, especially in revision surgery. When using costal cartilage, the possibility of inadequate cartilage material because of excessive calcification must always be kept in mind. Furthermore, cartilage may be harvested but found to be not ideal, causing unsatisfying results. OBJECTIVE: To report our experience with the use of preoperative ultrasonographic (US) examinations for quality analysis of costal cartilage. DESIGN, SETTING, AND PARTICIPANTS: In an academic research setting, US imaging of the anterior rib cage was performed before 83 revision rhinoplasties requiring costal cartilage grafting. MAIN OUTCOMES AND MEASURES: Cartilage volume, quality, sex-specific calcification patterns, and the location of hidden calcification islands within viable cartilage were recorded. RESULTS: Two different calcification patterns, 1 central and 1 peripheral, were identified. CONCLUSIONS AND RELEVANCE: We found this cost-effective technique to be a valuable tool for easy preoperative cartilage assessment. Furthermore, US screening guides the surgeon to areas of harvestable cartilage and to cartilage that is best suited for rhinoplasty in terms of distribution patterns of calcification areas. LEVEL OF EVIDENCE: NA.

Analysis of the accuracy of high-resolution computed tomography techniques for the measurement of stapes prostheses.

PURPOSE: Severe cochleovestibulopathy is a complication after stapes plasty and CT may be needed to assess intravestibular intrusion depth of the stapes piston. The accuracy of modern CT systems in this task has not been established. METHODS: Stapes plasty was performed on six cadaver ears, and Soft CliP titanium pistons were inserted. Specimens were then examined using three different CT systems: single source 64-row, dual source 64-row and flat-panel computed tomography (FD-CT). Piston length, width and intravestibular intrusion were measured by four independent observers. Temporal bone dissection was then performed and vestibular piston intrusion measured microscopically. RESULTS: Piston dimensions were overestimated by all observers and CT systems. Intravestibular penetration as assessed by CT was consistently greater than the value found on cadaveric anatomical dissection. On average, the CT measurement of width was 0.176 mm (44%) greater, length 0.125 mm (6.25%) greater and intrusion 0.333 mm (39.2%) greater than the anatomical measurements. FD-CT showed better image quality and partly less bias in several measurements, but penetration depth was still variably overestimated. CONCLUSION: CT measurement consistently overestimated intravestibular piston dimensions and vestibular intrusion. Modern temporal bone imaging systems are not yet able to depict the stapes piston position with a sufficient degree of accuracy.

Imaging of cochlear implant electrode array with flat-detector CT and conventional multislice CT: comparison of image quality and radiation dose.

CONCLUSION: Cochlear implantation assessment is possible using commercially available standard flat-detector computed tomography (FD-CT) protocols. Image quality is superior to multislice CT (MSCT). The radiation dose of FD-CT is lower in comparison with MSCT standard protocols and may therefore overcome the limitations of MSCT in the evaluation of cochlear implants. OBJECTIVE: FD-CT offers higher spatial resolution than MSCT. Our objective was to compare the image quality of FD-CT to conventional MSCT in the visualization of a cochlear implant electrode array with respect to radiation exposure. METHODS: An isolated temporal bone specimen was scanned using a commercially available FD-CT system and a 4 and 64 row MSCT scanner. Different scanning protocols were used. Image quality was assessed by four independent readers using a scoring system with different criteria describing delineation of the cochlea and the electrode array, image noise and spatial resolution. Radiation dose was measured using the CT dose index (CTDI) and a 16 cm acrylic phantom. RESULTS: Image quality was rated superior for FD-CT for all criteria by all readers. Single electrode contacts were only visible in FD-CT and assessment of implant position was improved by FD-CT. The radiation dose of FD-CT was half that of MSCT standard protocols.

Salivary simulation with ascorbic acid enhances sonographic diagnosis of obstructive sialadenitis.

PURPOSE: High-frequency ultrasound (US) is routinely used to evaluate various diseases of the salivary glands. Normally, the duct network of the submandibular and parotid glands is not visible during US assessment. In obstructive sialadenitis of the parotid and submandibular glands, localization of the obstacle is often difficult. METHODS: In a case-control study, the sonographic visibility of the duct before and after stimulation with oral ascorbic acid (vitamin C) was compared with sialendoscopy as the gold standard. Twenty male and 23 female patients suffering from salivary gland diseases were included in this study and compared with 25 healthy volunteers. US examination of the parotid and submandibular glands was performed before and after oral ascorbic acid stimulation. Changes in visibility of the main excretory duct were recorded and US diagnoses were compared with results of sialendoscopy. RESULTS: In 7 of 25 controls, the main duct became partially visible after stimulation. In the group of 43 patients, the main duct was depicted before stimulation in 27 patients (63%). After ascorbic acid stimulation, the main duct became visible in 41 patients (95%). Grading the stimulated duct dilation by measuring diameters at different points revealed no correlation with the underlying type of pathology. CONCLUSIONS: Application of ascorbic acid prior to diagnostic US examination facilitates the sonographic evaluation of obstructive salivary gland diseases.