Static Ultrasonography Research Articles

Real-Time Ultrasonography and the Evaluation of Static Images Yield Different Results in the Assessment of EU-TIRADS Categories.

The studies on the effectiveness of various TIRADS in the diagnostics of thyroid nodules differ in the method of ultrasound image assessment: real time (rtUS) vs. static ultrasonography (stUS). The aim of the study was to evaluate the impact of those two methods on the categorization of nodules in EU-TIRADS. Three experienced raters assessed 842 nodules in routine rtUS and reassessed with the use of sUS. Reproducibility of the assessment of malignancy risk features and categorization of nodules with EU-TIRADS was estimated with Krippendorff's alpha coefficient (Kα). The reproducibility of EU-TIRADS categories on sUS in relation to rtUS was in range 70.9-76.5% for all raters (Kα: 0.60-0.68) with the highest reproducibility for category 3 (80.0-86.5%) and the lowest for category 5 (48.7-77.8%). There was a total disagreement of the identification of microcalcifications on sUS in relation to rtUS, a strongly variable reproducibility of marked hypoechogenicity (12.5-84.6%, Kα: 0.14-0.48) and a tendency toward more frequent identification of the non-oval shape on sUS. The percentage of agreement for each pair of raters in assigning the EU-TIRADS category on sUS was in the range 71.6-72.3% (Kα: 0.60-0.62). The method of sonographic image evaluation influences the nodule's feature assessment and, eventually, the categorization within EU-TIRADS.

Reliability and measurement error of the proximal, medial and distal portions of the vastus lateralis muscle thickness measured with extended field of view ultrasonography

The image obtained by static ultrasonography (US), despite being a validated measure to identify muscle thickness (MT), has a visualization capacity limited by the size of the transducer. The extended field of view (EFOV) is a more recent technique of obtaining muscle images by the US, which allows observing MT over the entire length of the muscle. The purpose of the study was to determine the reliability and the intra- and inter-rater error of the MT measurement in the proximal, medial and distal portions of the vastus lateralis using the EFOV US. Twenty-five men (age = 24 ± 4 years) paid a visit to the laboratory. Two independent US technicians identified the anatomical landmarks and collected the images using EFOV US, with a 4 cm linear transducer, 10 MHz frequency and 6 cm image depth. After all collections, a third researcher codified the images, which were sent to two independent image raters. After a week, the images were shuffled, recoded and sent back to the same evaluators. The values ​​of the typical error of the measurement, coefficient of variation and intraclass correlation coefficient intra and inter-rater ranged between 0.01 and 0.03 cm, 0.47 and 2.32%, 0.990 and 0.998, respectively, for the two evaluators. The Bland-Altman analysis indicated high agreement and homoscedastic error of all comparisons. The high reliability and low errors observed, less than the increments typically found in training studies, reveal the great potential for EFOV US to determine MT in different portions of the vastus lateralis muscle.

Morphological and mechanical properties of lower limbs in competitive racewalkers: Associations with performance

Racewalking is an unconventional form of competitive gait that elicits a unique loading profile on lower limb muscles and tendons. This study mapped the structural and mechanical properties of lower limbs in competitive racewalkers and made associations with World Athletics competition performance points. Fourteen international racewalkers (seven men, seven women) were recruited for this study. Static ultrasonography was used to quantify muscle and tendon morphological characteristics. An isokinetic dynamometer was used to measure passive musculotendinous stiffness of the triceps surae, isometric (seven knee/ankle angle combinations) and isokinetic (four angular velocities) strength parameters in the plantarflexors and dorsiflexors, and isokinetic knee flexion and extension strength at five angular velocities. Correlations were found between performance and fascicle length of gastrocnemius medialis (r = –0.569, p = 0.034), dorsiflexor strength at 120°/s (r = 0.649, p = 0.016) and knee flexor strength at 30°/s (r = 0.632, p = 0.020). No associations were found for isometric plantarflexion or passive stiffness properties. Overall, the study showed various morphological and mechanical properties are associated with performance in competitive racewalkers. These associations seem to be related to the specific and unique biomechanical characteristics of racewalking.

Real-time vs static scoring in musculoskeletal ultrasonography in patients with inflammatory hand osteoarthritis

ObjectivesAgreement between real-time and static ultrasonography has not been studied in musculoskeletal diseases. We studied this agreement in inflammatory hand OA.MethodsUltrasonography was performed blinded to clinical information of 30 joints of 75 patients with hand OA, treated with prednisolone in a randomized placebo-controlled double-blind trial. Images were scored real-time at acquisition and stored images were scored static (paired in known chronological order) for inflammatory features and osteophytes (score 0–3). Agreement between methods was studied at joint level with quadratic weighted kappa. At patient level intra-class correlations (ICC) of sum scores and change in sum-scores (delta baseline—week 6) were calculated. Responsiveness of scoring methods was analysed with generalized estimating equations (GEE) with treatment as independent and ultrasonography findings as dependent variable.ResultsAgreement at baseline was good to excellent at joint level (kappa 0.72–0.88) and moderate to excellent at patient level (ICC 0.58–0.91). Agreement for change in sum scores was poor to fair for synovial thickening and effusion (ICC 0.18 and 0.34, respectively), while excellent for Doppler signal (ICC 0.80). Real-time ultrasonography discriminated between prednisolone and placebo with a mean between-group difference of synovial thickening of −2.5 (95% CI: −4.7, −0.3). Static ultrasonography did not show a decrease in synovial thickening.ConclusionWhile cross-sectional agreement between real-time and static ultrasonography is good, static ultrasonography measurement of synovial thickening did not show responsiveness to prednisone therapy while real-time ultrasonography did. Therefore, when ultrasonography is used in clinical trials, real-time dynamic scoring should remain the standard for now.

Effects of 1 year of training on the performance of ultrasonographic image interpretation: A preliminary evaluation using images of Sjögren syndrome patients.

PurposeThis study investigated the effects of 1 year of training on imaging diagnosis, using static ultrasonography (US) salivary gland images of Sjögren syndrome patients.Materials and MethodsThis study involved 3 inexperienced radiologists with different levels of experience, who received training 1 or 2 days a week under the supervision of experienced radiologists. The training program included collecting patient histories and performing physical and imaging examinations for various maxillofacial diseases. The 3 radiologists (observers A, B, and C) evaluated 400 static US images of salivary glands twice at a 1-year interval. To compare their performance, 2 experienced radiologists evaluated the same images. Diagnostic performance was compared between the 2 evaluations using the area under the receiver operating characteristic curve (AUC).ResultsObserver A, who was participating in the training program for the second year, exhibited no significant difference in AUC between the first and second evaluations, with results consistently comparable to those of experienced radiologists. After 1 year of training, observer B showed significantly higher AUCs than before training. The diagnostic performance of observer B reached the level of experienced radiologists for parotid gland assessment, but differed for submandibular gland assessment. For observer C, who did not complete the training, there was no significant difference in the AUC between the first and second evaluations, both of which showed significant differences from those of the experienced radiologists.ConclusionThese preliminary results suggest that the training program effectively helped inexperienced radiologists reach the level of experienced radiologists for US examinations.

Dynamic ultrasonography of the medial meniscus during walking in knee osteoarthritis

BackgroundMedial meniscal extrusion (MME) is a risk factor for the progression of knee osteoarthritis (OA). MME evaluation is crucial and it is commonly performed using magnetic resonance imaging (MRI) or static ultrasonography. We developed a prototype flat-shaped ultrasound transducer to visualize the actual meniscal movements during walking. ObjectiveThe aim of this study was to investigate whether it is feasible to visualize and evaluate the meniscal movements during walking using the novel flat-shaped ultrasound transducer for dynamic ultrasonography. MethodsSix participants who were diagnosed with primary unilateral or bilateral tibiofemoral knee OA on radiography (mean age, 67.1 ± 9.9 years; males/females, 4/2) and six healthy volunteers without any symptoms in their knees (mean age, 26.3 ± 4.0 years; males/females, 4/2) were enrolled in this study. The movement of the medial meniscus during walking was visualized using the novel transducer and the gait motion was recorded as video images that were synchronized with the ultrasonogram. MME and ΔMME (the difference between the minimum and maximum MME during the stance phase of the gait cycle) were evaluated in those with OA and compared with those in healthy volunteers. ResultsIn both groups, MME was visualized clearly in the stance phase. The mean values of MME and ΔMME in the knee OA group were significantly greater than those in the control group (P < .01). ConclusionsDynamic meniscal movement during gait can be evaluated with the specially developed novel ultrasound transducer. Our approach will be helpful in unveiling unknown pathological mechanisms in knee OA.

Diagnostic performance of ATA, BTA and TIRADS sonographic patterns in the prediction of malignancy in histologically proven thyroid nodules.

We aimed to compare the malignancy risk stratification of histologically proven thyroid nodules using the 2015 American Thyroid Association (ATA) Management Guidelines, 2014 British Thyroid Association (BTA) Guidelines for the Management of Thyroid Cancer and the Thyroid Imaging Reporting and Data System (TIRADS). Thyroid nodules measuring > 1 cm resected over 5.5 years were retrospectively studied. Demographic information as well as cytology and histopathology results were collected. Static ultrasonography (US) images and radiologists' reports of each resected nodules were reviewed and classified based on the above risk classification systems. A total of 167 thyroid nodules from 150 patients were examined. More malignant nodules were solid (78.4% vs. 62.5%; p = 0.049) or hypoechoic (70.6% vs. 28.6%; p < 0.001), and had irregular margins (35.3% vs. 8.0%; p < 0.001), taller-than-wide morphology (9.8% vs. 2.7%; p = 0.031), microcalcifications (33.3% vs. 8.0%; p < 0.001), disrupted rim calcifications (9.8% vs. 0.9%; p = 0.012) or associated abnormal cervical lymphadenopathy (13.7% vs. 0.9%; p = 0.001) compared with benign nodules. The guidelines' diagnostic performance was: ATA - sensitivity 98.0%, specificity 17.3%, positive predictive value (PPV) 35.0%, negative predictive value (NPV) 95.0%; BTA - sensitivity 90%, specificity 50.9%, PPV 45.5%, NPV 91.8%; and TIRADS - sensitivity 94.0%, specificity 28.2%, PPV 37.3%%, NPV 91.2%. Sonographic patterns outlined by the three guidelines displayed high sensitivity and NPV. Although isolated suspicious US features cannot predict malignancy risk, they should be considered when risk stratifying nodules that do not fit into particular sonographic patterns based on current guidelines.

Clinical and ultrasonographic features of male breast tumors: A retrospective analysis.

ObjectiveThe purpose of this study was to determine clinical and ultrasonographic characteristics of male breast tumors.MethodsThe medical records of male patients with breast lesions were retrieved from an electronic medical record database and a pathology database and retrospectively reviewed. A total of 112 men (125 breast masses) with preoperative breast ultrasonography (US) were included (median age, 59.50 years; age range, 15–96 years). Data extracted included patient age, if the lesions were bilateral, palpable, and tender, and the presence of nipple discharge. Breast lesion features on static US images were reviewed by three experienced radiologists without knowledge of physical examination or pathology results, original breast US image interpretations, or surgical outcomes. The US features were documented according to the BI-RADS (Breast Imaging-Reporting and Data System) US lexicons. A forth radiologist compiled the data for analysis.ResultsOf the 125 breast masses, palpable tender lumps and bilateral synchronous masses were more likely to be benign than malignant (both, 100% vs 0%, P < 0.05). Advanced age and bloody discharge from nipples were common in malignant lesions (P <0.05). A mass eccentric to a nipple, irregular shape, the presence of an echogenic halo, predominantly internal vascularity, and rich color flow signal on color Doppler ultrasound were significantly related to malignancy (all, P < 0.05). An echogenic halo and the presence of rich color flow signal were independent predictors of malignancy.ConclusionSpecific clinical and US characteristics of male breast tumors may help guide treatment, and determine if surgery or conservative treatment is preferable.

Inter-exam agreement and diagnostic performance of the Korean thyroid imaging reporting and data system for thyroid nodule assessment: Real-time versus static ultrasonography

ObjectiveTo investigate the inter-exam agreement for thyroid nodule between real-time ultrasonography (US) assessment and retrospective US interpretation and to compare the diagnostic performance between two methods by using the most recently published guidelines for the US-based management of thyroid nodules, the Korean Thyroid Imaging Reporting and Data System (K-TIRADS). MethodsThe study included 253 nodules in 238 patients for the inter-exam agreement and 201 nodules in 190 patients for the diagnostic performance. Real-time and retrospectively static US images were analyzed according to the US descriptors and final categories of the K-TIRADS. Inter-exam agreements between real-time US assessments and static US image interpretation were analyzed, as was the diagnostic performance of both methods. ResultsOverall inter-exam agreements were almost perfect for orientation (κ = 0.868); and substantial for composition, spongiform appearance, echogenicity, shape, margin, calcification, and final K-TIRADS categories (κ = 0.754, 0.786, 0.747, 0.670, 0.666, 0.778, and 0.754, respectively). Specifically, moderate agreements were observed for predominantly cystic composition and ill-defined margin. The overall diagnostic performances of both real-time US assessment and retrospective US interpretation using the K-TIRADS were comparable. ConclusionsOverall inter-exam agreements between real-time and retrospective US image interpretation for thyroid nodules using the K-TIRADS were equal or more than a substantial. Therefore, the use of K-TIRADS can provide consistent description and assessment for thyroid US regardless of the timing of interpretation.

A Comparative Study of Real-Time and Static Ultrasonography Diagnoses for the Incidental Detection of Diffuse Thyroid Disease

The aim of this study was to compare the diagnostic accuracy of real-time and static ultrasonography (US) for the incidental detection of diffuse thyroid disease (DTD). In 118 consecutive patients, a single radiologist performed real-time US before thyroidectomy. For static US, the same radiologist retrospectively investigated the sonographic findings on a picture-archiving and communication system after 3 months. The diagnostic categories of both real-time and static US diagnoses were determined based on the number of abnormal findings, and the diagnostic indices were calculated by a receiver operating characteristic (ROC) curve analysis using the histopathologic results as the reference standard. Histopathologic results included normal thyroid (n = 77), Hashimoto thyroiditis (n = 11), non-Hashimoto lymphocytic thyroiditis (n = 29), and diffuse hyperplasia (n = 1). Normal thyroid and DTD showed significant differences in echogenicity, echotexture, glandular margin, and vascularity on both real-time and static US. There was a positive correlation between US categories and histopathologic results in both real-time and static US. The highest diagnostic indices were obtained when the cutoff criteria of real-time and static US diagnoses were chosen as indeterminate and suspicious for DTD, respectively. The ROC curve analysis showed that real-time US was superior to static US in diagnostic accuracy. Both real-time and static US may be helpful for the detection of incidental DTD, but real-time US is superior to static US for detecting incidental DTD.

Direct ultrasound methods

Early confirmation of incorrect endotracheal tube (ETT) placement is of vital importance when performing emergency airway management. No ideal confirmation technique has been proposed under all circumstances. Recently, ultrasonography was suggested as a useful tool for confirmation of correct positioning of the ETT. The aim of this study is to assess the diagnostic accuracy of ultrasonography for detection of proper ETT placement. This prospective study was carried out in the emergency department from February to October 2012. The ultrasonography was performed by a trained senior resident in two phases: (a) as the intubation was being performed (dynamic phase) and (b) after the intubation had been completed (static phase). A linear probe was placed transversely over the cricothyroid membrane during the intubation process (dynamic phase) and on the anterior neck just superior to the suprasternal notch in the static method. Operating characteristics were calculated for both dynamic and static determination of ETT placement. Sixty patients were enrolled in each study group. The sensitivity, specificity, positive predictive value, and negative predictive value of the dynamic technique for determining correct endotracheal intubation were 98.1% [95% confidence interval (CI), 88.8-99.9%], 100% (95% CI, 51.6-100%), 100% (95% CI, 91.5-100%), and 85.7% (95% CI, 42-99.2%), respectively. Using the static technique, all testing characteristics listed previously were 100%. In this study, we found acceptable sensitivity, specificity, positive predictive value, and negative predictive value for prediction of tracheal ETT placement with the use of dynamic and static ultrasonography.

US of gastrointestinal tract disease.

The potential use of ultrasonography (US) in evaluating gut disease has been underappreciated in most diagnostic imaging departments in North America. The impression that US has a questionable role in bowel assessment is related to the operator-dependent nature of the modality, the technical challenges of performing bowel US examinations, and the lack of familiarity of radiologists and technologists with the US appearances of normal and abnormal bowel. However, with development of technical experience by the sonographer and integration of a clinical focus at patient evaluation, US can become a powerful tool for bowel assessment. Unlike computed tomography and magnetic resonance imaging, it provides a widely available, noninvasive, inexpensive method for evaluating the gut without the use of ionizing radiation. These factors are of particular importance in young patients and those who require recurrent follow-up imaging. Because US is performed with real-time imaging, the modality also allows the sonographer to view and assess the motility properties of the bowel, a feature that has not been previously used to its full potential. Color Doppler US can yield useful information about mural vascularity in bowel disease when used in conjunction with gray-scale findings and clinical symptoms. Radiologists should be familiar with the static and dynamic US appearances of the normal and abnormal bowel, recognize features of various pathologic conditions, and understand potential errors at imaging interpretation. Online supplemental material is available for this article.

Ultrasonographic observation of the healing process in the gap after a Ponseti-type Achilles tenotomy for idiopathic congenital clubfoot at two-year follow-up

BackgroundPonseti management usually requires Achilles tenotomy during the final stage of serial casting. However, we lack a good understanding of the sequential tendon healing process after tenotomy in the Ponseti bracing protocol. The purpose of this study was to clarify the ultrasonographic process of tendon healing in the gap for up to twoyears after Ponseti-type Achilles tenotomy in patients with clubfeet. MethodsWe conducted an ultrasonographic study to clarify the sequential changes in gap healing for up to twoyears after tenotomy. The subjects were 23 patients with 33 clubfeet. Achilles tenotomy was performed at mean 10.4 (8–16) weeks after birth. Dynamic and static ultrasonography was performed before tenotomy and at 1, 2, 3, 4, 6, 8, and 12weeks as well as at 4, 6, 12, 18, and 24months after tenotomy. ResultsContinuity and gliding were noted within fourweeks. The united portion continued to thicken for up to threemonths after tenotomy. Starting from the fourth month, the healed portion began to lose its thickness, and this process continued into the sixth month. At oneyear, the thickness of the tendon did not differ much from that of the tendon on the opposing foot. In cases where patients had clubfoot on both feet and underwent simultaneous tenotomies, measurement of the tendons could not be accurately compared. At twoyears after tenotomy, slight irregularity of the internal structure persisted when compared with the unaffected foot. In addition, clinical and X-ray findings were evaluated simultaneously, and no recurrence was confirmed. ConclusionsTo our knowledge, our results are the first to describe the process of gap healing in the tendon after tenotomy up to and beyond twoyears, as recommended in the Ponseti bracing protocol.Level of evidence IV.

The value of dynamic imaging for standardization of abdominal ultrasonography.

Digital video recording of dynamic images is a potential way to improve the reproducibility of abdominal ultrasonography (US). Static US and dynamic US were compared using contrast-enhanced computed tomography (CE-CT) as a reference standard, and the value of stored video images was verified. The subjects were 120 individuals who had undergone CE-CT ≤1month before undergoing US. After static US, dynamic US was carried out according to the Scanning Procedure for Abdominal Ultrasonography described in this paper, and records of 30 separate scans were saved on digital video discs (DVD) as individual video files for interpretation. The findings from static US and dynamic US were compared. With respect to the abdominal US signs covered in this evaluation, dynamic US achieved a detection rate equivalent to or better than that of static US. Detection rates were significantly more frequent on dynamic US for: enlarged hepatic hilum lymph nodes (P<0.001); gallbladder wall thickness (P<0.01); cystic lesions of the liver, bright liver, and splenomegaly (P<0.05). Dynamic US is a valuable tool because it enables repeated evaluation of target organs with playback speed adjustment.

Use of chest sonography in acute-care radiology

Diagnosis of acute lung disease is a daily challenge for radiologists working in acute-care areas. It is generally based on the results of chest radiography performed under technically unfavorable conditions. Computed tomography (CT) is undoubtedly more accurate in these cases, but it cannot always be performed on critically ill patients who need continuous care. The use of thoracic ultrasonography (US) has recently been proposed for the study of acute lung disease. It can be carried out rapidly at the bedside and does not require any particularly sophisticated equipment. This report analyzes our experience with chest sonography as a supplement to chest radiography in an Emergency Radiology Unit. We performed chest sonography – as an adjunct to chest radiography – on 168 patients with acute chest pathology. Static and dynamic US signs were analyzed in light of radiographic findings and, when possible, CT. The use of chest US improved the authors' ability to provide confident diagnoses of acute disease of the chest and lungs.

The Sensitivity and Specificity of Transcricothyroid Ultrasonography to Confirm Endotracheal Tube Placement in a Cadaver Model

Confirmation of endotracheal (ET) tube placement is critical when performing emergency airway management. No single confirmation strategy has emerged as ideal in all circumstances. Our objective in this study was to assess the sensitivity and specificity of a novel approach to verify endotracheal intubation using transcricothyroid ultrasonography (US). We performed a prospective, randomized double-blinded trial in a human cadaver model. A 7.5-MHz curvilinear probe was placed longitudinally over the cricothyroid membrane as cadavers were randomly intubated in either the trachea or esophagus in two phases: 1) as the intubation was being performed (dynamic) and, 2) after intubation had been completed (static). Volunteer emergency medicine (EM) residents, blinded to tube placement, assessed for esophageal vs. tracheal ET placement using dynamic and static US views. Sensitivity, specificity, positive predictive value, and negative predictive value for detecting esophageal ET placement with 95% confidence intervals were calculated. Seven EM residents made a total of 70 dynamic and 70 static assessments of ET position using transcricothyroid US. Dynamic assessment resulted in 97% sensitivity and 100% specificity for detecting esophageal ET placement. Static assessment resulted in only 51% sensitivity and 91% specificity. This pilot study suggests that dynamic transcricothyroid US is a potentially accurate method of confirming ET placement during the intubation process. Further investigation in live humans is warranted to validate these data.

Ultrasonic and radiographic study of laxity in hip joints of young dogs

In the present study, 22 hip joints of Whippet (four), Rottweiler (five) and Labrador Retriever (two) young dogs were evaluated with the aim of comparing the ultrasonic examination of coxofemoral joints with the radiographic evaluations, both distraction and conventional procedures, for the early diagnosis of passive laxity. The study was based on static ultrasonography, conventional radiography (CR) and distraction radiography (DR) methods. In order to quantify the relationship between the femur head and the acetabulum, the alpha (alpha) and gamma (gamma) angles were measured by ultrasonographic examination, the Norberg angle (NA) was measured by CR, and the distraction index (DI) was measured by DR. It was observed a negative correlation between angles alpha and gamma (r= -0,756; P&lt;0.001) and correlation between DI and NA (r= -0.474; P&lt;0.026). No correlation was observed between angles alpha and gamma in relation to DI and NA (alpha and DI: r= -0.380; P&lt;0.081; alpha and NA: r= 0.013; P&lt;0.954; gamma and DI: r= 0.338; P&lt;0.124; gamma and NA: r= -0.192; P&lt;0.391). The static ultrasonographic did not prove to be a sensitive method to earlier detection of passive laxity of coxofemoral joints in dogs aging 14 and 15 day-old. The distraction index of DR was efficient in early detecting the passive laxity in dogs averaging five months old, when compared to the NA of CR. Two false negative dogs were detected by the DI. The CR method was relevant to detect osteoarthritis alterations, helping the diagnosis of hip dysplasia (HD).

The diagnostic value of ultrasonography to determine the temporomandibular joint disk position

Objective. Temporomandibular joint (TMJ) arthrography and magnetic resonance imaging are the imaging techniques of choice in patients presenting with signs and symptoms of TMJ disorders suggesting soft tissue pathosis. With the disadvantage of arthrography as an invasive procedure and magnetic resonance imaging posing a problem in clinical availability and cost, the purpose of this study was to determine whether ultrasonography could be used to assess the presence or absence of disk displacement in patients with TMJ disorders. Study design. In 17 patients, 100 TMJ positions were investigated by static and dynamic ultrasonography to analyze the diskcondyle relationship. To compare the respective findings with those of a diagnostic method offering high accuracy, coronal and sagittal magnetic resonance imaging was carried out immediately afterwards. Results. With static ultrasonography showing a sensitivity of 0.41 and a specificity of 0.70 and dynamic ultrasonography a sensitivity of 0.31 and a specificity of 0.95, the data revealed that static and dynamic ultrasonography are marginal in detecting the presence of disk displacement, but dynamic ultrasonography is sensitive in detecting the absence of disk displacement. However, with a positive predictive value of 0.61 and a negative predictive value of 0.51 for static ultrasonography, and a positive predictive value of 0.88 and a negative predictive value of 0.55 for the dynamic technique, the results indicate that both modalities are insufficient in establishing a correct diagnosis for the presence or absence of disk displacement. Conclusion. In view of the fact that dynamic ultrasonography proved to be a reliable diagnostic aid for the detection of normal disk position, the results of this study should be of further interest and encourage research in its potential uses and diagnostic capabilities.