Sonography in carpal tunnel syndrome with normal nerve conduction studies.

INTRODUCTION: We assessed the yield of high-resolution ultrasonography (HRUS) in patients with clinically definite carpal tunnel syndrome (CTS) and normal nerve conduction studies (NCS). METHODS: This blinded, prospective, cross-sectional study involved 35 patients (60 hands) with clinically definite CTS and normal NCS, and 20 controls (40 hands). Cross-sectional area (CSAs) of the median nerve at the level of the pisiform bone and flexor retinaculum thickness (FRT) were measured. RESULTS: CSA was abnormal in 48.6% of patients (confidence interval 32.0-65.2%, P = 0.95). FRT was increased in only 34.3% (18.3-49.7%), but was independently abnormal in 2 patients. CSA abnormalities correlated with positive provocative tests and sensory loss. The HRUS changes were mild. CONCLUSIONS: HRUS confirms clinically diagnosed CTS in about half of the patients with normal NCS.

Effect of a neck collar on upper airway size in children sedated with propofol-midazolam combination during magnetic resonance imaging.

INTRODUCTION: Propofol and midazolam are widely used for pediatric magnetic resonance imaging (MRI) sedation. Increasing depth of sedation may be associated with airway obstruction. A neck collar supporting the mandible and maintaining the head in slight extension may be beneficial in maintaining airway patency. AIM OF THE STUDY: Primary aim: To assess upper airway size with and without a neck collar during pediatric MRI sedation with propofol-midazolam. Secondary aim: To evaluate complications encountered during the procedure. MATERIALS AND METHODS: Sixty patients aged 2-4 years scheduled for MRI of the brain were selected. They were sedated with intramuscular midazolam 0.1 mg·kg(-1) 30 min before the procedure. Patients were sedated with i.v. propofol 1 mg·kg(-1) and continued with 50-100 µg·kg(-1) ·min(-1) . T1 3D fast-field echo axial sequence from the nasopharyngeal roof to subglottic region was taken with and without application of a neck collar. Airway dimensions were measured and analyzed at the base of the tongue, soft palate, and at the epiglottis. RESULTS: At the base of the tongue and soft palate, the cross-sectional area (CSA) and the anteroposterior diameter of the airway were respectively statistically significantly higher when the neck collar was applied. The CSA at the epiglottis was significantly less with application of the neck collar. Complications were not significantly different between the two sequences. CONCLUSION: Application of a soft neck collar in children aged 2-4 years may enhance the retropalatal and retroglossal airway dimensions during pediatric sedation in the supine position.

Imaging of the spine: Where do we stand?

The number of patients presenting with spine-related problems has globally increased, with an enormous growing demand for the use of medical imaging to address this problem. The last three decades witnessed great leaps for diagnostic imaging modalities, including those exploited for imaging the spine. These developments improved our diagnostic capabilities in different spinal pathologies, especially with multi-detector computed tomography and magnetic resonance imaging, via both hardware and software improvisations. Nowadays, imaging may depict subtle spinal instability caused by various osseous and ligamentous failures, and could elucidate dynamic instabilities. Consequently, recent diagnostic modalities can discern clinically relevant spinal canal stenosis. Likewise, improvement in diagnostic imaging capabilities revolutionized our understanding of spinal degenerative diseases via quantitative biomarkers rather than mere subjective perspectives. Furthermore, prognostication of spinal cord injury has become feasible, and this is expected to be translated into better effective patient tailoring to management plans with better clinical outcomes. Meanwhile, our confidence in diagnosing spinal infections and assessing the different spinal instrumentation has greatly improved over the past few last decades. Overall, revolutions in diagnostic imaging over the past few decades have upgraded spinal imaging from simple subjective and qualitative indices into a more sophisticated yet precise era of objective metrics via deploying quantitative imaging biomarkers.

Femoroacetabular impingement: can the alpha angle be estimated?

OBJECTIVE: Femoroacetabular impingement is an important entity with well-described radiographic findings. One of the criteria of the cam type of femoroacetabular impingement is femoral head-neck dysplasia, denoted mathematically as the "alpha angle." Several observers have reported that direct measurement of the angle may not be necessary because subjective appraisal may yield similar results. We sought to scientifically determine the accuracy of a subjective assessment, using the calculated angle as the gold standard. MATERIALS AND METHODS: At 1.5 T, 50 consecutive patients' hips were evaluated on sets of oblique axial images. Two musculoskeletal radiologists recorded their subjective opinion as to the alpha angle using a confidence scale of 1-5. Direct mathematic measurement of the alpha angle was done by a third independent observer and correlated with the subjective results. Correlations between the subjective and measured angles and interobserver variation were calculated. RESULTS: Statistically, significant variability was seen in the subjective assessment of the alpha angle. When the alpha angle was > 55 degrees, the area under the receiver operating characteristic curve (AUC) was 0.606, indicating that visual assessment is a poor predictor of a wide alpha angle. Even in patients with a measured normal alpha angle (< 55 degrees), slightly fewer than half were subjectively thought to possibly, likely, or definitely have abnormal angles. Similarly, more than half of the abnormal cases (alpha angles > 55 degrees) were subjectively thought to possibly or probably be normal. CONCLUSION: Subjective assessment of alpha angles is suboptimal unless one is quite confident of a bone abnormality.

Radiographic and magnetic resonances contrast agents: Essentials and tips for safe practices.

With extended and continued expansion of medical imaging utilization in modern medical practice over last decade, radiologists as well as other faculty staff dealing with radiographic and magnetic resonances contrast media (CM) have to be well oriented with their potential hypersensitivity reactions and recognize high-risk groups liable to develop it and enable early recognition. Radiologists and other medical staff involved in administration and dealing with CM have to be ready to implement prompt, practical and effective management plan to deal with these scenarios should they emerge. Strategies to prevent potential contrast-induced acute and delayed renal injuries have to be routinely exercised. Paying attention to the pregnant and nursing women, pediatrics, diabetics, as well as other fragile populations is of utmost importance for patient safety during contrast administrations. Radiologists should play a pivotal role in orienting patients about necessity to use CM for their imaging studies, in case it is needed, and assure them about its safety. Moreover, they have to be oriented with the medico-legal issues related to use of CM. These will pay as improved patient safety as well as safe daily working environmentat different levels of radiology practices.

Forefoot: a basic integrated imaging perspective for radiologists.

Imaging of the forefoot is increasingly requested for patients with metatarsalgia. Awareness with specific anatomic arrangements exclusive for the forefoot and widely variable pathologic entities associated with metatarsalgia helps the radiologist to tailor a cost-effective imaging approach. This will enable reaching a specific diagnosis as much as possible with subsequent proper patient management. This pictorial review aims to provide basic understanding for the different imaging modalities used in studying the forefoot. After that, certain anatomic arrangements exclusive for the forefoot are discussed. The final section of this review describes the imaging findings of some common forefoot problems.