Sonography of the nasal cartilage: technique and normal anatomy

The cartilagineous parts of the nose may be involved in a wide range of pathologies ranging from trauma and infection to malignancy. If pathology is suspected on examination, an easy-to-use imaging modality would be helpful in everyday clinical work. Until now, sonography of the nasal cartilage has not been described. This short letter describes the technique and normal anatomy of the nasal cartilage on sonography. Sonography may evolve into a powerful imaging tool in imaging of the nasal cartilage.     

Sonography of the quadriceps muscle: Examination technique,normal anatomy,and traumatic lesions

Lesions of the quadriceps muscle (QM) are frequently seen by sonographers, and in most cases they are the result of sports-related trauma. An accurate assessment of the severity of the lesion is essential, particularly when the patient is a professional athlete. In most cases, careful history-taking and a thorough physical examination are sufficient for making the diagnosis and indicating the most suitable imaging studies for each case. Clinical assessment alone, however, may not be sufficient for distinguishing contusions from small, partial tears or for estimating the size of a tear. Therefore, at least in patients who are professional athletes, imaging studies are necessary to plan appropriate therapy that will allow prompt functional recovery. Muscles cannot be visualized with conventional radiography, but it is used routinely in prepubertal patients because it can detect apophyseal detachments, which are the most frequent muscle lesion in this age group. Radiography is also useful when myositis ossificans is suspected. Magnetic resonance imaging, thanks to its excellent tissue contrast, allows simultaneous assessment of muscle, joint, and bone planes. It remains a second-line study due to its high cost and relatively low availability. It is also associated with various contraindications, the most important of which is the presence of a cardiac pacemaker. Ultrasonography has a number of advantages, including widespread availability, absence of contraindications, and low cost. It can also be used for dynamic studies of the muscle during contraction and relaxation, and if doubts arise, scans can easily be obtained of the contralateral muscle for comparison purposes. These qualities make it an excellent tool for follow-up of patients with QM lesions, when follow-up is necessary. This article reviews the anatomy of the QM, the technique used for standard ultrasound examination of this muscle, its normal appearance on ultrasound, and the sonographic characteristics of the most common traumatic lesions that affect it.     

Ultrastructural pathology of peripheral nerves in patients with diabetic neuropathy

Sural nerve lesions in patients with clinically manifest diabetic neuropathy were investigated electron microscopically. Myelinated nerve fibers were reduced in all the diabetic patients. Axonal degeneration of both myelinated and unmyelinated nerve fibers was most conspicuous finding in the diabetic sural nerves. Structural changes of the axons were represented by axonal dwindling, depletion of axoplasmic organelles, vacuolarization and an increase in neurofilaments. Accumulation of glycogen-like particles and deposition of electron homogeneous amorphous materials were noted within a few axons. On the other hand, there could also be found degenerative changes of myelin sheaths, various kinds of cytoplasmic inclusion bodies (crystalloid, lamellar inclusion bodies and lipids-like droplets), aggregates of glycogen particles in the Schwann cell cytoplasm and basement membrane hyperplasia of Schwann cells in all the subjects. Furthermore, multiplication and thickening of the basement membrane of vasa nervorum were constant findings of the diabetic sural nerves. The vascular changes, demyelination and axonal degeneration of the cases were not apparently correlated with each other. There was no special relationship between nerve tissue changes and clinical symptoms or laboratory findings. These results indicated that the peripheral nerve lesions in human diabetics were mainly due to metabolic impairment of nerve fibers, accompanying dysmetabolism of Schwann cells and diabetic microangiopathy, and that these changes proceeded independently.     

Sonography of the knee: intra-articular pathology

MRI is the gold-standard imaging technique for evaluation of the intra-articular structures of the knee, and the use of sonography remains controversial. Sonography nevertheless is a useful alternative in several conditions: Inflammatory joint diseases, where it is appropriate for early diagnosis and follow-up of joint effusion and synovitis; peri-articular masses, where it is the best modality for guidance of needle puncture or biopsy; suspected meniscus or ligament lesion, where it may provide a positive diagnosis but is not sufficient to exclude intra-articular lesions; and loose bodies, where it is an outstanding modality for diagnosing lesions not evident on radiographs.     

Breast sonography: technique, equipment, and normal anatomy

In order to interpret breast sonograms successfully, it is necessary to understand the technical factors that affect the image. It is especially important to be aware of the effects of focal zone, power, time gain compensation, and gray scale selection on cyst/solid differentiation, the primary indication for breast sonography. Adequate breast examinations can be performed with either high-frequency automated whole-breast ultrasound units or hand-held instruments with a transducer operating at 5 MHz or greater frequency, and with a depth of focus of no more than 3 cm. Familiarity with the normal breast sonogram, including the variations in the relative amounts of parenchyma, connective tissue, and fat that occur with increasing age and parity, is essential for the identification, characterization, and localization of abnormalities.     

Sonography of the costal cartilage: Normal anatomy and preliminary clinical application

Costal cartilages of 10 controls and 12 patients with Tietze's syndrome (n = 6), deformed (exaggerated bowing) cartilage (n = 4), focal enlargement (n = 1), and cancer-invaded cartilage (n = 1) were examined with ultrasonography. In controls, ultrasonography detected 237 of 240 costal cartilages (98.8%) and 58 of 105 intercartilage connections (55%) with three variations. Correlation with CT was available in 7 patients (1 Tietze's syndrome, 4 deformities, 1 cartilage enlargement, and 1 cancer) among 8 patients whose CT results were known to the sonographer. Sonography showed normal (n = 4) or marginally blurred (n = 2) cartilages in 6 Tietze's syndromes. Ultrasonography is a promising technique in the examination of costal cartilages. © 1995 John Wiley & Sons, Inc.     

Imaging of the parapharyngeal space: anatomy and pathology

A multitude of histologic neoplasms occur within the boundaries of the parapharyngeal space. Contrast enhanced computed tomography and recently MRI have greatly enhanced the preoperative diagnosis of parapharyngeal space tumors. MRI is currently the modality of choice in evaluating masses originating in the parapharyngeal space or masses from adjacent spaces which grow into the parapharyngeal space. Gadolinium DTPA enhanced MRI of head and neck tumors is helpful for demonstrating neoplastic involvement of paranasal sinus, perineural tumor extension, or intracranial extension of neoplasms. Parapharyngeal space tumors are equally demonstrated by unenhanced MRI. The majority of tumors involving the parapharyngeal space are from the deep portion of the parotid gland or from minor salivary glands, and the majority of these tumors are benign mixed tumors. Based on the CT appearance and enhancement characteristics, it is difficult to accurately distinguish a minor salivary gland tumor from a neurogenic tumor. MR tissue signal characteristics alone cannot be reliably utilized in making this distinction. Internal carotid artery displacement remains the most reliable distinguishing feature. Minor salivary gland tumors will displace the internal carotid artery posterior and lateral, whereas neurogenic tumors will displace the internal carotid artery anterior and medial.     

Skull base, orbits, temporal bone, and cranial nerves: anatomy on MR imaging

Accurate delineation, diagnosis, and treatment planning of skull base lesions require knowledge of the complex anatomy of the skull base. Because the skull base cannot be directly evaluated, imaging is critical for the diagnosis and management of skull base diseases. Although computed tomography (CT) is excellent for outlining the bony detail, magnetic resonance (MR) imaging provides better soft tissue detail and is helpful for evaluating the adjacent meninges, brain parenchyma, and bone marrow of the skull base. Thus, CT and MR imaging are often used together for evaluating skull base lesions. This article focuses on the radiologic anatomy of the skull base pertinent to MR imaging evaluation.     

超声与神经阻滞

高频超声可清晰地显示外周神外,用超声引导行外周神经阻滞能更好地减少操作的盲目性并提高成功率。本文就国外对外周神经的超声影像学研究,超声引导外周神经阻滞技术的临床应用和评价作一综述。     

The facial nerve: anatomy and common pathology.

The seventh cranial nerve is responsible for much of what makes us individual--the facial expression worn by each individual. The facial nerve (CN VII) is commonly divided into 4 segments for examination: the nucleus and tracts, the cistemal segment that traverses the internal auditory canal, the intratemporal segment (through the bony facial nerve canal), and the peripheral segment. Immediately on leaving the temporal bone at the stylomastoid foramen, the peripheral segment of CN VII becomes much more complicated to follow and is essentially invisible to imaging. Each segment of the facial nerve may be involved by differing pathology. In this report we break down the facial nerve into more easily understood divisions and cover the common pathology of each of these segments.     

Scrotal ultrasonography with emphasis on the extratesticular space: anatomy,embryology, and pathology

Sonography is the imaging modality of choice in detecting and characterizing pathologic conditions affecting the extratesticular space. Although most abnormalities are benign, many may simulate or represent malignant processes. Accurate diagnosis is therefore essential and must be based not only on the sonographic findings but also on accurate clinical history and physical examination findings. This article reviews the anatomy, embryologic development, and pathologic conditions affecting the extratesticular space.     

Ultrasonography of the scrotum: technique, anatomy, and pathologic entities.

OBJECTIVE: To review the ultrasonographic technique, anatomy, and pathologic entities found in the scrotum during evaluation of scrotal masses, acute scrotal pain, and male infertility. METHOD: A pictorial review of cases with diagrams of pertinent anatomic features and findings is presented. RESULTS: Ultrasonography in conjunction with color and pulsed Doppler imaging has supplanted other imaging modalities in the evaluation of scrotal diseases and disorders. Ultrasonography is valuable in the evaluation of the acutely painful scrotum in addition to scrotal masses and male infertility. Advances in ultrasonographic spatial and low-contrast resolution have improved our ability to more clearly define diagnoses for the referring urologist and have led to new observations that are currently being investigated and have yet to be fully understood. Microlithiasis and the mottled appearance of seminiferous tubule sclerosis and atrophy are 2 such entities. This article reviews the pertinent normal scrotal anatomy and the use of ultrasonography in the evaluation and classification of acute scrotal pain, scrotal masses, male infertility, and trauma. This review article also discusses pitfalls of color Doppler imaging in assessment of the scrotum and how to avoid them. CONCLUSION: The use of ultrasonography in the evaluation of the scrotum benefits from an understanding of scrotal anatomy and familiarity with potential pitfalls of color Doppler and pulsed Doppler evaluation.     

Carpal tunnel: Normal anatomy,anatomical variants and ultrasound technique

The carpal tunnel is an osteofibrous canal situated in the volar wrist. The boundaries are the carpal bones and the flexor retinaculum. In addition to the medial nerve, the carpal tunnel contains nine tendons: the flexor pollicis longus, the four flexor digitorum superficialis and the four flexor digitorum profundus. Ultrasound (US) study of the carpal tunnel generally involves short-axis imaging of the tendons, and in the presence of disease, long-axis imaging and dynamic maneuvers are added. There are numerous reports of anatomical variants of the wrist involving vessels, nerves, tendons and muscles, and they can all be studied by US. Some are particularly relevant from a clinical point of view and will therefore be accurately described. The anatomy is complex, and the US operator should therefore be thoroughly familiar with the normal anatomy as well as the anatomical variants that may have a role in the pathogenesis of carpal tunnel syndrome or influence treatment.