Hypoechoic Structure Research Articles

Mitral Valve Blood Cyst Detected by Multimodality Imaging

A 25-year-old woman was referred for exertional dyspnea, atypical chest pain, and a systolic murmur. Transthoracic echocardiography (Fig. 1, A and B; Video 1 , view video online) showed a round mobile hypoechoic structure attached to the anterior mitral valve leaflet on its ventricular side. Computed tomography scan (Fig. 1C) showed an isodense mass measuring 16 × 19 mm in diameter. On cardiac magnetic resonance imaging (Fig. 1D), this nonenhancing mass was isointense on turbo spin echo-T1 (Fig. 1E) and T2-weighted (Fig. 1F) imaging.

Localization of the recurrent laryngeal nerve using ultrasound (923.5)

INTRODUCTION: The anatomical course of the recurrent laryngeal nerve (RLN) deep to the thyroid gland predisposes it to iatrogenic damage during thyroid surgery. The course of the nerve and its anatomical variations are well documented in the literature. The aim of this study was to localize the RLN in relation to key surgical landmarks with the aid of non‐invasive modalities such as ultrasound. METHODS: We examined 50 adult healthy individuals with the aid of Logiq E ultrasound unit using a 12Hz linear transducer. In addition, 20 cadaveric specimens were examined with the aid of ultrasound and then dissected to identify the RLN. RESULTS: The RLN was identified in 10 individuals (20%) as a linear hypoechoic structure in the tracheoesophageal groove. The RLN was found in 6 cadaveric specimens. Despite the fact that the RLN itself was not identified in the majority of the necks, the ultrasound can identify the plane between the thyroid gland and the esophagus, where the RLN can most commonly be found. CONCLUSIONS: This study introduces a new, non‐invasive technique for localizing the RLN and the space between the thyroid and the esophagus. This technique might be of benefit for presurgical localization of the RLN or ultrasound‐guided needle procedures.

An Unusual Cause of Right Upper Quadrant Pain and Emesis

A 43-year-old otherwise healthy female presented to the ED with approximately 8 h of intermittent sharp right upper quadrant (RUQ) abdominal pain, nausea, and vomiting. Her vital signs were unremarkable and physical examination revealed a middle-aged female in moderate distress due to pain. She had RUQ tenderness with a positive Murphy’s sign. Laboratory studies including complete blood count, complete metabolic panel, and lipase were within normal limits. The patient underwent a bedside RUQ ultrasound (US) (Figure 1) followed by computed tomography (CT) (Figures 2 and 3) of the abdomen and pelvis. The US revealed a hypoechoic structure between the diaphragm and liver without peristalsis on multiple views and cholelithiasis without evidence of cholecystitis. The CT confirmed the suspicion that this structure was the small bowel crossing between the diaphragm and the liver, also revealing a transition

Successful Detection and Removal of a Functional Parathyroid Adenoma in a Pony Using Technetium Tc 99m Sestamibi Scintigraphy

Successful Detection and Removal of a Functional Parathyroid Adenoma in a Pony Using Technetium Tc 99m Sestamibi Scintigraphy

Biometry of the fetal corpus callosum by three‐dimensional ultrasound

To construct reference ranges of quantitative characteristics of the fetal corpus callosum. Women referred to a tertiary center for sonographic examination were recruited to undergo a detailed fetal scan from 17 to 41 weeks of gestation. Three-dimensional (3D) sonographic volumes of normal fetal brains were acquired and analyzed offline. We obtained three different measurements of the corpus callosal length, as well as the height (/thickness) of its segments, namely the rostrum, genu, body and splenium. Initially we recruited 604 pregnant women, of whom 138 were excluded because of various disorders/abnormalities, multiple pregnancy or gestational age < 18 weeks. Thus, included in the analysis were 466 sonographic volumes of normal fetal brains from singleton pregnancies, acquired by transabdominal ( n = 170) or transvaginal (n = 296) ultrasound. The corpus callosum was visualized as a hypoechoic structure. Reference ranges were established for the following parameters: curved corpus callosal length, inner-inner corpus callosal length, outer-outer corpus callosal length, rostrum height, genu height, body height and splenium height. We observed non-linear growth and an approximately four-fold increase in all corpus callosal lengths, a three-fold increase in rostrum height, a four-fold increase in genu height, a two-fold increase in body height and a three-fold increase in splenium height between 18 and 41 weeks. The growth patterns of rostrum and body height appeared to be similar: there was rapid development until 24 and 22 weeks of gestation, respectively, and growth slowed beyond this period. The growth patterns of genu and splenium were also similar, being characterized by progressive growth throughout gestation. Using 3D ultrasound, we have constructed reference charts for measurements of the corpus callosum. Knowledge of the normal growth pattern may be useful for evaluation of abnormal development of the corpus callosum, and so help in the accurate diagnosis of pathologies such as hypogenesis and dysgenesis.

Cystic Adventitial Disease of the Common Femoral Vein

We report on a 52-year-old female patient who presented with a 6-month history of right lower extremity swelling and tenderness. The patient was treated as an outpatient with full anticoagulation, without any improvement. Her medical history was significant for hypertension and high cholesterol, and she had a full coagulopathy profile that was negative for any hypercoagulable syndrome. On examination, the patient was moderately obese, with significant tenderness over the medial aspect of the right groin. A venous duplex examination revealed hypoechoic structure ± acute deep vein thrombosis of right common femoral vein (CFV). A computed tomography of the venous phase revealed an eccentric compression over the medial wall of the right CFV. During surgical exploration, adventitial cystic mucinous disease was enucleated from the medial wall of the right CFV, and the pathological examination confirmed the diagnosis. The postoperative course was uneventful, and all swelling and tenderness were completely resolved. The patient continued to do well, and she had an unremarkable venous duplex evaluation at her 6-month follow-up.

Nerve Hematoma Mimicking DVT

This case study describes a patient who underwent an upper extremity venous examination to evaluate for possible deep vein thrombosis (DVT). Sonography showed no evidence of thrombus in the veins of the deep or superficial system. Adjacent to the veins of the peripheral arm, however, an enlarged hypoechoic structure was visualized that had a very similar appearance to DVT. With further imaging, hyperechoic linear bands were visualized at the proximal end of the hypoechoic structure. The appearance suggested that this structure was related to the median nerve, but its normal appearance was altered by a large mass inside the nerve sheath. Given the patient’s history, the finding most likely represents a nerve hematoma.

Ultrasound Visualization of the Superficial Peroneal Nerve in the Mid-calf

THE superficial peroneal nerve (SPN) arises from the common peroneal nerve at the level of the fibular neck and descends in the lateral compartment of the leg. In the distal half of the leg, the SPN is sandwiched between peroneus brevis and the intermuscular septum that separates the anterior and lateral compartments of the leg, and gradually ascends into a superficial location before eventually piercing the crural fascia.1,2 Here the SPN divides into medial and intermediate dorsal cutaneous nerves, which travel subcutaneously to supply the dorsum of the foot.3The SPN is traditionally blocked by “blind” subcutaneous infiltration of local anesthetic across the dorsum of the foot at the intermalleolar line. The SPN may, however, be reliably located and blocked using ultrasound by placing a high-frequency (10–15 MHz) linear-array transducer transversely across the lateral aspect of the leg midway between the fibular head and lateral malleolus. The chief landmark is the fibula, which in cross-section casts an acoustic shadow with a peaked appearance. The “peak” of this shadow points toward the intermuscular septum (IMS) and the SPN. The nerve is visible as a hyper- or hypoechoic structure lying between peroneus brevis (PB) and extensor digitorum longus (EDL) just deep to the crural fascia (dotted arrows, fig. A). The identity of the SPN can be confirmed by tracing it distally toward the ankle, and observing the nerve rise through the crural fascia into a subcutaneous location (fig. B). The nerve may also widen, reflecting its bifurcation into its terminal branches.

Ultrasonographic examination of the abdomen of the goat. II. Liver, spleen, urinary tract and greater omentum

This review article describes the ultrasonographic findings of the liver, spleen, urinary tract and greater omentum that were previously obtained in studies of healthy female Saanen goats. Real-time B-mode ultrasonography and a linear or convex 5.0 to 7.5 MHz transducer are used to scan standing goats from both sides. The urinary bladder and urethra are also examined transrectally. The liver is scanned from the intercostal spaces (ICSs) on the right from dorsal to ventral. The parenchymal pattern consists of numerous fine echoes that are homogenously distributed across the entire organ. The dorsal visible margin of the liver runs parallel to the lung in a cranioventral to caudodorsal direction. The visible extent of the liver is largest in the 7th and 8th ICSs and the maximum thickness is measured in the 10th ICS. The caudal vena cava has a triangular shape in cross section and is seen only at the 11th or 12th ICS. The portal vein is oval to circular in cross section with stellate ramifications into the liver parenchyma. The gallbladder is pear-shaped and sometimes extends beyond the ventral margin of the liver depending on the amount of bile. In most goats, the gallbladder is only seen from the 9th or 10th ICS. The spleen is scanned from the left where it is almost always seen from the 11th and 12th ICSs. The parenchymal ultrasonographic pattern is similar to that of the liver. The splenic vessels are embedded in the parenchyma and are seen in longitudinal or cross section. The kidneys are best visualized from the flank and last two ICSs on the right. The ultrasonographic appearance varies with the sectional plane. In a sagittal plane through the hilus, the parenchyma is homogenous with fine, evenly distributed echoes. The medullary pyramids are seen near the sinus as oval to circular hypoechoic structures. The hyperechoic sinus is at the centre of the kidney. The urinary bladder is best visualized transrectally but can also be seen in many goats from either inguinal region. The content of the bladder is usually anechoic and the diameter ranges from 1.0 to 4.8 cm. The urethra is seen transrectally as two adjacent parallel echoic lines without an apparent lumen.

CORRELATIVE ULTRASOUND ANATOMY OF THE FELINE BRACHIAL PLEXUS AND MAJOR NERVES OF THE THORACIC LIMB

Brachial plexus avulsions commonly occur in cats due to traumatic injuries involving the shoulder. Ultrasound may be an effective method for detecting injured nerves. Additional applications may include characterization of brachial plexus neoplasms and guidance of anesthetic nerve blocks. Aims of this study were to describe ultrasonographic approaches and the normal appearance of this plexus and other major nerves of the thoracic limb in cats. Eight feline cadavers were used to determine anatomic landmarks, obtain cross-sectional anatomic images of the target nerves, and compare these with ultrasound images. An ultrasonographic study was performed in five fresh feline cadavers to assess the brachial plexus and its major components at the levels of the axilla and proximal, middle and distal (lateral and medial approaches) humeral regions. Five healthy adult cats were recruited for an in vivo ultrasonographic study using the same protocol described for the cadaver ultrasonographic study. The roots of the brachial plexus appeared as a cluster of small, round hypoechoic structures surrounded by a hyperechoic rim in the axillary approach. The radialis, medianus, and ulnaris nerves were individually visualized on proximal and middle humeral approaches. The medianus and ulnaris nerves were easily identified on the medial aspect of the humerus in the distal approach. The superficial branch of radialis nerve was seen on the lateral aspect of the distal humerus approach. The nerves appeared as oval-to-round hypoechogenic structures with a hyperechogenic rim. Future studies are needed to compare findings from this study with those in cats with confirmed brachial plexus injuries or other lesions.

A reply

I thank Brammar and Sharma for their comments on our recent editorial [1] about maximising interscalene catheter safety. We are in complete agreement with the interscalene catheter placement technique the authors propose. Interestingly, the described technique is very similar to one I developed in 2005 with outcome data from a formal prospective audit of over 300 patients published a short time later [2]. I would also add the following. The sonogram supplied is of good quality. Often, all that can be seen is one nerve root (occasionally, roots cannot be seen at all). For this reason, and because accurate catheter (and therefore needle) placement is critical to the technique's success, we recommend concomitant neurostimulation to confirm the target hypo-echoic structure is, in fact, a nerve root. One motor response (preferably deltoid, biceps or triceps) is all that is required to confirm the appropriate root. Single-injection techniques do not require the same needle tip precision. Because the needle is aligned in the direction of the plexus, if using a large calibre blunt needle (e.g. 18-G Tuohy), nerve root penetration is almost certainly impossible, so we try to place the needle as close as possible to the target roots, but still within the middle scalene muscle as the authors propose [3]. We agree with threading the catheter several centimetres past the needle tip, but then withdrawing to 3–4 cm beyond the original needle tip position (after needle removal) [4]. Less than 3 cm increases the risk of subcutaneous placement resulting from movement of the patient's head. More than 5 cm increases the risk of the catheter's deviating away from an optimal position. The catheter's position can indeed be verified by observing local anaesthetic spread, but we do not do this for the following reasons: firstly, observing local anaesthetic spread via the catheter is technically challenging when using the out-of-plane technique. Secondly, as the catheter is blindly left 3–4 cm beyond a needle tip aligned parallel to the plexus, it simply cannot deviate significantly away from the plexus [4]. Finally, it is uncertain what the operator should do if they can't see local anaesthetic spread; removing such catheters will result in the removal of many appropriately placed catheters. The optimal local anesthetic dose for the initial catheter bolus to maximise postoperative analgesia and minimise motor block is 20 ml ropivacaine 0.375%. Local anaesthetic-induced myotoxicity has yet to be confirmed as a clinically relevant issue. Finally, we urge caution when comparing success rates between studies, as there can be multiple confounding variables [5]. A detailed description of the above technique with video is available at http://ultrasoundblock.com.

Disorder of Sexual Development with Sex Chromosome Mosaicism 46 XY and 47 XXY

ABSTRACTIncidence of abnormalities of sex chromosome is reported to be 1 in 448 new born babies. The association between clinical phenotype and sex chromosome abnormality is highly variable. A 34-year-old unmarried female patient reported to out patient department with complaints of primary amenorrhea and occasional pain in the lower abdomen. On examination, her height was 160 cm and body mass index (BMI) was 27 kg/m2. Breast development was Tanner stage 4, pubic hair was tanners stage 1 and no axillary hair was noted. Ultrasonography showed a hypoechoic structure in the place of uterus measuring around 1.7 × 1.1 × 1.0 cm and hypoechoic structures were also noted in relation to iliac vessels suggestive of gonads. Karyotyping showed 46 XY and 47 XXY mosaicism. Bilateral gonadectomy was done and histopathology showed testicular atrophy with Leydig cell hyperplasia. This case is reported in view of the interesting clinical presentation of this rare mosaicism.How to cite this articleGovindaraj SK, Muralidhar L, Venkatesh S, Saxena RK. Disorder of Sexual Development with Sex Chromosome Mosaicism 46 XY and 47 XXY. Int J Infertility Fetal Med 2013;4(1):34-37.

Inflammatory markers in patients with internal carotid artery stenosis.

IntroductionAvailable reports underline the significance of the inflammatory process in the development, progression and destabilisation of atherosclerotic plaques in the internal carotid artery (ICA). The aim of this study was to evaluate the relationship between the degree of ICA stenosis, ultrasound plaque morphology and serum concentration of selected inflammatory markers.Material and methodsSixty-five patients with ICA stenosis > 50% (39 symptomatic) and 30 healthy volunteers were enrolled in the study. Clinical, neurological examination and laboratory evaluation (leucocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), fibrinogen, tumour necrosis factor-α (TNF-α), interleukins (1β, 6 and 10), anti-cytomegalovirus IgG antibody titre) were performed. Stenosis grade ≥ 70%, ulcerations on the plaque surface and a hypoechoic (or predominantly hypoechoic) structure of the plaque, obtained by colour-coded duplex examination, were accepted as the characteristics of unstable stenoses.ResultsUnstable ultrasound features of ICA stenosis were found significantly more often in symptomatic than in asymptomatic patients (71.79% vs. 30.71% for stenosis degree ≥ 70%, p = 0.001 and 61.23% vs. 38.46% for unstable plaque morphology, p = 0.01). Patients with ICA stenosis had significantly higher serum concentrations of interleukin-6, fibrinogen, ESR and higher CRP values than the individuals from the control group (p = 0.001, p = 0.009, p = 0.036, p = 0.009 respectively). Patients with unstable plaques structure had significantly higher concentrations of TNF-α, interleukin-6, fibrinogen, higher number of leukocytes, monocytes and higher CRP values than patients with stable plaques (p = 0.008, p = 0.049, p = 0.012, p = 0.0002, p = 0.006, p = 0.0003 respectively). No significant differences in above-mentioned parameters between the groups with stenosis < 70% and ≥ 70% were found.ConclusionsThere is a relationship between the activity of the selected inflammatory markers in serum and atherosclerotic unstable internal carotid artery stenosis. There is no relationship between serum concentration of inflammatory markers and degree of carotid artery stenosis.

Endoscopic ultrasound-guided fine needle aspiration of the celiac ganglion: A diagnostic pitfall

Endoscopic ultrasound guided fine-needle aspiration (EUS-FNA) is now widely used as a primary tool in the evaluation of lymphadenopathy in both the mediastinum and abdomen. A sympathetic ganglion may be mistaken for an enlarged lymph node on endoscopic ultrasound and are rarely sampled as such. A 51-year-old female presented with a history of weight loss, vomiting for several months, and right upper quadrant discomfort. Computed tomography (CT) and magnetic resonance imaging (MRI) scans showed a dilated common bile duct (CBD) with a possible periampullary mass, paraaortic, and pericelial lymph nodes suspicious for metastatic disease. Endosonography revealed a 17 mm oval hypoechoic structure with distinct margins in the para-aortic, celiac axis region suggestive of an enlarged lymph node. An EUS-FNA was done. Cytology revealed ganglion cells with large oval epithelial-like cells with round nuclei and prominent nucleoli consistent with a benign sympathetic ganglion. It is crucial for the cytopathologist to be aware of the fact that the endoscopist might have sampled a celiac ganglion instead of a celiac lymph node and be able to distinguish the cytological features of a benign sympathetic ganglion from a malignant process.

ULTRASONOGRAPHIC MEASUREMENTS OF ADRENAL GLANDS IN CATS WITH HYPERTHYROIDISM

Feline hyperthyroidism is potentially associated with exaggerated responsiveness of the adrenal gland cortex. The adrenal glands of 23 hyperthyroid cats were examined ultrasonographically and compared to the adrenal glands of 30 control cats. Ten hyperthyroid cats had received antithyroid drugs until 2 weeks before sonography, the other 13 were untreated. There was no difference in adrenal gland shape between healthy and hyperthyroid cats: bean-shaped, well-defined, hypoechoic structures surrounded by a hyperechoic halo in 43/60 (71.6%) healthy cats and 34/46 (73.9%) hyperthyroid cats; more ovoid in 13/60 (21.6%) healthy cats and 9/46 (19.6%) hyperthyroid cats while more elongated in 4/60 (6.7%) healthy cats, 3/46 (6.5%) hyperthyroid cats. Hyperechoic foci were present in 9/23 (39.1%) hyperthyroid cats and 2/30 (6.7%) healthy cats. The adrenal glands were significantly larger in hyperthyroid cats, although there was overlap in size range. The mean difference between hyperthyroid cats and healthy cats was 1.6 and 1.7 mm in left and right adrenal gland length, 0.8 and 0.9 mm in left and right cranial adrenal gland height, and 0.4 and 0.9 mm in left and right caudal adrenal gland height. There was no significant difference between the adrenal gland measurements in treated and untreated hyperthyroid cats. The adrenomegaly was most likely associated with the hypersecretion of the adrenal cortex documented in hyperthyroid cats. Hyperthyroidism should be an alternative to hyperadrenocorticism, hyperaldosteronism, and acromegaly in cats with bilateral moderate adrenomegaly.

Identification of Continuity of Transected Nerve on Sonography After Neck Dissection: Direct Sign of Traumatic Neuroma

Traumatic neuroma can be confused with a metastatic lymph node after neck dissection for malignancy, thereby increasing patient anxiety and necessitating fine needle aspiration (FNA). To date, however, there have been no reports showing a direct ultrasonographic (US) sign of traumatic neuroma that could help distinguish it from a metastatic lymph node after neck dissection. Here, we describe a patient with traumatic neuroma who showed a direct US sign after total thyroidectomy with modified radical neck dissection (MRND). A 61-year-old man who had undergone total thyroidectomy with bilateral MRND for papillary thyroid carcinoma was found to have an oval-shaped nodule in his right lateral neck by US examination, which was first suspected of being a metastatic lymph node. However, when the position of the US transducer was changed to the oblique plane, a thin, cord-like, hypoechoic structure was found to be connected to the nodule. This structure passed between the longus capitis and scalenus medius muscles in an upward direction, and was ultimately located in the groove of the right transverse process of the C4 vertebra. Based on this anatomic relation, we concluded that the nodule was a traumatic neuroma and did not perform an unnecessary FNA. The detection of a mass in the line of the transected nerve may be a direct US indication of traumatic neuroma after neck dissection.

Ultrasound guided supraclavicular nerve blockade: first technical description and the relevance for shoulder surgery under regional anaesthesia

Ultrasound guided supraclavicular nerve blockade: first technical description and the relevance for shoulder surgery under regional anaesthesia

Multiple Granular Cell Tumors of the Ascending Colon: A Case Report and Review of the Literature

Purpose: Introduction: Granular cell tumor (GCT) is a very uncommon entity that rarely affects the GI tract. It is usually detected incidentally on routine colonoscopy in asymptomatic patients. Because of its morphological pattern and its submucosal location, it can often be mislabeled as a malignant lesion. Due to its low incidence no clear standards of therapy have been described. We report an unusual form of GCT of the ascending colon diagnosed and treated by endoscopic ultrasound (EUS) resulting ultimately in right hemicolectomy. Case: A 32 year-old woman presented with crampy abdominal pain, diarrhea and hemoccult positive stools. Initial colonoscopy revealed four firm submucosal nodules in the cecum and ascending colon. Chase biopsies reported nonspecific chronic mucosal inflammation without visualization of submucosal tissue. Due to the submucosal location of the masses a full workup for carcinoid was sent with negative results. A follow up colonoscopy six months later showed no changes in the submucosal nodules. Repeat biopsies with jumbo forceps were non-diagnostic. EUS revealed 5 well defined hypoechoic nodular structures in the right colon. Submucosal resection of the two smaller and most distal lesions was performed. The same evening, the patient is diagnosed with acute ruptured viscus. Exploratory laparotomy with right hemicolectomy was performed identifying perforation points at one of the mucosectomy sites. Pathology reports from EUS revealed a submucosal mass strongly positive for S-100 with no clear necrosis or mitotic activity clearly suggestive of GCT. Surgical pathology confirmed the same diagnosis. Discussion: GCT are rare and typically benign tumors. Schwan cells are currently the most acceptable derivation site. It might occur anywhere in the body with a GI incidence close to 1%. The most common site in the GI tract is the esophagus, followed by the stomach, colon and perianal region. With < than 2 cm in diameter, and frequently reported as solitary masses, GCTs are often diagnosed as incidental findings during routine endoscopy. Positive immunohistochemical markers such as S-100 and Neuron Specific Enolase strongly suggest the diagnosis. Rate of malignancy depends on tumor size (usually > 4 cm) and adjacent tissue spreading (muscularis propia). EUS is a very effective tool in evaluating submucosal lesions. Although endoscopic resection is the preferred treatment, surgery has also been considered for cases where malignant features are present. It is imperative for the gastroenterologist to include GCT in the differential diagnosis of submucosal tumors of the colon.

Sonographic Appearance of the Posterior Interosseous Nerve at the Wrist

The purpose of this study was to determine whether sonography can identify the distal posterior interosseous nerve at the wrist. On the basis of previous anatomic descriptions, high-resolution musculoskeletal sonography was used in an attempt to identify the distal posterior interosseous nerve in the wrists of 20 unembalmed cadaveric specimens (11 male and 9 female; ages 54-98 years). High-frequency scanning (17-5 MHz) of the fourth dorsal extensor compartment revealed a small (1-3 mm) hypoechoic structure located on the compartment floor, presumed to represent the posterior interosseous nerve. Electronic calipers measured the distance between Lister's tubercle and this structure, as well as the structure's radial-ulnar width and volar-dorsal height. The presumed posterior interosseous nerves of 10 specimens were then injected with diluted colored latex using sonographic guidance. Subsequent dissection definitively identified the sonographically visualized and injected structure. Dissection revealed latex within the posterior interosseous nerve in all 10 injected specimens, thus confirming that the sonographically visualized structure represented the distal posterior interosseous nerve. The nerve was identified sonographically in all 20 examined specimens, was located an average of 4.88 mm (range, 2.10-10.0 mm) ulnar to Lister's tubercle, and had an average width and height of 2.35 mm (range, 1.20-3.50 mm) and 1.01 mm (range, 0.80-1.40 mm), respectively. High-resolution sonography can reliably identify the distal posterior interosseous nerve within the fourth dorsal extensor compartment. Clinicians should consider formal evaluation of the posterior interosseous nerve in patients presenting with dorsal wrist pain syndromes. Future investigations should explore the potential role of sonographically guided percutaneous procedures directed at the posterior interosseous nerve.

US summit: neonatal spine – how to do it

Sonography of the spine is performed as a screening examination in neonates with cutaneous lesions associated with spinal cord abnormalities, such as deep sacral dimples, dorsal midline masses, hemangiomas, skin tags, hairy tufts, skin discoloration and sinus tracts; congenital anomalies with a high incidence of occult spinal dysraphism, including imperforate anus, caudal regression syndrome, cloacal malformation and cloacal exstrophy; vertebral body anomalies; and tumors located near the vertebral canal such as neuroblastoma, sacrococcygeal teratoma and presacral masses in patients with Currarino triad. Additional indications include assessment of hemorrhage following birth injury or lumbar puncture, and in the detection of epidural abscesses. Infants are usually examined in the prone position. A small bolster or pillow placed under the pelvis accentuates the lumbar lordosis and thereby aids in the sonographic delineation of the lumbosacral junction. If prone positioning is not possible, the study can also be performed with the infant lying on his or her side. A neonate who is fed immediately prior to or during the examination will usually lie quietly as scanning is performed. The neonatal spinal cord can be assessed with US due to a lack of ossification of the predominantly cartilaginous posterior arches of the spine. As the posterior spinal elements progressively ossify, the quality of the US images declines and, in most cases, is inadequate by 6 months of age. In patients with spinal dysraphism, however, the persisting acoustic window permits US scanning at any age. Most studies are limited to an evaluation of the lumbosacral spine, as, for example, in the investigation of a sacral dimple or to determine the presence of a hematoma after a traumatic or unsuccessful lumbar puncture. However, in selected patients, an examination of the entire spinal canal is performed, from the craniocervical junction to the coccyx. Scanning is generally accomplished with high-frequency linear-array transducers with images obtained in transverse and longitudinal planes. The craniocervical junction is best imaged with a smaller footprint sector transducer to permit optimal imaging through the foramen magnum. The normal neonatal spinal cord appears as a tubular, hypoechoic structure with hyperechoic walls. The central canal is hyperechoic, and the surrounding subarachnoid space is anechoic. The vertebral bodies located anterior to the spinal canal appear as discrete, echogenic structures. In the axial plane, the spinal cord is round or oval in shape. Echogenic dentate ligaments can be seen extending laterally from the spinal cord to attach to the arachnoid and dura mater. The cord gradually tapers at the level of the first or second lumbar vertebral body to form the conus medullaris. The fibrous filum terminale arises from the tip of the conus medullaris and extends into the sacral canal. The filum appears echogenic and is surrounded by the echogenic nerve roots of the cauda equina. A cystic structure is occasionally noted at the tip of the conus medullaris. This terminal ventricle, or filar cyst, is a normal developmental variant. The level of the conus medullaris must be determined in every patient. It usually lies above the level of the L2 vertebral body, although it can extend as low as the upper third of the L3 vertebral body. A low-lying cord can result from tethering and requires further evaluation with MRI. Determination of vertebral level can be accomplished in a Disclaimer Dr. Paltiel has no financial interests, investigational or offlabel uses to disclose.