Sonography of the chest wall: A pictorial essay

Optimal techniques of ultrasound-guided superficial and deep parasternal intercostal plane blocks: a cadaveric study

INTRODUCTION

The optimal techniques of a parasternal intercostal plane (PIP) block to cover the T2-T6 intercostal nerves have not been elucidated. This pilot cadaveric study aims to determine the optimal injection techniques that achieve a consistent dye spread over the second to sixth intercostal spaces after both ultrasound-guided superficial and deep PIP blocks. We also investigated the presence of the transversus thoracis muscle at the first to sixth intercostal spaces and its sonographic identification agreement, as well as the location of the internal thoracic artery in relation to the lateral border of the sternum.

METHODS

Ultrasound-guided superficial or deep PIP blocks with single, double, or triple injections were applied in 24 hemithoraces (three hemithoraces per technique). A total volume of dye for all techniques was 20 mL. On dissection, dye distribution over the first to sixth intercostal spaces, the presence of the transversus thoracis muscle at each intercostal space and the distance of the internal thoracic artery from the lateral sternal border were recorded.

RESULTS

The transversus thoracis muscles were consistently found at the second to sixth intercostal spaces, and the agreement between sonographic identification and the presence of the transversus thoracis muscles was >80% at the second to fifth intercostal spaces. The internal thoracic artery is located medial to the halfway between the sternal border and costochondral junction along the second to sixth intercostal spaces. Dye spread following the superficial PIP block was more localized than the deep PIP block. For both approaches, the more numbers of injections rendered a wider dye distribution. The numbers of stained intercostal spaces after superficial block at the second, fourth, and fifth intercostal spaces, and deep block at the third and fifth intercostal spaces were 5.3±1.2 and 5.7±0.6 levels, respectively.

CONCLUSION

Triple injections at the second, fourth, and fifth intercostal spaces for the superficial approach and double injections at the third and fifth intercostal spaces for the deep approach were optimal techniques of the PIP blocks.

Ultrasonographic evaluation of costal cartilage for microtia reconstruction surgery

PURPOSE

Autogenous costal cartilage grafts have gained the golden standard method in microtia reconstruction. Right now, there was no useful method to assess the quality of costal cartilage before microtia reconstruction surgery. The purpose of this study was to evaluate the role of ultrasonography in assessing costal cartilage in patients who were ready to do microtia reconstruction surgery.

METHODS

A prospective controlled study was conducted to collect 65 patients who underwent microtia reconstruction and underwent ultrasonography of costal cartilage before operation. The results of costal cartilage calcification and honeycombed phenomenon measured by ultrasonography were compared with those during operation. The age-specific patterns in calcification and honeycombed phenomenon were explored.

RESULTS

According to the results of ultrasonography, the positive rate of calcification was 10.9% in patients under 18 years old, while 80% in patients over 18 years old. The positive rate of honeycombed phenomenon was 2.8% in patients under 12 years old, 42.9% in patients between 12 and 18 years old, and 25% in patients over 18 years old. Compared with intraoperative results, the accuracy rate of ultrasonography for calcification was 100%. The accuracy rate for honeycombed phenomenon was 83.3%.

CONCLUSION

Ultrasonography has high accuracy rate in assessing the calcification and honeycombed phenomenon of the costal cartilage, which was of vital importance for microtia reconstruction. The quality of costal cartilage changed with the age.

Chest Ultrasonography in Modern Day Extreme Settings: From Military Setting and Natural Disasters to Space Flights and Extreme Sports

Chest ultrasonography (CU) is a noninvasive imaging technique able to provide an immediate diagnosis of the underlying aetiology of acute respiratory failure and traumatic chest injuries. Given the great technologies, it is now possible to perform accurate CU in remote and adverse environments including the combat field, extreme sport settings, and environmental disasters, as well as during space missions. Today, the usage of CU in the extreme emergency setting is more likely to occur, as this technique proved to be a fast diagnostic tool to assist resuscitation manoeuvres and interventional procedures in many cases. A scientific literature review is presented here. This was based on a systematic search of published literature, on the following online databases: PubMed and Scopus. The following words were used: "chest sonography," " thoracic ultrasound," and "lung sonography," in different combinations with "extreme sport," "extreme environment," "wilderness," "catastrophe," and "extreme conditions." This manuscript reports the most relevant usages of CU in the extreme setting as well as technological improvements and current limitations. CU application in the extreme setting is further encouraged here.

Chest wall - a structure underestimated in ultrasonography. Part III: Neoplastic lesions

Chest wall neoplasms mainly include malignancies, metastatic in particular. Differential diagnosis should include clinical data; tumor location, extent, delineation; the degree of homogeneity; the presence of calcifications; the nature of bone destruction and the degree of vascularization. The aim of the paper is to present both the benefits and limitations of ultrasound for the diagnosis of chest wall neoplasms. The neoplastic process may be limited to the chest wall; it may spread from the chest wall into the intrathoracic structures or spread from the inside of the chest towards the chest wall. Benign tumors basically originate from vessels, nerves, bones, cartilage and soft tissues. In this paper, we briefly discuss malformations of blood and lymphatic vessels, glomus tumor as well as neurogenic tumors originating in the thoracic branches of the spinal nerves and the autonomic visceral system. Metastases, particularly lung, breast, kidney cancer, melanoma and prostate cancer, are predominant tumors of the osteocartilaginous structures of the chest wall. Plasma cell myeloma is also relatively common. The vast majority of these lesions are osteolytic, which is reflected in ultrasound as irregular cortical defects. Osteoblastic foci result only in irregular outline of the bone surface. Lipomas are the most common neoplasms of the chest wall soft tissue. Elastofibroma is another tumor with characteristic echostructure. Desmoid fibromatosis, which is considered to be a benign lesion with local aggressivity and recurrences after surgical resection, represents an interesting tumor form the clinical point of view. Ultrasonography represents an optimal tool for the monitoring of different biopsies of pathological lesions located in the chest wall. Based on our experiences and literature data, this method should be considered as a preliminary diagnosis of patients with chest wall tumors.

Chest wall - underappreciated structure in sonography. Part II: Non-cancerous lesions

The chest wall is a vast and complex structure, hence the wide range of pathological conditions that may affect it. The aim of this publication is to discuss the usefulness of ultrasound for the diagnosis of benign lesions involving the thoracic wall. The most commonly encountered conditions include sternal and costal injuries and thoracic lymphadenopathy. Ultrasound is very efficient in identifying the etiology of pain experienced in the anterior chest wall following CPR interventions. Both available literature and the authors' own experience prompt us to propose ultrasound evaluation as the first step in the diagnostic workup of chest trauma, as it permits far superior visualization of the examined structures compared with conventional radiography. Sonographic evaluation allows correct diagnosis in the case of various costal and chondral defects suspicious for cancer. It also facilitates diagnosis of such conditions as degenerative lesions, subluxation of sternoclavicular joints (SCJs) and inflammatory lesions of various etiology and location. US may be used as the diagnostic modality of choice in conditions following thoracoscopy or thoracotomy. It may also visualize the fairly common sternal wound infection, including bone inflammation. Slipping rib syndrome, relatively little known among clinicians, has also been discussed in the study. A whole gamut of benign lesions of thoracic soft tissues, such as enlarged lymph nodes, torn muscles, hematomas, abscesses, fissures, scars or foreign bodies, are all easily identified on ultrasound, just like in other superficially located organs.

Sonographic diagnosis of a radiographically occult displaced fracture of a costal cartilage

We report the case of a 22-year-old athlete who sustained a blunt thoracic trauma to the right chest causing a costal cartilage fracture. Plain radiographs revealed no abnormalities while sonographic (US) examination performed a week later because of persistent pain led to the diagnosis of a displaced fracture of the right tenth costal cartilage. A follow-up US examination confirmed the healing of the fracture and allowed the patient to return to competitive sport activity. We recommend the use of US in patients with persisting pain after thoracic trauma with negative plain radiographs of the ribs to rule out radiographically occult costal cartilage fractures. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:605-607, 2017.

Chest wall - underappreciated structure in sonography. Part I: Examination methodology and ultrasound anatomy

Chest wall ultrasound has been awarded little interest in the literature, with chest wall anatomy described only in limited extent. The objective of this study has been to discuss the methodology of chest wall ultrasound and the sonographic anatomy of the region to facilitate professional evaluation of this complex structure. The primarily used transducer is a 7–12 MHz linear one. A 3–5 MHz convex (curvilinear) transducer may also be helpful, especially in obese and very muscular patients. Doppler and panoramic imaging options are essential. The indications for chest wall ultrasound include localized pain or lesions found or suspected on imaging with other modalities (conventional radiography, CT, MR or scintigraphy). The investigated pathological condition should be scanned in at least two planes. Sometimes, evaluation during deep breathing permits identification of pathological mobility (e.g. in rib or sternum fractures, slipping rib syndrome). Several structures, closely associated with each other, need to be considered in the evaluation of the chest wall. The skin, which forms a hyperechoic covering, requires a high frequency transducer (20–45 MHz). The subcutaneous fat is characterized by clusters of hypoechoic lobules. Chest muscles have a very complex structure, but their appearance on ultrasound does not differ from the images of muscles located in other anatomical regions. As far as cartilaginous and bony structures of the chest are concerned, the differences in the anatomy of the ribs, sternum, scapula and sternoclavicular joints have been discussed. The rich vascular network which is only fragmentarily accessible for ultrasound assessment has been briefly discussed. A comprehensive evaluation of the chest wall should include the axillary, supraclavicular, apical and parasternal lymph nodes. Their examination requires the use of elastography and contrast-enhanced ultrasound.

Pediatric chest ultrasound: a practical approach

Chest ultrasonography is an important imaging adjunct for diagnosing and managing disease in children. Compared with CT and MRI, ultrasound is cheaper, portable and provides vascular or flow-related information that cannot otherwise be obtained noninvasively. The spatial and temporal resolution of ultrasound is excellent, particularly for superficial structures. In cases where a suspicious abnormality is found, tissue sampling can be performed percutaneously with US guidance. Ultrasound also excels at demonstrating and characterizing pleural fluid collections. As concerns about radiation exposure increase among laypersons and doctors alike, there is a compelling argument for making ultrasonography the initial imaging study of choice for many thoracic abnormalities in a child. In this review the authors discuss and illustrate the US findings of some of the more common chest complaints in children.

Imaging review of lipomatous musculoskeletal lesions

Lipomatous lesions are common musculoskeletal lesions that can arise within the soft tissues, bone, neurovascular structures, and synovium. The majority of these lesions are benign, and many of the benign lesions can be diagnosed by radiologic evaluation. However, radiologic differences between benign and malignant lipomatous lesions may be subtle and pathologic correlation is often needed. The use of sonography, computed tomography (CT), and magnetic resonance imaging (MRI) is useful not only in portraying fat within the lesion, but also for evaluating the presence and extent of soft tissue components. Lipomas make up most soft tissue lipomatous lesions, but careful evaluation must be performed to distinguish these lesions from a low-grade liposarcoma. In addition to the imaging appearance, the location of the lesion and the patient demographics can be utilized to help diagnose other soft tissue lipomatous lesions, such as elastofibroma dorsi, angiolipoma, lipoblastoma, and hibernoma. Osseous lipomatous lesions such as a parosteal lipoma and intraosseous lipoma occur less commonly as their soft tissue counterpart, but are also benign. Neurovascular and synovial lipomatous lesions are much rarer lesions but demonstrate more classic radiologic findings, particularly on MRI. A review of the clinical, radiologic, and pathologic characteristics of these lesions is presented.