Tactile fremitus is normally found over the mainstem bronchi near the clavicles in the front or between the scapulae in the back. Produces a low-pitched, resonant note of high amplitude over normal gas-filled lungs. See this image and copyright information in PMC. Auscultate in a pattern as shown in the images below. Chest. The sounds heard during auscultation can be classified as breath sounds, created by air movement through the airways, and adventitious, or added sounds, which have multiple mechanisms of generation. Additional conditions, such as increased intra-abdominal pressure due to obesity, can further facilitate their onset. Those with comorbidities, skeletal deformity, acute or chronic respiratory illness were excluded. The normal distribution of data sets was tested with the Anderson-Darling test. Start near the apices and move down in a ladderlike pattern until below the level of the diaphragm is reached or breath sounds are no longer appreciated. Imaging of the diaphragm: anatomy and function. Am J Respir Crit Care Med. Take measurements at the end of deep inspiration and expiration. Nonpulmonary sounds must also be appreciated during auscultation of the chest. Observe two deep breaths. You are being redirected to Granata F, Gaeta M. Magnetic resonance imaging of the diaphragm: from normal to pathologic findings. Normal diaphragmatic excursion should be 35cm, but can be increased in well-conditioned persons to 78cm. Pulmonary Examination Findings of Common Disorders, Table 2. On quiet and deep inspiration both hemidiaphragms move downward as the anterior chest wall moves upward. Unable to load your collection due to an error, Unable to load your delegates due to an error. The crus atrophies with paralysis but not with eventration ( Fig. Careers. Ultrasonography recordings were . Bilateral eventration. 1994 Nov. 150(5 Pt 1):1291-7. 27(4):237-49. It is usually no more than 90 degrees, with the ribs inserted at approximately 45-degree angles. Auscultation should be performed with the diaphragm of the stethoscope applied directly to the skin, as clothing and other materials can dampen or distort perceived sounds. Coach the patient in taking in a slow deep breath with the mouth open and then letting it out without forcing it or pursing the lips. The available chest radiographs and the clinical findings were reviewed and correlated with the sonographic findings. Crepitus is the sensation of crackles under the fingertips during superficial palpation of the chest wall. Visual inspection can be used to appreciate the level of distress, use of accessory muscles, respiratory position, chest structure, respiratory pattern, and other clues outside of the chest. Areas of well-aerated lung will be resonant, or tympanic, to percussion. There is often a sharp transition and undercutting at the edges of an eventration ( Fig. Normal and abnormal diaphragmatic motion and diaphragmatic paralysis can be assessed with ultrasonography, which is often preferred for examination in children and young adults. [QxMD MEDLINE Link]. There may be upward (paradoxical) motion on deep or even quiet breathing, and the mediastinum usually shifts away from the side of paralysis during inspiration. 454 0 obj <>/Filter/FlateDecode/ID[]/Index[424 53]/Info 423 0 R/Length 136/Prev 997436/Root 425 0 R/Size 477/Type/XRef/W[1 3 1]>>stream This type of crackle is more often associated with pulmonary edema and asthma. With eventration, the entire contour of the hemidiaphragm is visible on lateral view, whereas with Morgagni hernia the contour is obscured by the hernia contents and surrounding mediastinal tissue. On the other hand, partial eventration is common; it may be acquired, and it usually affects patients older than 60 years, typically involving the anteromedial portion of the right hemidiaphragm. Asymmetry and diaphragmatic excursion can be assessed by placing one hand posteriorly on each hemithorax near the level of the diaphragm, palms facing anteriorly with thumbs touching at the midline. These vesicular sounds vary considerably from patient to patient; thus, it is important to compare one hemidiaphragm to another by listening in a symmetrical pattern, as shown in the image below. Normal diaphragmatic excursion should be 35 cm, but can be increased in well-conditioned persons to 78 cm. -, Houston JG, Fleet M, Cowan MD, McMillan NC. 8600 Rockville Pike 0 The diaphragm is composed of a central tendon and a peripheral muscular component, both provided of three major openings that allow the passage of vascular (caval and aortic hiatuses) and gastroenteric (esophageal hiatus) structures. Differential breathing patterns can give clues to diseases of multiple different organ systems as much as the respiratory system itself. This causes increased transmission of whispered words, called pectoriloquy. Differential Diagnoses of Crackles. . Left dominance is twice as common as right dominance and the mean left excursion is greater than the mean right excursion. ; Decreased tactile fremitus, because vibrations travel poorly through air filled spaces. [QxMD MEDLINE Link]. The sound is created by turbulent air flowing through a narrowed trachea or larynx and is loudest over the trachea. MRI has demonstrated to be particularly accurate in the detection and characterization of the fluid and solid components of the cysts [Figure 9].[15-17]. It is generally defined as a zoonotic infection caused by the incidental ingestion of the eggs of a small tapeworm parasite (Echinococcus granulosus), and the involvement of the diaphragm is of rare occurrence. Only 19 cases showed a right to left ratio of less than 50% (5 men and 14 women). 1986 Jul. [10], However, when positive, the US is usually followed by MRI for a more accurate assessment in terms of fetal lung volume, organ herniation, and neonatal survival prediction [Figure 2].[10]. As a result, weakness or paralysis with impaired excursion and cranial dislocation of the diaphragm can be detected, with consequent lung parenchyma atelectasis and respiratory distress. If both hemidiaphragms are elevated, but the thicknesses of the crura are preserved, bilateral paralysis is unlikely, and some cause of abdominal distension, such as mass, ascites, or excess fat, is more likely. PMC This determines the range of movement of the diaphragm. Diaphragmatic crural thickness in eventration and paralysis. Within the formers, the left hemidiaphragm has demonstrated to be the most vulnerable, due to the lack of liver protection and the inherent structural weakness. Fluoroscopic examination of the diaphragm ("sniff test") is very useful in diagnosing diaphragmatic paralysis. The aims of this study were to determine reference values for diaphragmatic excursion and thickness, as evaluated by sonography in healthy infants and children, and identify correlations between them and anthropometric measurements, age, and sex. (Chest wall motion may be attenuated compared to that on slow deep inspiration.) Pleural effusion the buildup of pleural fluid in the pleural cavity. The lung exam. This can occur in a pneumothorax, hemothorax, pleural effusion, or parenchymal consolidation, which includes the feeding airway. Would you like email updates of new search results? Adventitious sounds are the medical term for respiratory noises beyond that of normal breath sounds. Yang X, Sun H, Deng M, Chen Y, Li C, Yu P, Zhang R, Liu M, Dai H, Wang C. J Clin Med. Some of the more common causes of unilateral diaphragmatic paralysis are compression or invasion of the phrenic nerve by a neoplasm or iatrogenic injury during birth or open heart surgery. [1, 2]. Average diaphragmatic excursion was 2.5 cm between inspiratory and expiratory scans (2.7 cm in men, 2.3 cm in women; p = .5 . Differential Diagnoses of Crackles (Open Table in a new window). We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Excursion is usually one rib interspace or more. 5th Ed. Check us out on Facebook for DAILY FREE REVIEW QUESTIONS and updates! The ideal position for auscultation is to place the patient in a sitting position. Imaging of the diaphragm: anatomy and function. The B-mode was applied for diaphragmatic identification, and the M-mode was employed for the recording of the amplitude of diaphragm contraction during quiet breathing, deep breathing and sniffing. These cookies will be stored in your browser only with your consent. Note the hyper-resonance of the left lower anterior chest due to air filled stomach. Observe a second deep breath and at the end of the expiration, tell the patient to close the mouth and sniff. Clipboard, Search History, and several other advanced features are temporarily unavailable. [12,13], Nevertheless, additional sequences can be acquired in all three planes, allowing at the same time lesion characterization and surrounding body tissue evaluation [Figures 4-7 and Videos 2 and 3].[3,6]. Areas of increased vibration or fremitus correspond to areas of increased tissue density such as those caused by consolidation by pneumonia or malignancy. [8,14], Benign entities are usually asymptomatic unless their size leads to a mass-effect, generally with respiratory impairment. Lloyd T, Tang YM, Benson MD, King S. Diaphragmatic paralysis: The use of M mode ultrasound for diagnosis in adults. Measurement of diaphragmatic motion by ultrasound is being utilized in different aspects of clinical practice. New York: Elsevier; 2010. To assess for tactile fremitus, ask the patient to say 99 or blue moon. Bronchophony:Ask the patient to say 99 in a normal voice. This sound is characterized by crackles synchronous with cardiac contraction, and not with respiration. On the other hand, conventional fluoroscopy, ultrasound (US), and magnetic resonance (MR) are able to overcome the mere morphologic assessment, extending the evaluation to the diaphragmatic functionality, through a real-time appraisal.[3-5]. Normal areas of tympany overlie the gastric bubble, often obscuring the dullness induced by the spleen. In some cases, a collapsed lung is caused by air blisters (blebs) that break open, sending air into the space around the lung. Place the palms of both your hands over the lower thorax, with your thumbs adjacent to the spine and your fingers stretched laterally. The diaphragm is seen as a thick, Visualization and measurement of right diaphragmatic excursion by M-mode ultrasound. Normally, fremitus is most prominent between the scapulae and around the sternum. This measures the contraction of the diaphragm. Eventration is usually asymptomatic but may become symptomatic if the eventration is large or the patient is obese because obesity can raise intraabdominal pressure and further compromise diaphragmatic function. While the patient is speaking, palpate the chest from one side to the other. Left dominance is twice as common as right dominance and the mean left excursion is greater than the mean right excursion. Congenital diaphragmatic hernias are determined by an incomplete fusion of the pleuroperitoneal membranes and/or the embryologic mesodermal elements of the diaphragm. Among all, magnetic resonance imaging (MRI) has demonstrated to be the most accurate technique in providing a morphologic and functional assessment of the diaphragm as well as information about the adjacent structures. 1995 Sep. 8(9):1584-93. On lateral view excursion is usually greater posteriorly, particularly on the right; it may be slightly asymmetric, and the right side may lag, particularly anteriorly. Chest. the diaphragm relaxes during expiration: moves upwards; both hemidiaphragms move together; in healthy patients 1-2.5 cm of excursion is normal in quiet breathing 2; 3.6-9.2 cm of excursion is normal in deep breathing 2; up to 9 cm can be seen in young or athletic individuals in deep inspiration 2; excursion in women is slightly less than men 2 During the pulmonary examination, inspection is a useful tool for the physician from which much information can be garnered. 8(2):265-72. Also, there is often 1 to 2cm upward displacement of the resting position of the hemidiaphragms. Analytical cookies are used to understand how visitors interact with the website. On pathologic examination a totally eventrated hemidiaphragm consists of a thin membranous sheet attached peripherally to normal muscle at points of origin from the rib cage. Repeat on the other side, is usually higher up on the right side. Lung sound nomenclature. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. In well-conditioned clients, excursion can measure up to. A thorough fluoroscopic examination includes watching the hemidiaphragms in both frontal and lateral projections with the patient upright and often also supine, particularly if the patient complains of dyspnea when lying down or is suspected to have bilateral paralysis. Safai Zadeh E, Grg C, Prosch H, Horn R, Jenssen C, Dietrich CF. Rales or crackles, abnormal sounds heard over the lungs with a stethoscope. The thorax and cardiovascular system. For the rest of this chapter we will use eventration to mean partial eventration . Beyond the morphologic and structural assessment, the use of dynamic gradient echo recalled acquisitions for the evaluation of diaphragmatic excursion has been longstanding established. Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with SunAgri and INRAE in Avignon between 2019 and 2022. If it is less than 35cm the patient may have a pneumonia or a pneumothorax in which a chest x-ray is diagnostic for either.[1]. Dullness noted to the left of the ster-num between the third and fifth intercostal spaces is a normal finding because it is the location of the heart. This measures the contraction of the diaphragm. If a patient is to remain recumbent, roll the patient from one side to the other to examine the back. At ultrasonography the diaphragm appears as a thick echogenic line. The site is secure. B. Normal: The lung is filled with air (99% of lung is air). M-mode sonography of diaphragmatic motion: Description of technique and experience in 278 pediatric patients. Due to the wider availability, CT-scan is generally the first- line imaging study, especially in emergency situations, while the US represents a staple approach for a functional assessment. The patient can be asked to temporarily cease respiration to appreciate this difference. Even decubitus positioning can be used if clinically relevant. The author shows that unequal excursion of the two leaves of the diaphragm is a normal finding. Documentation of a basic, normal respiratory exam should look something along the lines of the following: The chest wall is symmetric, without deformity, and is atraumatic in appearance. An official website of the United States government. In normal individuals, both . -, Li G, Wei J, Huang H, Gaebler CP, Yuan A, Deasy JO. [6], Normally the diaphragm looks like a thin band with low signal intensity on both the T1-w and T2-w images.[3]. Cugell DW. If the paralysis is on the left, the stomach and splenic flexure of the colon relate to the inferior surface of the hemidiaphragm and usually contain more gas than normal. The diaphragm is a dome-shaped musculotendinous structure placed between the thorax and the abdominal cavity. Temporary or permanent, unilateral or bilateral diaphragmatic functional deficiencies can arise at three levels: The nervous system, the muscle, or the neuromuscular junction. One dog with bilateral diaphragmatic paralysis showed paradoxical movement of both crura at the end of inspiration. The diagnosis of paralysis requires observing quiet and deep inspiration. government site. 78.5 ). Backward, its relaxation increases the thoracic pressure enabling expiration. However, when a consolidation is present, this aeration and attenuation is reduced. The normal breathing rate is 10-14 breaths per minute, with an approximate 1:3 ratio of inspiration to expiration. Early inspiratory crackles occur immediately after initiation of inspiration and are more often associated with interstitial lung disease. Table 2. Scott G, Presswood EJ, Makubate B, Cross F. Lung sounds: how doctors draw crackles and wheeze. endstream endobj startxref [1,6], Innervation is provided by the phrenic nerves, originating from nerve roots C3C5. Learn how and when to remove this template message, "Diaphragmatic Excursion-Posterior Lungs", https://en.wikipedia.org/w/index.php?title=Diaphragmatic_excursion&oldid=973014894, Articles needing additional references from January 2014, All articles needing additional references, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 14 August 2020, at 22:53. Physical examination of the adult patient with respiratory diseases: inspection and palpation. Normally the right dome of the diaphragm is higher in position as compared to the left dome, if the left dome of the diaphragm is elevated (>2 cm) diaphragmatic palsy should be suspected. From this site, the infection can easily diffuse into the thorax, involving mediastinum, pleura, and lung parenchyma with the formation of a bronchial fistula. Collapsed lung can be caused by an injury to the lung. Diminished chest movement occurs with barrel chest, restrictive disease, and neuromuscular disease. These crackles are softer, and higher in pitch, while coarse crackles are louder and lower in pitch. Axial CT (A) near level of celiac artery and coronal reformat (B) in a patient with elevation of the left hemidiaphragm by large eventration show normal thickness of the right crus, Key Points: Abnormalities of Diaphragmatic Motion, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), Lymphangioleiomyomatosis and Tuberous Sclerosis, Occasional transient upward motion of right anterior hemidiaphragm during strong sniffing, Weakness more evident on rapid deep inspiration with weak hemidiaphragm lagging behind normal side, Adjacent basal atelectasis; ipsilateral crus thinning on CT, Absent downward motion or bilateral upward motion, Adjacent basal atelectasis; supine imaging necessary to show absent motion; bilateral crus thinning on CT, Reduced downward motion of affected segment; occasional upward motion. It affects men and women with equal frequency. The lateral view also shows the anterior and upward movement of the chest wall on inspiration. [7] Late inspiratory crackles begin in the first half of inspiration and continue until the end of inspiration. . Nazir A Lone, MD, MBBS, MPH, FACP, FCCP Physician in Pulmonary and Critical Care Medicine, Peconic Bay Medical Center, Northwell Health studies are probably needed to determine whether there is any correlation between the patient's age and the range of normal diaphragmatic excursion. Thus, they are caused by pathology leading to the narrowing of bronchi, most commonly COPD, asthma, and bronchitis. Necessary cookies are absolutely essential for the website to function properly. Imaging of the diaphragm: anatomy and function. This should be performed over the anterior and posterior chest. Please confirm that you would like to log out of Medscape. You can help Wikipedia by expanding it. Most patients eventually develop respiratory failure. Fluoroscopy. The lung adjacent to a paralyzed hemidiaphragm often has subsegmental atelectasis resulting from elevation and reduced motion. [1, 2]. There is great variability depending on the intensity and pitch of the voice and the structure and thickness of the chest wall. They are often characterized by secretions within the large airways and can be heard in a wide variety of pathologies, any of which cause increased secretions, such as in cystic fibrosis, pneumonia, bronchitis, pulmonary edema, or emphysema. The diaphragmatic excursion was higher in males than females. Background: Diaphragmatic excursion during spontaneous ventilation (SV) in normal supine volunteers is greatest in the dependent regions (bottom). Therefore, radiologists and physicians should be aware of the diagnostic possibilities of this safe and valuable technique and confident with the images achievable. Again, because upward (paradoxical) motion on sniffing could reflect weakness, eventration, or paralysis, the fluoroscopic diagnosis of hemidiaphragmatic paralysis is not based on sniffing but instead on the absence of downward motion on slow, deep inspiration. Tactile fremitus increases with pneumonia or pulmonary edema and decreases in pleural effusion or lung hyperinflation. There may even be transient upward (paradoxical) motion, particularly of the right anterior hemidiaphragm. Conclusions: In eventration the diaphragm, although thin, remains visible as a continuous layer over the elevated abdominal viscera and retroperitoneal or omental fat. M-mode ultrasound is used to measure diaphragmatic motion, and interpretation is similar to that used in fluoroscopy. Tension pneumothorax is accumulation of air in the pleural space under pressure, compressing the lungs and decreasing venous return to the heart. These cookies do not store any personal information. The use of accessory muscles can also indicate increased work of breathing and should be noted on initial assessment. However, abnormal breath sounds may include: rhonchi (a low-pitched breath sound) crackles (a high-pitched breath sound). [8], On the other hand, rhabdomyosarcoma and leiomyosarcoma are the most frequent cancers, both characterized by poor prognosis. A real-time imaging of diaphragmatic function can be performed through fluoroscopy, US, and MRI during normal respiration, deep breathing, or sniffing. Maximum diaphragm excursion and slopes during inspiration and expiration . American Association for Bronchology and Interventional Pulmonology, International Association for the Study of Lung Cancer, American College of Critical Care Medicine, Association of Pulmonary and Critical Care Medicine Program Directors, World Association for Bronchology and Interventional Pulmonology. Haisam Abid, MBBS is a member of the following medical societies: Pakistan Medical and Dental CouncilDisclosure: Nothing to disclose. Diagnostics (Basel). The authors certify that they have obtained all appropriate patient consent forms. Decreased diaphragmatic excursion, prolonged expiration are common to all of the chronic obstructive lung diseases. 1987 Oct. 136(4):1016. Turn the patient back into the frontal position. Bilateral paralysis occurs occasionally after cardioplegia for cardiac surgery; this form is usually reversible with time. Patients with bilateral diaphragmatic paralysis or weakness usually have severe respiratory symptoms, mainly dyspnea and orthopnea, sometimes with a sense of suffocation when supine or when immersed in water. The pulmonary exam is one of the most important and often practiced exam by clinicians. The transmitted sounds will be louder over the area of consolidation. The sounds may occur continuously or intermittently and can include crackles, rhonchi, and wheezes. On supine position there may be excess elevation of the resting position of the hemidiaphragm. Nath AR, Capel LH. The position a patient assumes during respiration may also lend clues to a diagnosis. Maximal excursion of the diaphragm may be as much as 8 to 10 cm . On supine views there is excess elevation of the resting positions of both hemidiaphragms. 2009 Feb;135(2):391-400. doi: 10.1378/chest.08-1541. This site needs JavaScript to work properly. This is commonly a medical emergency and should be recognized early. Postgrad Med J. However, US limitations consist in the restricted field of view, the possible impairment of lung air or bowel gas superimposition, and the strictly reliance on the operators expertise. Share cases and questions with Physicians on Medscape consult. On lateral view excursion is usually greater posteriorly, particularly on the right; it may be slightly asymmetric, and the right side may lag, particularly anteriorly. The patients level of distress should be immediately assessed, as those in severe distress may be experiencing impending respiratory failure that requires intubation. Murray and Nadel's Textbook of Respiratory Medicine. Turn the patient into the lateral position, with arms out of the field of view. and transmitted securely. Whispered pectoriloquy can be elicited by having the patient whisper a repeated phrase (typically ninety nine). HHS Vulnerability Disclosure, Help Pulmonary Examination Findings of Common Disorders (Open Table in a new window). References: [3 . Bilateral hemidiaphragmatic weakness can also occur after prolonged mechanical ventilation and may signal that the patient cannot be weaned from the ventilator. Hemidiaphragmatic weakness often becomes more obvious on rapid, deep inspiration, with the weak hemidiaphragm lagging behind the normal side. Compared to 82 abnormal hemidiaphragms, 76 had abnormal sonographic findings (size < 2mm or decreased thickening with inspiration); compared to 49 normal hemidiaphragms, there were no false-positive ultrasound findings. -, Gierada DS, Curtin JJ, Erickson SJ, Prost RW, Strandt JA, Goodman LR. Kussmaul breathing is a rapid, large-volume breathing caused by acidotic stimulation of the respiratory center; it can indicate metabolic acidosis. Excursion should be equally bilaterally and measure 3-5 cm in. This should occur symmetrically between the two hemithoraces so that sounds may be compared between sides. [4], In particular, the latter considerations are particularly important in the challenging differential diagnosis of lung diseases from diaphragm weakness in patients suffering from respiratory failure.[6]. On supine and semisupine views this mechanism is defeated, and excursion of the hemidiaphragms is severely reduced. Because sound is transmitted more strongly through nonair-filled lung, increased fremitus suggests a loss or decrease in ventilation in the underlying lung. Any lung or pleural disease can give rise to a decrease in overall chest expansion. Diaphragm excursion are greater in men than in women [43, 45, 46, 49]. Again observe two deep breaths, then two quiet breaths, and note the resting positions of both hemidiaphragms at end expiration. The correct diagnosis of diaphragmatic pathologies can be challenging, especially in the context of an accurate differentiation from respiratory diseases. [QxMD MEDLINE Link]. Accessibility [4], Palpation is the tactile examination of the chest from which can be elicited tenderness, asymmetry, diaphragmatic excursion, crepitus, and vocal fremitus. Though the lung is collapsed, a large amount of air is trapped in the pleural space. Computed tomography (CT)-scan can provide morphological but not functional information about the diaphragm. Normal breath sounds are classified as tracheal, bronchial, bronchovesicular, and vesicular sounds. Schraufnagel DE, Murray JF. The supine view is needed to reveal bilateral hemidiaphragmatic paralysis when the apparently normal diaphragm excursion on upright views is actually passive movement from use of the abdominal muscles. hb```GD@ 9.D0(f87/hS /Pfo"FS/'h7(-=r%Dg9QPbwP4"X$A)i1cbe|aO02p Vs8ipk0{BU}0 = f The level of the diaphragm may be higher on the right. Phrenic nerve stimulation may benefit patients with intact phrenic nerve function and absence of myopathy, such as those with high cervical spine injuries causing bilateral hemidiaphragmatic paralysis. 9th ed. Mason RJ, Broaddus VC, Martin TR, et al, eds. (https://www.facebook.com/medschoolmadeeasy) Check out our website for TONS OF FREE REV. [5, 6, 12], Stridor is a loud, rough, continuous, high-pitched sound that is pronounced during inspiration; it indicates proximal airway obstruction. [1, 2]. Cystic echinococcosis (or hydatid disease) is considered a separate chapter in the field of cystic lesions. The patterns of normal breath sounds are created by the effect of body structures on air moving through airways. The diaphragmatic excursion was higher in males than females. The main role of CT in patients with eventration is in distinguishing the abnormality from a focal bulge along the diaphragm that might represent hernia or even tumor. According to this study normal range of chest expansion was(2-5 cm) (mean=3.35cm,SD=0.685) for females and (2 5.5cm)(mean=3.38 cm, SD=0.734) for males where the best result was in athletics. csgo post match titles list, creed rise to glory promo code oculus quest,
Difference Between Buckingham Palace And Windsor Castle, Gamot Sa Butlig Na May Tubig, Recent Arrests In Waycross, Ga, Jill Myfm Divorce, Freight Class Codes Chart, Articles D
diaphragmatic excursion normal findings 2023