Lung UlrasoundGamal Rabie Agmy ,MD ,FCCPProfessor of Chest Diseases, Assiut UniversityERS National Delegate of Egypt
Normal lung surfaceLeft panel: Pleural line and A line (real-time).The pleural line is located 0.5 cm below the rib line in the adult.Its visible length between two ribs in the longitudinal scan isapproximately 2 cm. The upper rib, pleural line, and lower rib (verticalarrows) outline a characteristicpattern called the bat sign.
• An obvious difference appears on either side of the pleuralline (arrow).• The motionless superficial layers generate horizontal lines.• Lung dynamics generate lung sliding (sandy pattern). Thispattern is called the seashore sign.Normal lung: M mode.
Interstitial syndrome.Lichtenstein D A , Mezière G A Chest 2008;134:117-125
Thoracic ultrasound examination is considered positive forinterstitial syndrome when at least two scans per side showmultiple B lines:in this case (cardiogenic pulmonary edema), positive scans are detected allover the anterolateral chest.
Am. J. Respir. Crit. Care Med.,Volume 156, Number 5, November1997, 1640-1646The Comet-tail ArtifactAn Ultrasound Sign of Alveolar-Interstitial Syndrome
Pneumonia• It is commonly visualized by TUS as ahypoechoic consolidated area of varying sizeand shape, with irregular borders.• The echotexture can appear homogeneous orinhomogeneous.• The most common sonographic feature ofpneumonia is the air bronchogram, which ischaracterized by lens-shape internal echoeswithin the hypodense area or echogenic linesand corresponds to air inclusions or air-filledbronchioles and bronchi.
PneumoniaPosterior intercostal scan shows a hypoechoicconsolidated area that contains multipleechogenic lines that represent an airbronchogram.
Pneumonia; fluid bronchogram• Conversely, the fluidbronchogram is characterizedby anechoic or hypoechoictubular structures in thebronchial tree.
Post-stenotic pneumoniaPosterior intercostal scan shows a hypoechoicconsolidated area that contains anechoic,branched tubular structures in the bronchial tree(fluid bronchogram).
Pleural effusion and alveolar consolidation; typical example of PLAPS.Lichtenstein D A , Mezière G A Chest 2008;134:117-125
Contrast-enhanced ultrasonographyof pneumoniaA: Baseline scan showsa hypoechoicconsolidated areaB: Seven seconds afteriv bolus of contrastagent, the lesion showsmarked andhomogeneousenhancementC: The lesion remainssubstantially unmodifiedafter 90 s.
Contrast-enhanced ultrasonography evaluation ofpneumonia with pleural effusion.Baseline scan shows parenchymalconsolidation with air bronchogram(arrows) and subtle surroundingeffusion (arrowheads)After iv bolus of contrast agent, theconsolidation is enhanced and betterdemarcated from the effusion
A 45-year-old patient presenting in the emergency department with cough, pleuritic pain anddyspnoea. Double-view chest x-ray showed no sign of pneumonia (A, B). A CT scan (C)confirmed the presence of a right basal consolidation shown by lung ultrasound (D).
Summarizing Sonographicfindings in pneumonia• • Liver like in the early stage• • Air bronchogram• • Lenticular air trappings• • Fluid bronchogram (poststenotic)• • Blurred and serrated margins• • Reverberation echos in the margin• • Hypoechoic abscess formation
Lung abscesses• They typically appear as round or oval, largelyanechoic lesions.• In the early stage, small abscesses are visible asa pathological collection of fluid irregularlysettled in a consolidated, liver-like infiltrate.• Depending on the capsule formation, the edgeof the abscess can be smooth and echodense.• Microabscesses are often visible as anechoicareas within the pneumonic consolidation.
Lung abscess at CEUS.A: An anechoic ovallesion is surroundedby an echodensecapsule;B: After iv bolus ofcontrast agent, thelesion shows nocontrast agent uptake,whereas the capsule isstrongly enhanced
Lung abscess with airinsidethe lesionA: High amplitude echoesare clearly visible (arrow), aswell as multiple echogenicsmall air inclusions(arrowheads);B: Corresponding computedtomography scan shows thesame findings
Pulmonary embolism (PE)• The sensitivity of TUS for PE has been estimated torange from 80% to 94%, the specificity from 84%and 92%, and the overall accuracy from 82% to91%.• Although CTPA is undoubtedly the method ofchoice to obtain a definitive diagnosis of PE, TUSshould be taken into consideration in somecircumstances, particularly in critically ill patientswho might not tolerate transport for other imagingmodalities, in cases of pregnancy, contrast agentallergy, or renal failure.
Dynamic course of pulmonary infarctionA: Lateral intercostalscan ofthe right lung shows a typicaltriangular-shapedperipherallesion;B: computed tomographyscanof the lateral segment of thelowerright lobe showsatriangularpleural-basedlesionwith the vertex towards thehilumC: After 40 d, the lesion is nolonger visible by computedtomography scan;D: The lesion appears reducedin size at transthoracicultrasonography examination.
Pulmonary embolism. A 1.2 – 1.5 mm triangular subpleurallung consolidation. B. Vascular sign at the margin, not central
•On color Doppler sonography,PE-based peripheral lesions donot show flow signals inside,a phenomenon defined as“consolidation with littleperfusion”
Contrast-enhancedultrasonographyofpulmonary infarctionAfter iv bolus ofcontrast agent, thelesion shows nocontrast agentuptake in thearterial phase,which suggeststhe absence ofblood supply.
Sonomorphology of peripheral pulmonaryembolism• Echopoor• Well demarcated• 1-3 (0.5-7) cm in size• Pleural based• Triangular > rounded• Central bronchial reflexion (> 3 cm)• Vascularization stop• 2.5 lesions/patient on average• 2/3 dorsobasal located• Small pleural effusion
Schematic representation of the parenchymal, pleural and vascularfeatures associated with pulmonary embolism.(Angelika Reissig, ClausKroegel. Respiration2003;70:441-452)
The Late sign of atelectasis:• The late sign appeared when the air inside theconsolidation was progressively absorbed, whichyielded a loss of volume of the lesion with thetypical static air bronchogram inside.• Pleural effusion is almost always associated withcompression atelectasis and frequently withobstructive atelectasis.• In the case of compression atelectasis, theeffusion is typically larger compared to thatassociated with obstructive atelectasis.
Relaxation atelectasissPosteriorintercostalscan showsa liver-like consolidation withthetypicalshapeof a jelly bag capsurrounded by pleuraleffusion.
Contrast-enhanced ultrasonographyevaluation of compression atelectasis.Baseline scan shows a liver-likeconsolidation surrounded bymultiloculated pleural effusionTwelvesecondsafter iv bolus of contrast agent,the consolidationshows marked andhomogeneousenhancement, whereas pleuraleffusion showsno enhancement.
Obstructive atelectasis• It shows a liver-like and inhomogeneousechotexture with secretion-filled bronchi (fluidbronchogram) and variable shape.• The real-time TUS visualization ofbronchograms during breathing movements canoften enable one to distinguish betweenobstructive atelectasis and pneumonia.• The presence of the dynamic air bronchogramindicates pneumonia, while a static airbronchogram suggests obstructive atelectasis.
Posterior intercostal scan shows a hypoechoic consolidatedarea that contains anechoic, branched tubular structures inthe bronchial tree (fluid bronchogram).
CEUS in Peripheral bronchialcarcinomas CEUS can help to define better necrotic areasthat are depicted as anechoic regions insidethe enhanced viable tumor. The infiltrative growth of solid tissue withoutregard to anatomical structures ischaracteristic of malignancy
Peripheral bronchial carcinoma.Posteriorintercostal scanshows ahypoechoicconsolidationwith relativelywell-delineatedborders. The airbronchogram isabsent.
Bronchial carcinoma infiltrating the pleural wall.A: Posterior intercostalscanshowsa hypoechoiclesionaccompaniedby rib destruction (arrows);B: Twenty-four secondsafter iv bolusof contrast agent, the lesionappearsinhomogeneouslyenhanced;thedisrupted rib appears moreechogenicthan the tumor(arrowheads), as a consequenceofthe incompletetissue suppressiondue to the strong echogenicityofbone tissue.
Contrast-enhanced ultrasonography ofbronchial carcinomaA: Baseline scan shows a hypoechoiclesion with irregular bordersTen seconds after iv bolus ofcontrast agent, the pulmonaryparenchyma near the lesion isalready enhanced (arrows),whereas the lesions is stillunenhancedB:Twenty seconds later, the lesionshows delayed inhomogeneousenhancement, which indicates apreferential bronchial arterial supply
Pulmonary metastasisPosterior intercostal scan shows a round-shaped, clear-bordered lesion.
Prof.Maha KGhanem,MD, FCCPLung cancer. A rounded, tumoral fringes,central echopoor necrotic lesion with Birregular neovasculaization
Sonomorphology of pulmonarycarcinomas• Hypoechoic, inhomogeneous• Rounded, polycyclic• Sharp, serrated margins• Ramifications and fringes• Infiltration of chest wall• Irregular vascularization