Perfusion Patterns of Peripheral Organizing Pneumonia (POP) Using Contrast-Enhanced Ultrasound (CEUS) and Their Correlation with Immunohistochemically Detected Vascularization Patterns

Abstract

Purpose: To describe the perfusion patterns of peripheral organizing pneumonia (POP) by contrast-enhanced ultrasound (CEUS) and their correlation with vascularization patterns (VPs) represented by immunohistochemical CD34 endothelial staining. Methods: From October 2006 until December 2020, 38 consecutive patients with histologically confirmed POPs were standardized-examined by CEUS. The time to enhancement (TE; classified as an early pulmonary-arterial [PA] pattern of enhancement vs. delayed bronchial-arterial [BA] pattern of enhancement), the extent of enhancement (EE; classified as marked or reduced), the homogeneity of enhancement (HE; classified as homogeneous or inhomogeneous), and the decrease of enhancement (DE; classified as rapid washout [<120s] or late washout [≥120s]) were evaluated retrospectively. Furthermore, tissue samples from the study patients were immunohistochemically stained with CD34 antibody. The presence of avascular areas (AAs) and the VPs were evaluated in all tissue samples. Results: The majority of POPs showed a BA pattern of enhancement (71.1%), an isoechoic marked enhancement (76.3%), and an inhomogeneous enhancement (81.6%). A rapid DE was observed in 50.0% of cases. On CD34 staining, all POPs had a chaotic VP, indicating BA neoangiogenesis. AAs (abscess, necrosis, hemorrhage) were identified in (41.9%) cases with an inhomogeneous enhancement on CEUS. Conclusion: On CEUS, POPs predominantly revealed a marked inhomogeneous BA pattern of enhancement with a rapid washout in 50% of cases. Furthermore, we demonstrated that the presence of a PA pattern of enhancement, found in 28.9% of POPs, did not exclude a BA neoangiogenesis as an important feature of chronic inflammatory and malignant processes.

Peripheral Pulmonary Lesions in Confirmed Pulmonary Arterial Embolism

“…Pattern 2: An inhomogeneous enhancement within a single lesion, defined as a perfused PPL with coexisting peripheral pleural‐based nonperfused areas within the lesion 8–10,24,25 …”

B‐mode ultrasound and contrast‐enhanced ultrasound for evaluation of pneumonia: A pictorial essay

“…The patients frequently have immune suppression due to an underlying malignant disease or systemic inflammatory disease. However, the definitive diagnosis can be made only by histological confirmation 41 . Various underlying pathomechanisms may lead to radiation pneumonitis (Figure 19), aspiration pneumonitis (Figure 20), or obstructive pneumonitis (Figure 21).…”

“…On CEUS, chronic organising pneumonia 41 (Figure 25) and granulomatous inflammation (Figure 26) 40 may show a bronchial‐arterial pattern of enhancement with rapid washout similar to the pattern of malignancy and are considered to be pitfalls in the diagnosis of pneumonia. The definitive diagnosis is made histologically 40,41 . Another important obstacle to diagnosis is lepidic growth adenocarcinoma, which can mimic pneumonia clinically, on B‐mode LUS and on CEUS (Figure 27).…”

“…However, the definitive diagnosis can be made only by histological confirmation. 41 Various underlying pathomechanisms may lead to radiation pneumonitis (Figure 19 ), aspiration pneumonitis (Figure 20 ), or obstructive pneumonitis (Figure 21 ). The diagnosis can be made only based on the clinical background of the patient.…”

Diagnostic Performance of Point Shear Wave Elastography (pSWE) Using Acoustic Radiation Force Impulse (ARFI) Technology in Mesenteric Masses: A Feasibility Study

“…In addition, magnetic resonance imaging (MRI), positron emission tomography–computed tomography (PET-CT), and B-mode ultrasound (US) are used for evaluating MMs [ 2 , 3 , 9 , 10 ]. As a new trend in US imaging, contrast-enhanced ultrasound (CEUS) is used to assess perfusion patterns of various pathologies, including MMs [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Another new trend in US imaging is US elastography, which is a non-invasive tool for assessing tissue stiffness, with guidelines available for hepatic and non-hepatic applications [ 21 , 22 , 23 , 24 , 25 , 26 ].…”