The images on the left show the similarities between chronic eosinophilic pneumonia and organizing pneumonia. various lesions are of different ages). On the left a 47-year old female patient with a dry cough, slightly breathless and a normal blood analysis. The combination of interlobular and intralobular septal thickening represents the reticular pattern. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF. Also notice the hilar lymphadenopathy. Alveolar edema manifests as … Nakagawa H Scherlag BJ Patterson E Ikeda A Lockwood D Jackman WM. It is one of the best educational CD's ever made. Conglomerate masses in a perihilar location. Centrilobular emphysema: characterized by airspaces that have no perceptible wall, centrilobular artery seen as dot in the centre. Mosaic pattern with areas of ground-glass atenuation and areas of low attenuation. On the left a patient with a NSIP. The mean left ventricular ejection fraction was 53.2 ± 7.1%. Alveolar Sarcoidosis (2) interstitial pattern: one of several chest radiographic patterns associated with interstitial infiltration or thickening, including honeycomb pattern, miliary pattern, reticulonodular pattern, or septal lines. On the left two different patients with similarl HRCT findings. On the left a patient who was involved in a traffic accident and within hours developed ARDS. Patients with OP associated with collagen vascular diseases respond less well to therapy with steroids. Additional pleural fluid and lung metastases. On the left three different patients with lung cysts. Presence of thickening of the interlobular septa of the lungs as seen on a CT scan. Nagamoto Y Park JS Tanubudi D Ko YK Ban JE Kwak JJet al. Peribronchial thickening, also known as peribronchial cuffing, is a term used to describe a hazy radiologic appearance that results from excess fluid or mucus build-up, according to Radiopaedia.org. Note: edema can have a very unusual appearance and be distributed very patchy: some areas are filled with fluid as opposed to other areas in immediate vicinity which appear normal. Scroll through the images. Silicosis / Pneumoconiosis: predominantly centrilobular and subpleural nodules. Definition. This is caused by the fact that the proteinacious material, which is removed from the alveolar space by macrophages is transported to the interstitium and thus leads to thickening of septa. In our experience, this is the thickest area of the interatrial septum, and allows for clear visualization of measurements on cardiac CT images. The mean CFAE area (6.7 ± 13.6 mm2 vs. 30.8 ± 40.9 mm2 vs. 38.8 ± 52.4 mm2, P = 0.164) and CFAE area index (4.2 ± 9.3 vs. 16.2 ± 20.5 vs. 17.3 ± 21.8, P = 0.204) in RA were not significantly different among groups. There is a cavitating lesion and typical tree-in-bud appearance. Differential diagnosis of Organizing Pneumonia. Further large-scale, prospective studies will be required to define the pathophysiological role of the interatrial septum in atrial remodelling and clinical outcome after catheter ablation in persistent AF. Extra-pulmonary ARDS Cystic bronchiectasis: 'signet ring sign'. Radiofrequency ablation was delivered at a target temperature of 48°C and power in the range of 25–35 W (Stockert generator, Biosense Webster, Inc., Diamond Bar, CA, USA or IBI 1500T11, St. Jude Medical, Inc., MN, USA) using a 4 mm open irrigated-tip catheter (Thermocool, Biosense Webster, Inc., Diamond Bar, CA, USA or Cool Path Duo, St. Jude Medical, Inc., MN, USA). However, in most patients, interstitial thickening is not extensive. Multivariable analysis incorporating LA size and volume, CFAE area, CFAE area index, the presence of CFAEs in LA septal area, and IAST group was performed to evaluate the predictors of acute procedural failure during catheter ablation. We evaluated the association between interatrial septal thickness (IAST) with the extent of complex fractionated atrial electrograms (CFAEs) in the left atrium (LA) and acute procedural results in patients with persistent atrial fibrillation (AF). The differental diagnosis of the CT-images is basically the same as of the chest film. When IAST or CFAEs were measured, the physician was blinded to the results of each other. Chang SL Tuan TC Tai CT Lin YJ Lo LW Hu YFet al. On the left some diseases with a nodular pattern. Interstitial thickening is pathological thickening of the pulmonary interstitium and can be divided into: interlobular septal thickening intralobular septal thickening See also interlobular septa secondary pulmonary lobules HRCT terminology The micronodular changes may appear in a cluster pattern. NSIP is a very inhomogeneous group. On the left another patient with Lymphangitic Carcinomatosis. On the left another typical presentation of sarcoidosis with mediastinal lymphadenopathy and small nodules in a perilymphatic distribution along bronchovascular bundles and along fissures (yellow arrows). Cysts have bizarre shapes, they may coalesce and than become larger. It started as small noduli, which progressed over time to cavitating nodules. RB-ILD: seen in smokers, upper lobe predilection, usually associated with centrilobular emphysema. Lymphangitic Carcinomatosis results from hematogenous spread to the lung, with subsequent invasion of interstitium and lymphatics. Patients respond promptly to treatment with steroids. Notice how ill-defined these centrilobular nodules are. This represents a hematogenous dissemination of infection and may occur in association with either primary or postprimary disease. Silicosis and CWP occur in a specific patient group (construction workers, mining workers, workers exposed to sandblasting, glass blowing and pottery). American Journal of Roentgenology, Vol 173, 1617-1622, by Santiago E. Rossi, MD, Jeremy J. Erasmus, MD, H. Page McAdams, MD, Thomas A. Sporn, MD and Philip C. Goodman, MD. The idiopathic interstitial pneumonias (IIPs) comprise a heterogenous group of disorders. On the left a patient with rheumatoid arthritis and bilateral peripheral consolidations as a result of organizing pneumonia. All smokers have various degrees of respiratory bronchiolitis, but it is usually asymptomatic. It may present as organizing pneumonia, eosinophilic pneumonia, fibrosis, hypersensitivity pneumonitis or even as ARDS. transplant recipients and patients on chemotherapy. From left to right: Lymphangiomyomatosis, LIP and Langerhans cell histiocytosis. During a mean follow-up of 27.7 ± 8.2 months after a single ablation procedure, 29 patients (40.8%) maintained sinus rhythm without anti-arrhythmic drugs. Sarcoid granulomas frequently cause nodular or irregular thickening of the peribronchovascular interstitium. Scherr D Dalal D Cheema A Cheng A Henrikson CA Spragg Det al. The key findings in chronic hypersensitivity pneumonitis are: On the left a patient with chronic hypersensitivity pneumonitis. Interatrial septal thickness was measured at a single site 1 cm inferior to the fossa ovalis. Pulmonary interstitial high-resolution computed tomography abnormality. Asked him if should be concerned about lung cancer (grandmother died from it even though never smoked), and he said to wait till ct results. In turn, the degree of IAST may serve a predictive marker for the acute intraprocedural success of AF ablation. Differential diagnosis of Lymphangitic Carcinomatosis. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048). There is a mosaic pattern. These findings suggest that IAST can be a marker of atrial substrate and electrical remodelling of the LA in patients with persistent AF. Differential diagnosis of Silicosis / Pneumoconiosis. Acute interstitial pneumonia (AIP, earlier named Hamman Rich Pneumonitis) is a rare idiopathic lung disease characterized by diffuse alveolar damage with subsequent fibrosis. Patient is ventilated with PEEP (positive end expiratory pressure ) leading to a barotrauma of the lung parenchyma: there are multiple subpleural cysts and a bilateral pneumothorax. Patients with the lowest tertile of IAST group showed (A) significant higher rates of acute procedural success by means of AF termination, either converting to SR or AT during catheter ablation (87.5% vs. 73.9% vs. 62.5%) (P = 0.048) and (B) tendency of higher proportion of converting to sinus rhythm (P = 0.145). The CFAE area in the RA was not evaluated in all patients. On the left a chest film of a 19 year old patient with Langerhans cell histiocytosis. Periobronchial thickening is also associated with congestive heart failure, cystic fibrosis, lung cancer, pulmonary edema, Kawasaki disease, smoke inhalation and other conditions or illnesses. Special Thanks Note the absence of a lymphatic distribution pattern (peribronchovascular and along fissures), which would be suggestive of sarcoidosis. Interlobular septal thickening is commonly seen in patients with interstitial lung disease. When AF converted to AT, activation mapping and ablation for AT were performed until a sinus rhythm was restored. In both miliary TB and metastases the nodules have a random distribution. Miscellaneous processes that manifest septal thickening or simulate this feature. by Hansell DM. Note the difference in the density of the air within the bronchus and surrounding lungparenchyma (dark bronchus sign). A 12-lead surface electrocardiogram was performed at every visit. Smooth interlobular septal thickening is present when the septa are easily seen and appear thicker than normal, but otherwise have a normal appearance (Fig. The first chest film shows bilateral consolidations in the lower lobes (arrow), initially interpreted as infection. After double transseptal puncture, anticoagulation was started with unfractionated heparin, maintaining an activated clotting time between 300 and 350 s. We used 3D-mapping-guided geometry (NavX System, St. Jude Medical, Inc., St. Paul, MN, USA) for electroanatomical mapping in all patients. Solvent-dependent termination, size and stability in polyynes synthesized. Differential diagnosis of Hypersensitivity Pneumonitis. *P < 0.05, ‡P < 0.001. Initial infection with consolidation, adenopathy and pleural effusion.Secondary TB : Usually located in the apical segments of upper lobes with cavitation Endobronchial spread: May occur in both primary and secondary TB, when the infection is not contained.Hematogenous spread (miliary TB): May occur in both primary and secondary TB, when the infection is not contained. On the left radiological pathological correlation of Langerhans cell histiocytosis in respectively nodular stage and early and late cystic stage. Persistent AF was defined according to the HRS/EHRA/ECAS 2012 Consensus Statement on Catheter and Surgical Ablation of AF as AF with duration longer than 7 days or AF requiring electrical or pharmacological cardioversion to restore sinus rhythm.9. This study is the first to demonstrate a relationship between IAST and CFAEs of LA in AF. The history of this patient is suggestive for the diagnosis dermatomyositis. Emphysema, when it is severe, can mimick Langerhans cell histiosytosis. The appearance of sarcoidosis can howev… Chronic hypersensitivity pneumonitis The chest film on the left shows diffuse areas with nodular air space opacifications. In some of them the old names are used and in some the newer ones. Lymphangitic carcinomatosis with hilar adenopathy and thickening of the central bronchovascular interstitium. Prior work demonstrated that CFAEs were mostly observed in areas of slow conduction and/or at pivot points of wavelets turnaround at the end of functional block arcs. Irregular interlobular septal thickening is typically seen in fibrotic lung disease and is usually associated with thickening of the fine interstitial network within the secondary pulmonary lobule, the so-called intralobular septa. On CT studies, interstitial lung disease typically manifests as small nodules (1–5 mm) with a peribronchovascular distribution extending from the hilum to the periphery along with interlobular septal thickening . On the left a patient who is treated with cytotoxic drugs for a hematologic malignancy. Differentiation has to be made on the basis of clinical and laboratory findings. Respiratory bronchiolitis (RB), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and desquamative interstitial pneumonia (DIP) represent different degrees of severity of small airway and parenchymal reaction to cigarette smoke (8). This study demonstrates that IAST measured by cardiac CT is significantly associated with the extent of LA CFAEs and CFAE area index irrespective of LA size or body mass index in persistent AF patients. This is termed progressive primary tuberculosis. Why some people develop ARDS and others do not is unknown. Pulmonary Drug Toxicity: Radiologic and Pathologic Manifestations, Bilateral hilar lymphadenopath + pulmonary disease. Here another case of hypersensitivity pneumonitis. On the left a typical case of alveolar proteinosis with extensive thickening of interlobular and intra-lobular septa. CFAE, complex fractionated atrial electrogram; CT, computed tomography; IAST, interatrial septal thickness. The radiographic appearance of honeycombing comprises reticular densities caused by the thick walls of the cysts. Complex fractionated atrial electrograms of the RA were targeted if AF persisted after extensive LA ablation. Radiologically however these diseases cannot be clearly separated because of the overlap of CT findings. Pleural effusion due to pleuritic carcinomatosis ( > 50% of patients). A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Nademanee K McKenzie J Kosar E Schwab M Sunsaneewitayakul B Vasavakul Tet al. Extrapulmonary risk factors are sepsis, pancreatitis, multiple blood transfusions, trauma and the use of drugs such as heroin. CFAE, complex fractionated atrial electrogram; IAST, interatrial septal thickness; LA, left atrial. Amiodarone was discontinued at least 1 month before the ablation procedure. 4). There are areas of consolidation and extensive areas of ground-glass density with a crazy-paving appearance. Systemic symptoms such as fatigue, night sweats and weight loss are common. Ventricular tachycardia catheter ablation after repaired tetralogy of Fallot: how to overcome an electrical short circuit. In the dependent parts of the lung there is also some consolidation, so there is a gradient from front to back. Always look for small nodules along the fissures, because this is a very specific and typical sign of sarcoidosis. The findings in this patient are not as specific as in the former case, but this was also organizing pneumonia, but now related to collagen vascular disease. Drug-induced lung disease is a major source of iatrogenic lung injury. Alveolar proteinosis: sharply demarcated secondary lobeles with ground glass attenuation as opposed to secondary lobules with normal aeration, superimposed inter and intralobular septal thickening (crazy paving). The symptoms are often severe and last three months or more. It is usually easy to recognize the pattern of UIP on HRCT. Often with calcifications. Interlobular septal thickening on pulmonary HRCT. Miliary TB: random nodules of the same size. Bronchovascular bundle thickening was seen in 13 patients (30%), whereas ill-defined centrilobular GGO nodules were observed in five patients (12%). Hypersensitivity pneumonitis: ill defined centrilobular nodules. Epicardial adipose tissue can provoke chronic inflammation of the left atrium (LA), which may contribute to the genesis or perpetuation of atrial fibrillation (AF).1,2 We previously demonstrated that interatrial septal thickness (IAST) was significantly correlated with total epicardial adipose tissue and independently associated with structural remodelling of the LA in patients with persistent AF.3 Several reports have shown that atrial arrhythmias are related to thickening of IAST with fibrosis or fatty infiltration of the interatrial septum, either as a cause or as a result of the arrhythmia.4,5 Thinning of the IAST after conversion to sinus rhythm was demonstrated.6 Interestingly, complex fractionated atrial electrograms (CFAEs), which are targeted to modify the atrial substrate for AF during catheter ablation, are typically found on the interatrial septum of remodelled LA.7,8 Both IAST and CFAEs might independently reflect the extent of atrial substrate for the development and maintenance of AF; however, little is known about the association of IAST and CFAEs. Hypersensitivity pneumonitis (HP) is also known as extrinsic allergic alveolitis (EAA). The local Institutional Review Board approved this study and all patients provided written informed consent. Significance of Interlobular Septal Thickening. (B) Improved parenchymal changes with ongoing septal thickening 18 months following cessation of immunosuppression. Thickening of the interlobular septa can be smooth, nodular or irregular, with many entities able to cause more than one pattern. Detailed view of the left upper lobe. There is hilar and paratracheal adenopathy and no sign of pulmonary involvement. In a patient with a known malignancy lymphangitic carcinomatosis would be high in the differential diagnostic list. This could be the result of an idiopathic form of fibrosis like idiopathic pulmonary fibrosis and non-specific interstitial pneumonitis or fibrosis in chronic hypersensitivity pneumonitis and longstanding sarcoid. Similar clinical outcomes observed in our study may have resulted from relatively small population in each group and different monitoring methods. Pearson's correlation method was used to calculate the relationship between the IAST and the extent of CFAEs and CFAE index. It offers a wide variety of cases dealing with common HRCT patterns of disease, diffuse lung diseases and their significance, and clinical characteristics. However 5-10% of smokers have a clinically significant lung disease in association with RB, presenting with symptoms, lung function tests and auscultatory findings at clinical examination. The dominant pattern is ground glass opacification. The CFAE area in LA was not significantly correlated with LA size or volume (r = −0.073, P = 0.5453 and r = −0.140, P = 0.247, respectively). Park JH Pak HN Kim SK Jang JK Choi JI Lim HEet al. These electrograms were recorded with the ablation catheter in a stable position for at least 6 s (to avoid artefacts) using the 3D automated software of the NavX system.12 This area was coded in white and pink on the CFAE map. Nonspecific interstitial pneumonia cellular pattern. Usual Interstitial Pneumonitis (UIP) is a histologic diagnosis. Masses may cavitate due to ischemic necrosis. The presence of a few thickened interlobular septa can be seen in a wide variety of … The HRCT shows diffuse areas of ground-glass density in the lower lobes and some mosaic pattern as the sole abnormality. There is only one clue to the diagnosis and that is the presence of small nodules that can be identified in image 3, but these are difficult to see. This patient had a rash and muscle weakness. In 'HRCT part I : basic interpretation' the terminology is introduced and a practical approach is given for the interpretation of HRCT examinations. On the left a patient who developed ARSD as a result of pneumonia (i.e. Pulmonary interstitial high-resolution computed tomography abnormality. ARDS, Acute Interstitial Pneumonia. There are many causes of interlobular septal thickening, and this should be distinguished from intralobular septal thickening. Peripheral consolidations with upper lobe predominance (photo negative of pulmonary edema). Cavitation in TB RESULTS: Interlobular septal thickening was present in 56 (60%) of 94 patients with idiopathic bronchiectasis, excluding those with trivial septal thickening (34 of 94, 36%). Had CXR as originally thought had chest infection and 3 diff. Definition. Cysts are distributed diffusely throughout the lungs and upper and lower lobes are involved to a similar degree. It is characterized by non-caseating granulomas in multiple organs, that may resolve spontaneously or progress to fibrosis. Depending on filling with fluid or with tumor cells, septal thickening is irregular or smooth. Centrilobular and subpleural distribution, Irregular conglomerate masses, known as progressive massive fibrosis. Drug-induced organizing pneumonia is commonly caused by Bleomycin and Cyclophosphamide and other drugs like Methotrexate, Amiodarone, Nitrofurantoin and Penicillamine (9). Interlobular septal thickening, thickening of fissures and thickening of the peribronchovascular interstitium (bronchial cuffing). The most challenging differential diagnosis in this patient is centrilobular emphysema. The high right atrium (RA), low RA, and coronary sinus were mapped with a decapolar catheter (Bard Electrophysiology, Inc., Lowell, MA, USA) and steerable duo-decapolar catheter (St. Jude Medical, Inc., Minnetonka, MN, USA) inserted through the left femoral vein. The mean duration of AF before catheter ablation was 7.1 ± 5.5 years. On HRCT, numerous clearly visible septal lines usually indicates the presence of some interstitial abnormality. Consolidation in apical segments of upper lobes or superior segments of lower lobes. The patients were seen in an outpatient clinic at 1 week and 1, 3, 6, 9, and 12 months after the procedure and then every 6 months thereafter. The predominant finding is ground glass opacity (GGO). The findings are not specific for PCP, but in this clinical setting PCP is the most likely diagnosis. Lymphangitic Carcinomatosis is seen in carcinoma of the lung, breast, stomach, pancreas, prostate, cervix, thyroid and metastatic adenocarcinoma from an unknown primary.