Secondary Lobule
The top image (a) shows an anatomic drawing of a secondary lobule of the lung subtended by a lobular bronchiole (lb) and arteriole (pa). The interlobular septum contains the venule (red) lymphatic (yellow) and septum (maroon)
The anatomical specimen of the lung (b) shows normal intralobular parenchyma while image c shows the centrilobular arteriole (navy blue) and centrilobular bronchiole (teal) and interlobular venule (red) and lymphatics (yellow) The interlobular septum is slightly thickened
Ashley Davidoff TheCommonVein.net

Infection Inflammation

Disease Infection Inflammation

Allergic Bronchopulmonary Aspergillosis (ABPA) Bronchitis and Bronchiectasis 

ABPA and Small Airway Disease Right Lower Lobe 
54 year old female with history of asthma, bronchitis, bronchiectasis, ABPA 
Current CT scan  shows extensive  small airway disease in the right lower lobe, magnified in lower image with centrilobular nodules and thickened interlobular septa characterized by  ground glass micronodules.
Ashley Davidoff TheCommonVein.net

Allergic Bronchopulmonary Aspergillosis (ABPA) Bronchitis and Bronchiectasis 

CT scan Left Upper Lobe ABPA  – Tree in Bud  
60 year old male with history of asthma, allergic bronchopulmonary aspergillosis (ABPA)
CT scan shows left  upper lobe bronchiectasis  and soft tissue/fluid  impaction in the anterior segmental and subsegmental airways associated with tree in bud appearance (yellow arrowhead) and centrilobular nodules (red arrowhead) reminiscent of associated small airway disease
Ashley Davidoff TheCommonVein.net

TB

Micronodules Right Upper Lobe
68 year old female presented with malaise night sweats weight loss QuantiFeron gold positive, with a past history of treated TB in her native country as a child.  Axial CT images through the upper lobe shows a miliary pattern of disease affecting interlobular septa, centrilobular and tree in bud nodular patterns.  Bronchoscopy isolated Mycobacterium complex.  She was treated with good result
Ashley Davidoff MD TheCommonVein.net mycobacterium-complex-TB-68-008

Chronic Eosinophilic Pneumonia (CEP)

Acute Eosinophillic Pneumonia
Alveolar and Interalveolar Interstitial Infiltration with Eosinophils and Inflammatory Exudate – Ground Glass Changes
The ground glass changes are a combination of the cellular and exudative inflammatory response in the small airways, alveoli, interalveolar septa and interstitium, and thickened alveolar septum
The diagram shows the abnormal secondary lobule (a) The involved components include the small airways(b) alveoli and interalveolar interstitium (c) and the thickened interlobular septum (d) surrounding the secondary lobule due to an inflammatory process, cellular infiltrate and congestion of the venules and lymphatics in the septum.  An anatomic specimen of a secondary lobule from a patient with thickened interlobular septa and interstitial thickening is shown in image e, and is overlaid in red (f) . A magnified view of an axial  CT of the lungs in a patient with acute eosinophillic pneumonia shows thickened interlobular septa and centrilobular nodules (g) The inflammatory changes in the aforementioned structures result in an overall increase in density of the lung manifesting as ground glass changes (g) and overlaid in red (h) 
Ashley Davidoff MD The CommonVein.net  lungs-0762
Upper Lobe Peripheral Infiltrates Centrilobular Nodules, and Interlobular Septal Thickening
CT scan in the coronal performed 6 months ago at the time of clinical presentation shows upper lobe predominant peripheral infiltrates more prominent in the left upper lobe. Subsequent diagnosis by BAL of chronic eosinophilic pneumonia (CEP) was made
Ashley Davidoff TheCommonVein.net
Interlobular Septal Thickening Centrilobular Nodule and Consolidation
CT scan in the axial plane performed 6 months ago at the time of clinical presentation, shows upper lobe interlobular septal thickening, and peripheral consolidations which are findings characteristic of chronic eosinophilic pneumonia (CEP) in the appropriate clinical setting. Note of prominent centrilobular nodule likely reflects small airway involvement Subsequent diagnosis by BAL of chronic eosinophilic pneumonia (CEP) was made
Ashley Davidoff TheCommonVein.net
Upper Lobe Peripheral Infiltrates Centrilobular Nodules, and Interlobular Septal Thickening
CT scan in the coronal performed 6 months ago at the time of clinical presentation shows upper lobe predominant peripheral infiltrates more prominent in the left upper lobe. Subsequent diagnosis by BAL of chronic eosinophilic pneumonia (CEP) was made
Ashley Davidoff TheCommonVein.net

CHF

CT Moderate CHF with Cardiomegaly Kerley B Lines Bilateral Pleural Effusions
CT scan at the lung bases shows Kerley B Lines bilateral small pleural effusions, right greater than left. Diagnosis Moderate CHF
Ashley Davidoff TheCommonVein.net
50 year old female with diabetes, chronic renal failure with congestive heart failure.  CT in the coronal plane shows diffuse ground glass changes, thickening of the interlobular septa, and centrilobular nodules  
Ashley Davidoff MD TheCommonvein.net  50-007-CT

Pulmonary Venous Congestion and Thrombosis

Thrombosed Left Upper Pulmonary Vein and Secondary Hemorhage
26 year old male who presents with shortness of breath a few months following RFA ablation for atrial fibrillation.  Image a shows the left upper lobe thrombosed and the left lower vein contrast filled
  Image b (the lung windows) shows thickening of the interlobular septa and secondary lobules distended with material, porobably representing blood.
 
following male SOB s/p RFA ablation for atrial fibrillation lung pulmonary let upper lobe pulmonary vein thrombosed secondary lobule interlobular septa are thickened secondary lobule destroyed dx pulmonary vein thrombosis secondary to radiofrequency ablation therapy iatrogenic CTscan Courtesy Ashley Davidoff MD Scott Tsai MD key words
ground glass changes pulmonary infarction venous infarction
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