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Friday, 22 April 2011

Influenza A - H1N1


  • Influenza A - causes influenza in birds.
  • Single stranded RNA virus
  • Subtypes labeled according to hemaglutinin (H1-16), and neuraminidase (N1-9) present on the surface envelope of the virus
Some overviews of studies related to radiologic findings in influenza A and H1N1 patients:

8 patients evaluated
A rapidly progressive pneumonia with high mortality rate was observed especially for cases with late admission. The major radiologic abnormalities were extensive pneumonic infiltration with segmental and multifocal distribution, mostly located in lower zones of the lung. No pleural effusion and hilar lymphadenopathy was noted.

RSNA: H1N1: Initial Chest Radiographic Findings in Helping Predict Patient Outcome
179 H1N1 influenza patients, 39 had findings related to influenza, Characteristic imaging findings included the following: ground-glass (69%), consolidation (59%), frequently patchy (41%), and nodular (28%) opacities. Bilateral opacities were common (62%), with involvement of multiple lung zones (72%). Findings in four or more zones and bilateral peripheral distribution occurred with significantly higher frequency in patients with adverse outcomes compared with patients with good outcomes.
Extensive involvement of both lungs, evidenced by the presence of multizonal and bilateral peripheral opacities, is associated with adverse prognosis. Initial chest radiography may have significance in helping predict clinical outcome but normal initial radiographs cannot exclude adverse outcome.

Previous studies have reported chest radiographic findings of consolidation and ground-glass opacity in patients with swine-origin influenza A (H1N1). Results Of 159 H1N1 influenza patients, The predominant radiographic findings were consolidation (93% of all patients, 91% of adults and 100% of children) and ground- glass opacity (74% of all, 77% of adults and 57% of children). Pulmonary emboli were detected by CT in 2/9 (22%) patients. Conclusion The pandemic 2009 swine influenza causes common and widely distributed infiltrates on chest radiographs among hospitalized patients, which are not peculiar to usual respiratory viral infections, and these findings can not be differentiated from usual bacterial pneumonia.

PubMed - a literature review:
Novel influenza A (H1N1) at the origin of the 2009 pandemic flu developed mainly in subjects of less than 65 years contrary to the seasonal influenza, which usually developed in elderly patients of more than 65 years. Influenza A(H1N1) can arise in serious forms within 60 to 80% of cases a fulminant acute respiratory distress syndrome (ARDS) "malignant and fulminant influenza" in subjects without any comorbidity, which makes the gravity and the fear of this influenza. The fact that this influenza A (H1N1) can develop in healthy young patients and evolve in few hours to a severe ARDS with a refractory hypoxemia gave to the foreground the possible interest of the recourse to extracorporeal oxygenation (ECMO) in some selected severe ARDS (5- 10%). A bacterial pneumonia was associated to H1N1 influenza in approximately 30% of the cases as at admission in ICU or following the days of the admission justifying an early antibiotherapy associated to the antiviral treatment by oseltamivir (Tamiflu). Obesity, pregnancy and respiratory diseases (asthma, COPD) seem to be associated to the development of a severe viral pneumonia due to influenza A (H1N1) often with ARDS. Older age, high APACHE II and SOFA scores and a delay of initiation of the antiviral treatment by oseltamivir are associated to higher morbidity and mortality.


(Text sources:, PubMed, RSNA, EJR )
(Images: )

Questions remain unanswered:
- What are the age groups at risk?
-What are the typical CXR, CT features?
- What are the dynamics of CXR, CT features?
- Frequently associated comorbidities?
- When should the Radiologist start thinking of H1N1?

Radiographic swallowing, barium enema studies

Traction type diverticulum at the level of the hilum.


Lower third esophageal stenosis with a pre-stenotic dilation, the foamy esophageal content is an indication of achalasia.


Epiphrenic diverticulum.

Diverticulosis sigmae


(Images: Pecs University Department of Radiology)

Tuesday, 19 April 2011

Chest x-ray & the CT follow ups:

Crazy paving pattern:
(pulmonary hemorrhage)

It consists of scattered or diffuse ground-glass attenuation with superimposed interlobular septal thickening and intralobular lines. This finding has a variety of causes, including infectious, neoplastic, idiopathic, inhalational, and sanguineous disorders. Specific disorders that can cause the crazy-paving pattern include Pneumocystis carinii pneumonia, mucinous bronchioloalveolar carcinoma, pulmonary alveolar proteinosis, sarcoidosis, nonspecific interstitial pneumonia, organizing pneumonia, exogenous lipoid pneumonia, adult respiratory distress syndrome, and pulmonary hemorrhage syndromes.



Round Atelectasis

Round atelectasis (also known as folded lung or Blesovsky syndrome) is an unusual type of atelectasis where there is infolding of a redundant pleura . The way the lung collapses can at times give a false mass like appearance.

It can be seen association with

HRCT : Chest
  • almost always seen adjacent to a pleural surface
  • comet tail sign 2 : produced by the pulling of bronchovascular bundles giving the shape of a comet tail




  • Lymphadenopathy, (80%) most common finding – bilateral hilar/paratracheal
    Usually not visible at 2 years; may persist for many years
    Nodes may calcify, sometimes eggshell calcification
  • Lung disease, (<50%), often manifest with nodal regression
  • Pattern and Distribution:
    • Reticulonodular opacities (90%)
    • Large airspace nodules with air bronchograms
    • Fibrosis mid and upper lung zones
    • Upper lobe cyst formation with aspergilloma

Stage 0 – clear chest radiograph (5 – 15%, at presentation)

Stage 1 – lymphadenopathy (45 – 65%); 60% resolve completely

Stage 2 – lymphadenopathy and lung opacities (30 – 40%)

Stage 3 – Lung opacities (10 – 15%)

Stage 4 – fibrosis with or without lymphadenopathy (5 – 25%)

  • Atypical appearance
    • Atypical lymphadenopathy - unilateral hilar, posterior mediastinal
    • Airway compression
    • Unilateral lung disease
    • Cavitary lung lesions
    • Pleural effusion

CT may show lymphadenopathy at left paratracheal, AP window, anterior mediastinum, retroperitonealHRCT, may be abnormal with normal CXR.

Predominantly involves the mid and upper lung zones

Pattern: 1 – 5 mm centrilobular nodules along brochovascular structures, septa, and periphery of lobuleOften extends in a swath from the hilum to lung periphery Ground glass opacities
Progressive massive fibrosis, distortion, honeycombing, cysts, bullae, traction bronchiectasis
Mycetomas in cavities and cystsLarge and small airway stenoses

Differential Diagnosis:
Granulomatous diseases : TB, fungal infection, berylliosis, extrinsic allergic alveolitisDiseases with granuloma-like reactions: lymphoma, carcinoma, metastases
Chronic eosinophilic pneumonia, BOOP Pathological Features Common systemic disease. Widespread noncaseating granulomas, that resolve or cause fibrosis.

Etiology: unknown

Onset – usually age 20 to 40

Asymptomatic, or fatigue, malaise, weight loss, fever, respiratory symptoms, erythema nodosum, uveitis, skin lesions, arthropathy, bone lesions

In < 2% TB precedes sarcoidosis or develops later.
80% of cases resolve completely; in 20% fibrosis develops that may destroy and distort the lung
Anemia, leukopenia, elevated sedimentation rate, hypercalcemia, nephrolitiasis.
Cutaneous anergy.

Usually not treated; steroids in severe cases
Recurrence in transplanted lung has been reported
Prognosis worse in blacks
Mortality – 2 – 7%; death from respiratory failure, cor pulmonale, hemorrhage



Tracheal distention following intubation


CXR performed after VATS biopsy

CT scan showing multiple peripheral contrast enhancing leasions

- The chest x-ray of this patient could resemble a pneumonia or even edema, but the round multiple leasions seen on the CT suggest pulmonary mets.
- The patients lung leasions were incidentally found as part of a neurosurgical pre op. check up. - - The patient had a 6 month long history of coughing and fever.
- The histology results has not returned yet...


Fibrosis pulmonum mai grad.
Pneumonia l.d.

The CT suggested active TBC, with caverna and a preexisting silicosis.

Calcified hilar lymphnodes

Microbiology from lung biopsy specimen: negative
Labs: WBC: 21000 , Neutrophyl: 91 (37-80), Lymphocyte: 5 (10-50), CRP 19

Monday, 18 April 2011


under construction...

-The immune response to Mycobacterium tuberculosis is mediated by T lymphocytes.
-The correlation between CRP concentrations and viable counts of tubercle bacilli isolated from sputum of patients with pulmonary tuberculosis, though statistically significant, is weak.

- Increased neutrophyls
- Inncreased ESR

- Decreased RBC
- Decreased lymphocytes

- Decreased Calcium and Sodium

- Decreased albumin, decreased protein levels, decreased globulins.

Chest x-ray:

In active pulmonary TB, infiltrates or consolidations and/or cavities are often seen in the upper lobes with or without mediastinal or hilar lymphadenopathy or pleural effusions ( tuberculous pleurisy). However, lesions may appear anywhere in the lungs. In disseminated TB a pattern of many tiny nodules throughout the lung fields is common - the so called miliary TB. In HIV and other immunesuppressed persons, any abnormality may indicate TB or the chest X-ray may even appear entirely normal.

Abnormalities on chest radiographs may be suggestive of, but are never diagnostic of, TB. However, c

hest radiographs may be used to rule out the possibility of pulmonary T

B in a person who has a positive reaction to the tuberculin skin test and no symptoms of disease.

Cavitation or consolidation of the apexes of the upper lobes of the lung may be discernible by a chest x-ray.


(Text main source:

(Images:, google images)

Chest x-rays

Eosinophilic pneumonitis:

Peripheral consolidations with upper lobe predominance


Signs of pulmonary TB


Azygous lobe


Sclerotic coronary

Which one could it be?


Met from a cervix tumor


Lung cyst


Sclerotic areas in the thyroid gland on a trachrea air-stripe image


Golden S sign: indicated by the red arrows, is a sign of right upper lobe atelectasia, dystelectasia. The blue arros are pointing to the pleural line - PTX. The purpule circle is showing a small amount of HTX in the left lateral sinus.


Mediastinitis that developed after a thoracotomy.
Take note of the blurring of mediastinal contours on both sides, and left sided HTX.


Ptx on the right sided that developed after the insertion of a central canule into the right jugular vein.

Ptx l.u.


Bilateral PTX following a Nuss operation of pectus excavatum, take notice of the two pectus metal plates that are inserted subcutaneously.


Enlarged RV:

The enlarged RV pushes the heart elevating its apex up from the diaphragm.

Th left lung appears to have a decreased transperancy when compared to the contralateral side, this film was taken in an AP projection.


Hiatus hernia:

Red arrows indicating the double contuor, blue arrows showing the fluid level, gastric content level.


The increased interstitial pattern, and peribronchial drawing are signs of chronic bronchitis


- Post irradiation pneumonia: This patient is suffering from a gastric malignancy, and had undergone radiotherapy as a palliative treatment.

WBC: 26000(4000-10000) Neutrophyl 88 (37-80) Lymphocyte 7 (10-50) RDW 18%(11-16)

Solitary pulmonary nodule (SPN) - a CT exam has been advised for this pt, but has not been performed yet.
The nodule is located in the vicinity of the minor fissure, therefore it could also be fluid inside the fissure, after diuresis it has not changed shape, or size, therefore to exclude malignancy a CT has to be performed.
The HTX is frequently seen in malignant SPN's.

Cloud like interstital shadowing of both lungs - lung edema
WBC- 17700 Neutrophyl: 88(37-80) Lymphocyte 3,5 (10-50) - therefore pneumonia cannot be ruled out.

Where does the drain tube end?
This radiograph shows the importance of lateral images, on the PA image the tube seems to be ending in the trachea, but when we take a closer look at the lateral image we find that the drain tube is posterior to the tracheal air stripe.

-Air-fluid levels indicating the presence of a hydroptx.
- Arrows showing thin pleural line

The patient has undergone a left upper lobe lobectomy
-PTX on the left side
-Elevated left hemidiaphragm
-Trachea pulled to the left

Atelectetic line on the left side, commonly seen in post op. patients due to poor inspiration.
Small fissure on right side.

PTX l.d.

Pneumonia l.d. in the right lower lobe
CRP: 102 WBC: 6200 Neutrophyl: Lymphocyte:


Subcutaneous emphysema
PTX l.d.

HTX l.s., left dorsal sinus

(Images: Pécs University Department of Radiology)