Clinical History
An 18-year-old male patient presented to ENT department with a chronic history of sinusitis.
On further questioning the patient also revealed a history of multiple lower respiratory tract infections.
On physical examination heart sounds were heard best on the right side of the chest.
Imaging Findings
The heart apex points towards the right (dextrocardia). The horizontal fissure is seen in the left hemithorax.
Cystic changes and 'tram tracking' are noted in both lower lobes, in keeping with bronchiectasis.
Aortic arch is right-sided.
The stomach gas bubble is seen beneath the right hemidiaphragm in keeping with situs inversus.
Discussion
Kartagener syndrome is a rare (incidence of 1:32, 000) autosomal recessive disorder which affects the dynein arms in cilia lining the respiratory epithelium and fallopian tubes, and within the flagella of sperm [1]. The abnormal microstucture of the cilia results in their abnormal motility and defective function [2].
Kartagener syndrome is one of a group of disorders classified as primary ciliary dyskinesias. The syndrome also involves situs inversus, chronic sinusitis and bronchiectasis (with lower lobe predominance.)
The abnormal ciliary function results in reduced mucus clearance and this in turn acts as a substrate for the growth of bacteria. Patients present with chronic lower respiratory tract infections, but also sinusitis and otitis media. The chronicity of the infections invariably leads to bronchiectasis due to chronic damage of the bronchial tree. Similarly, chronic otitis media may lead to hearing loss. The syndrome is associated with infertility due to defective sperm motility.
Though clinical signs and symptoms may be typical for the syndrome, the diagnosis is often only made when irreversible damage has been caused.
Bronchiectasis is a common finding both on plain radiography and Computed Tomography (especially high resolution CT).
Though the underlying aetiology for bronchiectasis is varied, the radiologist should identify any secondary aids to narrow the differential diagnosis.
In Kartagener syndrome, such additional findings include those pointing to situs inversus. Such findings can be identified on both plain films and CT, and include dextrocardia, a left-sided liver, a displaced gastric bubble, and the left lung having 3 lobes as identified by a left-sided horizontal fissure [3].
Additional views or sequences showing paranasal sinusitis and the clinical history of chronic recurrent respiratory tract infections also point towards Kartagener syndrome as a unifying diagnosis.
Thus the radiologist should be familiar with the clinical and radiological manifestation of the disease, and should raise the possibility of the diagnosis.
The diagnosis is usually made by a combination of imaging studies, audiological testing, pulmonary function tests and semen analysis. The diagnosis is confirmed by mucosal biopsy which is examined for ciliary movement. Electron microscopy analysis for abnormal ciliary microstructure is also possible though not commonly used in clinical practice.
Screening tests include the saccharin test and the measurement of nasal and exhaled nitric oxide.
Early diagnosis is the key to reduce the incidence of infections and slow the progression of the disease. Chest physiotherapy is used as a first line treatment to clear inspissated mucus. Aggressive measures to prevent respiratory infections and treatment of superinfection are thought to slow disease progression.
Even with aggressive measures, structural destruction often progresses relentlessly, and patients may require lung or lung/heart transplantation [4]. Kartagener syndrome can be suggested initially by a radiologist reading a plain X-ray or CT. Therefore sound knowledge of the radiological signs and clinical symptoms is essential. The findings of bronchiectasis and situs inversus should lead to a full clinical work-up of the syndrome. Early diagnosis may slow disease progression, thus prompt identification is crucial.
Differential Diagnosis List
Kartagener syndrome
Primary ciliary dyskinesia
Dextrocardia
Bronchiectasis
