Transcript Diagnostic methods - University of Yeditepe Faculty of Medicine, 2011

Diagnostic methods in
pulmonary medicine
Dr. S. Özdoğan
Imaging
 Chest
x-ray
 Computed Tomography
 Magnetic Resonance Imaging
 PET CT
 Ventilation Perfusion Scan
 Pulmonary
function tests
 Skin Prick Test
 Bacteriologic evaluation
 PPD (Tuberculin test)
 Blood gas analysis
 Thoracentesis and drainage
 Pleural biopsy
 Bronchoscopy
Plain Chest Radiography
Right anterior oblique
Normal position
and technique
Right anterior obligue
Examination in order
 Trachea,
mediastinum
 Bilateral diaphragm, sinuses
 Hiler regions
 Lung Paranchym
 Bone and soft tissue
Pathologic signs in chest x ray
 Changes
in the size or localization of the
normal components
 Extra densities
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White shadows, consolidation
• Homogenious
• Inhomogenious
• Calcification
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Black areas, (pure air)
• Air cysts
• Bullae
• pneumothorax
Paranchymal Radiologic patterns
 Reticular:
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Kerley B (basal)
Kerley C: Central short
Kerley A: longer in middle zone
 Nodule:
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lineer density
round shaped < 3cm opacities
Asiner: 4-8 mm
Milier: 2-4 mm
 Mass:
> 3cm diameter
Silhouette sign (-)
Silhouette sign (+)
Bone and soft tissue
 Fractures
 Air
 Extra
densities
 PA
Chest x ray
 Lateral chest x-ray
 Lateral decubitis
 Apicolordotic
chest x-ray
Thorax CT (Indications)
 Any
abnormality seen on a chest
radiograph
 To examine the borders of a lesion and
its relation to neighbouring tissues
 To get hystospecific details according to
the density (HU)
 To examine chest wall and vertebral
pathologies
 Evaluation of metastasis
Normal Anatomy
Pathologies on Thorax CT
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Solid lesions in the
lung, localization,
density
 Pleural lesions,
density?
 Mediastinal lesions
and lymph nodes
 Vasculer pathologies
(intraluminal trombus)
in contrast
enhancement
HRCT
Pathologies:
Normal paranchym
Reticular
Nodular
Consolidation, Ground grass
Cystic
Skin Prick Test
 Type
I immunologic reaction
 Sensitivity to a particular antigen is
detected
 Negative
control (SF) should be negative
 Positive control (Histamine) should be
positive
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False negative:
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Antihistamine
Test solution quality
First week after an
anaphylactic reaction
Technical problem
Old age
Diabetes, peripheral
neuropathy
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False positive
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Dermografism
Egzema
Microbiologic examination for
tuberculosis
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Materials:
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Sputum
Bronchial lavage
Pleural effusion
Gastric aspiration
Serebrospinal fluid
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Urine
Debrids of abscess
Bone marrow
Any tissue
Sputum ARB examination (smear) should be performed in at least 3
different materials
 Direct
microscopic exam.
 Homogenisation
 Culture 10-100 bacilli/ml
5000-10000 bacilli/ml
Direct microscopy is the most rapid and
simple diagnostic method for pulmonary
tuberculosis and it shows the infectious
potential of the patient.
Ziehl’s Neelsen Staining
Carbolfuchsin
Alcohol
Methylen blue
Flourescent microscopic technique (Auromin rhodamine dye)
Culture for tb
 Higher
sensitivity
 Isolation of MOTT
 Drug sensitivity examination
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Solid medium
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Löwenstein-Jensen:
Conventional
technique, egg based,
sensitivity 80-85 %,
specificity 98 %. 4-6
weeks of incubation.
Middlebrook 7H107H11:non egg based
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Liquid medium
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BACTEC: radiometric
determination of CO2,
14-21 days for
bacterial growth
MGIT: Flouresans
increases as the
oksigen is used by
bacilli, 15-18 days of
incubation
 Other
techniques for rapid diagnosis of
tb:
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PCR
Nucleic acide hybridization
HPLC (High performance liquid
chromatoraphy)
RFLP (Restriction fragment length
polymorphism)
Typing,
index case
evaluation,
resistance
evaluation
Tuberculin skin test (PPD)
 The
Mantoux test (intracutaneus
administration of 5 units of purified protein
derivate tuberculin)
 Type IV (delayed type hypersensitivity)
reaction maximum at 48-72 hours
 0,1 ml 5TU PPD is injected intradermally
and the diameter of enduration formed
after 72 hours is recorded
Interpretation
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In BCG vaccinated
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0-4 mm negative
5-14 mm can be due
to BCG
>=15 mm positive
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In non BCG
vaccinated
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0-4 mm negative
If 5-9 mm Should be
repeated in 7-14 days;
if same negative, If
>=10 mm positive
 >=5
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mm is accepted positive in:
Immunosuppresive patients
HIV (+)
Malnutrition
(Booster Phenomenon)
 Delayed
type hypersensitivity resulting
from mycobacterial infection or BCG
vaccination may gradually wane with
years.
 Initial skin test results may be negative,
the stimulus of a first test may boost or
increase the size of the reaction to a
second test administered 1 week later.
False Negative Reactions
 Ante-allergic
period
 Causes of Anergy :
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Viral infections, varicella
Typhoo, Brucellosis, leprosy, pertusis
Lymphoid tissue diseases
Lymphoma, leukemia, sarcoidosis
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Renal insufficiency
Malnutrition
Viral vaccines
Imminosuppresive treatment
Atopic dermatitis
Milier Tb
Blood gas analysis
 Examination
of Arterial Blood Gas
 Drawn from artery- radial, brachial,
femoral
 Invasive technique
 Allen test should be performed if radial
artery will be preferred
What Is An ABG?
pH
[H+]
PCO2 Partial pressure CO2
PO2
Partial pressure O2
HCO3 Bicarbonate
BE
Base excess
SaO2
Oxygen Saturation
Normal ABG values
pH
7.35 – 7.45
PCO2
35 – 45 mmHg
PO2
80 – 100 mmHg
HCO3
22 – 26 mmol/L
BE
-2 - +2
SaO2
>95%
THORACENTESIS
Diagnostic Thoracentesis is performed for the examination of fluid
accumulated in the pleural cavity and is indicated in all cases of
pleural efusion of unknown origin
Therapotic thoracentesis is performed for the drainage of excess
fluid accumulated in the pleural cavity
The site should be selected according to
clinical examination
If the effusion is small thoracentesis can
be performed under ultrasound guidance
After cleaning the skin with
antiseptic solution a 20 gauge or
larger needle is inserted above
the superior aspect of the lower
rib
Above the superior aspect of the lower rib to
minimize the danger of injury to intercostal
vessels and nerves
Pleural biopsy
 Small
biopsy from pariethal pleura
 Cope needle or Abrams needle is used
most frequently
 Local anesthesia with 5-10 cc lidocain 2%
 Indications: exudative effusions with
unknown etiology
Bronchoscopy
 Performed
by Flexible Fiberoptic
bronchoscope
 Local anesthesia, sedation
Rigid
Bronchoscopy
Indications
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Diagnostic
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Abnormal chest radiograph
Chronic cough
Hemoptysis
Localised wheese and
stridor
Bronchogenic carcinoma
(Staging, follow up)
Recurrent pneumonia
Atelectasis
Foreign body aspiration?
Vocal cord paralysis,
hoarseness
Pulmonary infections
Vocal cord or
diaphragmatic paralysis
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Therapeutic
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Retained secretions,
mucus plugs
Foreign body
Laser therapy
Brachytherapy
Tracheobronchial stent
palcement
Dilatation of stenosis
Intralesional injection
Therapeutic lavage