Reticular pattern
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Transcript of Reticular pattern
Reticular Pattern
Gamal Rabie Agmy, MD, FCCP
Professor of chest Diseases,
Assiut university
Reticular Pattern A reticular pattern results from the summation
or superimposition of irregular linear opacities.
The term reticular is defined as meshed, or in
the form of a network. Reticular opacities can be
described as fine, medium, or coarse, as the
width of the opacities increases.
A classic reticular pattern is seen with
pulmonary fibrosis, in which multiple curvilinear
opacities form small cystic spaces along the
pleural margins and lung bases (honeycomb
lung)
HRCT of the lung
Reticular pattern – definition
Glossary of Terms for Thoracic Imaging – Radiology 2008; 246:697
HRCT of the lung
thickening of the interstitial fiber network by
Reticular pattern – significance
fluid fibrous tissue infiltration by cells or other material
pulm. edema lymphangitic carcin. veno-occlusive dis. alveolar proteinosis IPF collagen vascular dis. drug-related fibrosis amyloidosis
Predominant pattern Associated / occasional finding sarcoidosis pneumoconiosis pulm. hemorrhage asbestosis
HRCT of the lung
Reticular pattern – HRCT
numerous, clearly visible interlobular septa outlining lobules of characteristic size and shape
interlobular septal thickening
very fine network of lines within visible lobules
intralobular interstitial thickening
several layers of air-filled cysts, 3-10 mm in diameter, with thick walls (1-3 mm)
honeycombing
Reticular pattern
Interlobular septal thickening – dd
smooth thickening
pulm. edema pulm. hemorrhage lymphangitic carc. lymphoma
nodular thickening
lymphangitic carc. sarcoidosis amyloidosis
irregular thickening
fibrosis
Reticular pattern
Interlobular septal thickening – pulmonary edema
smooth septal thickening, isolated or in combination with ground-glass opacity
peribronchovascular and subpleural interstitial th.
perihilar and gravitational distribution, bilateral findings of CHF
Reticular pattern
Interlobular septal th. – lymphangitic carcinomatosis
tumor filling of pulmonary vessels and lymphatics direct tumor infiltration of the interstitium vascular and lymphatic distension distally to tumor
emboli or obstruction
breast ca. lung ca. stomach ca. pancreas ca.
Secondary to:
prostate ca. adenoca. of
unknown origin
Reticular pattern
Interlobular septal th. – lymphangitic carcinomatosis
smooth or nodular septal thickening smooth or nodular thickening of peribronchovascular
interstitium and fissures thickening of the intralobular axial interstitium
focal or asymmetric distribution
Reticular pattern
Interlobular septal thickening – sarcoidosis
reticulation is not a predominat finding distorsion of the lung architecture and secondary
lobule anatomy is common, especially when septal thickening is present
upper lobe predominance
Reticulation or not reticulation ……
“crazy paving”
Reticulation or not reticulation ……
alveolar proteinosis
Reticular pattern
Interlobular septal thickening – “crazy paving”
scattered or diffuse ground-glass attenuation with superimposed interlobular septal thickening and intralobular lines
described in a variety of infectious, neoplastic, idiopathic, inhalation, and sanguineous disorders of the lung
Rossi SE – Radiographics 2003; 23:1509
Reticular pattern
Honeycombing – significance
air-containing cystic spaces having thick, fibrous walls lined by bronchiolar epithelium
fibrosis is present
UIP is likely the histologic pattern
IPF is very likely, in the absence of a known disease
Reticular pattern
Honeycombing – differential diagnosis
basal distribution
middle/upper distribution
chronic HP sarcoidosis
IPF collagen vasc. dis. asbestosis drugs
honeycombing / intralobular reticulation
basal and peripheral distribution
typical HRCT findings
sens. 77% spec. 72% PPV 85% PPV 96%*
Swigris JJ – Chest 2005; 127:275
lung biopsy in patients who do not show typical features
Reticular pattern
Honeycombing – idiopathic pulmonary fibrosis
* confident diagnosis
Reticular pattern
Honeycombing – collagen vascular diseases
rheumatoid arthritis and scleroderma almost indistinguishable from UIP due to IPF associated findings, typical of the disease, may help in the
differential diagnosis
Reticular pattern
Honeycombing – drug reaction
findings of fibrosis, similar to those seen in IPF peripheral and subpleural predominance highest incidence with cytotoxic agents temporal relationship between drug administration and
development of pulmonary abnormalities
Honeycombing – chronic hypersensitivity pneum.
possible association with poorly defined nodules, mosaic attenuation or air-trapping
upper and middle zone predominance
Reticular pattern
Intralobular interstitial thickening – significance
thickening of the pulmonary interstitium at a sublobular level isolated (fibrosis) in association with septal thickening or the “crazy paving” pattern
very fine linear structures below the resolution of HRCT (gg appearance)
Reticular pattern
adapted from: Webb RW – HRCT of the lung, III ed; 2001
interlobular septal thickening
irregular, lung distorsion
nodular smooth
• fibrosis (sarcoidosis,
asbestosis)
• pulm. edema • linf. carc. • hemorrhage
• sarcoidosis • linf. carc.
Reticular pattern
adapted from: Webb RW – HRCT of the lung, III ed; 2001
honeycombing
• IPF (60%) • collagen vascular dis. • drug reaction • asbestosis (uncommon)
subpleural, posterior LL predominance
• sarcoidosis • chronic HP • radiation
other distribution (UL; parahilar)
Reticular pattern
adapted from: Webb RW – HRCT of the lung, III ed; 2001
intralobular interstitial thickening
& septal thickening & GGO
isolated
NSIP
findings of fibrosis
honeycombing differential dx
Reticular pattern
In the reticular pattern there are too many lines, either as
a result of thickening of the interlobular septa or as a
result of fibrosis as in honeycombing.
Focal septal thickening in lymphangitic carcinomatosis
Septal thickening and ground-glass opacity
with a gravitational distribution in a patient
with cardiogenic pulmonary edema.
Tree-in-bud
Centrilobular nodules m/b further characterized by presence or
absence of ‘‘tree-in-bud.’’
Tree-in-bud -- Impaction of centrilobular bronchus with mucous,
pus, or fluid, resulting in dilation of the bronchus, with associated peribronchiolar inflammation .
Dilated, impacted bronchi produce Y- or V-shaped structures
This finding is almost always seen with pulmonary infections.
27
Tree-in-bud
Tree-in-bud describes the appearance of an irregular and often nodular
branching structure, most easily identified in the lung periphery.
Typical Tree-in-bud appearance in a patient with active TB.
Attenuation pattern
High Attenuation pattern
GROUND GLASS
CONSOLIDATION
Low Attenuation pattern
Emphysema
Lung cysts (LAM, LIP, Langerhans cell histiocytosis)
Bronchiectasis
Honeycombing
Dark bronchus sign in ground glass opacity.
Complete obscuration of vessels in consolidation.
Ground-glass opacity
Broncho-alveolar cell carcinoma with ground-glass
opacity and consolidation
Consolidation
Two patients with chronic consolidations as a result of COP
(cryptogenic organizing pneumonia)
Mosaic attenuation
The term 'mosaic attenuation' is used to describe density
differences between affected and non-affected lung areas.
Mosaic attenuation
Lung density and attenuation depends
partially on amount of blood in lung tissue.
May be due to
vascular obstruction,
abnormal ventilation or
airway disease
37
Mosaic pattern in a patient with hypersensitivity pneumonitis
Mosaic pattern in a patient with chronic thromboemboli
Crazy Paving Pattern
Crazy Paving is a combination of ground glass opacity with
superimposed septal thickening
Crazy Paving can be seen in:
Alveolar proteinosis
Sarcoid
NSIP
Organizing pneumonia (COP/BOOP)
Infection (PCP, viral, Mycoplasma, bacterial)
Neoplasm (Bronchoalveolarca (BAC)
Pulmonary hemorrhage
Edema (heart failure, ARDS, AIP)
CRAZY PAVING PATTERN
It is scattered or diffuse ground-glass
attenuation with superimposed interlobular
septal thickening and intralobular lines.
Causes:
42
Crazy Paving in a patient with Alveolar proteinosis.
Crazy Paving
Combination of ground glass
opacity and septal thickening :
Alveolar proteinosis.
Combination of
ground glass opacity
and septal thickening
: Alveolar proteinosis 45
Head cheese sign
It refers to mixed
densities which includes
# consolidation
# ground glass
opacities
# normal lung
# Mosaic perfusion
• Signifies mixed
infiltrative and
obstructive disease
Head cheese sign
Common cause are :
1. Hypersensitive pneumonitis
2. Sarcoidosis
3. DIP
47
Headcheese sign
Headcheese sign in
hypersensitivity
pneumonitis.
HRCT scan shows lung with
a geographic appearance,
which represents a
combination of patchy or
lobular ground-glass opacity (small arrows) and mosaic
perfusion (large arrows).
Low Attenuation pattern
Emphysema
Lung cysts (LAM, LIP, Langerhans cell
histiocytosis)
Bronchiectasis
Honeycombing
Differential diagnosis of
interstitial lung diseases
Reticular pattern
Nodular pattern
High Attenuation pattern
Low Attenuation pattern
Lymphangitic
carcinomatosis:
irregular septal
thickening, usually
focal or unilateral
50% adenopathy',
known carcinoma.
Cardiogenic pulmonary edema: incidental finding in HRCT, smooth septal thickening with basal predominance (Kerley B lines), ground-glass opacity with a gravitational and perihilar distribution, (peribronchial cuffing)
Cardiogenic
pulmonary edema
Lymphangitic
carcinomatosis
Lymphangitic
carcinomatosis with
hilar adenopathy
Nodular pattern
1.Hypersensitivity pneumonitis:
2.Miliary TB: random nodules
3.Sarcoidosis
4.Hypersensitivity pneumonitis
Nodular pattern
Hypersensitivity pneumonitis Miliary TB
Sarcoidosis Hypersensitivity pneumonitis
Low Attenuation pattern
Lymphangiomyomatosis (LAM) LCH
Honeycombing Centrilobular emphysema
Low Attenuation pattern (2)
Centrilobular emphysema: Langerhans cell histiocytosis (LCH)
Honeycombing. Lymphangiomyomatosis (LAM)