HRCT Interpretation

3,421 views

Published on

Published in: Health & Medicine, Business
  • Be the first to comment

HRCT Interpretation

  1. 1. HRCT InterpretationPadmanabhan Krishnan, MD
  2. 2. Raoof, S. , CHEST 2006; 129:805
  3. 3. Secondary Pulmonary Nodule Basic unit of lung structure and function Smallest unit of lung structure marginated by interlobular septa Septa more peripheral, less or absent centrally Polyhedral 10-25mm diameter Terminal bronchiole supplies the SPL Arteries paired with bronchi Veins run in the periphery of lobule Lymphatics are along axial skeleton perivascular peribronchial up to terminalbronchioles and peripheral along interlobular septa and pleura SPL contains 5-15 acini – 8mm dia Acinus is the structure distal to end terminal bronchiole (30,000 TB) andcontains 2–5 generation of RB and alveolar duct and alveolar sacs (300 million) End terminal bronchiole 2.5mm from interlobular septae and pleura 2nd generation RB site of small particle deposition less than 5 micron HRCT:• PA > 0.2mm D at which point are present the distal terminal bronchiole, and 1stgeneration RB (not seen)• Acini at distal tip of peripheral branching artery
  4. 4. Abnormal secondary lobule Lymphatic distribution Nodular - perilymphatic● SP, septal, axial● SARC, SIL, BERY, Kap, lymphoma Septal thickening● Interlobular● LC Lobular / Acinar distribution – fibrosis Inter / Intralobular septae, reticular, honeycomb UIP, NSIP, CHP, Asbestosis Vascular distribution Nodular – random● SP, septal, non-axial● Mets, miliary Septal thickening – interlobular● VOD, CH, MS Centrilobular nodule - tree-in-bud● Tumor embolism Airway distribution Centrilobular nodule - Tree-in-bud● Bronchiolitis Centrilobular nodule – ground glass● SAHP, RBILD Centrilobular nodule and ectasia● M. avium, DPB Lobular / Acinar distribution - filling Ground glass, airspace, crazy paving● COP, CEP, AP, BAC
  5. 5. Raoof, S. , CHEST 2006; 129:805
  6. 6. Abnormal secondary lobule Lymphatic distribution Nodular - perilymphatic● SP, septal, axial● SARC, SIL, BERY, Kap, lymphoma Septal thickening● Interlobular● LC Lobular / Acinar distribution – fibrosis Inter / Intralobular septae, reticular, honeycomb UIP, NSIP, CHP, Asbestosis Vascular distribution Nodular – random● SP, septal, non-axial● Mets, miliary Septal thickening – interlobular● VOD, CH, MS Centrilobular nodule - tree-in-bud● Tumor embolism Airway distribution Centrilobular nodule - Tree-in-bud● Bronchiolitis Centrilobular nodule – ground glass● SAHP, RBILD Centrilobular nodule and ectasia● M. avium, DPB Lobular / Acinar distribution - filling Ground glass, airspace, crazy paving● COP, CEP, AP, BAC
  7. 7. Raoof, S. , CHEST 2006; 129:805
  8. 8. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  9. 9. HRCT PATTERNSNODULAR PATTERN lymphohematogenous Bronchiolar terminal bronchiole Vascular intralobular arteryLYMPHOHEMATOGENOUS subpleural on fissures and septaePERYLYMPHATIC RANDOMaxial skeleton end of vesselsperivascular / peribronchial cavitationupper lobes basilar-sarcoidosis -mets-berylliosis -miliary TB/ histoplasmosis/crypto-silicosis/ CWP -septic emboli-lymphoma -vasculitis-Kaposis -amyloidosisRaoof S., CHEST 2006;129:805
  10. 10. Raoof, S. , CHEST 2006; 129:805
  11. 11. Sarcoidperilymphatic
  12. 12. sarcoid
  13. 13. Lymphomaperilymphatic
  14. 14. HRCT PATTERNSNODULAR PATTERN lymphohematogenous Bronchiolar terminal bronchiole Vascular intralobular arteryLYMPHOHEMATOGENOUS subpleural on fissures and septaePERYLYMPHATIC RANDOMaxial skeleton end of vesselsperivascular/ peribronchial cavitationupper lobes basilar-sarcoidosis -mets-berylliosis -miliary TB/ histoplasmosis/crypto-silicosis/ CWP -septic emboli-lymphoma -vasculitis-Kaposis -amyloidosisRaoof S., CHEST 2006;129:805
  15. 15. Raoof, S. , CHEST 2006; 129:805
  16. 16. METSrandom
  17. 17. Wegener’srandom
  18. 18. miliary
  19. 19. Miliaryrandom
  20. 20. HRCT PATTERNSNODULAR PATTERN lymphohematogenous Bronchiolar terminal bronchiole Vascular intralobular arteryLYMPHOHEMATOGENOUS subpleural on fissures and septaePERYLYMPHATIC RANDOMaxial skeleton end of vesselsperivascular / peribronchial cavitationupper lobes basilar-sarcoidosis -mets-berylliosis -miliary TB/ histoplasmosis/crypto-silicosis/ CWP -septic emboli-lymphoma -vasculitis-Kaposis -amyloidosisRaoof S., CHEST 2006;129:805
  21. 21. HRCT - Nodular PatternBRONCHIOLAR Centrilobular nodules: small airways of secondary lobule 1-3mm away from pleura Not sub pleural Not on fissures or septaePrimary bronchiolar disease Mixed bronchiolarSharp branching nodules PeribronchiolarTree-in-bud ground glass nodules+/-tree-in-budMAI, MTB sub acute HPAspergillus respiratory bronchiolitis - ILDDPB, DAB LIPFollicular bronchiolitis Early LCHImmune bronchiolitis – UC metastatic Calcification (CRF)mineral dust bronchiolitisnylon flock workers diseaseSecondary to bronchiectasissilicosisVascular• Tree-in-bud/ ground glasstumor embolismPlexogenic arteriopathy of PAHRaoof, S. CHEST 2006; 129:805
  22. 22. Raoof, S. , CHEST 2006; 129:805
  23. 23. Tree-in-Bud AppearanceBronchiolitisRare- tumor cell emboli – intralobular artery
  24. 24. Tree-in-bud / MAIbronchiolar
  25. 25. Bronchiolitis - MTB
  26. 26. Subacute HPbronch / peribronch / gg
  27. 27. RBILD
  28. 28. Avium / DPB
  29. 29. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  30. 30. HRCTRETICULAR PATTERN - UIP peripheral reticular lines / inter and intralobular septae honeycomb Traction bronchiectasis None or minimal ground glass Gradient increasing from apex to base Skip areas Diagnostic accuracy high Idiopathic Familial CVD - RA Drugs – NFT, Busulphan Asbestosis = basilar – bands – pleural calcification Chronic HP = upper and midzones Hermansky-Pudlak syndromeAcute exacerbation of UIP● above + ground glass● Peripheral – better prognosis – Fibroblastic Foci+++● Diffuse – worse prognosis – DADAMJRCCM.198:372;2008AIP● Diffuse ground glass + airspace● Traction bronchiectasis● honeycomb
  31. 31. UIP
  32. 32. Chronic HP
  33. 33. Asbestosis
  34. 34. HRCTRETICULAR PATTERN - UIP (acinar fibrosis) peripheral reticular lines honeycomb Traction bronchiectasis None or minimal ground glass Gradient increasing from apex to base Skip areas Diagnostic accuracy high Idiopathic Familial CVD - RA Drugs – NFT, Busulphan Asbestosis = basilar – bands – pleural calcification Chronic HP = upper and midzones Hermansky-Pudlak syndromeAcute exacerbation of UIP above + ground glass Peripheral – better prognosis – Fibroblastic Foci+++ Diffuse – worse prognosis – DADAMJRCCM.198:372; 2008AIP Diffuse ground glass + airspace Traction bronchiectasis honeycomb
  35. 35. Acute Exacerbation UIP- peripheral
  36. 36. Acute exacerbation UIP- diffuse
  37. 37. HRCTRETICULAR PATTERN - UIP (acinar fibrosis) peripheral reticular lines honeycomb Traction bronchiectasis None or minimal ground glass Gradient increasing from apex to base Skip areas Diagnostic accuracy high Idiopathic Familial CVD - RA Drugs – NFT, Busulphan Asbestosis = basilar – bands – pleural calcification Chronic HP = upper and midzones Hermansky-Pudlak syndromeAcute exacerbation of UIP above + ground glass Peripheral – better prognosis – Fibroblastic Foci+++ Diffuse – worse prognosis – DADAMJRCCM.198:372; 2008AIP Diffuse ground glass + airspace Traction bronchiectasis honeycomb
  38. 38. AIPHC/gg
  39. 39. Reticular Pattern - NSIPinflammation and fibrosis Predominantly basilar Significant ground glass Subpleural sparing low sensitivity, high specificity No honeycombing, some cystic change Traction BronchiectasisDiagnostic accuracy 50% Cellular NSIP Fibrotic NSIP Associated with CVD Undifferentiated CVD – T. King
  40. 40. NSIP- cellular
  41. 41. NSIP-fibrotic
  42. 42. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  43. 43. Cystic Pattern Parenchymal Bronchiectasis ParenchymalLCH irregular shaped cysts, stellate:3-10mm; upper lobe Ground glass centrilobular nodules Air trapping – mosaic patterns Spares costophrenic anglesLAM Thin walled oval cysts Normal parenchyma Pleural effusion-chylous normal or hyperinflated lung angiomyolipomaLIP Ground glass centrilobular nodules Diffuse ground glass Thin walled cysts PCP, papilomatosis, Birt-Hogg-Dube disease
  44. 44. LAM
  45. 45. LIP
  46. 46. PCP
  47. 47. Cystic Pattern Parenchymal Bronchiectasis ParenchymalLCH irregular shaped cysts, stellate:3-10mm; upper lobe Ground glass centrilobular nodules Air trapping – mosaic patterns Spares costophrenic anglesLAM Thin walled oval cysts Normal parenchyma Pleural effusion-chylous normal or hyperinflated lung angiomyolipomaLIP Ground glass centrilobular nodules Diffuse ground glass Thin walled cysts PCP, papilomatosis, Birt-Hogg-Dube disease
  48. 48. BronchiectasisVessel at wall of cyst – signet ringCyst stacked in tubular orientationCyst stacked in branching patternDilated, irregular, thickened airwaysMucus-filled airwaysDiameter of peripheral airway to accompanyingartery = >1● HGG ● CD● ABPA ● tracheobronchomegaly● CF ● α-1 antitrypsin deficiency● DPB
  49. 49. Bronchiectasiscentral
  50. 50. Distalmucocele
  51. 51. BronchiolarectasisDPB
  52. 52. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  53. 53. Raoof, S. , CHEST 2006; 129:805
  54. 54. Septal Pattern – lymphatic/venous Secondary lobule outlined- interlobular septum● Smooth – pulmonary veno-occlusive disease, mitralstenosis, capillary hemangiomatosis, LC● Beaded – lymphangitic carcinomatosis, lymphoma,lymphangiomatosis, sarcoidRare = non-Langerhans’ cell histiocytosis (bone+pleura)amyloidosis
  55. 55. smooth
  56. 56. LCsmooth
  57. 57. smooth
  58. 58. LCbeaded
  59. 59. PHTN – PA 39mm39.2mm
  60. 60. PHTN and septal thickening? PVOD
  61. 61. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  62. 62. Airspace Patterns Diffuse ground-glass Patchy consolidation (peripheral) Inter and intralobular septal thickening / ground glass/crazy paving Reverse halo/atoll sign Hogshead cheese sign Perilobular pattern Organising pneumonia – COP/BOOP Chronic eosinophilic pneumonia Alveolar proteinosis Desquamative interstitial pneumonitis Alveolar microlithiasis Alveolar sarcoid BAC
  63. 63. COP(reverse halo/atoll sign)
  64. 64. COP – perilobular pattern
  65. 65. Sarcoid- Hogshead cheese
  66. 66. AHP/ Hogshead cheese
  67. 67. Crazy paving
  68. 68. Alveolar Sarcoid
  69. 69. HRCT – ILD/DPLDNodularLymph-hematogenousReticularHoneycombCystic SeptalInterlobularAirspaceGround glassCrazy pavingPLSARC/ BRYLSilicosisLymphomaKaposiRandomMetsMiliary TBUIPIPFRAHPSCHPAsbestosisdrugparenchymalLCH (gg)LAMLIP (gg)AirwayBronchiectasisvenousMSPVODPCHCOPCEPAlv proteinosisAlv mcrlithiaDIPAIPAHPSAHPBAClymphaticLCLymphomasarcoidNSIP (gg)AIP (gg)BronchiolarBronchiolitisSAHP (gg)RB-ILD (gg)LCH (gg)Vasculartumor emboli
  70. 70. Emphysema - CL
  71. 71. Emphysema - PA
  72. 72. CL + PS emphysema
  73. 73. HRCT - ILD/DPLDNodularPL LHSarc/Berylliosis MetsSilicosis Miliary TBLymphomaKaposiBronchiolarSAHPRB-ILDLCHBronchiolitisAcinar fibrosis /Reticular/HoneycombUIPCHPAsbestosisNSIPAIPSeptal / InterlobularVenous LymphaticCHF LCMS LymphomaPVODAcinar filling/ ground glassCOPCEPAlveolar proteinosisAlveolar microlithiasisDIPAIPSAHPAHPBACHyperlucencyCentrilobular emphysemaParaseptal emphysemaPanacinar emphysemaCysticParenchymal BronchiectasisLCHLAMLIP
  74. 74. Inter-observer variation in HRCT Diagnosis131pts- Royal Brompton Hospital, LondonMedian (range) kwCoefficient of agreementIPF 0.63 (0.48-0.78)NSIP 0.51 (0.27-0.78)Sarcoidosis 0.70 (0.58-0.84)Extrinsic allergicalveolitis0.60 (0.36-0.78)COP 0.49 (0.06-0.76)Smoking related ILD 0.51 (0.20-0.73)For CT diagnosis of pulmonary embolus Kappa = 0.72-0.9Aziz ZA, et al Thorax. 2004; 59:506-511
  75. 75. Interpretation of lung cysts Parenchymal cyst•LAM, LIP, LCH, PCP Acinar cyst•Honeycomb-UIP Bronchiectatic cyst•ABPA, CF, CD Centrilobular and panacinar emphysema
  76. 76. LAM
  77. 77. Acinar cyst - honeycomb - UIP
  78. 78. Bronchiectatic cyst
  79. 79. CL + PS emphysema
  80. 80. Pt with more than one form of cystCL emphysema + bronchiectasis + honeycombsmoker with asbestosis
  81. 81. Bronchiectasis – ILD mimic
  82. 82. Centrilobular emphysema – mimic ILD
  83. 83. Dilated esophagus
  84. 84. Paraseptal Emphysema – mimic ILD
  85. 85. CT features of tuberculosis Cavity Transbronchial spread – tree-in-bud Transbronchial and hematogenous
  86. 86. Tuberculosis – TB spread
  87. 87. Tuberculoma – TB spread
  88. 88. Tuberculosisbronchiolitis + hematogenous
  89. 89. TB bronchiolitis + hematogenous
  90. 90. Mosaic CT Patterns Ground glass – inflammation/ fibrosis airway obstruction (best seen on expiration)• COPD• small airway disease Vascular obstruction• chronic thrombotic pulmonary hypertension• sickle cell disease• vasculitis
  91. 91. Airway obstruction
  92. 92. Vascular obstruction
  93. 93. CTPHTN
  94. 94. ground glass

×