TuberculomaPathogenesis:• Localized parenchymal TB with alternating activation andhealing.• it may occur in the setting of 1ry and post-1ry TB.Location:Right upper lobe (but can occur in any other lobe).Radiological manifestations:• Rounded nodule with well defined margins.• 0.5 - 4cm in diameter• Usually single but may be multiple.• +/- calcification.• +/- cavitation.• +/- satellite nodules.
1ry TB pneumonia Post-1ry TB pneumoniaChildren AdultSegmental or lobarconsolidation.Patchy & nodular opacitieswhich may be bilateralInvolve any part of the lung. apico-posterior segment ofUL.Superior segment of LL.Associated withlymphadenopathy.Not associated withlymphadenopathy.Healing is complete withoutany sequelae.Healing by fibrosis.Caviatation.Or both.
Miliary TBEtiology:• It results from hematogenous dissemination ofinfection from pulmonary nidus.• It can be 1ry or post-1ry TB.Location:Randomly distributed with mild basilar predominance.Radiology:CXR: miliary shadows (nodules < 2mm).CT: sharply defined miliary shadows (nodules < 2mm).Association:TB chronic lesionsConsolidation, cavitation or calcified LN.
Millet seeds (الدخن )بذورThe term miliary is derived from the radiographic pictureof diffuse discrete nodular shadows about the size ofmillet seeds = 2mm.
Airway lesions of TB• Endobronchial tuberculosis.• Bronchiectasis.• Broncho-stenosis.• Broncholithiasis.
Endobronchial TBPathogenesis:• Cavitation & communication with bronchial treeLocation:• Lower dependent lung zones, distant from theoriginal cavity.Radiological manifestations:• X-ray:• Micro-nodules with lobar or segmental distribution.• CT:• Tree in bud opacities.Association:• Cavitation.
Broncho-stenosisPathogenesis::• Endobronchial TB.• Extrinsic pressure from enlarged peribronchial TB.Location:• Central air ways.CT:• Active stage:Irregular luminal narrowing with wall thickening,enhancement & enlarged adjacent lymph nodes.• Fibrotic stage:Concentric narrowing, uniform thickening with involvement ofa long segment.
• Lymphadenopathy with partial obstruction of the leftmain bronchus resulting in obstructive emphysema ofthe left lung. Bronchoscopy and biopsy revealed T.B.
DD of broncho-stenosisEndobronchial TB Bronchogenic carcinomaDouble obstructive lesions Low density mass at theobstructive site.Multiple bronchial wallcalcificationsSever distortion of thebronchi
Broncholithiasis• Presence of calcified or ossified materialwithin the lumen of the tracheo-bronchialtree.Pathogenesis:• Erosion of bronchial wall by calcifiedperibronchial lymph node.CT:• Calcified lymph node with findings ofbronchial obstruction.
Vascular TB• Hypertrophy of bronchial vessels.• Rasmussen aneurysm.
Hypertrophy of bronchial arteriesPathogenesis:• Due to vasculitis.C.P:• Hemoptysis.Location:• Peribronchial.CT:• Peribronchial rounded & tubular densities similar toenlarged lymph nodes.• It may protrude into the lumen of the ectatic bronchi.
Rasmussen aneurysmPathogenesis:• Vasculitis of a pulmonary artery within atuberculous cavity.Location:• Within a tuberculous cavity.CT:• Rounded enhancing lesions within atuberculous cavity.• It may cause life threatening hemoptysis.
TB lymphadenopathy• Is the hall mark of primary T.B.• Its incidence decreases with age.Pathogenesis:• Formation of tuberculous caseating granulomas in the lymphnodes.Location:• Right paratracheal and hilar lymph nodes.CT:• Central low attenuation.• Peripheral rim enhancement.• Obliteration of the perinodal fat.• Usually nodal size doesn’t exceed 2 cm.Association:Parenchymal involvement.
DD of lymphadenopathy• 1- Metastases• 2- Lymphoma• 3- other infections e.g. histoplasmosis &varicella.• 4- Sarcoidosis
Esophageal TBPathogenesis:• Extension from adjacent lymph nodes.Location:• subcarinal region (due to anatomic proximity ofthe esophagus to lymph nodes).Radiological manifestations:• Traction diverticula (triangular in shape).• Esophago-mediastinal or esophago-bronchialfistula, manifested as (pneumomediastinum).• Esophagobronchopleural fistula:
Esophageal traction diverticulum• Triangular or tent shaped.• Wide neck.• It empties when theesophagus is collapsedas it contains all layers.• Calcified mediastinal LNadjacent to thediverticulum.
Pericardial tuberculosisPathogenesis:• Extension from adjacent lymph nodes due to closeanatomic proximity of the lymph nodes & posteriorpericardial sac.Location:Radiological manifestsions:• Pericardial effusion:• Constrictive pericarditis– Pericardial thickening > 4 mm.– Pericardial calcification.Association:• Lymphadenopathy.
Fibrosing mediastinitis• N.B: the most common cause of mediastinitis ishistoplasmosis.Pathogenesis:• TB lymphadenitis with reactive fibrous changes.Radiological manifestations:Plain x-ray:• Mediastinal widening or localized mass.CT:• Mediastinal or hilar mass with or without calcification.• Diffuse obliteration of mediastinal fat.• Tracheo-bronchial narrowing.• Vascular encasement.
Pleural manifestations of TB• Pleural effusion.• Chronic TB empyema.• Fibrothorax.• Broncho-pleural fistula.• Pneumothorax.• Malignancy associated with chronic empyema.Pleural TB
TB empyema• Persistent purulent pleural fluid containing TB bacilli.Pathogenesis:• Rupture of subpleural cavity.• Hematogeneous dissemination.• Direct extension from infected lymph nodes.Location:• almost always unilateral.Radiological manifestations:• Plain x-ray:• CT:• L oculated fluid collection.• Pleural thickening.• Pleural calcification.• Extrapleural fat proliferation.• Milk of calcium with calcium / fluid level.• Pseudochylous effusion with fat / fluid level.• Associated pulmonary TB (subpleural cavitation)
TB spondylitis TB arthritis TB osteomyelitis50% of skeletalTB34% of skeletalTB16% of skeletalTBAny age Middle age &elderlyChildren < 5 y(rare in adults)Thoraco-lumbarregionLarge weightbearing jointsAny bone can beaffected.Paradiscal type.Central type.Anterior type.Appendicial type.Mono-articular. Metaphyseal.
TB spondylitis TB arthritis TB osteomyelitisHematogeneousspread (Batsonvenous plexus).Trans-cartilagenousspread into discmaterial.Subligamentousspread (beneathanteriorlongitudinalligament)HematogeneousspreadTransphysealspread to theepiphysis (on thecontrary topyogenicosteomyelitis).
TuberculousspondylitisPyogenicspondylitisEarly preservation of thedisc space.Early & sever narrowingof the disc space.Absent reactive sclerosis Reactive sclerosis.Marginal calcification ofpsoas abscess.No calcificationSkip lesions No skip lesions
Tuberculous arthritis Pyogenic arthritisGradual narrowing of thejoint space.Early & sever narrowingof the joint space.Peripheral boneerosions.Central bone erosions.Fibrous ankylosis Bony ankylosis.Kissing sequestra
TuberculousosteomyelitisPyogenicosteomyelitisTransphyseal spread. No transphyseal spread.Little or no periosteal reaction. Periosteal reaction.Little or no surrounding sclerosis Surrounding sclerosis.
Special forms of TBosteomyelitis• TB dactylitis.• Cystic TB.
Marginal (paradiscal) TB spondylitisPlain x ray:• Disc space narrowing:• Due to involvement of the disc material.MRI:• Abnormal bone marrow signal alongadjacent vertebral end plates.• Disc space narrowing.
Anterior (subperiosteal) lesionPlain x-ray:• Anterior scalloping (gouge effect):• Due to stripping of the periosteum and ALL ischemia & pressure necrosis of the anteriorvertebral body.MRI:• Subligamentous abscess.• Preservation of the discs.• Abnormal signal involving multiple vertebralsegments.
Central lesion• Centered on the vertebral body.• Disc is not involved.• Spread of infection through Baston’s venousplexus.Plain x-ray:• Central rarefaction.• +/- Vertebral collapse (vertebra plana).MRI:• abnormal signal along the vertebral body withpreservation of the disc material.• DD with metastasis, lymphoma & eosinophilicgranuloma.
Posterior (appendicial) type• Isolated infection of the pedicles, lamina,transverse processes & spinous process.• Erosive lesions with paravertebralabscess.
Skip lesions• Involvement of non contiguous vertebrae.
DD of Coned cecum• Crohns - TI involved more than cecum• TB - colon involvement greater than TI; usually havepulmonary TB; no reflux from cecum to TI• Amebiasis - cecum involved in 90% of chronicamebiasis; TI normal; ileocecal valve fixed in openposition• UC - backwash ileitis occurs 10% of time through gapingileocecal valve• Actinomycosis - uncommon may simulate appendicitis,palpable abdominal masses and draining fistulas• Typhlitis - necrotizing process of multifactorial origininvolving predominantly the right colon; most common inchildren with leukemia; typically begins 1-2 weeksfollowing chemotherapy- may also occur in adults with hematologic malignancy- there is bowel wall thickening, mucosal ulceration,intramural hemorrhage and necrosis
TB peritonitisPathology:• Direct haematogenous spread,• Rupture of a tuberculous intra-abdominallymph node.Types:• Wet type (commonest).• Dry type.• Fibrotic type.
Wet TB peritonitis• Exudative high attenuation ascites.• May be free or loculated.• Measurement of ascitic fluid adenosinedeaminase level is diagnostic.
Cervical TB lymphadenopathyscrofulaUS:• Nodal matting.• Surrounding soft tissue edema is less marked thanwould be expected given the size of the collections.Duplex:• Prominent hilar vascularity (on the contrary ofmalignant LN which show prominent peripheralvascularity).US guided FNAC:• Has 92% sensitivity & 97% specificity.
Renal size• Diffusely enlarged (T.B pyonephrosis fromureteric stricture).• Focally enlarged with displacement ofadjacent calyces (tuberculoma).• Shrunken kidney small scarred nonfunctioning kidney with dystrophiccalcification (putty kidney).• May be normal size.
Parenchymal calcifications• Amorphous.• Punctate.• Confluent calcifications.• Cumulus cloud opacity:• Due to calcification in caseous material incaverno-caseous type.• Complete cast of calcification (puttykidney) end stage renal TB(autonephrectomized kidney).
Collecting systemUneven caliectasis:unequal dilatation of renalcalyces due to varyingdegree of stenoses.Hydrocalicosis:• dilated calyx due toinfundibular stenosis.Phantom calyx:• non opacified calyx due toinfundibular stenosis.