Abdominal lymphadenopathy is most common
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Lymphadenopathy (tuberculous lymphadenitis)
Enlarged, centrally necrotic nodes with hypoattenuating centers and hyperattenuating enhancing rims
Nodes often calcify after healing
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Tuberculosis peritonitis
Variables amounts of free or loculated complex ascites with infiltration of omentum ± discrete masses
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Gastrointestinal tuberculosis
Ileocecal region affected in 90% of cases
Asymmetric wall thickening of ileocecal valve and medial cecum
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Adrenal tuberculosis
Acute: Enlarged adrenals (often appears as discrete, centrally necrotic adrenal mass)
Chronic: Small adrenals with dots of calcification and low signal on all MR sequences
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Renal tuberculosis
Most common CT finding is renal calcification (50%)
Papillary necrosis is a very common early finding
Focal wedge-shaped hypodense areas, small hypodense nodules, or discrete renal abscess
Urothelial thickening, caseous debris, and strictures of calyces and infundibuli may lead to hydronephrosis
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Hepatosplenic tuberculosis
Hepatosplenomegaly with hypodense nodules of variable size
CLINICAL ISSUES
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Often presents with fever, weight loss, and abdominal pain
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May or may not have evidence of pulmonary TB
Negative chest radiograph or negative tuberculin skin test does not exclude extrapulmonary TB
TERMINOLOGY
Abbreviations
Definitions
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Infection by
Mycobacterium tuberculosis
IMAGING
General Features
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Best diagnostic clue
Most common sites of involvement in abdomen are lymph nodes, GU tract, peritoneum, and GI tract
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Abdominal lymphadenopathy most common (2/3 cases)
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GU tract is most common organ system involved
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Any abdominal/pelvic organ or structure may be involved
Liver, spleen, biliary tree, pancreas, and adrenal glands unusual and more likely in HIV patients or patients with miliary TB
Imaging Recommendations
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Best imaging tool
CECT
Radiographic Findings
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Often no evidence of lung disease (CXR or CT can be normal)
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Lymphadenopathy (tuberculous lymphadenitis)
Can range from increased number of normal-sized nodes to massively enlarged conglomerate nodal masses
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Mesenteric and peripancreatic lymph nodes most commonly involved
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Multiple groups often affected simultaneously
Enlarged, necrotic nodes with hypoattenuating centers and hyperattenuating enhancing rims on CT (40-60%)
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Characteristic of caseous necrosis
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Mixed attenuation nodes are also possible
Nodes calcify with healing: TB probably most common cause of mesenteric nodal calcification
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Tuberculosis peritonitis
3 imaging patterns: Wet, dry, and fibrotic fixed
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Wet type: Large amount of free or loculated ascites
Higher than water density due to protein/cellular content
Complex ascites with septations or fibrinous strands
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Dry type: Mesenteric and omental thickening, fibrous adhesions, and caseous nodules
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Fibrotic fixed: Discrete masses in omentum with matted loops of bowel ± loculated ascites
CT is ∼ 69% sensitive for TB peritonitis
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Difficult to distinguish from carcinomatosis
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Carcinomatosis more likely to demonstrate discrete implants or omental caking
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Gastrointestinal tuberculosis
Ileocecal region affected in 90% of cases
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Common site due to presence of lymph tissue and stasis of bowel contents in that location
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Cecum and terminal ileum are usually contracted (cone-shaped cecum) with asymmetric wall thickening of ileocecal valve and medial cecum
Ileocecal valve is “gaping”
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Strictures, regional inflammation common
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Regional lymphadenopathy with central caseation
Involvement of stomach and proximal small bowel is rare
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Stomach: Affects antrum and distal body, often simulating peptic ulcer disease
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Duodenum: Wall thickening and luminal narrowing
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Any portion of GI tract can be theoretically involved
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Hepatosplenic tuberculosis
Related
Diagnostic Imaging_ Gastrointes - Michael P Federle