Answer for BIR CoW 18 Jan 2026
Calcaneal Osteomyelitis
Findings
Diffuse T2 PDFS high signal intensity with internal T1/T2 PD non enhancing hypointensity involving calcaneum with subtle irregularities over lateral cortex showing contrast enhancement. Ill defined enhancing soft tissue thickening with internal non enhancing areas reflecting necrosis noted adjacent to the calcaneum in its lateral aspect. - Features suggestive of calcaneal osteomyelitis. Relatively well defined peripherally enhancing T2 PDFS hyperintense collection with internal hypointensity in navicular bone - possibility of intraosseous abscess
Discussion
Calcaneal tuberculous osteomyelitis is an uncommon manifestation of skeletal tuberculosis, often presenting with insidious heel pain and minimal systemic symptoms, leading to delayed diagnosis. Mycobacterium tuberculosis is the main causative organism and only a few cases are attributable to Mycobacterium bovis. Atypical mycobacteria, such as Mycobacterium kansasii, Mycobacterium marinum, Mycobacterium scrofulaceum, and Mycobacterium avium complex account for approximately 1–4% of cases of TB. Plain Radiography: Early radiographs may be normal. As the disease progresses, imaging reveals ill-defined osteolytic lesions within the calcaneus, commonly involving the cancellous bone. Margins are typically irregular with minimal periosteal reaction. Unlike pyogenic osteomyelitis, reactive sclerosis is mild. Joint space is usually preserved in early stages. Computed Tomography (CT): CT better delineates cortical destruction, sequestrum formation, and extent of lytic lesions. It is particularly useful in identifying subtle cortical breaches and guiding biopsy. Calcaneal TB may show punched-out lytic areas with minimal surrounding sclerosis. Magnetic Resonance Imaging (MRI): MRI is the modality of choice for early diagnosis and assessment of disease extent. T1- Low signal intensity T2/STIR - high signal intensity in the calcaneal marrow, representing marrow edema and inflammatory infiltration. Post-contrast images - heterogeneous enhancement with possible central non-enhancing areas suggestive of caseation or abscess formation. Associated soft tissue involvement, sinus tracts, and adjacent joint involvement (subtalar joint) are well visualized.
References
Resnick D, Kransdorf MJ. Bone and Joint Imaging. 3rd ed. Elsevier; Chapter on infectious diseases of bone. Greenspan A, Beltran J. Skeletal Radiology: The Bare Bones. Lippincott Williams & Wilkins. Teo HE, Peh WC. Skeletal tuberculosis in children. Pediatric Radiology. 2004;34:853– 860.
Findings
Diffuse T2 PDFS high signal intensity with internal T1/T2 PD non enhancing hypointensity involving calcaneum with subtle irregularities over lateral cortex showing contrast enhancement. Ill defined enhancing soft tissue thickening with internal non enhancing areas reflecting necrosis noted adjacent to the calcaneum in its lateral aspect. - Features suggestive of calcaneal osteomyelitis. Relatively well defined peripherally enhancing T2 PDFS hyperintense collection with internal hypointensity in navicular bone - possibility of intraosseous abscess
Discussion
Calcaneal tuberculous osteomyelitis is an uncommon manifestation of skeletal tuberculosis, often presenting with insidious heel pain and minimal systemic symptoms, leading to delayed diagnosis. Mycobacterium tuberculosis is the main causative organism and only a few cases are attributable to Mycobacterium bovis. Atypical mycobacteria, such as Mycobacterium kansasii, Mycobacterium marinum, Mycobacterium scrofulaceum, and Mycobacterium avium complex account for approximately 1–4% of cases of TB. Plain Radiography: Early radiographs may be normal. As the disease progresses, imaging reveals ill-defined osteolytic lesions within the calcaneus, commonly involving the cancellous bone. Margins are typically irregular with minimal periosteal reaction. Unlike pyogenic osteomyelitis, reactive sclerosis is mild. Joint space is usually preserved in early stages. Computed Tomography (CT): CT better delineates cortical destruction, sequestrum formation, and extent of lytic lesions. It is particularly useful in identifying subtle cortical breaches and guiding biopsy. Calcaneal TB may show punched-out lytic areas with minimal surrounding sclerosis. Magnetic Resonance Imaging (MRI): MRI is the modality of choice for early diagnosis and assessment of disease extent. T1- Low signal intensity T2/STIR - high signal intensity in the calcaneal marrow, representing marrow edema and inflammatory infiltration. Post-contrast images - heterogeneous enhancement with possible central non-enhancing areas suggestive of caseation or abscess formation. Associated soft tissue involvement, sinus tracts, and adjacent joint involvement (subtalar joint) are well visualized.
References
Resnick D, Kransdorf MJ. Bone and Joint Imaging. 3rd ed. Elsevier; Chapter on infectious diseases of bone. Greenspan A, Beltran J. Skeletal Radiology: The Bare Bones. Lippincott Williams & Wilkins. Teo HE, Peh WC. Skeletal tuberculosis in children. Pediatric Radiology. 2004;34:853– 860.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!