Mycobacterial infections: still a millennium bug--the imaging features of mycobacterial infections

Central nervous system and spinal cord tuberculosis: Revisiting an important disease

Tuberculosis is a worldwide pandemic. Estimated that about 25% humans are colonized by Mycobacterium tuberculosis and about 1% are believed to develop the infection in the central nervous system (CNS-TB). Given the importance of this disease and its high levels of morbidity and mortality, it is imperative that every radiologist must be reminded of the most common findings of CNS-TB as there are several related differential diagnoses for this disease. The most common form CNS-TB is tuberculous meningitis (TBM), characterized mostly by basal meningitis, but infarction, hydrocephalus and tuberculomas could be present. Intracerebral tuberculosis is characterized by tuberculomas that can have different imaging features according to their stage. Vascular and spinal complications of tuberculosis are also reported. This review compiles the classic and unusual findings regarding CNS-TB together with new diagnostic scores in which neuroimaging have an important role.

Diagnosing pyogenic, brucella and tuberculous spondylitis using histopathology and MRI: A retrospective study

The present study examined the histopathological and magnetic resonance imaging (MRI) features of pyogenic, brucella and tuberculous spondylitis (PS, BS and TS, respectively). A total of 22 PS, 20 BS and 20 TS patients were included in the study. Histopathological examination was used to assess the lesion structure and composition, and the MRI observation identified the lesion location and signal features. The following histopathological and MRI features were identified significantly more in patients with PS than in patients with BS and TS: Predominant neutrophil infiltration, abnormal intervertebral disk signal, lesions on the ventral and lateral sides of the vertebral bodies, and thick and irregular abscess walls. The following histopathological and MRI features were identified significantly more in patients with BS than in patients with PS and TS: Predominant lymphocyte infiltration, new bone formation, epithelioid granuloma, lesions on the ventral sides of the vertebral bodies, no, or very mild, vertebral body deformation, no abnormal paraspinal soft tissue signal, no intraosseous or paraspinal abscesses, and thin and irregular abscess walls. The following histopathological and MRI features were identified significantly more in patients with TS than in patients with BS and PS: Sequestrum, Langerhans giant cells, caseous necrosis, lesions primarily in the thoracic region and on the lateral sides of the vertebral bodies, no obvious intervertebral disk damage, obvious vertebral body deformation, abnormal paraspinal soft tissue signal, intraosseous or paraspinal abscesses, and thin and smooth abscess walls. In conclusion, it can be suggested that these significant differences in histopathological and MRI features between the three different types of spondylitis may contribute towards the differential diagnosis of the diseases.

MRI characteristics of tuberculous spondylitis

Spondylitis is the most common osseous manifestation of Mycobacterium tuberculosis infection. Although treatable, it continues to cause significant mortality and morbidity. Early diagnosis through familiarity with its imaging characteristics is essential to permit rapid treatment and prevent potential life-limiting consequences. In this review, we demonstrate the key magnetic resonance imaging features of this disease.

Cavitating pulmonary tuberculosis in children: correlating radiology with pathogenesis

BACKGROUND

Cavitating pulmonary tuberculosis (PTB) is generally known as a disease of adults, with children typically having features of primary PTB.

OBJECTIVE

To group children with PTB and cavities according to possible pathogenesis by evaluating the clinical and radiological findings.

MATERIALS AND METHODS

The clinical and radiological findings in ten randomly selected children with PTB and cavitations on chest radiographs were retrospectively reviewed and evaluated.

RESULTS

Three groups emerged: group 1 (four children) had cavities, usually single and unilateral in the classic upper lobe distribution of postprimary PTB; group 2 (three children) developed progressive primary spread of disease with extensive and bilateral pulmonary cavities; and group 3 (three children) developed cavities secondary to airway obstruction by mediastinal lymph nodes with consequent distal collapse and consolidation. Children in group 1 responded well to treatment and had unremarkable recoveries. Children in group 2 were all below 2 years of age with complicated recoveries. Children in group 3 had frequent complications resulting in one fatality.

CONCLUSION

Cavities in PTB in children may arise by one of three possible mechanisms with a relatively equal incidence. A study is underway to determine the incidence of cavity formation associated with mediastinal lymphadenopathy and airway obstruction.

[Neuroradiologic emergencies in infectious pathology]

The main goal of urgent imaging evaluation of patients with suspected CNS infection is to differentiate infectious from tumoral or vascular lesions in order to provide appropriate management. MR imaging, including diffusion weighted imaging and spectroscopy, is superior to CT imaging to characterize lesion location and etiology. The CT and MRI features of the more frequent bacterial, viral and parasitic CNS infections will be described.

Tuberculosis

Approximately one-third of the world population is infected with Mycobacterium tuberculosis, the organism that causes tuberculosis (TB). After a brief resurgence beginning in the mid-1980s, the incidence of TB is once again declining in the United States. Health care workers, including dentists and their staff, however, remain at risk for occupational acquisition of the disease. This risk can be managed by educating dental health care workers about the oral and systemic manifestations of TB and the mechanisms by which it is spread so that appropriate measures may be taken in the office to minimize the opportunity for disease transmission.