Pyogenic and tuberculous discitis: magnetic resonance imaging findings for differential diagnosis

Abstract

Spondylodiscitis represents 2%-4% of all bone infections cases. The correct diagnosis and appropriate treatment can prevent complications such as vertebral collapse and spinal cord compression, avoiding surgical procedures. The diagnosis is based on characteristic clinical and radiographic findings and confirmed by blood culture and biopsy of the disc or the vertebra. The present study was developed with Clementino Fraga Filho University Hospital patients with histopathologically and microbiologically confirmed diagnosis of spondylodiscitis, submitted to magnetic resonance imaging of the affected regions. In most cases, pyogenic spondylodiscitis affects the lumbar spine. The following findings are suggestive of the diagnosis: segmental involvement; ill-defined abscesses; early intervertebral disc involvement; homogeneous vertebral bodies and intervertebral discs involvement. Tuberculous spondylodiscitis affects preferentially the thoracic spine. Most suggestive signs include: presence of well-defined and thin-walled abscess; multisegmental, subligamentous involvement; heterogeneous involvement of vertebral bodies; and relative sparing of intervertebral discs. The present pictorial essay is aimed at showing the main magnetic resonance imaging findings of pyogenic and tuberculous discitis. Keywords: Magnetic resonance imaging; Discitis; Intervertebral disc; Spinal tuberculosis.Espondilodiscites representam 2%-4% de todos os casos de infecções no esqueleto. Seu rápido diagnóstico e tratamento apropriado podem evitar complicações, tais como colapsos vertebrais, compressão medular, evitando a realização de procedimentos cirúrgicos. Seu diagnóstico é baseado em achados clínicos e radiológicos característicos, sendo confirmado por hemoculturas, biópsia do disco ou da vértebra. Este estudo foi realizado com pacientes do Hospital Universitário Clementino Fraga Filho que tiveram o diagnóstico histopatológico ou microbiológico comprovado de espondilodiscite e realizaram ressonância magnética das regiões acometidas. Espondilodiscites piogênicas acometem preferencialmente a coluna lombar. Os principais sinais sugestivos são: acometimento segmentar; abscessos de limites pouco definidos; acometimento precoce do disco intervertebral; acometimento homogêneo dos corpos vertebrais e discos intervertebrais. A espondilodiscite tuberculosa afeta preferencialmente os segmentos vertebrais torácicos. As imagens mais sugestivas são: abscesso de paredes delgadas e bem definidas; envolvimento subligamentar multissegmentar; acometimento heterogêneo dos corpos vertebrais; discos intervertebrais relativamente poupados. O objetivo deste ensaio iconográfico é apresentar os principais aspectos das espondilodiscites piogênica e tuberculosa nas imagens por ressonância magnética. Unitermos: Ressonância magnética; Discite; Disco intervertebral; Tuberculose da coluna vertebral. AbstractResumo * Study developed in the

Magnetic Resonance Imaging in Differentatial Diagnosis of Pyogenic Spondylodiscitis and Tuberculous Spondylodiscitis

“…The majority of publications devoted to MR imaging of nonspecific and specific spondylitis describe similar symptomatology [ 10 , 20 , 21 , 22 , 23 ].…”

“…Ming-Chau Chang et al observed greater extent of vertebral destruction in tuberculous infection, heterogeneous signal from vertebral bodies following contrast administration in tuberculosis, and homogeneous contrast enhancement in purulent inflammation [ 22 ]. Likewise, Souza et al emphasized the significance of vertebral enhancement pattern as a differentiating feature [ 22 , 23 ].…”

“…Na-Young Jung et al, Souza et al, Griffith et al [ 12 , 23 , 30 ] demonstrated involvement of several vertebral bodies as more characteristic for tuberculosis. Lee presented the same observation in his review article [ 3 ].…”

“…Many reports published to date indicate sparing of intervertebral discs in tuberculous spondylitis [ 23 , 24 , 31 , 32 ], which was linked to the fact that mycobacteria do not produce proteolytic enzymes. In our study intervertebral disc destruction was similar in both types of inflammation, which might be due to longer disease duration before MR imaging.…”

Osteoid osteoma: diagnosis and treatment

“…Perfusion-weighted imaging has also been quite useful in the identification of the nidus of osteoid osteomas and in the diagnosis of the tumor. Most osteoid osteomas present with early and intense gadolinium enhancement, with a washout-type curve (type IV) resulting from the nidus hypervascularization ( 9 , 10 ) .…”