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 Table of Contents  
SYMPOSIUM POST SURGICAL SPINE INFECTION
Year : 2018  |  Volume : 1  |  Issue : 1  |  Page : 7-16

Imaging of postoperative spinal infections


1 Department of Radiodiagnosis, Krishna Institute of Medical Sciences, Secunderabad, Telangana, India
2 Department of Spine surgery, Uday Omni Hospitals & Apollo Health City, Hyderabad, Telangana, India
3 Department of Radiodiagnosis, Armed Forces medical college, Pune, Maharashtra, India

Date of Web Publication17-Jan-2018

Correspondence Address:
Dr. Vadapalli Sai VenkataRammohan
Krishna Institute of Medical Sciences, Secunderabad, Hyderabad, Telangana
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/isj.isj_27_17

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  Abstract 


The spectrum of postoperative spinal infections includes superficial and deep infections, wound infections, spondylodiscitis, intraspinal epidural abscess, infective arachnoiditis, the extraspinal pre- and paravertebral extension of intraspinal abscesses, and necrotic collections. Imaging modalities for detection of these pathologies include plain radiographs, multidetector computed tomography, magnetic resonance imaging (MRI), and radionucleotide scintigraphy. MRI allows adequate visualization of both the bony structures and soft tissues. Contrast enhanced MRI with gadolinium is the imaging modality of choice to delineate postprocedural and postoperative spine infections and complications. MRI has high sensitivity and specificity in the diagnosis of postoperative spondylodiscitis, epidural abscesses, and infective arachnoiditis. Metallic orthopedic hardware may produce artifacts that degrade image quality which is resolved by a metal artifacts reduction sequence to optimize the image quality in bone and soft tissues. F-18 fluorodeoxyglucose positron-emitted tomography is superior to MRI not only in patients with surgical history and high grade infection but also in the patient with low grade spondylodiscitis.

Keywords: F18 bone scan, magnetic resonance imaging, multidetector computed tomography, scintigraphy


How to cite this article:
VenkataRammohan VS, Mulukutla RD, Vadapalli AS. Imaging of postoperative spinal infections. Indian Spine J 2018;1:7-16

How to cite this URL:
VenkataRammohan VS, Mulukutla RD, Vadapalli AS. Imaging of postoperative spinal infections. Indian Spine J [serial online] 2018 [cited 2018 May 22];1:7-16. Available from: http://www.isjonline.com/text.asp?2018/1/1/7/223444




  Introduction Top


Postoperative wound infection of the spine maliciously increases the morbidity, mortality, and health-care costs of the patient. Despite the currently available antibiotics, advances in surgical techniques and postoperative care, postoperative deep wound infection significantly compromises the outcome of spinal surgeries. The largest contributing factor being the long duration of operations, increasing number of spine surgeries on elderly as well as immunocompromised patients, and the growth in availability and prevalence of spinal instrumentation in recent times.[1]

A thorough clinical examination, use of advanced imaging techniques and their careful evaluation can lead to early diagnosis. A radiologist equipped with modern imaging techniques can aid in differentiating between normal postoperative changes and early infection.

Infection due to an involvement of various pathogens, commonly a single or less frequently of the polybacterial type is often seen postoperatively. Gram-positive, Gram-negative bacteria, mycobacteria, and rarely fungal infections may be responsible for postoperative spinal infection and spondylodiscitis, more so in immunocompromised patients.[2]

The organisms that predominate in these infections are Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus sp.[2] Gram-negative organisms that can be encountered are Pseudomonas aeruginosa,  Escherichia More Details coli, and Proteus species. Gram-negative organisms are more likely to occur in lower lumbar surgical interventions.

Anaerobic microorganisms such as Propionibacterium acnes ( P.acnes Scientific Name Search ), part of the normal skin flora, have been increasingly reported to cause various orthopedic related surgical site infections including spine surgeries. P. acnes are difficult to detect in patients undergoing spinal surgery with instrumentation.


  Imaging in Spinal Infections Top


Radiographs, multidetector computed tomography (MDCT), radionuclide bone scans, and magnetic resonance imaging (MRI) have all been used for imaging the postoperative spine.[3] MRI is widely used because it allows adequate visualization of both the bony structures and soft tissues. It can also directly visualize the spinal cord and the lumbosacral/brachial plexuses. Metallic orthopedic hardware may produce artifacts that degrade image quality. A metal artifact reduction sequence (MARS) has been developed to optimize image quality in bone and soft tissues and is used routinely with many pulse sequences.[4] Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) is a novel imaging technique for separating fat and water and reducing susceptibility artifacts due to metal hardware.

Structural imaging techniques rely on changes in normal anatomy and morphology to make a diagnosis, but in the postoperative scenario where normal anatomy is altered, these methods have low sensitivity.[5] Functional imaging studies such as diffusion-weighted MRI studies are performed to improve diagnostic accuracy with high negative predictive value.[6],[7]

The most sensitive modality to detect infections, with the sensitivity of 93% and specificity of 97% for early detection is MRI as it allows better definition of paravertebral and epidural spaces and allows assessment of neural compression elements.[6]

With the option of diffusion-weighted sequences, diffusion-weighted MRI can differentiate between pyogenic, tubercular,[6],[7] and fungal discitis by their apparent diffusion coefficient (ADC) value profile.

This article illustrates the imaging features of spinal infection on multiple imaging modalities as a common postoperative complication associated with various surgical and instrumentation techniques.

Infection and its manifestations

Postoperative spinal infection can be either superficial or deep. It can result in abscess formation in the paravertebral muscles or the epidural space, such as meningitis or arachnoiditis as well as present as spondylodiscitis.

Failure of fusion secondary to infection may place stress on the instrumentation. Continuous motion of the surgical site results in hardware failure, loosening, displacement, or deformation.[8]

Malpositioning (of pedicular screws, bone grafts, cages, and plates) are the most common postoperative complications encountered.[9] The other complications may range from hematomas and fluid collections in the surgical bed, recurrent disk herniation and epidural scar formation.

Plain radiographs

Plain radiographs usually show no specific changes in first 3 weeks of a spinal infection.[10] Later, in the course of the disease, after 4–6 weeks they may show lytic destruction, disc space narrowing, and foci of sclerosis with paravertebral soft-tissue collections or abscesses. Hence, plain radiographs have a role in the inspection and monitoring of implants and their complications. For example, lysis around the implants called as periprosthetic osteolysis suggestive of loosening [Figure 1].
Figure 1: Postoperative spine with L4–L5 laminectomy and discectomy with spondylodiscitis. Plain radiograph anteroposterior and lateral views shows laminectomy at L4–L5 (Black arrow) with end plate erosions of L5 with reduced disc height

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  • It is a cost effective, easily available imaging.
  • The spinal instrumentation and the alignment assessment is better appreciated.
  • Insensitive to early changes of infection of vertebral bodies and intervertebral discs
  • Intra- and extra-spinal collections and abscesses are not visualized
  • Arachnoiditis and cerebrospinal fluid leaks cannot be seen
  • Implant loosening is not visible in early stages.


Multi-detector computed tomography (MDCT)

Computed tomography (CT) is the examination of choice for the assessment of the bony structures of the spine. Assessment of the soft-tissue structures of the spine is often limited and augmentation with contrast medium administration can be indicated. CT is fast and well-tolerated by most patients.

CT scans show areas of early bony destruction and soft-tissue collections with better anatomical detail than plain radiographs.

Early changes include end plate erosions followed by lytic destruction of the vertebral bodies [Figure 2].
Figure 2: Multidetector computed tomography sagittal reformat with metal artifact reduction technique showing pedicular screws with minimized artifacts with lytic destruction of L3 body in mycobacterial infection

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MDCT plays a role in tissue characterization by providing guidance for tissue biopsy of discitis or vertebral osteomyelitis, by fine-needle aspiration and cytology, and aspiration of pus from abscess cavities to provide a microbiological diagnosis including culture for identifying the organism and its antibiotic sensitivity before therapy.[11]

Conventional radiography may take up to 8 weeks to show changes of spondylodiscitis [10] compared to CT which may be positive after 3–4 weeks and shows bone destruction and endplate erosions, disc hypodensity, and flattening with soft-tissue changes such as loss of normal pre and para vertebral fat planes.[12]

Merits

  • Ideal in postoperative cases with spinal instrumentation for the evaluation of implant status with associated infection [Figure 3]
  • Demonstrates cortical bone destruction and osteolysis around the implant
  • Data acquisition time is concise under a minute
  • Low dose algorithms help in radiation dose reduction [3]
  • Metal artifact reduction techniques and three-dimensional multiplanar reformations and volume rendering yield excellent image [Figure 3][4]
  • Patients with pacemakers and aneurysmal clips and neurostimulators, cochlear implants who are otherwise contraindicated for MRI examination benefit from MDCT.
Figure 3: Multidetector computed tomography sagittal reformat with metal artifact reduction technique. L5–S1 spondylodiscitis is evident (black arrow)

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Demerits

  • Radiation dose – this disadvantage is countered by the use of low-dose algorithms and use of as low as reasonably achievable principles
  • Metallic artifacts degrade image quality especially stainless steel instrumentation.


Radio-nucleotide scan (Bone scintigraphy and technetium 99m, F-18 fluorodioxyglucose Positron-Emitted Tomography-CT (F-18 FDG-PET CT)

Bone scintigraphy is easily available, easily performed and rapidly completed but is not specific. Majority of instances of spinal infections show increased uptake of radiopharmaceutical [Figure 4].
Figure 4: Technetium 99m methyl diphosphonate nuclear scan showing D12–L3 spondylodiscitis (causative organism: mycobacterium tuberculosis): Increased bone uptake of technetium 99m methyl diphosphonate (arrow)

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Indications

  • Occult spinal infection clinically suspected with negative radiographs, CT scans and MRI
  • In patients who have pacemakers, metallic cardiac valves, aneurysmal clips, and neurostimulators and cochlear implants where MRI is contraindicated.


CT scans are helpful in patients with spinal instrumentation, where loosening and infection coexist.

Technetium 99m

Three-phase bone scintigraphy with single photon emission CT (SPECT) and analysis of uptake patterns could enhance the accuracy of the 99mTc-methylene diphosphonate (MDP) scan.[13]

Three-phase bone scintigraphy is performed with technetium-99m labeled diphosphonates (MDP) using a SPECT Gamma camera, the uptake depending on blood flow, new bone formation rate. The three-phase bone scan consists of the flow or perfusion phase, (acquired immediately after tracer injection), followed immediately by the blood pool or soft tissue phase and then bone phase consists of images acquired 2–4 h later.

The classic appearance of spinal osteomyelitis is focal hyperperfusion, focal hyperemia on blood pool phase, and focal bone uptake on third bone uptake phase [Figure 4].[14]

Merits of three-phase bone scintigraphy

  • Is widely available
  • Relatively inexpensive, easily performed and rapidly completed, and extremely sensitive
  • With an accuracy of more than 90%, three-phase bone scintigraphy is the nuclear medicine test of choice
  • For diagnosing osteomyelitis in bones not affected by underlying conditions.


Demerits of bone scintigraphy three phase scan

  • Abnormalities on bone scans reflect the rate of new bone formation in general and not infection specifically; hence, false positives occur as tumors, fractures, orthopedic hardware, and the neuropathic joint can all result in a positive three-phase bone scan in the absence of infection, hence, lacks specificity.


F-18 fluorodioxyglucose positron emitted tomography

F-18/FDG-PET is an optimal technique for the diagnosis of postoperative spinal infection. F-18 FDG-PET CT is also useful for the discrimination of residual and nonresidual spinal infections after treatment [Figure 5].[5],[14],[15]
Figure 5: F-18 positron.emitted tomography-CT imaging of postinstrumentation lumbar spine showing spondylodiscitis characterized by increased uptake in end plates and vertebral bodies at the level of L3 and L4 with elevated mean standardized uptake values of L3 and L4. Causative organism was Mycobacterium tuberculosis

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F-18 often identifies the presence of a postoperative disk space infection earlier than technetium-99m scans or plain films [Figure 6].[16]
Figure 6: F-18 bone scan showing increased uptake in D12 vertebral body and the disc showing increased uptake due to spondylodiscitis of pyogenic etiology due to Hemophilus influenza

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Other tracers for diagnosing spinal infection are being developed including radio labeled antibiotics, such as ciprofloxacin, streptavidin/indium-111-biotin complex, and radiolabeled antifungal tracers, which offer to differentiate between fungal and bacterial infection.[17]

The radiopharmaceutical given accumulates in inflammatory cells such as neutrophils, lymphocytes, macrophages, and the granulomatous tissue. Hence, its role in inflammatory and infectious diseases, besides cancer has been growing, and it has been useful in the cases of pyrexia of unknown origin, infected prostheses, osteomyelitis, sarcoidosis, arteritis, and rheumatoid arthritis and other diseases.[18],[19]

F-18/FDG-PET has several potential advantages and merits over conventional nuclear medicine tests including three phase bone scan:[14],[17]

  • It is performed on PET CT scanner which allows the FDG uptake areas to be co registered on multiplanar CT images with output data and results available in 30–60 min after. Normal bone marrow has only a low glucose metabolism which may allow distinction of cellular infiltrates from hematopoietically active marrow
  • Degenerative bone changes usually show only faintly increased FDG uptake compared to spinal osteomyelitis or spondylodiscitis
  • FDG-PET images are not affected by metallic implant artifacts and have a distinctly higher spatial resolution than images obtained with single photon emitting tracer like technetium 99 [Figure 7].
Figure 7: F-18/PET-CT bone scan in patient with L4/L5 and L5/S1 laminectomy with pedicular screws who was operated for spondylolisthesis developed spondylodiscitis as increased uptake of F18 tracer at L5–S1 Staphylococcus aureus infection (arrow)

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Gallium-67-C imaging plays a role as an adjunct to conventional bone scan for a better specificity of the study and to highlight extraskeletal sites of infection.[18]

F-18/FDG PET is superior to MRI not only in patients with surgical history and high grade infection but also in a patient with low-grade spondylodiscitis [19]. In fact, studies prove that F-18/FDG-PET/CT shows superior diagnostic value in the early course of spondylodiscitis when compared to MRI. After 2 weeks of symptoms, both modalities have similar yield. MRI showed the highest sensitivity in diagnosing epidural and spinal abscesses [Figure 8].[20]
Figure 8: Spondylodiscitis with anterior epidural abscess seen on postcontrast T1-weighted fat-suppressed sagittal sequence (arrow) in a postoperative laminectomy L4-L5 discectomy patient. Staphylococcus aureus was grown in culture

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Merits of radionucleotide scan

  • Early detection
  • Useful for monitoring and activity of disease
  • F18-FDG-PET/CT is more sensitive in diagnosing paravertebral abscesses and psoas abscesses [20]
  • FDG-PET appears to be the study of choice when chronic osteomyelitis is suspected to ascertain the status of the disease activity.[5]


Demerits of radionucleotide scan

  • Radiation exposure
  • Nonspecific. It cannot differentiate between pyogenic, tubercular, fungal infections, and neoplasia from each other unless registered with CT or MRI.


Magnetic resonance imaging (MRI)

MRI plays a pivotal role in imaging of patients with spinal instrumentation.[21] However, magnetic susceptibility artifacts from metallic devices pose problems in the form of degrading image quality due to artifacts. Titanium implants produce fewer artifacts with better image quality [Figure 9].
Figure 9: Magnetic resonance imaging T1- and T2-sagittal sequences showing susceptibility metallic artifacts due to pedicular screws at the level of L1 to L3 in a patient who developed postoperative spinal infection, spondylodiscitis at L1-L2. Poor image quality due to metallic hardware artifacts hinders accurate diagnostic characterization of vertebral signal abnormalities

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Incomplete fat saturation represents an additional challenge in evaluating the postoperative spine with metallic hardware. Many techniques are available to minimize susceptibility artifacts, for example, MARS (metal artifact suppression technique) and IDEAL [Figure 10] and [Figure 11].
Figure 10: Status post laminectomy with pedicular screws for traumatic listhesis causing susceptibility artifacts with poor image quality. No metal artifact reduction software was used. The postoperative study shows tuberculous infective spondylodiscitis at L4–L5 with short tau inversion recovery hyperintensity of the disc and end plates (arrow). Transition vertebra L5–S1 with sacralization is noted

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Figure 11: Use of metal artifact reduction technique in conjunction with spin echo T2 and T1 sequences reduces artifacts and improves image quality

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IDEAL water fat separation technique achieves uniform fat saturation and counters the effects of field inhomogeneity while maintaining high signal to noise ratio.[22]

Metallic hardware produces artifacts that degrade image quality. A MARS has been developed to optimize image quality in bone and soft tissues [Figure 12].[23],[24]
Figure 12: Short tau inversion recovery coronal in a postoperative patient with spinal instrumentation who developed spinal infection by Staphylococcus aureus. Marrow edema and marrow infiltration with end plate irregularity and paravertebral abscess (arrow) note the minimized susceptibility metallic artifacts due to use of metal artifact reduction sequence (black arrow)

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MRI findings suggestive of post procedural discitis include a decreased signal on T1 and an increased signal on T2-weighted images in the disk space, secondary to edema from the inflammation and infection (Mimic Modic I pattern) [Figure 13].[25]
Figure 13: Status postoperataive laminectomy with discectomy with postoperative fungal infection (peliomyces infection): T1 sagittal (precontrast, T2 sagittal and post contrast fat saturated T1 sagittal magnetic resonance imaging sequences: Spondylo discitis L4–L5 with T2 short tau inversion recovery hyperintensity with anterior epidural and prevertebral necrotic collection with intense contrast enhancement of l4 and l5 bodies and end plates and L4–L5 disc (arrows)

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Discal and paraspinal tissue contrast enhancement on fat-suppressed T1 postcontrast MRI sequences is suggestive of infection even in the absence of Modic's Type I end plate changes [Figure 14].[26]
Figure 14: Postoperative spine with L4–L5 laminectomy and discectomy with spondylodiscitis postcontrast T1 fat saturated sequence in sagittal and coronal planes showing intense end plate and posterior discal enhancement with intraspinal extension and left paravertebral extension. Biopsy: Chronic nonspecific discitis. Culture: Acinetobacter baumannii complex

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An epidural abscess is usually an isointense lesion with the cord or cauda equina on T1-weighted images with T2 and short tau inversion recovery sequence (STIR) hyperintensity with mass effect on the cord and thecal sac [Figure 14].[27]

Gadolinium-enhanced T1-weighted images show rim enhancement of the abscess wall with a necrotic nonenhancing matrix) [Figure 15] and [Table 1].
Figure 15: T2 sagittal with fat suppression image showing L4–L5 laminectomy with spondylodiscitis with intra discal and anterior epidural abscess with T2 hyper intensity of L4–L5 disc (white arrow)

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Table 1: MRI features of pyogenic, tuberculosis, fungal spondylitis. (+ positive signal; - negative signal)

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Key MRI features of spondylodiscitis

MRI is the imaging modality of choice due to very high sensitivity and specificity. It is also useful in differentiating between pyogenic infection, tuberculous, and fungal infections or a neoplastic process. In postoperative cases without spinal instrumentation, MRI is the best imaging modality of choice [28] [Figure 15] and [Figure 16].
Figure 16: Rim enhancing abscess in anterior epidural space with discal and endplate enhancement with right paravertebral soft-tissue extension (black arrow) spondylodiscitis with epidural abscess at L4-L5 levels (white arrow)

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The signal characteristics include [Table 1]:

T1-weighted images (T1WI)

  • Hypointense signal in the discs and end plates (fluid and bone marrow edema).


T2-weighted images (fat saturation or short tau inversion recovery sequence especially useful)

  • Hyperintense signal in disc space (due to fluid) and endplates (due to bone marrow edema)[29]
  • Loss of low signal cortex at endplates suggestive cortical bone lysis
  • High signal in paravertebral soft tissues on T2 more pronounced on fat-suppressed sequences such as STIR [Figure 17].
Figure 17: T2 sagittal and coronal lumbosacral spine with fat suppression in a patient with postlaminectomy for L5–S1 herniated intervertebral disc: recurrent extruded disc at L5–S1 with endplate edema at L5–S1

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Postcontrast T1 sequences

  • Peripheral rim-like enhancement around fluid collection(s) like a target pattern
  • Enhancement of vertebral endplates and pre- and para-vertebral soft tissues [Figure 18]
  • Ring-like enhancement around low-intense centre indicates central necrosis or liquefaction due to abscess formation. Postcontrast study is ideal to differentiate between inflammatory phlegmon from abscess [30] [Figure 19] and [Figure 20].
Figure 18: Postcontrast T1 coronal and axial sequences with fat suppression in a patient with post laminectomy for L5–S1 herniated intervertebral disc showing recurrent right paracentral extruded contrast enhancing disc at L5–S1.The enhancing disc component and end plates are consistent with infective spondylodiscitis as the noninfected disc does not enhance. Another differential is enhancing fibrovascular scar around an extruded disc. In addition, the presence of end plate enhancement apart from the clinical features favored a coexisting infection with recurrent extruded L5–S1 disc

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Figure 19: Postcontrast T1 coronal and axial sequences with fat suppression in a patient with postlaminectomy for L5–S1 herniated intervertebral disc showing recurrent right paracentral extruded contrast enhancing disc at L5–S1 are consistent with infective Spondylodiscitis as the noninfected disc does not enhance. Another differential is enhancing fibrovascular scar around an extruded scar. Additionally, the presence of end plate enhancement apart from the clinical features favored a coexisting infection with recurrent extruded L5–S1 disc

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Figure 20: Postprocedural infection (for lumbar puncture for cerebrospinal fluid analysis to rule out intracranial meningitis) shows foci of vertebral osteomyelitis (black arrow) on T1 pre- and post-contrast fat suppressed sequences. Cerebrospinal fluid culture showed Staphylococcus aureus

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Diffusion weighted imaging

Diffusion-weighted imaging (DWI) is useful only in postoperative patients without instrumentation [Figure 21].
Figure 21: Diffusion-weighted images of the dorsal cervical spine (right) with apparent diffusion coefficient map (left). Coronal diffusion-weighted images in the center shows restricted diffusion involving D8 body with low apparent diffusion coefficient values (black arrow) on coronal diffusion imaging in a patient with pyogenic osteomyelitis and spondylodiscitis (postprocedural complication). Cervical spine was normal

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DWI can show variable foci of restrictive diffusion seen as partially hyper and hypointense signal on ADC maps associated with high and low ADC values. The high ADC component may represent more serous fluid in caseated necrotic focus in a tuberculous abscess and relatively low ADC represents a secondary liquefaction with low viscosity pus.

This is in contrary to viscous pus formation due to frank liquefaction in pyogenic abscesses [31] [Figure 16] and [Figure 21].

  • Spinal DWI is potentially a very useful tool in diagnosing spinal and paraspinal infections by detection of small abscess or necrotic collections in the epidural space, paraspinal musculature, iliopsoas muscle, vertebral body, and disc
  • Infection hyperintense in acute stage on DWI with hypointensity on ADC maps (Low ADC values) due to restrictive diffusion resulting from viscous pus
  • Infection is hypointense on DWI in chronic stage and hyperintense on ADC maps (Due to high ADC values)
  • Spinal instrumentation interferes with image quality in diffusion weighted MRI which can be partially compensated by the use of special artifact reduction techniques.


Merits of magnetic resonance imaging

  • No radiation
  • Multiplanar capability
  • Excellent soft-tissue contrast
  • Spinal cord and nerve roots can be directly visualized
  • Early marrow involvement for early detection
  • MRI is shown to have the highest sensitivity and specificity in the diagnosis of postprocedural discitis.


Demerits of magnetic resonance imaging

  • Spinal instrumentation interferes with image quality in diffusion-weighted MRI which can be partially compensated by use of special artifact reduction techniques
  • Time-consuming: Multifocal infection requires a multistation whole spine examination which is time-consuming. Polyostotic involvement is better diagnosed with F-18/FDG-PET
  • Expensive.


The standard MRI protocol would be:

  • T1 sagittal
  • T2 sagittal
  • T1 and T2 axial
  • STIR coronal
  • Postcontrast fat saturation T1 axial coronal and sagittal sequences
  • Use of MARS technique or IDEAL techniques to reduce artifacts if spinal instrumentation is present.


Diffusion MRI: special optional if no spinal instrumentation is present: spinal diffusion with b values of 0, 800 or 1000 using spin echo EPI sequences with ADC maps.

Contra-indications

  • Patients with pacemakers, metallic aneurysmal clips, and cochlear neurostimulators
  • Pregnancy: MRI study is a relative contra-indication during the first trimester
  • Contrast study is contraindicated during pregnancy.



  Conclusion Top


The diagnostic challenges in postoperative spinal infection include spinal instrumentation and use of optimized imaging protocols and the choice of imaging technique as each technique suffers from inherent merits and demerits.

A multimodality imaging approach using MRI with pre and post contrast sequences including diffusion-weighted MRI sequence coupled with metal artifact reduction technique and nuclear medicine imaging such as F-18 bone scan and Tc99 scintigraphy enhance the early detection of infection and its extent accurately.

A high index of suspicion and experienced radiologist using modern imaging techniques can help the surgeon in arriving at an early diagnosis. Microbiological and histopathological studies and use of appropriate antibiotics with or without surgical debridement also aid to achieve the satisfactory result. Close cooperation between the treating surgeon and radiologist would go a long way in alleviating the suffering of the patient.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13], [Figure 14], [Figure 15], [Figure 16], [Figure 17], [Figure 18], [Figure 19], [Figure 20], [Figure 21]
 
 
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