Imaging of osteomyelitis: current concepts

Multislice SPECT/CT in benign and malignant bone disease: when the ordinary turns into the extraordinary

Nuclear medicine has entered a new era of multimodality imaging. Dedicated multislice single-photon emission computed tomography/computed tomography (SPECT/CT) cameras are relatively new additions to the diagnostic armamentarium in nuclear medicine. The integration of SPECT and CT provides precise anatomical localization and may enable characterization of abnormalities identified on planar or SPECT imaging by providing structural information by CT. The evidence in support of SPECT/CT is rapidly amounting but still relatively limited. To date, studies have suggested improved diagnostic confidence and specificity in the diagnosis of bone pathology. The combination of functional information and anatomical localization has the potential to influence medical practice with newer imaging algorithms. This review presents the current evidence and potential indications of SPECT/CT bone imaging in the assessment of benign and malignant conditions.

Osteomyelitis of the iliac crest: a rare complication following perforated appendicitis

BACKGROUND

Appendicitis is a common surgical emergency with numerous postoperative infective complications. We report an unusual case of iliac crest osteomyelitis as a late complication following emergency appendectomy for perforated gangrenous appendicitis.

METHODS

Review of the pertinent English language literature.

RESULTS

To the best of our knowledge, this is the first report in the English literature to describe iliac crest osteomyelitis as an infective complication of perforated gangrenous appendicitis. The diagnosis was made with the aid of magnetic resonance imaging and radioisotope bone scans. The complication was treated successfully with broad-spectrum intravenous antibiotics and physiotherapy.

CONCLUSION

Iliac crest osteomyelitis is indeed a rare complication of appendicitis. A heightened awareness and better understanding of this complication would necessitate early diagnosis and treatment.

The child with bone pain: malignancies and mimickers

Bone pain in children is common. The cause may be as benign as growing pains or as life-threatening as a malignancy. When a cause cannot be established by laboratory tests, physical examination or patient history, imaging of the affected body part is often obtained. Distinguishing benign from malignant processes involving the bones of children, based on imaging findings, can be challenging. The most common benign conditions that mimic pediatric bone tumors on imaging are Langerhan's cell histiocytosis and osteomyelitis. In this review, the current literature regarding the pathology and imaging of these conditions is reviewed. Benign conditions are compared with the most common pediatric bone tumors, Ewing sarcoma and osteosarcoma, with an emphasis on clinical and imaging features that may aid in diagnosis.

Rheumatic diseases in the ancient Americas: the skeletal manifestations of treponematoses

INTRODUCTION

The effect of rheumatic and infectious diseases on skeletal remains provides an important source of information for knowledge of contemporary medicine. Few pathologic conditions have attracted so much interest as treponematoses. One of these, syphilis, was the most feared venereal disease throughout the civilized world until the introduction of penicillin in the 20th century.

OBJECTIVE

To describe paleopathological and ceramic illustrations of treponematoses in ancient Mexico.

MATERIALS AND METHODS

Paleopathological and ceramic material examples from the National Institute of Anthropology and History of Mexico were reviewed.

RESULTS

A unique paleopathologic site for treponemal diseases comprises the La Candelaria Cave skeletal collection from northern Mexico. The cave was used as a burial site and contained the bones of at least 83 adults and 33 subadults. Fifty-one percent of the recovered skulls possess erosions of the vault consistent with treponematoses. Some of these exhibit the impressive frontal bone lytic changes with irregular borders typical of caries sicca. In addition, periostosis of the long bones was found in up to 88% of the study sample, including 6 examples of saber-shin deformity of tibias. Radiocarbon dating (-C) of a bone retrieved from the cave ranges from 1100 to 1300 A.D. Additionally, a Pre-Hispanic ceramic figurine from the Mexican state of Nayarit depicting a lame man with multiple nodular skin lesions that suggest gummatous treponemal infection is described.

CONCLUSIONS

These ancient specimens reinforce the notion that treponemal infection was present on the American Continent before European penetration of the New World. These very advanced paleopathologic lesions and ceramic representations demonstrate the degree to which these diseases wrought devastation before the antibiotic era. In ancient times, treponematoses were true rheumatic diseases that produced profound skeletal abnormalities marked by periosteal accretion and bone destruction.

Diagnosis of osteomyelitis in children: utility of fat-suppressed contrast-enhanced MRI

OBJECTIVE

The purpose of this study was to determine whether the use of fat-suppressed contrast-enhanced MRI, compared with unenhanced MRI alone, increases reader confidence in the diagnosis of osteomyelitis and its complications in children.

MATERIALS AND METHODS

MRI studies of 78 skeletally immature children and adolescents (median age, 3.6 years) with suspected nonspinal osteomyelitis were reviewed in consensus by two readers. Unenhanced images were evaluated first and then contrast-enhanced MR images. Images were scored for the presence or absence of osteomyelitis, abscess, septic arthritis, and physeal involvement on a 5-point scale ranging from definitely absent to definitely present. Forty-two additional studies were evaluated to test interobserver agreement.

RESULTS

Osteomyelitis was clinically diagnosed in 40 cases (51%). There was no significant difference between the sensitivity and specificity of unenhanced MRI (p = 1.0) and those of contrast-enhanced MRI (p = 0.77) for the diagnosis of osteomyelitis. Nonetheless, there was a significant (p < 0.001) increase in confidence in the diagnosis of osteomyelitis and its complications. This increase in confidence was most pronounced for the diagnosis of abscess (46%). The addition of contrast enhancement was least useful in findings deemed definitely absent on unenhanced MR images.

CONCLUSION

Although it does not increase the sensitivity or specificity of the diagnosis, use of contrast-enhanced MRI does increase reader confidence in the diagnosis of osteomyelitis and its complications in cases in which bone or soft-tissue edema is found on unenhanced images. In the clear absence of edema on unenhanced images, however, contrast enhancement is not needed.

Radiographic imaging in osteomyelitis: the role of plain radiography, computed tomography, ultrasonography, magnetic resonance imaging, and scintigraphy

The diagnostic imaging of osteomyelitis can require the combination of diverse imaging techniques for an accurate diagnosis. Conventional radiography should always be the first imaging modality to start with, as it provides an overview of the anatomy and the pathologic conditions of the bone and soft tissues of the region of interest. Sonography is most useful in the diagnosis of fluid collections, periosteal involvement, and surrounding soft tissue abnormalities and may provide guidance for diagnostic or therapeutic aspiration, drainage, or tissue biopsy. Computed tomography scan can be a useful method to detect early osseous erosion and to document the presence of sequestrum, foreign body, or gas formation but generally is less sensitive than other modalities for the detection of bone infection. Magnetic resonance imaging is the most sensitive and most specific imaging modality for the detection of osteomyelitis and provides superb anatomic detail and more accurate information of the extent of the infectious process and soft tissues involved. Nuclear medicine imaging is particularly useful in identifying multifocal osseous involvement.