The bone scan in inflammatory osseous disease

Molecular Imaging of Infections: Emerging Techniques for Pathogen-Specific Diagnosis and Guided Therapy

Evaluation of patients that may be infected is challenging. Imaging to identify or localize a site of infection is often limited because of the nonspecific nature of the findings on conventional imaging modalities. Available imaging methods lack the ability to determine if antibiotics are reaching the site of infection and are not optimized to follow response to therapy. Positron emission tomography (PET) is a method by which radiolabeled molecules can be used to detect metabolic perturbations or levels of expression of specific targets. The most common PET agent is the glucose analog 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG). 18F-FDG has some applicability to localizing a site of infection, but its lack of specificity limits its usefulness. There is a need for the development of pathogen-specific PET radiotracers to address the imaging shortcomings noted above. Preclinical and clinical progress has been made, but significant challenges remain.

Do various imaging modalities provide potential early detection and diagnosis of medication-related osteonecrosis of the jaw? A review

OBJECTIVE

Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities' usage and findings of MRONJ to provide possible approaches for early detection.

METHODS

Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ.

RESULTS

Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T₁WI and hyperintense on T₂WI and STIR when necrotic bone shows hypointensity on all T₁WI, T₂WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ.

CONCLUSION

Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

Advances in Sensing Technologies for Monitoring of Bone Health

: Changing lifestyle and food habits are responsible for health problems, especially those related to bone in an aging population. Poor bone health has now become a serious matter of concern for many of us. In order to avoid serious consequences, the early prediction of symptoms and diagnosis of bone diseases have become the need of the hour. From this inspiration, the evolution of different bone health monitoring techniques and measurement methods practiced by researchers and healthcare companies has been discussed. This paper focuses on various types of bone diseases along with the modeling and remodeling phenomena of bones. The evolution of various diagnosis tests for bone health monitoring has been also discussed. Various types of bone turnover markers, their assessment techniques, and recent developments for the monitoring of biochemical markers to diagnose the bone conditions are highlighted. Then, the paper focuses on the potential assessment of the recent sensing techniques (physical sensors and biosensors) that are currently available for bone health monitoring. Considering the importance of electrochemical biosensors in terms of high sensitivity and reliability, specific attention has been given to the recent development of electrochemical biosensors and significance in real-time monitoring of bone health.

A novel approach of 67-Gallium-citrate three-phase bone scan to diagnose bone infection: A report of three cases

OBJECTIVES

67-Gallium-citrate three-phase bone scan (Ga-TPBS), a new approach for the diagnosis of bone infection is evaluated. The interpretation of TPBS is based on the normal physiological vascular endothelial-related response noted in infection.

MATERIALS AND METHODS

Three cases of suspected bone infection as determined by clinical, laboratory, and radiological examinations were further subjected to conventional technetium-99m-TPBS (Tc-99m-TPBS) and Ga-TPBS. Nuclear scan diagnosis of bone infection was made by the presence of generalized vasodilatation with increased capillary permeability noted on the flow and the pool phase of the TPBS and the comparative evaluation of the 4 h delayed Tc-TPBS and 24-48 h delayed Ga-TPBS. Diagnosis of bone infection was confirmed in all three cases on histopathologcal examination of the surgically excised tissues.

RESULTS

The data clearly indicated that all three cases of bone infection (osteomyelitis) had generalized massive flow and pool pattern. Infection could be diagnosed only on the Ga-TPBS by noting generalized vasodilatation with increased capillary permeability on the flow and the pool phase with focal retention of the radiotracer on the delayed scan.

CONCLUSIONS

By incorporating the concept of vascular endothelial-related response causing massive vasodilatation in infection, the interpretation of the Ga-TPBS can be more précised as it is based on the normal physiology. In comparison to two Tc-99m scans (white blood cell scan + bone marrow scan), a single Ga-TPBS is also cost-effective and compliance friendly. Larger, comparative, and statistically unbiased studies are needed.

Primary Chronic Osteomyelitis of the Jaws in Children: An Update on Pathophysiology, Radiological Findings, Treatment Strategies, and Prospective Analysis of Two Cases

Objective. Primary chronic osteomyelitis (PCO) of the jaws in children is associated with pain, trismus, and swelling. In children, temporomandibular joint involvement is rare and few studies have been published due to the relatively low incidence. This paper presents two cases of mandibular PCO in children with the involvement of the collum mandibulae. In addition, a review of the literature regarding demographic data, histological, radiological, and laboratory findings, and treatment strategies of PCO was also performed. Material and Methods. Prospective analyses of two PCO cases. A PubMed search was used and the articles were sorted according to their corresponding key area of focus. Results. Review of the literature revealed twenty-four cases of PCO with two cases of mandibular condyle involvement. The mean age was 18 years; the male to female ratio was 1 : 3. Most of the patients were treated with anti-inflammatory drugs in combination with decortication. Clinical recurrence was seen in 7 cases. Conclusion. A combination of anti-inflammatory drugs and surgical intervention appears to be the first choice of treatment. However, surgical removal of necrotic tissue adjacent to collum mandibulae has its limitations in children. Further investigations are of utmost importance in order to increase our knowledge and understanding of this disease.

Imaging of diabetic foot infections

Complications from diabetic foot infections are a leading cause of nontraumatic lower-extremity amputations. Nearly 85% of these amputations result from an infected foot ulcer. Osteomyelitis is present in approximately 20% of diabetic foot infections. It is imperative that clinicians make quick and successful diagnoses of diabetic foot osteomyelitis (DFO) because a delay in treatment may lead to worsening outcomes. Imaging studies, such as plain films, bone scans, musculoskeletal ultrasound, computerized tomography scans, magnetic resonance imaging, and positron emission tomography scans, aid in the diagnosis. However, there are several mimickers of DFO, which present problems to making a correct diagnosis.

Pediatric osteomyelitis: a scintigraphic case-based review

This review presents techniques to optimize bone scintigraphy for evaluation of the spectrum of abnormalities associated with pediatric osteomyelitis, with an emphasis on the approaches to patient preparation and positioning and to interpretation. The diagnosis of pediatric osteomyelitis can be challenging for several different reasons. Bone scintigraphy is especially useful when the site of osteomyelitis is unclear. Other imaging modalities, including radiography, ultrasonography, and magnetic resonance imaging, all have advantages and may have a role in evaluating the condition of the child with osteomyelitis. Pathophysiologic considerations unique to children contribute to a different clinical presentation of osteomyelitis in the pediatric population than that seen in adults. In addition, patient movement degrades image quality substantially, which is an important consideration for imaging children. Neonates have a higher incidence of multifocal osteomyelitis, and they represent a unique subset of the pediatric population with separate considerations. Several examples illustrate techniques to optimize imaging, as well as show the spectrum of abnormalities associated with pediatric osteomyelitis. Careful attention to bone scintigraphic technique ensures that high-quality images can be obtained, which will allow confident diagnosis of pediatric osteomyelitis.

The bone scan

Bone imaging continues to be the second greatest-volume nuclear imaging procedure, offering the advantage of total body examination, low cost, and high sensitivity. Its power rests in the physiological uptake and pathophysiologic behavior of 99m technetium (99m-Tc) diphosphonates. The diagnostic utility, sensitivity, specificity, and predictive value of 99m-Tc bone imaging for benign conditions and tumors was established when only planar imaging was available. Currently, nearly all bone scans are performed as a planar study (whole-body, 3-phase, or regional), with the radiologist often adding single-photon emission computed tomography (SPECT) imaging. Here we review many current indications for planar bone imaging, highlighting indications in which the planar data are often diagnostically sufficient, although diagnosis may be enhanced by SPECT. (18)F sodium fluoride positron emission tomography (PET) is also re-emerging as a bone agent, and had been considered interchangeable with 99m-Tc diphosphonates in the past. In addition to SPECT, new imaging modalities, including (18)F fluorodeoxyglucose, PET/CT, CT, magnetic resonance, and SPECT/CT, have been developed and can aid in evaluating benign and malignant bone disease. Because (18)F fluorodeoxyglucose is taken up by tumor cells and Tc diphosphonates are taken up in osteoblastic activity or osteoblastic healing reaction, both modalities are complementary. CT and magnetic resonance may supplement, but do not replace, bone imaging, which often detects pathology before anatomic changes are appreciated. We also stress the importance of dose reduction by reducing the dose of 99m-Tc diphosphonates and avoiding unnecessary CT acquisitions. In addition, we describe an approach to image interpretation that emphasizes communication with referring colleagues and correlation with appropriate history to significantly improve our impact on patient care.

Critically evaluating the role of diagnostic imaging in osteomyelitis

Early diagnosis, essential for timely appropriate treatment and reduction of complications, can be difficult. This article aims to give an overview of the role that different imaging modalities have to play in the diagnosis of osteomyelitis. Osteomyelitis is a heterogeneous disease in its pathophysiology, clinical presentation, and management. It infers inflammation of bone and marrow, whereas osteitis is inflammation of the bone only. Thus, a soft-tissue infection that reaches the bone surface but has not infected the marrow is osteitis and not osteomyelitis. Chronic osteomyelitis is divided into active and inactive forms. Newly appearing periosteal reaction or bone destruction within the chronic involucrum are indicators of activation. Imaging modalities represent different underlying pathophysiological processes that may be represented in differing types and differing phases of osteomyelitis. Sequential selection of appropriate imaging modalities requires a thorough understanding of the disease processes and the process by which each modality visualizes this dynamic disease process.

Role of modern imaging techniques for diagnosis of infection in the era of 18F-fluorodeoxyglucose positron emission tomography

During the past several years, it has become quite evident that positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) imaging can play a major role in the management of patients with suspected infection. Particularly, several groups have demonstrated that this powerful imaging methodology is very effective in the evaluation of osteomyelitis, infected prostheses, fever of unknown origin, and AIDS. In view of its extraordinary sensitivity in detecting disease activity and the ability to quantitate the degree of FDG uptake, PET might prove to be an appropriate modality for monitoring disease activity and evaluating response to therapy. FDG-PET has many advantages over existing imaging techniques for the diagnosis of infectious diseases. These include feasibility of securing diagnostic results within 1.5 to 2 h, excellent spatial resolution, and accurate anatomical localization of sites of abnormality. The availability of PET/computed tomography as a practical tool has further enhanced the role of metabolic imaging in many settings. In the future, this modality is very likely to be employed on a routine basis for detecting, characterizing, and monitoring patients with suspected and proven infection.

Imaging of osteomyelitis: current concepts

Osteomyelitis frequently requires more than one imaging technique for an accurate diagnosis. Conventional radiography still remains the first imaging modality. MRI and nuclear medicine are the most sensitive and specific methods for the detection of osteomyelitis. MRI provides more accurate information regarding the extent of the infectious process. Ultrasound represents a noninvasive method to evaluate the involved soft tissues and cortical bone and may provide guidance for diagnostic or therapeutic aspiration, drainage, or tissue biopsy. CT scan can be a useful method to detect early osseous erosion and to document the presence of sequestra. PET and SPECT are highly accurate techniques for the evaluation of chronic osteomyelitis, allowing differentiation from soft tissue infection.

[Nuclear medicine techniques in the diagnosis of orthopaedic diseases]

Nuclear medicine techniques show metabolic processes, allowing the diagnoses of many bone and joint disorders. For most orthopaedic indications three-phase bone scintigraphy is used, showing inflammatory bone and joint diseases, traumatic and post-operative disorders as well as necrotic or malignant changes. In addition to bone scintigraphy, there are radiopharmaceuticals to depict inflammatory processes. Finally, positron emission tomography is a modern imaging technique used mainly for tumor diagnostics, but also for detection of inflammation.

Evaluating diabetic foot infection with magnetic resonance imaging: Kuwait experience

OBJECTIVE

The aim of this study was to evaluate the capability of magnetic resonance imaging (MRI) to depict and characterize the changes seen in diabetic foot infections.

SUBJECTS AND METHODS

MRI studies of 29 diabetic patients with suspected foot infection were evaluated. Sagittal and transverse T1-weighted images before and after intravenous gadolinium, and transverse fat-suppressed T2-weighted images were performed on the affected regions. The MRI findings were compared to subsequent clinical and/or histopathological findings.

RESULTS

The MRI findings were: osteomyelitis in 14 patients, abscess in 5, cellulitis in 26, tenosynovitis in 4 and neuropathic joint in 8. Three cases were normal. Pathological confirmations were obtained in 19 patients. MRI and histological diagnosis were in concordance in 79% of osteomyelitis cases, 100% of neuropathy cases and 100% of cellulitis cases. The sensitivity and specificity of MRI in diagnosing osteomyelitis were 100 and 63%, respectively. The positive predictive and negative predictive values, and the accuracy were 79, 100 and 84%, respectively. MRI helped surgical planning for limb salvage procedures in 6 of the osteomyelitis cases and in a cellulitis case.

CONCLUSION

The results indicate that MRI is a sensitive and accurate imaging modality for the evaluation of foot infections in diabetic patients and for planning proper treatment.

Clinical feasibility of two-step streptavidin/111In-biotin scintigraphy in patients with suspected vertebral osteomyelitis

PURPOSE

Streptavidin accumulates at sites of inflammation and infection as a result of increased capillary permeability. In addition to being utilised by bacteria for their own growth, biotin forms a stable, high-affinity non-covalent complex with avidin. The objective of this investigation was to determine the diagnostic performance of two-step streptavidin/111In-biotin imaging for evaluating patients with suspected vertebral osteomyelitis.

METHODS

We evaluated 55 consecutive patients with suspected vertebral osteomyelitis (34 women and 21 men aged 27-86 years), within 2 weeks after the onset of clinical symptoms. Thirty-two of the patients underwent magnetic resonance imaging (MRI) and 24, computed tomography (CT). DTPA-conjugated biotin was radiolabelled by incubating 500 microg of DTPA-biotin with 111 MBq of 111In-chloride. Two-step scintigraphy was performed by first infusing 3 mg streptavidin intravenously, followed 4 h later by 111In-biotin. Imaging was begun 60 min later.

RESULTS

Streptavidin/111In-biotin scintigraphy was positive in 32/34 patients with spinal infection (94.12% sensitivity). The study was negative in 19/21 patients without infection (95.24% specificity). The corresponding results for MRI and CT were 54.17% and 35.29% (sensitivity), and 75% and 57.14% (specificity), respectively. All statistical parameters of diagnostic performance (Youden's J index, kappa measure of agreement with correct classification, accuracy, sensitivity, specificity, positive likelihood and negative likelihood) were clearly better for streptavidin/111In-biotin scintigraphy than for either MRI or CT.

CONCLUSION

Streptavidin/111In-biotin scintigraphy is highly sensitive and specific for detecting vertebral osteomyelitis in the first 2 weeks after the onset of clinical symptoms, and is potentially very useful for guiding clinical decisions on instituting appropriate therapy.

Bone scintigraphy in mycobacterium avium osteomyelitis: a case report

A 30-year-old woman who had a destructive Mycobacterium avium complex infection in the left inguinal fossa affecting the pubic bone underwent three-phase bone scanning to identify other possibly affected sites. Multiple skeletal lesions were seen scattered throughout the vertebral column, sternum, and pelvis. This case is presented to describe a rare extensive metastatic M. avium complex infection in an immunocompromised patient.

Upper extremity radionuclide bone imaging: shoulder, arm, elbow, and forearm

Along with resurgence of physical activity during these fitness conscious times, there is increasing participation by people of all ages in sporting activities. Enrollment in organized and recreational sports among young adults and children has increased with as many as 30% of adolescents participating in competitive high school athletics. Despite improvements in equipment, the number of sports-related injuries presenting for medical attention has increased. Injuries to the upper extremities account for more than 25% of all sports-related injuries, but receive disproportionately less attention compared to lower extremity injuries. If neglected, upper extremity injuries can end the career of a professional athlete and cause sufficient damage to hinder daily activities in a recreational participant. Overuse syndromes, brought on by repetitive microtrauma are sports-specific, and often challenging to diagnose. Accurate diagnosis requires a thorough understanding about mechanism of injury, site of pain, and knowledge of the sport. After a thorough physical exam, a variety of radiographic testing is often necessary to promptly diagnose and manage the injury so athletes can return to competition as soon as possible.

Multimodality imaging of osteomyelitis

Early diagnosis of osteomyelitis continues to be a clinical problem. Multiple imaging modalities are being used for the diagnosis of osteomyelitis, but none of them is ideal for all cases. The choice of modality depends on several factors based on an understanding of the pathophysiologic aspects of different forms of osteomyelitis. After a brief introduction outlining some basic principles regarding the diagnosis of osteomyelitis, pathophysiologic aspects are reviewed. Advantages and disadvantages of each imaging modality and their applications in different forms of osteomyelitis are discussed. The use of different imaging modalities in the diagnosis of special forms of osteomyelitis, including chronic, diabetic foot, and vertebral osteomyelitis, and osteomyelitis associated with orthopedic appliances and sickle cell disease is reviewed. Taking into account the site of suspected osteomyelitis and the presence or absence of underlying pathologic changes and their nature, an algorithm summarizing the use of various imaging modalities in the diagnosis of osteomyelitis is presented.

Spontaneous atlantoaxial osteomyelitis: no longer a rare case? Case report

The number of case reports concerning anterior atlantoaxial osteomyelitis has increased in the past decade. Although previously considered rare, this particular disease has become more prevalent for several reasons, including the increase in the elderly population, which is generally more susceptible to infectious problems. It is, therefore, imperative for physicians in general and neurosurgeons in particular to become aware of the existence of this problem and of the therapeutic options available.

Primary sternal osteomyelitis

Primary sternal osteomyelitis is a rare condition. Most of the recent cases have been reported in intravenous drug abusers. A case of primary sternal osteomyelitis with no apparent risk factors is reported. Diagnosing sternal osteomyelitis can be difficult, but failure to clinically recognize this type of infection in its early stages can lead to serious sequelae. The diagnosis should be suspected in a young patient presenting with acute inflammatory swelling over the sternum. It is further supported by leukocytosis, elevated sedimentation rate, lateral radiograph of the sternum, and positive Gram's stain. While bacteriological culture results are pending, antibiotic therapy with Staphylococcus aureus coverage should be initiated empirically. Diagnostic evaluation and management of the patients with this entity are briefly discussed.

Bone and gallium scans in postradiotherapy osteonecrosis of the jaw

The role of radiographic and nuclear imaging in evaluation of postradiotherapy osteonecrosis of the jaw was studied. Patients who had received imaging at diagnosis and following hyperbaric oxygen therapy were studied. Radiographic changes did not correlate with the clinical status of patients. All bone scans were abnormal at the time of diagnosis of osteonecrosis, but remained abnormal following changes in the clinical status of patients. Thus, the bone scan may aid in the detection of osteonecrosis. Gallium uptake did not aid i diagnosis, but did correlate with clinical findings following treatment. Persisting positive gallium scans may indicate the need for surgery following hyperbaric oxygen therapy.

Treatment of chronic traumatic bone wounds. Microvascular free tissue transfer: a 13-year experience in 96 patients

During a 13-year period at the Massachusetts General Hospital, Boston, Massachusetts, 97 microvascular free tissue transfers have been performed for soft-tissue reconstruction in 96 patients following bone debridement for chronic traumatic bone wounds. These 96 patients comprise a continuation study of 18 original patients reported in 1982. During a 13-year follow-up period (mean, 77.1 months), 95.8% of these 96 patients have enjoyed complete wound closure with a lack of drainage after the debridement and free tissue transfer. Most of the patients (89.6%) encountered in this study are ambulatory without assist and 5.2% of patients have undergone amputation. Twenty-three per cent of patients required subsequent segmental bone defect reconstruction in the lower extremity after infection eradication. The pathophysiology of chronic traumatic bony wounds is different from that of chronic hematogenous osteomyelitis and thus a high incidence of long-term successful management can be seen through complete wound debridement and adequate soft-tissue coverage.

Radionuclide imaging in osteomyelitis

The utility of bone imaging has remained significantly high despite the proven suboptimal specificity of the conventional three-phase bone scan. The quantitative four-phase study may play a role in maintaining its usefulness in the future. However, due to its extremely high sensitivity and excellent anatomical information, it remains as the first diagnostic study in most suspected cases of acute osteomyelitis. The future would see development of new imaging modalities aimed at enhancing the specificity for diagnosis of active osteomyelitis. The indium leucocyte study has been the single most important development in this respect in the last decade. NMR has been another important addition to complement the anatomical information for defining the extent and nature of infectious process--acute or chronic. It remains to be seen if the other investigative work on antigranulocyte antibodies or other imaging agents or techniques would make the future diagnosis of osteomyelitis more reliable and accurate using the nuclear medicine techniques.

Complications of fractures and their healing

The role of nuclear medicine studies in diagnosing late complications of fractures is described. Static bone scintigraphy is not helpful in predicting delayed or non-union of fractures. Several investigators have developed simple formulae comparing uptake in fracture site with adjacent or contralateral normal bone and described criteria that will predict problems with healing. These types of tests should only be used in patients who are at risk for delayed union. The scintigraphic diagnosis of infection complicating a fracture is difficult. Bone scintigraphy alone is not useful and combined 67Ga/99mTc MDP scanning has been disappointing. Most published series support the role in 111In WBC in this situation, but not all cases are correctly diagnosed. 111In (Chloride) cannot differentiate an infected from a delayed-healing fracture. Bone scintigraphy has a significant role in determining whether a bone graft is viable or not. Reflex sympathetic dystrophy is a rare complication of a fracture; it can be diagnosed by increased periarticular uptake on bone scan in all the joints of the affected part. Bone scintigraphy, especially when done with SPECT, is a very sensitive test for the diagnosis of avascular necrosis (AVN).

Magnification radiography in osteomyelitis

Osteomyelitis often eludes early diagnosis because plain film radiography is too insensitive and radionuclide bone scanning is nonspecific. In this study, 90 diabetic patients were studied with plain film and magnification radiographs of their feet. Among the 24 patients with osteomyelitis, plain radiographs suggested the diagnosis in 14 patients and magnification radiography was diagnostic in 18 of these patients. Thus, magnification radiography offers some diagnostic advantage in patients suspected of having osteomyelitis.

Miscellaneous conditions associated with arthritis in children

Miscellaneous conditions associated with arthritis in children are reviewed as distinct entities in the differential diagnosis of the many types of juvenile arthritis reviewed here and in other articles.

Diagnosis of vertebral osteomyelitis: clinical, radiological and scintigraphic features

Incidence of non-tuberculous vertebral osteomyelitis has been increasing significantly over the past 15 years. Its prompt diagnosis remains difficult. Presented here are five cases of vertebral osteomyelitis studied clinically, with laboratory studies, radiographically, and with Tc-99m bone and In-111 labeled white blood cells (In-111 WBC) scintigrams. Three of the cases are described in detail. The In-111 WBC studies were not found useful in detecting the infection in four out of the five patients. Reasons for these false negative results are discussed. Clinical, etiopathogenic and radiographic characteristics of vertebral osteomyelitis are also presented.

A diagnostic approach to lytic lesions of the mandible

Fifty seven patients with histologically proven cyst-like lesions of the mandible are reviewed. The importance of combining radiographic with scintigraphic imaging is stressed. These two imaging modalities are complementary in demonstrating both the biological activity and the extent of the lesion. In osteomyelitis the bone scan, which is more sensitive than the radiograph, is also the method of choice in assessing the result of treatment.

The radionuclide diagnosis, evaluation and follow-up of malignant external otitis (MEO). The value of immediate blood pool scanning

A patient suffering from malignant external otitis (MEO) underwent early blood pool scanning followed after 2 hours by 99m Tc MDP bone scanning and serial Ga-67 citrate scintigraphies of the skull. The former two procedures served as a diagnostic tool to MEO. The latter was used for estimating the extent of the infective process and for following-up the efficacy of treatment. The complementary role of these three procedures in the diagnosis and follow-up of MEO, with special emphasis on immediate blood pool scanning as part of the diagnostic procedure, is illustrated.

Diffuse sclerosing osteomyelitis of the mandible

The medical care of patients with diffuse sclerosing osteomyelitis (DSO) of the mandible has been unsatisfactory. The main reasons for this have been insufficient knowledge of the disease and its natural history, difficulties in establishing the correct diagnosis, and the unknown etiology. The clinical features and natural history of the disease were studied by means of repeated radiographic and scintigraphic recordings. The biopsy technique was improved by using a slowly rotating coarse trepan bur. Histological and enzyme histochemical investigations were performed for determination of the histopathological diagnosis. Orthopantomograms in combination with intraoral views and 99mTc-scintigraphy were used for the radiographic diagnosis and follow-up studies. Bacteriological and serological investigations were performed in attempt to clarify the obscure etiology. The occurrence in the patients' sera of antibodies to antigens prepared from cultured bacteria was studied. ASTA, IgM, IgG, and IgA were determined and lymphocyte stimulation tests were performed. The investigations made it possible to distinguish DSO as a separate entity with rather characteristic clinical, histological and radiographic features. The histological diagnosis was facilitated by an improved biopsy technique and enzyme histochemical recordings. Different rather unspecific tissue reactions were together found to form a pattern which was strongly indicative of DSO. The radiographic and scintigraphic investigations gave valuable findings which increased the diagnostic accuracy and improved the prognostic and therapeutic judgements. The bacteriological and serological investigations indicated that propionibacterium acnes and peptostreptococcus intermedius were of etiological importance but could not explain the chronicity of the disease. The results of the different investigations gave a better understanding of DSO and made it possible to provide more appropriate care for patients in different stages of the disease. Long-term antibiotic therapy was found to have a positive influence on the course of the disease in its early stages, while cortisone therapy, and sometimes decortication, were found to be more effective in chronic stages.