Imaging of soft tissue infections

Imaging of MSK infections in the ER

Musculoskeletal infections in the ER are not an uncommon presentation. The clinical context is critical in determining the suspicion for infection and degree of tissue involvement which can involve all layers from the skin to bones. The location, extent, and severity of clinically suspected infection directly relate to the type of imaging performed. Uncomplicated cellulitis typically does not require any imaging. Localized and superficial infections can mostly be evaluated with ultrasound. If there is a diffuse site (an entire extremity) or suspected deeper involvement (muscle/deep fascia), then CT is accurate in diagnosing, widely available, and performed quickly. With potential osseous involvement, MRI is the gold standard for diagnosing acute osteomyelitis; however, it has the drawbacks of longer scan times, artifacts including patient motion, and limited availability.

Imaging of Musculoskeletal Soft-Tissue Infections in Clinical Practice: A Comprehensive Updated Review

Musculoskeletal soft-tissue infections include a wide range of clinical conditions that are commonly encountered in both emergency departments and non-emergency clinical settings. Since clinical signs, symptoms, and even laboratory tests can be unremarkable or non-specific, imaging plays a key role in many cases. MRI is considered the most comprehensive and sensitive imaging tool available for the assessment of musculoskeletal infections. Ultrasound is a fundamental tool, especially for the evaluation of superficially located diseases and for US-guided interventional procedures, such as biopsy, needle-aspiration, and drainage. Conventional radiographs can be very helpful, especially for the detection of foreign bodies and in cases of infections with delayed diagnosis displaying bone involvement. This review article aims to provide a comprehensive overview of the radiological tools available and the imaging features of the most common musculoskeletal soft-tissue infections, including cellulitis, necrotizing and non-necrotizing fasciitis, foreign bodies, abscess, pyomyositis, infectious tenosynovitis, and bursitis.

Pediatric Musculoskeletal Infections: Imaging Guidelines and Recommendations

Pediatric musculoskeletal infections often pose a diagnostic challenge due to their frequently vague and nonspecific clinical presentation. Imaging evaluation is a crucial component to diagnostic workup of these entities. Changed epidemiology of these infections over the past 2 decades has resulted in increases in both disease incidence and severity in the pediatric population. Prompt and accurate diagnosis is essential in order to reduce the risk of morbid sequelae, and to optimize patient management. In this article, the unique pathophysiology of musculoskeletal infections and characteristic imaging findings in children compared with adults are reviewed.

Imaging update on musculoskeletal infections

The clinical diagnosis of musculoskeletal infections can be challenging due to non-specific signs and symptoms on presentation. These infections include infectious myositis, necrotising fasciitis, septic arthritis, septic bursitis, suppurative tenosynovitis, osteomyelitis, spondylodiscitis and periprosthetic infections. Diagnostic imaging is routinely employed as part of the investigative pathway to characterise the underlying infectious disease pattern, allowing expedited and customised patient management plans to optimise outcomes. This article provides an update on the various imaging modalities comprising of radiography, computed tomography, ultrasonography, magnetic resonance imaging and radionuclide procedures, and incorporates representative images of key findings in the different forms of musculoskeletal infections.

Clinical Relevance and Immunohistochemical Patterns of Silent Pituitary Adenomas: 10 Years of Single-centre Experience

BACKGROUND

Silent pituitary adenomas are clinically non-functional (i.e., without clinically evident pituitary hormone production).

INTRODUCTION

The aim of this study was to investigate subjects with silent pituitary adenomas for possible variations in their clinical status.

METHODS

A total of 102 patients who had undergone surgery for pituitary adenoma and had been diagnosed with silent pituitary adenoma was included in the study. The patients' preoperative and postoperative hormonal parameters and magnetic resonance imaging (MRI) features were collected, and pathological specimens were re-evaluated.

RESULTS

Immunohistochemistry results of the 102 patients were as follows: hormone-negative adenomas (n=35) 35.5%; FSH+LH-positivity (n=32) 31.3%; ACTH-positivity (n=11) 10.7%; α-subunit- positivity (n= 9) 8.8%; prolactin-positivity (n=8) 7.8%; GH-positivity (n=6) 5.4%; and plurihormonal adenoma (n=1). The mean sizes of SGA, SGHA, and SCA were 28.0±12.7, 30.0±16.0, and 27.7±8.9mm (p>0.05), respectively. With the exception of silent gonadotroph adenomas (SGAs), female gender dominance was shown in patients with silent growth hormone adenoma (SGHA) and silent corticotroph adenoma (SCA). Although no clinical relevance was observed in relation to hormonal excess, preoperative GH (4.21±4.6, vs. 0.27±0.36 p=0.00) was slightly more elevated in SGHA than in GH-negative adenomas. Additionally, preoperative basal ACTH values (47.3±28.7 vs. 23.9±14.4, p=0.003) were also higher in SCA compared to the other types. Our findings revealed SCAs to be of more aggressive behaviour than SGHAs and SGAs due to invasiveness in radiological imaging, their elevated re-operation, and postoperative ACTH values.

CONCLUSION

Silent pituitary adenomas represent a challenging diagnostic tumour group. Careful initial evaluation of patients with pituitary adenomas should consider any mild signs and symptoms of functionality, particularly in cases of GH- and ACTH-secreting adenomas.

Use of Magnetic Resonance Imaging for Orthopedic Trauma and Infection in the Emergency Department

Conditions affecting the musculoskeletal system constitute a significant portion of medical emergencies in the United States, with traumatic injury and infection being two of the most common etiologies. Although physical examination and plain radiographs are often sufficient to guide diagnosis and treatment, there are myriad traumatic and infectious pathologies that are commonly missed or simply not detectable on plain radiographs. Advanced imaging is subsequently warranted for additional workup.Magnetic resonance imaging (MRI) has become an increasingly used imaging modality for musculoskeletal complaints in the emergency department due to its superior visualization of soft tissues, focal edematous changes, and occult osseous insults often not visible on plain radiographs. Although multiple studies have evaluated its utility in the workup of emergency musculoskeletal complaints, there remains a dearth of literature examining the use of MRI for certain occult diagnoses.Radiologists, emergency clinicians, and orthopedic surgeons must be knowledgeable of the indications for MRI in the emergency setting, as delayed diagnosis may contribute to increased morbidity and possibly mortality. This review summarizes the use of MRI in diagnoses relating to trauma or infection among patients presenting to the emergency department with a musculoskeletal complaint.

Initial Debridement of Dorsal Hand Abscesses in the Operating Room Does Not Improve Outcomes

Background: Hand infections frequently involve the dorsal aspect of the hand and often develop secondary to some traumatic mechanism. Although Staphylococcus aureus is most commonly isolated, anaerobic and polymicrobial infections are not uncommon. To date, treatment is largely anecdotal, with some surgeons preferring a formal debridement in the operating room, while others opt for an initial debridement at the bedside. The goals of this study were to compare outcomes between treatment modalities and to identify the most common causative organisms. Methods: A 10-year retrospective chart review was conducted to identify adult patients who presented with a dorsal hand infection to a single, level 1, urban trauma center. Demographic data were collected as well as the abscess size, location, duration of symptoms, treatment administered, number of formal debridements, length of hospital stay, and complications. Results: The number of formal debridements was significantly less in the initial bedside debridement group (P < .01), as was the hospital length of stay (P < .01). There was no significant difference in hospital readmissions, complications, or infection due to methicillin-resistant Staphylococcus aureus. There was also no significant difference in abscess size, duration of symptoms, or demographic data including age, sex, comorbidities, intravenous drug use status, and immunocompromised status. Conclusions: An initial debridement of dorsal hand infections at the bedside is at least as effective as formal debridement in the operating room. This decreases number of formal debridements and days in the hospital, without any increase in complications. This permits safe, expeditious, and cost-effective treatment for this common condition.

Imaging and Laboratory Workup for Hand Infections

Hand infections can lead to significant morbidity if not treated promptly. Most of these infections, such as abscesses, tenosynovitis, cellulitis, and necrotizing fasciitis, can be diagnosed clinically. Laboratory values, such as white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and recently, procalcitonin and interleukin-6, are helpful in supporting the diagnosis and trending disease progression. Radiographs should be obtained in all cases of infection. Ultrasound is a dynamic study that can provide quick evaluation of deeper structures but is operator dependent. Computed tomographic and MRI studies are useful for evaluating deep space or bony infections and preoperative surgical planning.

Imaging musculoskeletal soft tissue infections

Musculoskeletal soft tissue infections are not uncommonly encountered in both the clinic and Emergency Department setting. The clinical diagnosis is not always evident as these infections can have variable presentations depending on the duration and depth of disease extension through the soft-tissue layers. Imaging often plays an important role in diagnosing the infection, defining the extent of involvement, directing tissue sampling, and in monitoring treatment response. After initial radiographs, ultrasound (US) is often the next modality utilized to evaluate patients with suspected soft tissue infections given its low cost, availability, portability, and potential for real-time guidance of fluid aspiration. The widespread use of cross-sectional imaging with magnetic resonance imaging (MRI) and computed tomography (CT) has greatly increased the radiological diagnosis in conditions where US may be limited. In addition, CT and MRI allow a thorough evaluation of disease extension, including assessment of joint spaces, tendons, and osseous changes indicative of bone involvement. This review will focus on the radiological findings of soft tissue infections on US, CT, and MRI.

Fasciitis and Streptococcal Toxic-shock Syndrome: The Importance of Early Diagnosis and Surgical Management

Introduction:

Fasciitis of the limb and toxic-shock syndrome due to Streptococcus Pyogenes infection is considered a surgical emergency. This condition may occur in previously healthy patients. It is a life-threatening condition with high morbidity rates when treatment is delayed due to poor diagnosis and non-surgical intervention.

Case Report:

17-year-old male patient sustained a minor ankle trauma while skating. Initials findings were a 1cm wound in relation with his left lateral malleolus and moderate swelling. About 6 h later, the patient was admitted at the emergency room with disproportionate limb pain, increased swelling, persistent fever, paleness, tachycardia, and hypotension. The patient was intubated due to his unstable hemodynamic condition and underwent fasciotomy of the limb. A vacuum-assisted closure device was used. After the first surgical procedure, patient’s condition radically improved. He was extubated with good clinical prognosis. He underwent several surgical procedures in a 3-weeks lapse until the wound finally healed.

Conclusion:

Streptococcal toxic-shock syndrome and limb fasciitis have no specific early signs or symptoms. It seems that clinical dissociation (disproportionate pain together with a minor wound) should become an alarm sign to trauma surgeons. It is important to contemplate this serious condition as differential diagnosis in every patient undergoing trauma with torpid evolution. Aggressive surgical management is the gold standard treatment and should not be delayed.

The Role of Computed Tomography in the Diagnosis of Necrotizing Soft Tissue Infections

BACKGROUND

The exact role of IV contrast-enhanced computed tomography (CT) in the diagnosis of necrotizing soft tissue infections (NSTIs) has not yet been established. We aimed to explore the role of CT in patients with clinical suspicion of NSTI and assess its sensitivity and specificity for NSTI.

METHODS

The medical records of patients admitted between 2009 and 2016, who received IV contrast-enhanced CT to rule out NSTI, were reviewed. CT was considered positive in case of: (a) gas in soft tissues, (b) multiple fluid collections, (c) absence or heterogeneity of tissue enhancement by the IV contrast, and (d) significant inflammatory changes under the fascia. NSTI was confirmed only by the presence of necrotic tissue during surgical exploration. NSTI was considered absent if surgical exploration failed to identify necrosis, or if the patient was successfully treated non-operatively.

RESULTS

Of the 184 patients, 17 had a positive CT and hence underwent surgical exploration with NSTI being confirmed in 13 of them (76%). Of the 167 patients that had a negative CT, 38 (23%) underwent surgical exploration due to the high clinical suspicion for NSTI and were all found to have non-necrotizing infections; the remaining 129 (77%) were managed non-operatively with successful resolution of symptoms. The sensitivity of CT in identifying NSTI was 100%, the specificity 98%, the positive predictive value 76%, and the negative predictive value 100%.

CONCLUSIONS

A negative IV contrast-enhanced CT scan can reliably rule out the need for surgical intervention in patients with initial suspicion of NSTI.

Magnetic resonance imaging of painful swollen legs in the emergency department: a pictorial essay

Patients presenting with a painful swollen leg are not infrequently encountered at the emergency department and can pose a diagnostic dilemma for attending physicians. The potential causes of leg pain and swelling include trauma, infection, inflammation, and neurogenic, vascular, and iatrogenic conditions; with magnetic resonance imaging (MRI) being an important tool in evaluation. We describe the MRI features of various conditions causing painful swollen legs. We also discuss the differential diagnosis and the useful clinical and laboratory findings that radiologists should be aware of, in order to arrive at an accurate diagnosis.

Radiologic Approach to Musculoskeletal Infections

Imaging is often used to establish a diagnosis of musculoskeletal infections and evaluate the full extent and severity of disease. Imaging should always start with radiographs, which provide an important anatomic overview. MRI is the test of choice in most musculoskeletal infections because of its superior soft tissue contrast resolution and high sensitivity for pathologic edema. However, MRI is not always possible. Alternative imaging modalities including ultrasound scan, computed tomography, and radionuclide imaging may be used. This article reviews the individual imaging modalities and discusses how specific musculoskeletal infections should be approached from an imaging perspective.

The utility of ultrasound for diagnosing purulent infections of the upper extremity

BACKGROUND

The purpose of this study was to determine the test characteristics of formal ultrasound when used to diagnose upper extremity soft tissue abscess in the setting of suspected infection.

METHODS

We completed a retrospective chart review of all patients who had formal ultrasounds at our institution for the indication of diagnosing upper extremity abscess between July 2010 and July 2013. Using presence of purulence as the gold standard for diagnosis of abscess, we calculated the test characteristics of ultrasound. We then performed a series of logistic regression models with ultrasound being the independent variable of interest.

RESULTS

Using search criteria consistent with upper extremity abscess, we identified 512 patients who underwent ultrasound examinations during our study period. Of these, 178 met the enrollment criteria. Ultrasound reports revealed 110 negative findings, 37 definitively positive findings, and 31 ambiguous findings. Forty-four patients had a final diagnosis of abscess, and 15 of these patients had negative or ambiguous ultrasounds. The sensitivity of definitively positive ultrasound was 65.9 %. The specificity was 94.0 %. Positive predictive value (PPV) of a definitively positive ultrasound result was 78.4 %, and negative predictive value (NPV) of a definitively negative result was 90 %. Logistic regression demonstrated a statistically significant association between definitively positive ultrasound and abscess, but no association between ambiguous ultrasound and abscess after adjustment for significant covariates.

CONCLUSIONS

Ultrasound is not a sensitive method to detect the presence of abscess in the setting of upper extremity infection. However, in this population of patients with suspected abscess, the negative predictive value was high with and without the inclusion of ambiguous results, suggesting reasonable utility of ultrasound as a rule-out test.

LEVEL OF EVIDENCE

Diagnostic study, Level II.

Point-of-Care Ultrasound Diagnosis of Deep Space Hand Infection

BACKGROUND

Point-of-care ultrasound is emerging as an important imaging modality for characterizing soft-tissue infections and provides advantages over physical examination and magnetic resonance imaging (MRI).

CASE REPORT

A 30-year-old man presented to the emergency department with extensive left upper extremity cellulitis. Magnetic resonance imaging of the left arm was preliminarily interpreted as soft-tissue swelling without evidence of deep-space infection. Point-of-care ultrasound revealed pockets of fluid with sonographic fluctuance tracking along the tendon sheath that were concerning for deep abscesses. Based on the ultrasound findings, the patient was taken emergently to the operating room, where multiple left hand and wrist loculated deep-space abscesses were decompressed. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case report highlights the significant advantages and easy-to-learn findings present in point-of-care ultrasound of musculoskeletal infections.

Lower limb complications of diabetes mellitus: a comprehensive review with clinicopathological insights from a dedicated high-risk diabetic foot multidisciplinary team

Diabetic complications in the lower extremity are associated with significant morbidity and mortality, and impact heavily upon the public health system. Early and accurate recognition of these abnormalities is crucial, enabling the early initiation of treatments and thus avoiding or minimizing deformity, dysfunction and amputation. Following careful clinical assessment, radiological imaging is central to the diagnostic and follow-up process. We aim to provide a comprehensive review of diabetic lower limb complications designed to assist radiologists and to contribute to better outcomes for these patients.

Positron emission tomography in spinal infections

Magnetic resonance imaging is the imaging method of choice for diagnosing infection of the spine in unoperated cases. 2-[(18)F]-fluoro-2deoxy-d-glucose positron emission tomography/computed tomography study is recommended to distinguish between spinal infection and common Modic change in patients with metallic implants and prosthetic replacements and for differentiating tuberculous from pyogenic spondylitis in ambiguous cases, reflecting the activity of the infection. Also, it seems to have a strong clinical impact in more than half of patients with infectious spondylitis, while it is superior to other imaging techniques in revealing residual disease after treatment and early response to therapy. New tracers as well as new hybrid modalities are under investigation.

Necrotizing fasciitis and its mimics: what radiologists need to know

OBJECTIVE

The purpose of this article is to review the imaging features of necrotizing fasciitis and its potential mimics. Key imaging features are emphasized to enable accurate and efficient interpretation of variables that are essential in appropriate management.

CONCLUSION

Necrotizing fasciitis is a medical emergency with potential lethal outcome. Dissecting gas along fascial planes in the absence of penetrating trauma (including iatrogenic) is essentially pathognomonic. However, the lack of soft-tissue emphysema does not exclude the diagnosis. Mimics of necrotizing fasciitis include nonnecrotizing fasciitis (eosinophilic, paraneoplastic, inflammatory (lupus myofasciitis, Churg-Strauss, nodular, or proliferative), myositis, neoplasm, myonecrosis, inflammatory myopathy, and compartment syndrome. Necrotizing fasciitis is a clinical diagnosis, and imaging can reveal nonspecific or negative findings (particularly during the early course of disease). One should be familiar with salient clinical and imaging findings of necrotizing fasciitis to facilitate a more rapid and accurate diagnosis and be aware that its diagnosis necessitates immediate discussion with the referring physician.

Necrotizing fasciitis: an urgent diagnosis

Necrotizing fasciitis (NF) is a rare, life-threatening soft-tissue infection and a medical and surgical emergency, with increasing incidence in the last few years. It is characterized by a rapidly spreading, progressive necrosis of the deep fascia and subcutaneous tissue. Necrotizing fasciitis is often underestimated because of the lack of specific clinical findings in the initial stages of the disease. Many adjuncts such as laboratory findings, bedside tests--e.g., the "finger test" or biopsy--and imaging tests have been described as being helpful in the early recognition of the disease. Imaging is very useful to confirm the diagnosis, but also to assess the extent of the disorder, the potential surgical planning, and the detection of underlying etiologies. The presence of gas within the necrotized fasciae is characteristic, but may be lacking. The main finding is thickening of the deep fasciae due to fluid accumulation and reactive hyperemia, best seen on magnetic resonance imaging.

Necrotizing soft tissue infections

Necrotizing soft tissue infections (NSTIs) are infrequent yet highly lethal infections, and a high index of suspicion is required for early diagnosis. Diagnosing NSTIs early can be challenging, and knowledge of the available tools is essential to provide appropriate treatment. The mainstay of treatment is early and complete surgical debridement combined with antimicrobial therapy, close monitoring with further debridement as needed, and physiologic support. Mortality continues to be high, and delayed surgical treatment is the most important risk factor. For the long-term recovery of patients with NSTI, providing early physiologic and nutritional support and physical rehabilitation is essential.

The role of MRI in image-guided needle biopsy of focal bone and soft tissue neoplasms

Magnetic resonance imaging (MRI) plays a critical role in the management pathway of both soft tissue and bone neoplasms, from diagnosis through to post-treatment follow-up. There are a wide range of surgical, oncological, and combined treatment regimes but these rely on accurate histopathological diagnosis. This article reviews the role of MRI in the planning of image-guided needle biopsy for suspected soft tissue and bone tumors.

Tuberculous pyomyositis: a rare but serious diagnosis

Tuberculous pyomyositis is a rare clinical entity with serious consequences if a diagnosis is not established early. A 53-year-old female with a past medical history of sarcoidosis and pulmonary fibrosis presented from an outside hospital with persistent fevers and a rash. She had been hospitalized multiple times at an outside hospital without any improvement in her symptoms. On examination, she was noted to have a large area of left upper lower extremity (LUE) tenderness with superimposed erythema. Laboratory data revealed a white blood cell count of 22,300. Computed tomography (CT) scans of the LUE, chest, and left lower extremity (LLE) showed multiple intramuscular abscesses in those regions without evidence of osteomyelitis. Subsequent drainage of the abscesses and resulting cultures revealed Mycobacterium tuberculosis. The patient was started on therapy with rifampin, isoniazid, pyrazinamide, and ethambutol. However, the patient developed hepatitis on these agents and subsequently went into septic shock with multiorgan failure. Care was eventually withdrawn as a result of a poor prognosis. This case illustrates the severe consequences of TB pyomyositis if not diagnosed promptly. While tuberculosis is uncommon in the United States, it should be an important consideration in the differential diagnosis of immunocompromised patients.

Magnetic resonance imaging of musculoskeletal infections: systematic diagnostic assessment and key points

Prompt diagnosis and treatment are essential in preventing the complications of musculoskeletal infection. In this context, imaging is often used to confirm clinically suspected diagnoses, define the extent of infection, and ensure appropriate management. Because of its superior soft-tissue contrast resolution, magnetic resonance imaging (MRI) is the modality of choice for evaluating musculoskeletal infections. This article describes the MRI features along the full spectrum of musculoskeletal infections and provides several illustrative case examples.

Necrotizing fasciitis of the lower limbs

We report an uncommon severe soft-tissue infection of the thighs in a male child with acute lymphoblastic leukemia. Early and aggressive medical treatment and the conservative surgical approach were successful. Necrotizing fasciitis should be suspected in any soft-tissue infection until it can be definitely ruled out, since prompt deliver of medical and surgical intervention is essential.

Pyomyositis

Poorly controlled diabetes is associated with an increased risk of infectious complications. With the increasing prevalence of diabetes, many more people are being looked after in primary care. We describe a case of pyomyositis, a potentially severe but uncommon complication of poorly controlled diabetes that was not recognised in the community. Clinicians looking after people with diabetes need to be aware that prolonged, unexplained symptoms need specialist assessment.

Cellulitis: diagnosis and management

Cellulitis is an acute infection of the dermal and subcutaneous layers of the skin, often occurring after a local skin trauma. It is a common diagnosis in both inpatient and outpatient dermatology, as well as in the primary care setting. Cellulitis classically presents with erythema, swelling, warmth, and tenderness over the affected area. There are many other dermatologic diseases, which can present with similar findings, highlighting the need to consider a broad differential diagnosis. Some of the most common mimics of cellulitis include venous stasis dermatitis, contact dermatitis, deep vein thrombosis, and panniculitis. History, local characteristics of the affected area, systemic signs, laboratory tests, and, in some cases, skin biopsy can be helpful in confirming the correct diagnosis. Most patients can be treated as an outpatient with oral antibiotics, with dicloxacillin or cephalexin being the oral therapy of choice when methicillin-resistant Staphylococcus aureus is not a concern.

MR imaging of skeletal soft tissue infection: utility of diffusion-weighted imaging in detecting abscess formation

PURPOSE

Our objectives were to assess if diffusion-weighted imaging (DWI) can help identify abscess formation in the setting of soft tissue infection and to assess whether abscess formation can be diagnosed confidently with a combination of DWI and other unenhanced sequences.

METHODS

Eight cases of soft tissue infection imaged with MRI including DWI were retrospectively reviewed.

RESULTS

Two male and six female patients were studied (age range 23-50 years). Unenhanced MRI including DWI was performed in all patients. Post-contrast images were obtained in seven patients. All patients had clinically or surgically confirmed abscesses. Abscesses demonstrated restricted diffusion. DWI in conjunction with other unenhanced imaging showed similar confidence levels as post-contrast images in diagnosing abscess formation in four cases. In two cases, although the combined use of DWI and other unenhanced imaging yielded the same confidence levels as post-contrast imaging, DWI was more definitive for demonstrating abscess formation. In one case, post-contrast images had a better confidence for suggesting abscess. In one case, DWI helped detected the abscess, where gadolinium could not be administered because of a contraindication.

CONCLUSION

This preliminary study suggests that DWI is a useful adjunct in the diagnosis of skeletal soft tissue abscesses.

Sensitivity of Computed Tomography in Detection of Perirectal Abscess

Most patients with anorectal abscess are diagnosed clinically based on pain, erythema, warmth, and fluctuance. Some patients, however, present with subtle or atypical signs. CT is easily accessible and is commonly used for diagnosis and delineation of anorectal abscess. The purpose of this study is to determine the sensitivity of CT scan in detecting perirectal abscesses and to see if immune status impacts the accuracy of CT. A retrospective study was conducted to identify patients from 2000 to 2009 with International Classification of Diseases, 9th Revision code 566 (anal or rectal abscess). Patients included had a CT scan less than 48 hours before drainage. Patients with CT-positive abscess were compared with patients with CT-negative abscess. Patients were categorized as either immunocompetent or immunosuppressed based on documentation of diabetes mellitus, cancer, human immunodeficiency virus, or end-stage renal disease. One hundred thirteen patients were included in this study. Seventy-four (65.5%) were male and the average age was 47 years. Eighty-seven of 113 (77%) patients were positive on CT for anorectal abscess. Sixty of 113 (53%) patients included in this study were immunocompromised. CT missed 26 of 113 (23%) patients with confirmed perirectal abscess. Eighteen (69%) of these patients were immunocompromised compared with CT-positive patients (42 [48%], P = 0.05). The overall sensitivity of CT in identifying abscess was 77 per cent. CT lacks sensitivity in detecting perirectal abscess, particularly in the immunocompromised patient.

Imaging of the diabetic foot diagnostic dilemmas

Multiple diagnostic imaging modalities are available and beneficial for the evaluation of the diabetic foot. There is not yet "one best test" for sorting out the diagnostic dilemmas commonly encountered. The differentiation of cellulitis alone from underlying osteomyelitis and the early detection of abscesses remain important diagnostic goals. Equally important, differentiation of osteomyelitis and neuroarthropathy remains a difficult job. This is often compounded by postoperative diabetic foot states status after reconstruction. Diagnostic evaluation often involves multiple studies that are complementary and that include conventional radiography, computed tomography, nuclear medicine scintigraphy, magnetic resonance imaging, ultrasonography, and positron emission tomography.

Imaging of musculoskeletal soft tissue infections

Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice.

Liposuction Sepsis – Be Alert

Postoperative infection in liposuction patients may be exceedingly difficult to clinically appreciate because of the skin edema, colour changes and even blistering that can occur. The authors outline such a case with practical advice about establishing an accurate and precise diagnosis of an early septic process.

Severe soft tissue infections

Severe skin and soft tissue infections (SSTIs) frequently require management in the ICU, in part related to associated septic shock or toxic shock syndrome or associated organ failure. Four fundamental management principles are key to a successful outcome in caring for patients who have severe SSTIs, including (1) early diagnosis and differentiation of necrotizing versus nonnecrotizing SSTI, (2) early initiation of appropriate empiric broad-spectrum antimicrobial therapy with consideration of risk factors for specific pathogens and mandatory coverage for methicillin-resistant Staphylococcus aureus (MRSA), (3) source control (ie, early aggressive surgical intervention for drainage of abscesses and debridement of necrotizing soft tissue infections), and (4) pathogen identification and appropriate de-escalation of antimicrobial therapy. MRSA has emerged as the most common identifiable cause of severe SSTIs; therefore, initiation of empiric anti-MRSA antimicrobials is warranted in all cases of severe SSTIs. In addition, appropriate critical care management-including fluid resuscitation, organ support and nutritional support-is a necessary component in treating severe SSTIs.

Sepsis requiring intensive care following intramuscular injections: two case reports

Introduction

Intramuscular injections can rarely result in serious infectious complications such as abscesses which may progress to bacteraemia and generalized sepsis. These complications are rare, but can be life threatening, as they can lead to multi-organ failure associated with high morbidity and mortality.

Case presentation

In this report we present two patients who developed life-threatening infections after intramuscular injections. They were admitted to the hospital, had prompt surgical drainage, required ICU admission for severe sepsis, were treated with an early goal-directed therapy protocol and had a good outcome.

Conclusion

Sepsis is a rare, potentially life-threatening complication after intramuscular injections. Timely surgical drainage followed by appropriate ICU care and early goal directed therapy is crucial and may contribute to a good outcome in these rare cases.