FOIA BMJ. Peri-orbital cellulitis is of concern in children because it may be secondary to occult underlying bacterial sinusitis or, rarely, due . It results in pain, erythema, oedema, and warmth. This content is owned by the AAFP. Diffuse thickening of the superficial fascia, which can be seen in the early phase of necrotizing fasciitis (c). Here is a summary of the indications for non-contrasted CT: Contrast helps enhance certain body structures. myriad of non-infective erythematous rashes, ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Because there is a risk of aspiration-induced pulmonary edema with concentrated iodine-based contrast agents, patients must be carefully selected. A paranasal sinus pathology is . We are grateful for the editorial assistance of Megan M. Griffiths, scientific writer for the Imaging Institute, Cleveland Clinic. Unable to load your collection due to an error, Unable to load your delegates due to an error. In B, the native left lung is small, with evidence of bronchiectasis, bronchiolectasis, and areas of honeycombing (black arrow). Version 10.1.2015, Intravenous contrast material exposure is not an independent risk factor for dialysis or mortality. It results in pain, erythema, edema, and warmth. It is essential to know the types of contrast agents, their risks, contraindications, and common clinical scenarios in which contrast-enhanced computed tomography is appropriate. Epub 2020 Oct 15. 4. CT Head or brain with and without contrast Note: MRI Brain with/without contrast is preferred. Check for errors and try again. In patients with normal renal function, repeat measurement of serum creatinine is not recommended after outpatient administration of IV contrast agents.7. endobj In particular, the evaluation of soft tissue infections, including cellulitus, myositis, fasciitis, abscess, and septic arthritis are often best evaluated by MRI or CT due to their excellent anatomic resolution and soft tissue contrast. Author disclosure: No relevant financial affiliations. There are several contrast agents that may be used in performing CT scans. of 20 consecutive patients with necrotizing fasciitis, CT revealed fascial thickening and fat stranding in 80%, soft tissue gas in 55%, and abscesses in 35%.22, CT is helpful in guiding surgical debridement and drainage by evaluating the extent of soft tissue and osseous involvement, identifying the potential infectious source and identifying potential complications including vascular rupture or tissue necrosis.1, 2,13,22, MRI is the gold-standard for soft-tissue infections as it provides excellent soft-tissue contrast resolution with a sensitivity of 93% for the diagnosis for necrotizing fasciitis.1, 24 Essential sequences include T1 weighted imaging to assess anatomy, and T2 fat saturated or short tauinversion-recovery sequences to look for fascial thickening and edema.3, 25 Post gadolinium sequences are helpful to delineate the extent of infection, identify abscesses and areas of necrosis, but may not be feasible in patients with acute renal failure, which is common in this patient population.3, 26, Deep fascial thickening and subfascial fluid accumulation can be seen as high signal on fluid sensitive sequences (Figures 8 and 9).21 The deep intramuscular fascia is usually protected in the setting of cellulitis, but is involved in necrotizing fasciitis.1 Fascial thickening begins in the superficial fascia and extends along the deep intermuscular fascia, not just in areas contiguous to the deep peripheral fascia.1, 18 Hyperintensity and thickness of the fascia greater than or equal to 3 mm on fat saturated T2 weighted or short tauinversion-recovery images with involvement of three or more compartments is a sensitive finding to suggest necrotizing fasciitis.3, 8,13,25,27 The absence of T2 hyperintensity within the deep fascia can essentially exclude a diagnosis necrotizing fasciitis.3, 18,21. 2 0 obj Typically, CT focusing on vascular disease (e.g., aneurysm, dissection) or renal or pancreatic pathology may include noncontrast-enhanced images to identify calcifications.20 Contrast-enhanced studies would be performed on the same day, in the same setting. In Vivo MicroCT Monitoring of Osteomyelitis in a Rat Model. Reinert CP, Pfannenberg C, Dittmann H, Gckel B, la Fougre C, Nikolaou K, Hoefert S. J Clin Med. Kim KT, Kim YJ, Won Lee J, Kim YJ, Park SW, Lim MK, et al.. Can necrotizing infectious fasciitis be differentiated from nonnecrotizing infectious fasciitis with MR imaging? This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Renal function should be assessed with a baseline creatinine level before administration as patients with impaired renal function are at risk for complications associated with IV contrast. The information provided is for educational purposes only. The location and extent of the inflammatory process was accurately demonstrated with axial CT scans in all cases. Swartz M. Clinical Practice. Sagittal CT reformation demonstrates linear fluid collection (arrow) deep to the rectus femoris muscle (b). Computed tomography (CT) with and without contrast: indications and protocols. Epidemiology Risk factors trauma foreign bodies 2015;2015:587857. doi: 10.1155/2015/587857. 2004;350(9):904-12. Contrast can cause acute renal failure. 2001;176(5):1155-9. 2019;10(1):47. Here is an overview of the indications for contrasted CT: CT Angiography, or CTA, is a type of contrasted CT scan used to evaluate the blood vessels. Contrast-related nephrotoxicity has been reported,11 although this has been challenged more recently.12 Suspected risk factors for this complication include advanced age, cardiovascular disease, treatment with chemotherapy, elevated serum creatinine level, dehydration, diabetes, use of nonsteroidal anti-inflammatory medications, myeloma,13 renal disease, and kidney transplant. Additionally, systemic features such as fevers and rigors may also be present. 3. CT pulmonary angiography with intravenous contrast in a patient being evaluated for arteriovenous malformation. What is the rationale for the laboratory workup for suspected pheochromocytomas and paragangliomas? endstream 1994;192(2):493-6. Ultrasonographic screening of clinically-suspected necrotizing fasciitis. 30 0 obj Sign In to Email Alerts with your Email Address. The decision to order contrast-enhanced CT is based on the clinical question being asked. Rahmouni A, Chosidow O, Mathieu D et al. Infection, inflammation, and edema of the lung parenchyma are usually well depicted on CT without contrast enhancement. Federal government websites often end in .gov or .mil. Adams, James, and Erik D. Barton. In particular, the evaluation of soft tissue infections, including cellulitus, myositis, fasciitis, abscess, and septic arthritis are often best evaluated by MRI or CT due to their excellent anatomic resolution and soft tissue contrast. In patients with elevated creatinine, withholding IV dye may be necessary. Iodinated contrast should be avoided for two months before administration of iodine 131. [18F]Fluoride Positron-Emission Tomography (PET) and [18F]FDG PET for Assessment of Osteomyelitis of the Jaw in Comparison to Computed Tomography (CT) and Magnetic Resonance Imaging (MRI): A Prospective PET/CT and PET/MRI Pilot Study. Unauthorized use of these marks is strictly prohibited. Cellulitis occurs after disruption of the skin and invasion of the subcutaneous tissues by microorganisms that may be skin flora, such as beta-haemolytic streptococci (most often),Staphylococcus aureus(including methycillin-resistant), or other bacteria 9. Fundic gland polyps: Should my patient stop taking PPIs? Interstitial lung disease 2. Prior to contrast administration, patients should be asked about previous allergy to CT contrast. N/A No CT WRIST LEFT WO CONTRAST (IMG3906) CT WRIST RIGHT WO CONTRAST(IMG3909) CT HAND LEFT WO CONTRAST (IMG3794) CT HAND RIGHT WO CONTRAST (IMG3797) 73200 In later stages, nonenhancement of the fascia may be seen due to necrosis, which can be helpful to differentiate from nonnecrotizing fasciitis.3, 28,29, Although more apparent on CT, gas in the soft tissues is represented by punctate or curvilinear T1 and T2 low signal with corresponding blooming artifact on gradient echo sequences.1, 18,25,30 Although a highly specific finding, the absence of soft-tissue gas does not exclude the diagnosis of necrotizing fasciitis.3, 11. N.p. Cross-sectional schematic diagram through the right thigh demonstrating the various findings of necrotizing fasciitis. In C, the transplanted lung is notable for areas of air trapping in the right upper lobe on expiratory images (blue arrow), which is associated with central airway narrowing. Fasciae of the Musculoskeletal System: MRI Findings in Trauma, Infection and Neoplastic Diseases. Check for errors and try again. Detailed protocols for premedication and management of contrast adverse reactions are beyond the scope of this review and the reader is advised to refer to dedicated manuals.10. These reactions are relatively rare and are usually mild but occasionally can be severe.9 Anaphylactoid reactions have an unclear etiology but mimic allergic reactions, and they are more likely to occur in patients with a previous reaction to contrast and in patients with asthma or cardiovascular or renal disease. One study showed similar increases in serum creatinine levels between inpatient populations who received IV iodinated contrast and those who did not.16, Noncontrast-enhanced CT is used in patients with head trauma and acute stroke. Concerns for using IV contrast during CT include a history of reactions to contrast agents, pregnancy, treatment of thyroid disease with radioactive iodine, use of metformin (Glucophage), and chronic or acutely worsening renal disease. Emerg Radiol. Contrast: A plain ct looks for stones. When the neoplasm has CT attenuation similar to that of adjacent structures (lymph nodes in the hilum, masses in the mediasti-num or chest wall), IV contrast can improve identification of the lesion and delineation of its margins and the relationship with adjacent structures (eg, vascular structures) (Figure 1). Order "WRIST" if only carpal area. Recent estimates place the number of computed tomography (CT) scans performed annually in the United States at approximately 70 million.1 Given the cost and radiation exposure, it is critical that CT is appropriate and performed with optimal technique. Initial radiographs show soft tissue gas (without puncture wound) or are normal with high clinical suspicion of necrotizing fasciitis. In patients with normal renal function, repeat measurement of serum creatinine is not recommended after outpatient administration of intravenous contrast agents. This risk is significantly increased in patients with chronic renal disease, diabetes, heart failure, and anemia. Additionally, systemic features such as fevers and rigors may also be present. 1998 Aug;6(3):537-59. 2009;16(4):267-76. That said, it is seldom required for diagnosing cellulitis and is therefore usually ordered for suspected complications or to rule out alternative diagnoses in cases of an atypical presentation. Most centers use nonionic contrast agents (which are generally low osmolality) for IV contrast studies.5 The rate of major reactions (e.g., anaphylaxis, death) is the same for ionic and nonionic IV contrast agentsan estimated one in 170,000 administrationsbut nonionic contrast has a lower rate of minor reactions.6 Approximately 5% to 12% of patients who receive high-osmolality contrast have adverse reactions, most of which are mild or moderate.7 Use of low-osmolality contrast has been associated with a reduction in adverse effects. 8. Horton L, Jacobson J, Powell A, Fessell D, Hayes C. Sonography and Radiography of Soft-Tissue Foreign Bodies. This can be filled at Baystate Pharmacies at 759 Chestnut Street and 3300 Main Street as well as at many local pharmacies. 1. These agents for enhancing the image created on CT may be delivered by a number of different routes, the most common of which are oral and intravenous. Chaudhry AA, Baker KS, Gould ES, Gupta R. Necrotizing fasciitis and its mimics: what radiologists need to know, Musculoskeletal infection: role of CT in the emergency department. Finally, imaging of the abdomen and pelvis to assess for renal stones also does not require CT contrast. 7. Nonanaphylactoid reactions are dependent on contrast osmolality and on the volume and route of injection (unlike anaphylactoid reactions).10 Typical symptoms include warmth, metallic taste, and nausea or vomiting. Cellulitis treatment usually includes a prescription oral antibiotic. Wronski M, Slodkowski M, Cebulski W, Karkocha D, Krasnodebski IW. Disease processes that involve calcifications may benefit from noncontrast-enhanced images because contrast may mask the appearance of calcifications. Children have a lower incidence of reactions to IV contrast agents, and most of these are mild (0.18% for low-osmolality agents).7,8, Risk factors for contrast reactions include multiple drug allergies and asthma. T2 weighted image with fat saturation of the left thigh demonstrates a large area of myonecrosis within the proximal rectus femoris muscle, with extensive muscular, fascial, and subcutaneous enhancement and edema, with crescentic fascial fluid collections, predominantly around the rectus femoris and sartorius, suggestive of necrotizing fasciitis. Assessment of interstitial lung disease does not require use of IV contrast; rather, a tailored protocol with thinner slices and non-contiguous expiratory images can be used to evaluate for air-trapping and dynamic airway compromise (Figure 4). CT with contrast can help to depict infection of the chest wall or mediastinum and in some instances can also delineate the route of spread.7, Contrast media used in CT contain iodine, which causes increased absorption and scattering of radiation in body tissues and blood. AJR Am J Roentgenol. However, contrast enhancement is used to evaluate suspected or known exudative effusions and empyema.6 It also aids the evaluation of metastatic or primary malignancy of the pleura, particularly in cases of occult disease, as enhancement and thickening of the pleura are of diagnostic interest. IV contrast may be used to visualize vasculature as well as the internal organs of the abdomen and pelvis. ADVERTISEMENT: Radiopaedia is free thanks to our supporters and advertisers. eCollection 2022. 9. Case 1: orbital and periorbital cellulitis, see full revision history and disclosures. 2021;50(12):2319-47. Contrast agents can be further classified as high or low osmolality, based on the iodine concentration. 2001 Oct;42(4-5):259-305. Barium suspension from fluoroscopy or CT will not produce an artifact on abdominal magnetic resonance imaging. 2021;50(12):2319-47. Barium suspensions are not nephrotoxic and can be used safely in patients with renal failure. Wysoki MG, Santora TA, Shah RM, Friedman AC. Radiol Clin North Am. N Engl J Med. Evaluation of chronic obstructive pulmonary disease also does not require IV contrast. Follow-up of a solitary pulmonary nodule also typically does not require contrast enhancement, though some investigators have reported high sensitivity with dynamic contrast enhancement of pulmonary nodules.4 This rep resents a rare clinical application of chest CT with and without contrast. Schmid M, Kossmann T, Duewell S. Differentiation of Necrotizing Fasciitis and Cellulitis Using MR Imaging. Hayeri MR, Ziai P, Shehata ML, Teytelboym OM, Huang BK. Would you like email updates of new search results? T2 weighted images with fat saturation demonstrates extensive high signal within the intermuscular septa surrounding the gastrocnemius and soleus muscle bellies suggestive of subfascial fluid (white arrows). government site. Family physicians often must determine the most appropriate diagnostic tests to order for their patients. Created for people with ongoing healthcare needs but benefits everyone. Many practices have their own protocols for IV dye administration in patients using metformin so nurse practitioners must familiarize themselves with these policies. The American Academy of Radiology recommends the use of IV contrast only if care of the patient cannot be accomplished without it. Ultrasound is usually the first investigation to evaluate a clinical suspicion of cellulitis. At the time the article was last revised David Carroll had There is subcutaneous emphysema (arrows) overlying the right ankle with plate and screw fixation seen (a). Cross-sectional imaging findings include asymmetric thickening of the fascia, soft-tissue air, blurring of fascial planes, inflammatory fat stranding, reactive lymphadenopathy, and nonenhancement of the muscular fascia. 2009;39(10):957-71. Search dates: November 2009 and April 27, 2010. It is injected through an intravenous line during the examination. It is injected through an intravenous line during the examination. Order "HAND" if entire wrist and hand. 2. Disclaimer. Laryngeal edema (severe or rapidly progressing), Methylprednisolone (Medrol), 32 mg orally 12 and 2 hours before contrast administration; plus diphenhydramine (Benadryl), 50 mg intravenously, intramuscularly, or orally 1 hour before contrast administration, Prednisone, 50 mg orally 13, 7, and 1 hour before contrast administration; plus diphenhydramine, 50 mg intravenously, intramuscularly, or orally 1 hour before contrast administration, Normal renal function and no comorbid disorder, Metformin (Glucophage) can be continued when contrast is administered; serum creatinine does not need to be measured, Normal renal function and at least one comorbid disorder, Metformin should be discontinued when contrast is administered; if the patient remains clinically stable and has no new intercurrent risk factors for renal impairment, metformin may be resumed in 48 hours without repeating serum creatinine measurement, Metformin should be discontinued when contrast is administered; resume only after careful reevaluation and monitoring of renal status, Noncontrast-enhanced CT of the head is the preferred initial study if performed within three hours of acute symptom onset; contrast-enhanced CT should be obtained for patients with symptoms lasting longer than three hours; contrast-enhanced CT combined with CT angiography of the neck may be needed for follow-up, Thin section high-resolution CT without contrast, Extremity soft tissue swelling, infection, or trauma, Contrast is necessary if vascular involvement or injury is suspected, Scan suspected area of trauma in cervical, thoracic, or lumbar spine, Abdominal and pelvic CT; oral or rectal contrast agent based on institutional preference, Protocols vary depending on cancer type and stage, Diverticulitis; suspected complications of inflammatory bowel disease, Intravenous contrast agent for diverticulitis; oral and/or rectal contrast agent can be administered to visualize bowel, Noncontrast-enhanced CT is sensitive for calcifications (chronic pancreatitis); contrast-enhanced CT is best for evolving pancreatitis or pancreatic pseudocyst, Many centers now include venous phase CT of the pelvis and lower extremities in combination with CT angiography of the lung. In a patient with colon cancer undergoing a workup for metastases, axial CT without contrast (A) shows prominence of the right hilar region (arrow). The diagnostic algorithm for lung cancer screening is evolving. Clipboard, Search History, and several other advanced features are temporarily unavailable. Suspected Osteomyelitis, Septic Arthritis, or Soft Tissue Infection (Excluding Spine and Diabetic Foot) Patients with a mild allergy may be pre-medicated with an antihistamine or steroids before imaging. <>/Metadata 2 0 R/ViewerPreferences 6 0 R>> Other CT findings include increase soft-tissue attenuation, subcutaneous edema and inflammatory fat stranding, which can also be seen in cellulitis.2,2123 In a study by Wysoki et al. %PDF-1.7 Almost always, CTs should be ordered with or without contrast, not both. the contents by NLM or the National Institutes of Health. It is also not used in patients with suspected acute stroke. Reference article, Radiopaedia.org (Accessed on 01 May 2023) https://doi.org/10.53347/rID-15554. Normally the subcutaneous tissue is hypoechoic with few hyperechoic strands (representing connective tissue). Fluid tracking along deep and intermuscular fascia, which can be seen in advanced cases (d). MRI's visualization of the bone marrow allows for the sensitive detection of osteomyelitis, although specificity for the diagnosis of osteomyelitis is aided by other findings, including cortical destruction. Mitchell C, Dolan N, Drsteler K. Management of Dependent Use of Illicit Opioids. The US Preventive Services Task Force currently recommends low-dose CT without contrast, along with appropriate patient counseling, for patients with a history of smoking and an age range as detailed in the Task Force statement.3. Compared to plain radiography, ultrasound, CT and MR provide higher sensitivity and specificity for the diagnosis of necrotizing fasciitis. Infect Dis Clin North Am. In the emergency setting, CT of the neck is often performed to investigate symptoms of acute infection or inflammation or symptoms of aerodigestive tract compromise referable to the neck. <>stream CT is commonly used to diagnose, stage, and plan treatment for lung cancer, other primary neoplastic processes involving the chest, and metastatic disease.2 The need for contrast varies on a case-by-case basis, and the benefits of contrast should be weighed against the potential risks in each patient. On MRI, the signal on T2-WI is variable depending on the etiology. . Special consideration should be given to geriatric patients, in whom cellulitis of the lower extremities is more likely to develop into thrombophlebitis. 7. dobrien Contrast-enhanced CT demonstrates a horse-shoe shaped perirectal air collection (arrows), extending into the subcutaneous tissues of the ischiorectal fossa and medial gluteal region (b). Patients with history of anaphylactic reaction should not receive contrast. Copyright 2023 The Cleveland Clinic Foundation. Computed tomography (CT) plays an important role in the diagnosis and treatment of many clinical conditions1 involving the chest wall, mediastinum, pleura, pulmonary arteries, and lung parenchyma. 8. NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. A 64-year-old male with Fourniers gangrene with perforated diverticulitis. no financial relationships to ineligible companies to disclose. Contrast materials are generally safe; however, as with any pharmaceutical, there is the potential for adverse reactions. We do not capture any email address. Cellulitis occurs after disruption of the skin and invasion of the subcutaneous tissues by microorganisms that may be skin flora, such as beta-hemolytic streptococci (most often),Staphylococcus aureus(including methycillin-resistant), or other bacteria 9. Iodinated contrast agents can cause reversible acute renal failure. Imaging of Musculoskeletal Soft Tissue Infections. Recent studies suggest that a combination of hydration, sodium bicarbonate, N-acetylcysteine, and decreased contrast volume may reduce this risk in high-risk populations.14,15, The question of whether this risk has been overstated has been raised in the medical literature. MRI Nomenclature for Musculoskeletal Infection. What are the treatment options for myasthenia gravis if first-line agents fail? Mediastinitis may likewise be iatrogenic or may spread from the oropharynx. 2001;176(5):1155-9. Department of Radiology Department of Radiology Outpatients requiring oral contrast for a CT scan require a prescription for Readi-Cat 2, 2 bottles of 450ml, take as directed. 1994;192(2):493-6. Unable to process the form. Compared to plain radiography, ultrasound, CT and MR provide higher sensitivity and specificity for the diagnosis of necrotizing fasciitis. Schmid M, Kossmann T, Duewell S. Differentiation of Necrotizing Fasciitis and Cellulitis Using MR Imaging. The purpose of this article is to review the imaging findings of necrotizing fasciitis as seen on radiograph, ultrasound, CT, and MRI, and to recognize the early findings in this potentially fatal disease. <> Potential Harms of Computed Tomography: The Role of Informed Consent. Maximum-intensity projection images reconstructed in the axial (A) and coronal (B) planes show bilateral arteriovenous malformations with corresponding feeding arteries (white arrows) and draining veins (black arrows). On MRI, the signal on T2-WI is variable depending on the etiology. Weaver JS, Omar IM, Mar WA, Klauser AS, Winegar BA, Mlady GW, McCurdy WE, Taljanovic MS. Pol J Radiol. It results in pain, erythema, edema, and warmth. A history of anaphylactic reactions would preclude IV contrast except in extreme emergencies. 8600 Rockville Pike As with barium agents, they must be diluted for CT compared with the concentrations used in fluoroscopy. Clinical presentations include skin erythema without a well-defined border, increased skin temperature, swelling of the affected area, and regional lymphadenopathy and lymphangitis. Patients with peripheral vascular disease or diabetes mellitusare particularly susceptible to cellulitis since minor injuries to the skin or cracked skin in the feet or toes can serve as a point of entry for infection. Skeletal Radiol. Normally the subcutaneous tissue is hypoechoic with few hyperechoic strands (representing connective tissue). In uncomplicated cellulitis, CT demonstrates skin thickening, septation of the subcutaneous fat, and thickening of the underlying superficial fascia. If the infection spreads to deeper tissues, soft-tissue abscess, infectious myositis, necrotizing fasciitis, and osteomyelitis can all be detected with CT. MRI is sensitive for distinguishing cellulitis alone from necrotizing fasciitis and infectious myositis and for showing subcutaneous fluid collections and abscesses. 9. 1998;170(3):615-20. When does chest CT require contrast enhancement? Zacharias N, Velmahos GC, Salama A, Alam HB, de Moya M, King DR, et al..