ADVANCED IMAGING CLINICAL APPROPRIATENESS GUIDELINES. Appropriate Use Criteria: Imaging of the Extremities. EFFECTIVE JANUARY 1, 2019 Proprietary

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1 CLINICAL APPROPRIATENESS GUIDELINES ADVANCED IMAGING Apprpriate Use Criteria: EFFECTIVE JANUARY 1, 2019 Prprietary 8600 West Bryn Mawr Avenue Suth Twer Suite 800 Chicag, IL Apprpriate.Safe.Affrdable AIM Specialty Health

2 Table f Cntents Descriptin and Applicatin f the Guidelines... 5 Administrative Guidelines... 6 Ordering f Multiple Studies... 6 Simultaneus Ordering f Multiple Studies... 6 Repeated Imaging... 6 Pre-Test Requirements... 7 Histry General Infrmatin/Overview... 8 Scpe... 8 Technlgy Cnsideratins... 8 Definitins... 8 Clinical Indicatins Cngenital and Develpmental Cnditins Blunt disease (Pediatric nly) Cngenital anmalies f the lwer extremity (Pediatric nly) Cngenital anmalies f the upper extremity (Pediatric nly) Cxa vara (Pediatric nly) Develpmental dysplasia f the hip (Pediatric nly) Discid meniscus (Pediatric nly) Tarsal calitin Infectin Sft tissue infectin Ostemyelitis Septic arthritis Inflammatry Cnditins Bursitis Capitellar stechndritis Epicndylitis Juvenile idipathic arthritis (Pediatric nly) Mysitis Plantar fasciitis Tensynvitis lng head f biceps Trauma Fracture Patellar dislcatin transient (Pediatric nly) Patellar sleeve avulsin (Pediatric nly) Trauma cmplicatins (Pediatric nly) Traumatic injuries acute/nt therwise specified Tumr/Neplasm Cpyright AIM Specialty Health. All Rights Reserved. 2

3 Brachial plexus mass Mrtn s neurma Ostechndrma r exstsis (Pediatric nly) Osteid stema (Pediatric nly) Pigmented villndular synvitis Psterir knee mass (Adult nly) Sft tissue mass nt therwise specified Ligament and Tendn Derangement Adhesive capsulitis (Adult nly) Labral tear hip Labral tear shulder Ligament tear knee Meniscal tear/injury Rtatr cuff tear (Adult nly) Tendn injuries-ft and ankle Tendn rupture biceps r triceps Tendn rupture ft and ankle Triangular fibrcartilage cmplex tear Ulnar cllateral ligament tear (elbw r thumb) Ligament and tendn injuries nt listed elsewhere Miscellaneus Jint Cnditins Avascular necrsis Chndrmalacia patella Hemarthrsis Intra-articular lse bdy Legg-Calve-Perthes disease (Pediatric nly) Liphemarthrsis (Pediatric nly) Ostechndral lesin (including stechndritis dissecans) Slipped capital femral epiphysis (Pediatric nly) Neurgenic Cnditins Brachial plexpathy Entrapment neurpathy Neurpathic stearthrpathy (Charct jint) (Adult nly) Tarsal tunnel Pain, unspecified Nn-specific hip pain (Pediatric nly) Persistent lwer extremity pain Upper extremity pain, unspecified Periperative Imaging, unspecified Periperative Imaging, unspecified Exclusins Limb malalignment, preperative Cpyright AIM Specialty Health. All Rights Reserved. 3

4 Osgd-Schlatter Ostearthritis Patellar tendinitis Sinding-Larsen-Jhanssn Transient (txic) synvitis References Cdes Histry Cpyright AIM Specialty Health. All Rights Reserved. 4

5 Descriptin and Applicatin f the Guidelines The AIM Clinical Apprpriateness Guidelines (hereinafter the AIM Clinical Apprpriateness Guidelines r the Guidelines ) are designed t assist prviders in making the mst apprpriate treatment decisin fr a specific clinical cnditin fr an individual. As used by AIM, the Guidelines establish bjective and evidence-based criteria fr medical necessity determinatins where pssible. In the prcess, multiple functins are accmplished: T establish criteria fr when services are medically necessary T assist the practitiner as an educatinal tl T encurage standardizatin f medical practice patterns T curtail the perfrmance f inapprpriate and/r duplicate services T advcate fr patient safety cncerns T enhance the quality f health care T prmte the mst efficient and cst-effective use f services The AIM guideline develpment prcess cmplies with applicable accreditatin standards, including the requirement that the Guidelines be develped with invlvement frm apprpriate prviders with current clinical expertise relevant t the Guidelines under review and be based n the mst up-t-date clinical principles and best practices. Relevant citatins are included in the References sectin attached t each Guideline. AIM reviews all f its Guidelines at least annually. AIM makes its Guidelines publicly available n its website twenty-fur hurs a day, seven days a week. Cpies f the AIM Clinical Apprpriateness Guidelines are als available upn ral r written request. Althugh the Guidelines are publicly-available, AIM cnsiders the Guidelines t be imprtant, prprietary infrmatin f AIM, which cannt be sld, assigned, leased, licensed, reprduced r distributed withut the written cnsent f AIM. AIM applies bjective and evidence-based criteria, and takes individual circumstances and the lcal delivery system int accunt when determining the medical apprpriateness f health care services. The AIM Guidelines are just guidelines fr the prvisin f specialty health services. These criteria are designed t guide bth prviders and reviewers t the mst apprpriate services based n a patient s unique circumstances. In all cases, clinical judgment cnsistent with the standards f gd medical practice shuld be used when applying the Guidelines. Guideline determinatins are made based n the infrmatin prvided at the time f the request. It is expected that medical necessity decisins may change as new infrmatin is prvided r based n unique aspects f the patient s cnditin. The treating clinician has final authrity and respnsibility fr treatment decisins regarding the care f the patient and fr justifying and demnstrating the existence f medical necessity fr the requested service. The Guidelines are nt a substitute fr the experience and judgment f a physician r ther health care prfessinals. Any clinician seeking t apply r cnsult the Guidelines is expected t use independent medical judgment in the cntext f individual clinical circumstances t determine any patient s care r treatment. The Guidelines d nt address cverage, benefit r ther plan specific issues. If requested by a health plan, AIM will review requests based n health plan medical plicy/guidelines in lieu f the AIM Guidelines. The Guidelines may als be used by the health plan r by AIM fr purpses f prvider educatin, r t review the medical necessity f services by any prvider wh has been ntified f the need fr medical necessity review, due t billing practices r claims that are nt cnsistent with ther prviders in terms f frequency r sme ther manner. Cpyright AIM Specialty Health. All Rights Reserved. 5

6 Administrative Guidelines Ordering f Multiple Studies Requests fr multiple imaging studies t evaluate a suspected r identified cnditin and requests fr repeated imaging f the same anatmic area are subject t additinal review t avid unnecessary r inapprpriate imaging. Simultaneus Ordering f Multiple Studies In many situatins, rdering multiple imaging studies at the same time is nt clinically apprpriate because: Current literature and/r standards f medical practice supprt that ne f the requested imaging studies is mre apprpriate in the clinical situatin presented; r One f the imaging studies requested is mre likely t imprve patient utcmes based n current literature and/r standards f medical practice; r Apprpriateness f additinal imaging is dependent n the results f the lead study. When multiple imaging studies are rdered, the request will ften require a peer-t-peer cnversatin t understand the individual circumstances that supprt the medically necessity f perfrming all imaging studies simultaneusly. Examples f multiple imaging studies that may require a peer-t-peer cnversatin include: CT brain and CT sinus fr headache MRI brain and MRA brain fr headache MRI cervical spine and MRI shulder fr pain indicatins MRI lumbar spine and MRI hip fr pain indicatins MRI r CT f multiple spine levels fr pain r radicular indicatins MRI ft and MRI ankle fr pain indicatins Bilateral exams, particularly cmparisn studies There are certain clinical scenaris where simultaneus rdering f multiple imaging studies is cnsistent with current literature and/r standards f medical practice. These include: Onclgic imaging Cnsideratins include the type f malignancy and the pint alng the care cntinuum at which imaging is requested Cnditins which span multiple anatmic regins Examples include certain gastrintestinal indicatins r cngenital spinal anmalies Repeated Imaging In general, repeated imaging f the same anatmic area shuld be limited t evaluatin fllwing an interventin, r when there is a change in clinical status such that imaging is required t determine next steps in management. At times, repeated imaging dne with different techniques r cntrast regimens may be necessary t clarify a finding seen n the riginal study. Repeated imaging f the same anatmic area (with same r similar technlgy) may be subject t additinal review in the fllwing scenaris: Repeated imaging at the same facility due t mtin artifact r ther technical issues Repeated imaging requested at a different facility due t prvider preference r quality cncerns Repeated imaging f the same anatmic area (MRI r CT) based n persistent symptms with n clinical change, treatment, r interventin since the previus study Repeated imaging f the same anatmical area by different prviders fr the same member ver a shrt perid f time Cpyright AIM Specialty Health. All Rights Reserved. 6

7 Pre-Test Requirements Critical t any finding f clinical apprpriateness under the guidelines fr specific imaging exams is a determinatin that the fllwing are true with respect t the imaging request: A clinical evaluatin has been perfrmed prir t the imaging request (which shuld include a cmplete histry and physical exam and review f results frm relevant labratry studies, prir imaging and supplementary testing) t identify suspected r established diseases r cnditins. Fr suspected diseases r cnditins: Based n the clinical evaluatin, there is a reasnable likelihd f disease prir t imaging; and Current literature and standards f medical practice supprt that the requested imaging study is the mst apprpriate methd f narrwing the differential diagnsis generated thrugh the clinical evaluatin and can be reasnably expected t lead t a change in management f the patient; and The imaging requested is reasnably expected t imprve patient utcmes based n current literature and standards f medical practice. Fr established diseases r cnditins: Advanced imaging is needed t determine whether the extent r nature f the disease r cnditin has changed; and Current literature and standards f medical practice supprt that the requested imaging study is the mst apprpriate methd f determining this and can be reasnably expected t lead t a change in management f the patient; and The imaging requested is reasnably expected t imprve patient utcmes based n current literature and standards f medical practice. If these elements are nt established with respect t a given request, the determinatin f apprpriateness will mst likely require a peer-t-peer cnversatin t understand the individual and unique facts that wuld supersede the pre-test requirements set frth abve. During the peert-peer cnversatin, factrs such as patient acuity and setting f service may als be taken int accunt. Histry Status Date Actin Reviewed and revised 07/26/2016 Independent Multispecialty Physician Panel review and revisin Created 03/30/2005 Original effective date Cpyright AIM Specialty Health. All Rights Reserved. 7

8 General Infrmatin/Overview Scpe These guidelines address advanced imaging f the extremities in bth adult and pediatric ppulatins. Fr interpretatin f the Guidelines, and where nt therwise nted, adult refers t persns age 19 and lder, and pediatric refers t persns age 18 and yunger. Where separate indicatins exist, they are specified as Adult r Pediatric. Where nt specified, indicatins and prerequisite infrmatin apply t persns f all ages. See the Cding sectin fr a list f mdalities included in these guidelines. Technlgy Cnsideratins In general, cnventinal radigraphs shuld be btained prir t advanced imaging. Cmputed tmgraphy (CT) is ften the preferred mdality fr evaluatin f displaced fractures and subluxatins, whereas stress fractures and sme incmplete and nn-displaced fractures may be better imaged with magnetic resnance imaging (MRI) r radinuclide bne scintigraphy. Tendns and ligamentus structures are better imaged using MRI. Use f cntrast is at the discretin f bth the rdering and imaging physicians. Implanted surgical hardware, including jint prstheses, may prduce sufficient lcal artifact t preclude adequate imaging thrugh the regin cntaining hardware. Disadvantages f CT include expsure t inizing radiatin and risks assciated with infusin f idinated cntrast media, including allergic reactins r renal cmprmise. The presence f implantable devices such as pacemakers r defibrillatrs, a ptential need fr sedatin in pediatric patients, and claustrphbia are the main limitatins f MRI. Infusin f gadlinium may als cnfer an unacceptable risk in persns with advanced renal disease. CT arthrgraphy and MR arthrgraphy are diagnstic tests perfrmed by injecting cntrast int the jint space prir t imaging. Injectin is generally perfrmed under flurscpic r ultrasund guidance. They are ften preferable t standard CT r MRI fr indicatins where visualizatin f the jint space integrity is needed. Definitins Phases f the care cntinuum are bradly defined as fllws: Screening testing in the absence f signs r symptms f disease Diagnsis testing based n a reasnable suspicin f a particular cnditin r disrder, usually due t the presence f signs r symptms Management testing t direct therapy f an established cnditin, which may include preperative r pstperative imaging, r imaging perfrmed t evaluate the respnse t nnsurgical interventin Surveillance peridic assessment fllwing cmpletin f therapy, r fr mnitring knwn disease that is stable r asymptmatic Statistical terminlgy 1 Cnfidence interval (CI) range f values which is likely t cntain the cited statistic. Fr example, 92% sensitivity (95% CI, 89%-95%) means that, while the sensitivity was calculated at 92% n the current study, there is a 95% chance that, if a study were t be repeated, the sensitivity n the repeat study wuld be in the range f 89%-95%. Cpyright AIM Specialty Health. All Rights Reserved. 8

9 Diagnstic accuracy ability f a test t discriminate between the target cnditin and health. Diagnstic accuracy is quantified using sensitivity and specificity, predictive values, and likelihd ratis. Hazard rati dds that an individual in the grup with the higher hazard reaches the utcme first. Hazard rati is analgus t dds rati and is reprted mst cmmnly in time-t-event analysis r survival analysis. A hazard rati f 1 means that the hazard rates f the 2 grups are equivalent. A hazard rati f greater than 1 r less than 1 means that there are differences in the hazard rates between the 2 grups. Likelihd rati rati f an expected test result (psitive r negative) in patients with the disease t an expected test result (psitive r negative) in patients withut the disease. Psitive likelihd ratis, especially thse greater than 10, help rule in a disease (i.e., they substantially raise the pst-test prbability f the disease, and hence make it very likely and the test very useful in identifying the disease). Negative likelihd ratis, especially thse less than 0.1, help rule ut a disease (i.e., they substantially decrease the pst-test prbability f disease, and hence make it very unlikely and the test very useful in excluding the disease). Odds rati dds that an utcme will ccur given a particular expsure, cmpared t the dds f the utcme ccurring in the absence f that expsure. An dds rati f 1 means that the expsure des nt affect the dds f the utcme. An dds rati greater than 1 means that the expsure is assciated with higher dds f the utcme. An dds rati less than 1 means that the expsure is assciated with lwer dds f the utcme. Predictive value likelihd that a given test result crrelates with the presence r absence f disease. Psitive predictive value is defined as the number f true psitives divided by the number f test psitives. Negative predictive value is defined as the number f true negatives divided by the number f test negative patients. Predictive value is dependent n the prevalence f the cnditin. Pretest prbability prbability that a given patient has a disease prir t testing. May be divided int very lw (less than 5%), lw (less than 20%), mderate (20%-75%), and high (greater than 75%) althugh these numbers may vary by cnditin. Relative risk prbability f an utcme when an expsure is present relative t the prbability f the utcme ccurring when the expsure is absent. Relative risk is analgus t dds rati; hwever, relative risk is calculated by using percentages instead f dds. A relative risk f 1 means that there is n difference in risk between the 2 grups. A relative risk f greater than 1 means that the utcme is mre likely t happen in the expsed grup cmpared t the cntrl grup. A relative risk less than 1 means that the utcme is less likely t happen in the expsed grup cmpared t the cntrl grup. Sensitivity cnditinal prbability that the test is psitive, given that the patient has the disease. Defined as the true psitive rate (number f true psitives divided by the number f patients with disease). Excellent r high sensitivity is usually greater than 90%. Specificity cnditinal prbability that the test is negative, given that the patient des nt have the disease. Defined as the true negative rate (number f true negatives divided by the number f patients withut the disease). Excellent r high specificity is usually greater than 90%. General prerequisites fr extremity imaging: Cnservative management a cmbinatin f strategies t reduce inflammatin, alleviate pain, and imprve functin, including but nt limited t the fllwing: Prescriptin strength anti-inflammatry medicatins and analgesics Adjunctive medicatins such as nerve membrane stabilizers r muscle relaxants Cpyright AIM Specialty Health. All Rights Reserved. 9

10 Physician-supervised therapeutic exercise prgram r physical therapy Manual therapy r spinal manipulatin Alternative therapies such as acupuncture Apprpriate management f underlying r assciated cgnitive, behaviral r addictin disrders Clinical reevaluatin In mst cases, reevaluatin shuld include a physical examinatin. Direct cntact by ther methds, such as by telephne r electrnic messaging, may substitute fr inpersn evaluatin when circumstances preclude an ffice visit. Clinical Indicatins The fllwing sectin includes indicatins fr which advanced imaging f the extremities is cnsidered medically necessary, alng with prerequisite infrmatin and supprting evidence where available. Indicatins, diagnses, r imaging mdalities nt specifically addressed are cnsidered nt medically necessary. It is recgnized that imaging ften detects abnrmalities unrelated t the cnditin being evaluated. Such findings must be cnsidered within the cntext f the clinical situatin when determining whether additinal imaging is required. General prerequisites fr extremity imaging include cnservative management and clinical reevaluatin, as defined abve. Dcumentatin f cmpliance with a plan f therapy that includes elements f cnservative management may be required. Exceptins may be cnsidered n a case-by-case basis. Cngenital and Develpmental Cnditins Blunt disease (Pediatric nly) Advanced imaging is cnsidered medically necessary fr preperative evaluatin when there is clinical cncern fr physeal bny bars and radigraphs are nndiagnstic. - CT r MRI lwer extremity Cngenital anmalies f the lwer extremity (Pediatric nly) Advanced imaging is cnsidered medically necessary fr diagnsis and management f ANY f the fllwing cnditins when radigraphs are nndiagnstic r nt sufficient t guide treatment: Acetabular dysplasia Cngenital shrt femur assciated with ANY f the fllwing: Achndrplasia Mucplysaccharidsis Neurfibrmatsis Skeletal dysplasias Spndylepiphyseal dysplasia Prximal fcal femral deficiency Cpyright AIM Specialty Health. All Rights Reserved. 10

11 - CT r MRI lwer extremity Cngenital anmalies f the upper extremity (Pediatric nly) Advanced imaging is cnsidered medically necessary fr diagnsis and management when radigraphs are nndiagnstic r nt sufficient t guide treatment. - CT r MRI upper extremity (jint r nn-jint) Cxa vara (Pediatric nly) Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Initial diagnsis fllwing nndiagnstic radigraph Surgical planning Hip pain - MRI lwer extremity - CT lwer extremity when MRI cntraindicated Develpmental dysplasia f the hip (Pediatric nly) Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Initial diagnsis fllwing nndiagnstic radigraph Surgical planning fr cmplex dislcatins Anticipated need fr perative management based n failure t respnd t bracing r late diagnsis Evaluatin f suspected surgical cmplicatins including grwth disturbance r avascular necrsis T determine adequacy f surgical reductin - MRI lwer extremity - CT lwer extremity when MRI cntraindicated Discid meniscus (Pediatric nly) Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - MRI lwer extremity - CT lwer extremity when MRI cntraindicated Tarsal calitin Advanced imaging is cnsidered medically necessary fr diagnsis and management when radigraphs are nndiagnstic r nt sufficient t guide treatment. Cpyright AIM Specialty Health. All Rights Reserved. 11

12 - CT r MRI lwer extremity Ratinale Tarsal calitin refers t fusin sseus, cartilaginus r fibrinus f the tarsal bnes, typically talcalcaneal r calcanenavicular (90%) 1 and is an imprtant cause f ft pain, especially in adlescents; it is respnsible fr ft pain in up t 13% f cases. 1 Radigraphs are cmmnly the initial diagnstic imaging study 2, 3 and have reasnable sensitivity (~80%) and high specificity (~97%) 1, 2 fr establishing the diagnsis f bny disease. Radigraphs are als useful t exclude ther causes f ft pain which can mimic the presentatin f tarsal calitin, especially acutely. When radigraphs are nndiagnstic r nt sufficient t guide treatment, CT r MRI can be used t further delineate the extent f disease and t identify ccult disease r assciated abnrmalities. 1 Infectin Sft tissue infectin Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Lcalizatin f knwn r suspected abscess, t direct surgical treatment Knwn r suspected fasciitis Other sft tissue infectin nt respnsive t treatment - CT r MRI upper extremity (jint r nn-jint) - CT r MRI lwer extremity Ostemyelitis Advanced imaging is cnsidered medically fr diagnsis and management when radigraphs are nndiagnstic r nt sufficient t guide treatment. - MRI upper extremity (jint r nn-jint) - MRI lwer extremity - CT upper r lwer extremity when MRI cntraindicated - FDG-PET fr chrnic stemyelitis Ratinale Thugh radigraphs ften d nt shw abnrmalities assciated with stemyelitis in the first tw weeks f the infectin, they can detect ther pathlgies that may cntribute t the patient s symptms. The infrmatin prvided by radigraphs generally cmplements that prvided by ther mdalities, s radigraphs shuld be perfrmed even when ther imaging is planned. Radigraphs are the apprpriate initial imaging study in stemyelitis because they can demnstrate findings suggestive f the diagnsis, but can als exclude r prvide infrmatin t suggest ther diagnses. The sensitivity f radigraphy is reprtedly 43%-75% and the specificity is 75%-83%. Abnrmal radigraphs are helpful, but the diagnsis cannt be excluded n the basis f negative radigraphs. The sensitivity and specificity f CT are nt well established, but the sensitivity is knwn t be lwer than that f MRI. Fr this reasn, the utility f CT is limited t specific situatins. Fr example, CT can be used t detect bny sequestra, and has an imprtant rle in determining perative therapy. 4 Overall, CT has a limited rle in the diagnsis f stemyelitis, and shuld be used nly when imaging is being dne t assess the extent f bne destructin, t direct a bipsy, r when MRI is cntraindicated. Fr early detectin f stemyelitis, MRI is superir t ther imaging mdalities. The sensitivity and specificity fr MRI are 78%-90% and 60%-90%, respectively. This cmpares t sensitivity and specificity f 67% and 50% fr CT, and 14%-54% and 68%- 70% fr radigraphy. 5 Cpyright AIM Specialty Health. All Rights Reserved. 12

13 The American Cllege f Radilgy Apprpriateness Criteria rate radigraphs as usually apprpriate fr initial evaluatin f suspected stemyelitis. CT, MRI, and ultrasund are all rated as usually nt apprpriate regardless f whether the studies are perfrmed with IV cntrast. Fr evaluatin f suspected stemyelitis fllwing radigraphs, MRI withut and with IV cntrast is preferred, with a cmment that radigraphs and MRI are bth indicated and cmplementary. MRI withut cntrast is generally apprpriate if cntrast is cntraindicated, and CT with IV cntrast is generally apprpriate if MRI is cntraindicated. 6 Septic arthritis ADULT Advanced imaging is cnsidered medically necessary in EITHER f the fllwing scenaris: Diagnsis f septic arthritis when ANY f the fllwing risk factrs are present: Underlying jint disease Jint prsthesis IV drug abuse Diabetes Presence f cutaneus ulcers Preperative planning fr established septic arthritis PEDIATRIC Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Initial diagnsis T evaluate fr assciated stemyelitis r cartilage invlvement Presurgical planning - MRI lwer extremity - MRI upper extremity (jint) - MRI upper extremity (nn-jint) when there is cncern fr spread f infectin int the adjacent sft tissue nt visualized n MRI jint - CT upper r lwer extremity when MRI cntraindicated Ratinale The diagnsis f septic arthritis is established by jint aspiratin and culture f the synvial fluid. Initial evaluatin fr septic jint shuld include radigraphy (t utline anatmic detail, evaluate fr radidense freign bdies r sft-tissue gas, and exclude alternate diagnses such as fracture, degenerative changes, r tumr). 6,7 Additinal imaging with CT r MRI may be utilized fr further evaluatin in children, high-risk adults, and fr preperative planning fr cnfirmed septic arthritis. In children, MRI may als be useful t evaluate fr assciated stemyelitis r cartilage invlvement. The American Cllege f Radilgy recmmends MRI t further clarify and stage cnditins diagnsed clinically and/r suggested by ther imaging mdalities, including, but nt limited t, the fllwing: inflammatry, infectius, neurpathic, degenerative, crystal-induced, r pst-traumatic arthritis. 8 Cmpared t ther advanced imaging mdalities, MRI is generally preferred fr septic arthritis fr its ability t assess sft tissue infectin, stemyelitis, and abscess. 6,7 MRI is highly sensitive fr the diagnsis f septic arthritis, althugh it still lacks specificity as it cannt reliably distinguish inflamed frm infected jints. 9 MRI is as sensitive as and mre specific than bne scintigraphy in the diagnsis f stemyelitis. 5 CT may be utilized when MRI is cntraindicated. Cpyright AIM Specialty Health. All Rights Reserved. 13

14 Inflammatry Cnditins Bursitis Applies t shulder indicatins nly. Advanced imaging is cnsidered medically necessary fr evaluatin f acute shulder pain in adults and acute r chrnic shulder pain in pediatric patients fllwing initial radigraphs when imaging is required t establish the diagnsis and the patient is a candidate fr crticsterid r anesthetic injectin. - MRI upper extremity jint - CT upper extremity fr pediatric patients nly Ratinale Fr suspected bursitis, initial imaging evaluatin shuld be with radigraphs, including anterir, psterir, axillary, and utlet views. 11 Capitellar stechndritis Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - MRI upper extremity jint - CT may be utilized when MRI cntraindicated Epicndylitis Advanced imaging is cnsidered medically necessary when BOTH f the fllwing criteria are met: Radigraphs are nndiagnstic There has been n substantial imprvement fllwing a trial f cnservative treatment Nte: Epicndylitis is generally cnsidered a clinical diagnsis and imaging usually des nt change management. Specialist evaluatin shuld be strngly cnsidered prir t advanced imaging. - MRI upper extremity jint - CT may be utilized when MRI cntraindicated Juvenile idipathic arthritis (Pediatric nly) Als see juvenile idipathic arthritis in Spine Imaging guidelines. Advanced imaging f the extremity is cnsidered medically necessary fr management f established juvenile idipathic arthritis when radigraphs are insufficient t determine apprpriate curse f therapy, particularly intra-articular therapy. - MRI upper extremity jint - MRI lwer extremity - CT when MRI cntraindicated r expected t be nndiagnstic Cpyright AIM Specialty Health. All Rights Reserved. 14

15 Ratinale Juvenile idipathic arthritis (JIA), the mst cmmn rheumatic disease f children and adlescents, is an umbrella term that encmpasses all frms f arthritis that begin befre age 16, persist fr mre than 6 weeks, and are f unknwn etilgy. Examples f JIA include ligarthritis, plyarthritis, systemic arthritis, psriatic arthritis, and enthesis-related arthritis. JIA is the mst cmmn childhd rheumatic entity with a prevalence f 0.6 t 1.9 in 1000 children. 12 JIA is primarily a clinical diagnsis. General practitiners shuld base diagnsis f JIA (and differential diagnsis) primarily n histry and clinical examinatin, with strng suspicin f JIA indicated by pain and swelling f single r multiple jints, persistent r wrsening lss f functin, fever f at least 10 days with unknwn cause (ften assciated with transient erythematus rash), decreased range f mtin, and jint warmth r effusin. 13 Labratry assessment with apprpriate tests can assist in increasing diagnstic certainty, excluding differential diagnses, and predicting patients likely t prgress t ersive disease. Base investigatins usually include erythrcyte sedimentatin rate r C-reactive prtein and full bld cunt, with cnsideratin given t rheumatid factr, antinuclear antibdy, and human leukcyte antigen B When there is clinical diagnstic dubt, cnventinal radigraphs (CR), ultrasund, r MRI can be used t imprve the certainty f a diagnsis f JIA abve clinical features alne. 14 MRI is the mst sensitive nninvasive imaging mdality t evaluate fr inflammatin f the jints, tendns, and entheses, and is the nly mdality that can depict bne marrw edema. Currently, MRI with cntrast is the mst sensitive tl fr determining active synvitis. 12 When the imaging mdalities were directly cmpared, MRI and ultrasund detected mre jint damage than CR, but primarily at the hip (MRI vs CR detectin rate, mean [range] 1.54-fld [ fld]; ultrasund vs CR detectin rate, mean 2.29-fld), and at the wrist (MRI vs CR detectin rate, 1.36-fld [ fld]). 14 Imaging studies help identify children with a high likelihd f early ersive jint damage, prviding an pprtunity t implement aggressive therapy at an early stage in an attempt t reduce mrbidity. 12 Mysitis Advanced imaging is cnsidered medically necessary in EITHER f the fllwing scenaris: Lcalizatin fr bipsy Mnitr respnse t therapy - MRI upper extremity nn-jint - MRI lwer extremity - CT may be utilized when MRI cntraindicated Plantar fasciitis Advanced imaging is cnsidered medically necessary in the fllwing scenari: Preperative evaluatin fllwing a failure f 6 mnths f physician-supervised cnservative treatment - MRI lwer extremity - CT may be utilized when MRI cntraindicated Tensynvitis lng head f biceps Advanced imaging is cnsidered medically necessary in the fllwing scenari: Evaluatin f acute shulder pain fllwing initial radigraphs when imaging is required t establish the diagnsis and the patient is a candidate fr crticsterid r anesthetic injectin - MRI upper extremity jint Cpyright AIM Specialty Health. All Rights Reserved. 15

16 - CT may be utilized when MRI cntraindicated Trauma Fracture Nte: Sites at high risk fr fracture include femral neck/prximal femur, tibia (anterir/lateral), great te sesamid, patella, scaphid, lunate, talus, navicular, and metatarsal base (secnd t fifth digits). ADULT Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Detectin f ccult fracture fllwing initial nndiagnstic radigraphs at high-risk sites nted abve. T define the extent f an acute fracture and psitin f fracture fragments T assess fracture healing fr delayed unin r nnunin when radigraphs are incnclusive PEDIATRIC Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Detectin f ccult fracture fllwing initial nndiagnstic radigraphs T assess fracture healing fr delayed unin r nnunin when radigraphs are incnclusive Preperative evaluatin when radigraphs d nt prvide adequate infrmatin t direct treatment in ANY f the fllwing situatins: T define the extent f an acute fracture Intra-articular fracture Physeal bar Salter-Harris fracture - CT r MRI upper extremity jint r nn-jint - CT r MRI lwer extremity Nte: MRI is preferred fr suspected ccult r stress fractures f high-risk sites nted abve. Ratinale Thugh MRI is ften mre sensitive than radigraphy in detecting ccult fractures, radigraphy remains the initial study f chice fr clinically suspected fractures with gd specificity (greater than 88%) but limited sensitivity (less than 56%). 15,16 CT is ften the preferred mdality fr evaluatin f displaced fractures and subluxatins, whereas stress fractures and sme incmplete and nn-displaced fractures may be better imaged with MRI r radinuclide bne scintigraphy. While many types f stress fractures are diagnsed clinically and managed cnservatively, 17 high-risk fracture sites are susceptible t nnunin. 18,19 Early diagnsis is imprtant, as these fractures may require prlnged immbilizatin r surgical interventin. 18 Advanced imaging, preferably MRI, is indicated when radigraphs are nndiagnstic t supprt this management change. SUSPECTED SCAPHOID FRACTURE Fr initial evaluatin f suspected scaphid fracture, radigraphs (via the finding f a fat pad sign) have a sensitivity f 82% (95% CI 77%-86%) and specificity f 72% (95% CI 68%-75%). The pretest prbability f scaphid fracture when radigraphs d nt demnstrate a fracture but the histry and physical examinatin are cnsistent with the diagnsis is 25%. Regarding fllw-up imaging after negative radigraphs, CT has a sensitivity f 83% (95% CI 75%-89%) and specificity f 97% (95% CI 94%-99%). The diagnstic accuracy f MRI is superir t CT, with 96% sensitivity (95% CI 92%-99%) and 98% specificity (95% CI 96%-99%). 20 SUSPECTED HIP FRACTURE WITH NEGATIVE OR INCONCLUSIVE RADIOGRAPHS Cpyright AIM Specialty Health. All Rights Reserved. 16

17 Stress r fragility fractures, especially thse f the subcapital hip, may prgress t cmplete fractures. Subcapital hip fractures are ften cmplicated by avascular necrsis unless surgically treated; as such, accurate detectin is imprtant. Clinically, these fractures mst cmmnly present with hip pain after trauma, and the patient may be unable t bear weight. When radigraphs are negative r indeterminate, MRI is sensitive and specific fr diagnsis and is better able t diagnse sft tissue causes f hip pain that may mimic fracture; these may include muscultendinitis and bursal abnrmalities. 21 There is cnsensus amng multiple high-quality evidence-based guidelines that advanced imaging (mst cmmnly MRI) is indicated in patients with suspected stress f fragility fracture when initial and r fllw-up radigraphy is negative. MRI has a high diagnstic yield in this patient ppulatin especially fr elderly patients and establishing the diagnsis frequently changes management. CHOICE OF Mderate evidence supprts MRI as the advanced imaging mdality f chice fr diagnsis f presumed hip fracture nt apparent n initial radigraphs. 21 Fr suspected hip fracture, MR imaging is the imaging study f chice when there is dubt regarding the diagnsis. If MR is nt available r nt feasible, a radiistpe bne scan r repeat plain radigraphs (after a delay f hurs) shuld be perfrmed. 22 A 2016 systematic review f imaging mdalities in lwer extremity stress fractures fund greater sensitivity fr MRI (68%-99%) than CT (32%-38%) and cmparable but wide-ranging specificities (4%-97% fr MRI, 88%-98% fr CT). In assessing the data, the authrs cnclude that MRI was identified as the mst sensitive and specific imaging test fr diagnsing stress fractures f the lwer extremity. 15 Highlighting the superir sensitivity f MRI, a recent retrspective study f 44 patients fund that MRI changed management in up t 61% f cases fllwing incnclusive radigraphs and CT. 23 Patellar dislcatin transient (Pediatric nly) Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - CT lwer extremity Patellar sleeve avulsin (Pediatric nly) Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - MRI lwer extremity - CT when MRI cntraindicated Trauma cmplicatins (Pediatric nly) Advanced imaging is cnsidered medically necessary t evaluate ANY f the fllwing: Chndrlysis Intra-articular bdies Premature grwth plate clsure - CT r MRI lwer extremity Traumatic injuries acute/nt therwise specified See pain indicatins r ligament/tendn derangements fr subacute r chrnic injuries. Advanced imaging is cnsidered medically necessary when radigraphs are nndiagnstic r nt sufficient t establish a diagnsis and/r direct management. Cpyright AIM Specialty Health. All Rights Reserved. 17

18 - CT r MRI upper r lwer extremity Ratinale Fr evaluatin f musculskeletal trauma, radilgists judge radigraphs t be essential r very imprtant fr use in the interpretatin f MRI. When advanced imaging is warranted, having radigraphs available at the time f advanced imaging allws the radilgist t mre apprpriately prtcl the study, as well as t determine which study will best assess the clinical and radigraphic cncerns. 16 Tumr/Neplasm See Onclgic Imaging guidelines fr management f an established tumr. Brachial plexus mass Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - MRI upper extremity (nn-jint) - CT upper extremity when MRI cntraindicated Mrtn s neurma Advanced imaging is cnsidered medically necessary when physical examinatin r ultrasund is nndiagnstic and imaging is required t direct treatment. - MRI lwer extremity - CT may be utilized when MRI cntraindicated Ostechndrma r exstsis (Pediatric nly) Advanced imaging is cnsidered medically necessary fr diagnsis in symptmatic patients r peridic surveillance fr malignant degeneratin. - CT upper extremity r lwer extremity - MRI upper extremity r lwer extremity Osteid stema (Pediatric nly) Advanced imaging is cnsidered medically necessary fr diagnsis and management when radigraphs are nndiagnstic r nt sufficient t guide treatment. - CT r MRI lwer extremity Pigmented villndular synvitis Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. Cpyright AIM Specialty Health. All Rights Reserved. 18

19 - MRI upper extremity jint - MRI lwer extremity - MR r CT arthrgram - CT upper extremity r lwer extremity when MRI cntraindicated Ratinale Pigmented villndular synvitis exists in bth diffuse and lcalized frms. Radigraphic findings are nnspecific, and radigraphs may be nrmal in up t apprximately 20% f cases. In lcalized disease, a sft tissue mass may be evident. In diffuse disease, there may be a jint effusin as well as ersive changes. Radigraphic changes including stepenia, jint space narrwing, and degenerative changes may less cmmnly be present. CT arthrgraphy and MR arthrgraphy reveal synvial thickening with ndular prjectins int the jint. 57 The extent f disease is better demnstrated with MR arthrgraphy than with CT arthrgraphy. Hwever, CT is ideal fr demnstrating bny ersin and subchndral cystic change. The CT appearance f pigmented villndular synvitis is less well described than its appearance n MR arthrgraphy. Because the clinical and radigraphic findings, particularly in diffuse disease, are nnspecific, MR is typically the study chsen as a fllw up t radigraphy. 57 Psterir knee mass (Adult nly) Advanced imaging is cnsidered medically necessary fr diagnsis f a palpable psterir knee mass fllwing nndiagnstic radigraph and ultrasund. - MRI lwer extremity - CT may be utilized when MRI cntraindicated Ratinale The initial evaluatin fr suspected ppliteal (Baker s) cyst shuld include an ultrasund and plain radigraphs. Plain radigraphy prvides limited infrmatin abut the ppliteal cyst, but may prvide additinal infrmatin n jint and bne abnrmalities such as lse bdies in the cyst r the general findings f stearthritis and inflammatry arthritis. Ultrasund, hwever, is preferred and cnsidered invaluable fr evaluatin f a Baker s cyst as it is readily available, nninvasive, invlves n expsure t radiatin, and allws assessment f the cyst including size, extent, and relatin t surrunding tissue. In the clinical scenari where plain radigraph and ultrasund are nndiagnstic fr a Baker s cyst, an MRI may be useful. As ultrasund is nt sensitive fr intra-articular lesins, an MRI can cnfirm the cystic, unilcular nature f a benign ppliteal cyst, evaluate its relatinship t anatmic structures in the jint and surrunding tissue, and delineate assciated intra-articular pathlgies. 24 Primary indicatins fr MRI f the knee include but are nt limited t diagnsis, exclusin, and grading f suspected synvial-based disrders (synvitis, bursitis, symptmatic plicae, and ppliteal cysts). 8 CT imaging is generally nt indicated. Sft tissue mass nt therwise specified ADULT Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Evaluatin f a palpable mass fllwing nndiagnstic radigraph Sft tissue evaluatin when prminent calcificatins are seen n radigraph Spntaneus sft tissue hemrrhage with r withut palpable mass Surveillance f a sft tissue mass identified n prir imaging withut pathlgic tissue cnfirmatin PEDIATRIC Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. Cpyright AIM Specialty Health. All Rights Reserved. 19

20 - MRI jint/nn-jint r CT upper extremity - MRI r CT lwer extremity Ratinale Amng patients presenting fr primary care evaluatin f a sft tissue mass, a benign cause is fund in 95% f cases. 25 Radigraphic findings are ften nnspecific. Hwever, there are sme radigraphic findings that are characteristic f certain masses. Examples include phlebliths, which are suggestive f hemangimas, as well as trabecular bne adjacent t a sft tissue mass, which when cmbined with a histry f trauma suggests mysitis ssificans. The radigraphic findings may help direct next steps in evaluatin f the mass, such as a clinical situatin where the mst apprpriate next study is CT. Fr mst sft tissue masses, MRI is the mre apprpriate fllw-up study. 26 Ligament and Tendn Derangement Nte: MRI is preferable t CT fr evaluatin f internal derangements f tendinus, ligamentus, and cartilaginus structures. Except where nted, CT shuld be limited t situatins where there is a cntraindicatin t MRI. Adhesive capsulitis (Adult nly) Advanced imaging is cnsidered medically necessary when BOTH f the fllwing criteria are met: Acute shulder pain with nndiagnstic radigraphs A minimum f 6 cnsecutive weeks f physician-supervised cnservative treatment fr the current episde f pain has been cmpleted, with lack f substantial imprvement n clinical reevaluatin - MRI upper extremity (jint) - CT upper extremity Ratinale There is n agreement n the imaging features f adhesive capsulitis. A single high-quality evidence-based guideline suggests that imaging is nt initially indicated but that MRI may be cnsidered prir t manipulatin. 10 Labral tear hip Advanced imaging is cnsidered medically necessary when the results f imaging are essential t establish a diagnsis and/r direct management. - MRI lwer extremity - MR r CT arthrgram Ratinale Cnsensus amng high-quality evidence-based guidelines is that imaging may be indicated when radigraphs are negative r equivcal. Recmmendatins abut chice f imaging study are incnsistent. MR arthrgraphy r CT arthrgraphy is apprpriate in patients with chrnic hip pain when a labral tear is suspected and radigraphs are negative, equivcal, r nndiagnstic. 27 MRI is useful in detecting muscultendinus pathlgy such as ilipsas tendinpathy. Althugh MRI is nt used widely t detect intra-articular injury, sme investigatrs reprt high accuracy (89%-95%) in detecting labral tears. Currently, the mst cmmn imaging prcedure used t cnfirm the diagnsis f intra-articular pathlgy, such as labral tears r chndral lesins, is MR arthrgraphy. 28 Cpyright AIM Specialty Health. All Rights Reserved. 20

21 A systematic review f 29 studies (13 MRI 1.5T], 16 MR arthrgraphy 1.5T]) assessing the diagnstic accuracy f MRI r MR arthrgraphy fr labral tear in 872 patients fund that bth cnventinal MRI and MR arthrgraphy prvide acceptable ability in detecting acetabular labral tears in adults. The sensitivity f MR arthrgraphy was greater than cnventinal MRI in detecting an acetabular labral tear when ne was present, but cnventinal MRI had a higher specificity than MR arthrgraphy in detecting a negative result when n labral tear was evident. The authrs cnclude that bth MRI and MR arthrgraphy may be useful adjuncts in the diagnsis f acetabular labral tears in adults, but MR arthrgraphy appears t be superir t cnventinal MRI based n the current evidence. 29 Labral tear shulder Suspected glenhumeral instability/labral tear based n EITHER f the fllwing: Recurrent anterir shulder dislcatin First-time dislcatin in a yung patient at high risk fr recurrence Suspected superir labrum anterir psterir (SLAP) tear in ANY f the fllwing scenaris: Acute trauma in persns under age 45 Acute traumatic event with evidence f suprascapular nerve entrapment Lack f imprvement r wrsening f symptms fllwing at least 4 weeks f cnservative therapy Management f labral tear Preperative imaging when labral tear has been diagnsed by a mdality ther than MRI, r mre than ne year has elapsed since MRI was perfrmed fr this diagnsis Pstperative evaluatin when at least 3 mnths have elapsed since surgical repair and there has been n clinical imprvement - MR r CT arthrgram - MRI upper extremity jint - CT may be cnsidered when MRI is cntraindicated Ratinale In general, MR arthrgram is mre accurate than MRI in diagnsing and excluding labral tears. CT and MR arthrgram have cmparable diagnstic accuracy in evaluatin f superir labral anterir t psterir (SLAP) tears, Bankart lesins, and humeral head/hill-sachs fractures. CT arthrgram may have slightly better diagnstic accuracy fr glenid rim fractures and anterir labral peristeal sleeve avulsin fractures. In the absence f intra-articular cntrast, CT shuld nly be perfrmed fr this indicatin when there is a cntraindicatin t MRI. In a meta-analysis cmparing MR arthrgram (N=2013) t MRI (N=1498) in patients with suspected SLAP tears, MR arthrgram was superir t MRI in the detectin f SLAP lesins. MR arthrgram had higher sensitivity (87% vs 76%), specificity (92% vs 87%), psitive likelihd rati (10.28 vs 5.89), and negative likelihd rati (0.14 vs 0.28) than MRI. 30 A 2012 meta-analysis by Smith et al. reviewed 4574 patients and 4667 shulders in patients presenting with suspected labral tear and clinical signs and/r symptms f shulder instability. MRI had a sensitivity f 76% (95% CI, 72%-80%) and specificity f 87% (95% CI, 84%-90%), while MR arthrgram had a sensitivity f 88% (95% CI, 86%-90%) and specificity f 93% (95% CI, 92%-95%) in the evaluatin f all labral tears. Fr evaluatin f anterir labral tears, MRI (sensitivity 92% [95% CI, 88%-96%], specificity 98% [95% CI, 98%-99%]) was mre accurate than MR arthrgram (sensitivity 84%, [95% CI, 79%-89%], specificity 93% [95% CI, 90%-95%]). N significant difference was fund between MRI and MR arthrgram in the detectin f psterir r superir labral tears. Fr SLAP tears, MR arthrgram shwed slightly higher diagnstic accuracy (sensitivity 83% [95% CI, 79%-87%], specificity 93% [95% CI, 90%-96%]) than MRI (sensitivity 79% [95% CI, 75%-93%], specificity 87% [95% CI, 83%-91%]). 31 Thugh MR arthrgram is cnsidered the reference standard fr shulder imaging, CT arthrgraphy culd als prvide a valuable preperative assessment, given its excellent spatial reslutin, multiplanar capacity, and high-cntrast reslutin. 32 In nntraumatic cases, there is agreement that imaging is nt initially indicated prir t 4 weeks f cnservative care. Clinical tests such as O Brien, Neer, and Yergasn tests are used t diagnse labral lesins. Since mst SLAP tears are assciated with ther pathlgy, the prvider shuld identify ther shulder cnditins, if any, and fllw apprpriate surgical indicatins. Indicatins fr surgical treatment f SLAP tears are nt standardized and remain smewhat Cpyright AIM Specialty Health. All Rights Reserved. 21

22 cntrversial. Expert pinin, including the American Academy f Orthpedic Surgens, recmmends initial cnservative care fr SLAP tears. In general, cnservative management shuld last a minimum f 6 t 12 weeks. Early surgery shuld be cnsidered nly when there is evidence f symptmatic suprascapular nerve cmpressin. 33 Besides the typical histry f repetitive dislcatin episdes, the diagnsis f chrnic anterir instability f the shulder is usually cnfirmed by imaging. Cnventinal radigraphs and CT scans can prvide useful infrmatin abut bne status, but s far, MR arthrgraphy represents the gld standard fr prearthrscpy evaluatin. 34 Ligament tear knee Advanced imaging is cnsidered medically necessary in ANY f the fllwing scenaris: Patient has cmpleted a minimum f 4 cnsecutive weeks f physician supervised cnservative treatment fr the current episde and has nt shwn substantial imprvement n clinical reevaluatin Pstperative evaluatin fllwing a ligament r tendn repair when there are new symptms Preperative evaluatin Nte: Psitive findings f any f these tests anterir r psterir drawer test, Lachman test, medial r lateral stress test, r pivt shift test may indicate the need fr interventin. - MRI lwer extremity Meniscal tear/injury Advanced imaging is cnsidered medically necessary in EITHER f the fllwing scenaris: Patient has cmpleted a minimum f 4 cnsecutive weeks f physician supervised cnservative treatment fr the current episde and has nt shwn substantial imprvement n clinical reevaluatin Preperative evaluatin in ANY f the fllwing scenaris: Psitive McMurray test with minimal knee flexin Symptms f lcking, inability t bear weight, r fully extend the knee Pain and swelling ccurring immediately after an acute injury A severe twisting injury after which activity culd nt be resumed Cncmitant anterir cruciate ligament tear - MRI lwer extemity Ratinale In patients with nntraumatic knee pain withut initial radigraphic evidence f underlying pathlgy, cnsensus amng multiple high-quality evidence-based guidelines suggests that a perid f cnservative care is indicated in patients prir t advanced imaging. 35,36 In patients withut grss instability r prir surgery, studies have shwn n difference in patient-centered utcmes (shrt r lng term pain, quality f life, functinal limitatins) fr patients with knee pain and suspected internal derangement wh receive MRI at the time f initial primary care cnsultatin versus delayed MRI after cnservative care and rthpedic referral. 37 In patients wh have failed cnservative treatment, r when histry r physical findings are suggestive f injury whereby surgical treatment is planned, an MRI is the mst apprpriate imaging study. 38 Strng evidence suggests that MRI can prvide cnfirmatin f injury and assist in identifying cncmitant knee pathlgy such as ther ligament, meniscal, r articular cartilage injury. 39 The use f CT fr evaluatin f internal knee pathlgy has been lked at prspectively in 2 separate trials. Heffernan et al. fund that multidetectr CT imaging had very high sensitivity and specificity fr anterir cruciate ligament (ACL) tears (87.5%-100%, with a specificity f 100%); hwever, CT had lw sensitivity fr ther sft tissue injuries f the knee. 40 In a secnd prspective study, the verall accuracy rates fr diagnsing a meniscal tear were 82%-88% with MR arthrgraphy and 74%-76% with CT arthrgraphy. The authrs cncluded that CT arthrgraphy was mderately accurate in the diagnsis f meniscal tears and can be used as an alternative prcedure when MR arthrgraphy cannt Cpyright AIM Specialty Health. All Rights Reserved. 22