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The Big Picture: Whole Body MRI STIR and its uses in a ... · thickening - possible melorheostosis...
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The Big Picture: Whole Body MRI STIR and its uses in a tertiary paediatric hospital Dr R Prasad 1 , Dr P Menon 2 , Dr H Chaudhry 2 , Dr C Landes 2 , Dr S Harave 2 . Alder Hey Children’s Hospital NHS Trust, Liverpool, UK. Abstract Purpose: Anecdotally in our centre, whole body MRI STIR (WBMS) is becoming the preferred imaging modality in assessing systemic disease in children, replacing the older imaging modality, bone scan. There are no current guidelines in this area. The authors aim to review the use of WBMS, and compare the findings with traditional bone scans. Methods: This was a retrospective study in which data was collected about WBMS performed in our centre from 2011- 2016. We compared the findings of WBMS with bone scan findings in the patients that had undergone both. Results: 126 WB MRI STIR scans were included in the study. The average patient age was 9 years. Most (66%) patients did not require GA. Most requests were for the investigation of rheumatological, infectious and oncological disease. Most (63%) of the scans had positive findings. 20 patients underwent a bone scan within 6 weeks of the WBMS. 15 of these had concurring findings on both scans. In the remaining 5 cases with discrepant findings, none were clinically significant. Conclusion: Our study demonstrates that in our practice, most findings on WBMS and bone scan are concurring. There was nothing clinically significant missed In the cases in which there were discrepant findings. The authors propose that WBMS is a very useful and effective imaging modality for imaging multi- focal disease in children. Without the use of ionising radiation, its allows the assessment of both osteoblastic and osteoclastic skeletal and extra- skeletal lesions. Further robust studies are needed to inform guidelines on the role of WBMS in the paediatric setting. Background Traditionally, nuclear medicine scans such as bone scans were the mainstay of imaging for multi-focal disease in children. However since around 2000, advances in MR technology and software have made whole body MR STIR (WBMS) imaging possible 1, 2 . STIR is a T2 fat suppressed sequence, resulting in water- containing structures demonstrating high signal. This is useful as most pathological lesions contain water. See Table 1 for the advantages and disadvantages of WBMS. Results Out of a total 138 WBMS scans performed between 2011 -2016, 126 were included. Mean age of patient : 9 years old (youngest 6 wks, oldest 18 yrs) % of patients that did not require GA: At least 66% (83) (Yes 14% (18), Unknown 20% (25)) Scan indication: 34% (43) oncology, 30% (38) rheumatology, 24% (31) infection, 11% (14) miscellaneous (Pie chart 1 shows the types of pathologies) Findings on WBMS: 63% with significant finding, 32% no findings, 6% incidental findings (ovarian cysts, non-pathological nodes, trace of fluid) 20 patients had a bone scan within 6 weeks of their WBMS, the results are shown in Table 4. Study aims The use of whole body MRI STIR (WBMS) in multi-focal disease paediatric disease is anecdotally increasing to become the preferred imaging modality over traditional bone scans. In the absence of guidelines, the authors aim to: 1. Formally review our use of WBMS 2. Compare the findings of WBMS with the findings on bone scans. Methods Table 2 shows the inclusion and exclusion criteria. 3 radiology registrars collected data, shown in Table 3, using information found on PACS. Discussion: Our study was limited as it was retrospective, and we had a relatively small number of patients who had undergone both WBMS and bone scan in the same clinical presentation. However the authors feel our study demonstrates that in our practice, most findings on WBMS and bone scan are concurring. There was nothing clinically significant missed by either modality In the cases in which there were discrepant findings. The authors propose that WBMS is a very useful and effective imaging modality for imaging multi-focal disease in children. Without the use of ionising radiation, it allows the assessment of both osteoblastic and osteoclastic skeletal and extra- skeletal lesions. It does however add to the pressures on the MR scanner, and poor specificity may lead to false positives. Some centres add diffusion weighted and/or T1 sequences to WBMS to reduce false positives, though scan time is lengthened. Further robust studies are needed to inform evidence-based guidelines on the role of WBMS in the paediatric setting. Table 4: Out of the 20 patients who underwent both WBMS and bone scans within 6 weeks, 15 had the same findings on both scans. The following 5 cases had discrepant findings. Case 1 indication : Toddler with treated metastatic rhabdomyosarcoma WBMS: High STIR signal in the proximal left tibia which could be new metastasis ( Fig. 1a) , BONE SCAN (same day) : no corresponding high signal in the left proximal tibia, overall increased uptake in the left leg due to increased use (Fig. 1b) OUTCOME: follow up x-ray showed sclerotic metaphyses (Fig. 1c) - felt to be in keeping with benign radiotherapy changes. Case 2 indication: Teenager with previously resected spinal tumour abroad, baseline imaging needed. WBMS: High signal in right iliac wing which could be new metastasis ( Fig. 2a). BONE SCAN (6 weeks prior): normal (Fig. 2b) OUTCOME: follow up WBMS 6 months later was normal (Fig. 2c) – initial WBMS finding was felt to have been artefactual. Case 3 indication : Teenager with relapsed Ewing’s tumour (Fig. 3a) BONE SCAN: Ewing’s tumour in the distal left femur. Two hot spots above the right iliac crest (Fig. 3b), could be new metastases. WBMS (same day): (Fig. 3c) No metastasis. OUTCOME: On balance bone scan finding was felt to be an artefactual finding. Case 4 indication: Teenager with multiple joint pains and swelling BONE SCAN: uptake in right index finger- dactylitis (Fig. 4a) , WBMS (2 weeks later): normal (Fig. 4b) OUTCOME: Dactylitis had probably resolved by the time the WBMS was performed. Case 5 indication: Teenager with juvenile idiopathic arthritis presenting with leg pains BONE SCAN: bilateral tibial shaft uptake which could be shin splints (Fig. 5a) WBMS (same day): normal (Fig. 5b) OUTCOME: X-ray 6 months later (Fig. 5c) found subtle diffuse cortical thickening - possible melorheostosis Table 3 Age of patient Did the patient have GA during WBMS? % (No.) Indication to do WBMS % (No.) Findings on WBMS (%) No. of patients who also had bone scan in the same episode WBMS and bone scan findings Table 1 WBMS advantages over bone scan WBMS disadvantages - No ionising radiation. Bone scans can involve up to 4.4mSV. 1 - The literature suggests that MRI STIR is more sensitive at detecting lesions than bone scans. 1,2 - Detects both osteoblastic and osteoclastic skeletal and extra-skeletal lesions. Bone scans only detect skeletal osteoblastic lesions. - Takes less time. WBMS is a 15 minute scan vs >4hrs total time needed for a bone scan appointment (radio-isotope is injected 4 hours prior to the scan) - Poor specificity for pathological lesions and susceptible to artifact. Benign lesions can may also demonstrate high signal on WBMS 3 - Younger patients require general anaesthetic (usually 4m- 4yr olds, similar bone scans) - Noisy and claustrophobic - Increases the burden of demand of the MR slots. Table 2 Inclusion Criteria Exclusion Criteria -WBMS on Alder Hey PACS (study code MSKES) -Performed between 2011-December 2016 - If other sequences besides STIR were used - If the radiology report was unavailable (usually because scan was from another trust) - If it was done as a post-mortem scan. References 1. Mentzel HJ, Kentouche K, Sauner D, et al. Comparison of whole-body STIR-MRI and 99mTcmethylene-diphosphonate scintigraphy in children with suspected multifocal bone lesions. Eur Radiol. 2004;14:2297–2302. doi: 10.1007/s00330-004- 2390-5. 2. Whole-Body MR Imaging for Detection of Bone Metastases in Children and Young Adul, Heike E. Daldrup-Link, Christiane Franzius, Thomas M. Link, Daniela Laukamp, Joachim Sciuk, Heribert Jürgens, Otmar Schober , and Ernst J. Rummeny , American Journal of Roentgenology 2001 177:1, 229-236 3. Fast STIR Whole-Body MR Imaging in Children, Christian J. Kellenberger, Monica Epelman, Stephen F. Miller, and Paul S. Babyn, RadioGraphics 2004 24:5, 1317-1330 4. Smets AM, Deurloo EE, Slager TJE, Stoker J, Bipat S. Whole-body magnetic resonance imaging for detection of skeletal metastases in children and young people with primary solid tumors - systematic review. Pediatric Radiology. 2018;48(2):241- 252. doi:10.1007/s00247-017-4013-8. Oncology 34% (43) Rheumatology = 30% (38) Infection 24% (31) 11% Miscellaneous • Hemihypertrophy • Complex idiopathic osteolytic syndrome, • LCH • 30% Rhuematology • Diagnosis or follow up of JIA, • SAPHO • Joint pain/joint swelling • Sarcoidosis, Vasculitis • 24% Infection: • Diagnosis and follow up of CRMO • Diagnosis and follow up of osteomyelitis • Pyrexia of unknown origin • 34% Oncology • Bony tumours, soft tissue tumours, neuroblastoma, rhabdomyosarcoma (diagnosis, staging and follow –up) PIE CHART 1 Fig. 1b Fig. 1c Fig. 2a Fig. 2b Fig. 2c Fig. 3a Fig. 1a Fig 3b Fig. 3c Fig. 4a Fig. 4b Fig. 5a Fig. 5b Fig. 5c
Transcript of The Big Picture: Whole Body MRI STIR and its uses in a ... · thickening - possible melorheostosis...
TheBigPicture:WholeBodyMRISTIRanditsusesinatertiarypaediatrichospitalDrRPrasad1,DrPMenon2,DrHChaudhry2,DrCLandes2,DrSHarave2.
AlderHeyChildren’sHospitalNHSTrust,Liverpool,UK.Abstract
Purpose:Anecdotallyinourcentre,wholebodyMRISTIR(WBMS)isbecomingthepreferredimagingmodalityinassessingsystemicdiseaseinchildren,replacingtheolderimagingmodality,bonescan.Therearenocurrentguidelinesinthisarea.TheauthorsaimtoreviewtheuseofWBMS,andcomparethefindingswithtraditionalbonescans.
Methods:ThiswasaretrospectivestudyinwhichdatawascollectedaboutWBMSperformedinourcentrefrom2011-2016. WecomparedthefindingsofWBMSwithbonescanfindingsinthepatientsthathadundergoneboth.
Results: 126WBMRISTIRscanswereincludedinthestudy.Theaveragepatientagewas9years.Most(66%)patientsdidnotrequireGA.Most requestswerefortheinvestigationofrheumatological,infectiousandoncologicaldisease.Most(63%)ofthescanshadpositivefindings.20patientsunderwentabonescanwithin6weeksoftheWBMS.15ofthesehadconcurringfindingsonbothscans.Intheremaining5caseswithdiscrepantfindings,nonewereclinicallysignificant.
Conclusion:Ourstudydemonstratesthatinourpractice,mostfindingsonWBMSandbonescanareconcurring.TherewasnothingclinicallysignificantmissedInthecasesinwhichtherewerediscrepantfindings.TheauthorsproposethatWBMSisaveryusefulandeffectiveimagingmodalityforimagingmulti-focaldiseaseinchildren.Withouttheuseofionisingradiation,itsallowstheassessmentofbothosteoblasticandosteoclasticskeletalandextra- skeletallesions.FurtherrobuststudiesareneededtoinformguidelinesontheroleofWBMSinthepaediatricsetting.
Background
Traditionally,nuclearmedicinescanssuchasbonescanswerethemainstayofimagingformulti-focaldiseaseinchildren.Howeversincearound2000,advancesinMRtechnologyandsoftwarehavemadewholebodyMRSTIR(WBMS)imagingpossible1,2.STIRisaT2fatsuppressedsequence,resultinginwater-containingstructuresdemonstratinghighsignal.Thisisusefulasmostpathologicallesionscontainwater.SeeTable1fortheadvantagesanddisadvantagesofWBMS.
ResultsOutofatotal138WBMSscansperformedbetween2011-2016,126wereincluded.
Meanageofpatient:9yearsold(youngest6wks,oldest18yrs)%ofpatientsthatdidnotrequireGA:Atleast66%(83)(Yes14%(18),Unknown20%(25))Scanindication:34%(43)oncology,30%(38)rheumatology,24%(31)infection,11% (14)miscellaneous(Piechart1showsthetypesofpathologies)FindingsonWBMS:63%withsignificantfinding,32%nofindings,6%incidentalfindings(ovariancysts,non-pathologicalnodes,traceoffluid)20patientshadabonescanwithin6weeksoftheirWBMS,theresultsareshowninTable4.
StudyaimsTheuseofwholebodyMRISTIR(WBMS)inmulti-focaldiseasepaediatricdiseaseisanecdotallyincreasingtobecomethepreferredimagingmodalityovertraditionalbonescans.Intheabsenceofguidelines,theauthorsaimto:1. FormallyreviewouruseofWBMS2. ComparethefindingsofWBMSwiththefindingson
bonescans.
MethodsTable2showstheinclusionandexclusioncriteria.3radiologyregistrarscollecteddata,showninTable3,usinginformationfoundonPACS.
Discussion:Ourstudywaslimitedasitwasretrospective,andwehadarelativelysmallnumberofpatientswhohadundergonebothWBMSandbonescaninthesameclinicalpresentation.Howevertheauthorsfeelourstudydemonstratesthatinourpractice,mostfindingsonWBMSandbonescanareconcurring.TherewasnothingclinicallysignificantmissedbyeithermodalityInthecasesinwhichtherewerediscrepantfindings.TheauthorsproposethatWBMSisaveryusefulandeffectiveimagingmodalityforimagingmulti-focaldiseaseinchildren.Withouttheuseofionisingradiation,itallowstheassessmentofbothosteoblasticandosteoclasticskeletalandextra- skeletallesions.ItdoeshoweveraddtothepressuresontheMRscanner,andpoorspecificitymayleadtofalsepositives.Somecentresadddiffusionweightedand/orT1sequencestoWBMStoreducefalsepositives,thoughscantimeislengthened.Furtherrobuststudiesareneededtoinformevidence-basedguidelinesontheroleofWBMSinthepaediatricsetting.
Table4:Outofthe 20patientswhounderwentbothWBMSandbonescanswithin6weeks,15 hadthesamefindingsonbothscans.Thefollowing5caseshaddiscrepantfindings.Case 1indication :Toddlerwithtreatedmetastatic rhabdomyosarcomaWBMS: High STIRsignalintheproximallefttibiawhichcouldbenewmetastasis(Fig.1a),BONESCAN(sameday):nocorrespondinghighsignalintheleftproximaltibia,overallincreaseduptakeintheleftlegduetoincreaseduse(Fig.1b)OUTCOME:followupx-rayshowedscleroticmetaphyses(Fig.1c)- felttobeinkeepingwithbenignradiotherapychanges.
Case2indication:Teenagerwithpreviouslyresectedspinaltumourabroad,baselineimagingneeded.WBMS:Highsignalinrightiliacwingwhichcouldbenewmetastasis(Fig.2a).BONESCAN(6weeksprior):normal(Fig.2b)OUTCOME:followupWBMS6monthslaterwasnormal(Fig.2c)– initialWBMSfindingwasfelttohavebeenartefactual.
Case3indication :TeenagerwithrelapsedEwing’stumour(Fig.3a)BONE SCAN: Ewing’stumourinthedistalleftfemur.Twohotspotsabovetherightiliaccrest(Fig.3b),couldbenewmetastases.WBMS(sameday):(Fig.3c)Nometastasis.OUTCOME:On balancebonescanfindingwasfelttobeanartefactualfinding.
Case4indication:TeenagerwithmultiplejointpainsandswellingBONESCAN:uptakeinrightindexfinger- dactylitis(Fig.4a),WBMS (2weekslater):normal(Fig.4b)OUTCOME:DactylitishadprobablyresolvedbythetimetheWBMSwasperformed.
Case5indication: Teenagerwithjuvenile idiopathicarthritispresentingwithlegpainsBONESCAN:bilateraltibialshaftuptakewhichcouldbeshinsplints(Fig.5a)WBMS (sameday):normal(Fig.5b)OUTCOME:X-ray6monthslater(Fig.5c)foundsubtlediffusecorticalthickening- possiblemelorheostosis
Table3
AgeofpatientDidthepatienthaveGAduringWBMS?%(No.)
IndicationtodoWBMS%(No.)
Findings onWBMS(%)
No. ofpatientswhoalsohad
bonescaninthesameepisode
WBMSandbonescanfindings
Table1WBMS advantagesoverbonescan WBMSdisadvantages
- Noionisingradiation.Bonescans caninvolveupto4.4mSV.1- TheliteraturesuggeststhatMRISTIRismoresensitiveatdetectinglesionsthanbonescans.1,2
- Detectsbothosteoblasticandosteoclasticskeletalandextra-skeletallesions. Bonescansonlydetectskeletalosteoblasticlesions.
- Takeslesstime.WBMS isa15minutescanvs >4hrstotaltimeneededforabonescanappointment(radio-isotopeisinjected4hourspriortothescan)
- Poorspecificityforpathologicallesionsandsusceptibletoartifact.Benignlesionscanmay alsodemonstratehighsignalonWBMS3- Youngerpatientsrequiregeneralanaesthetic(usually4m- 4yrolds,similarbonescans)- Noisyandclaustrophobic- IncreasestheburdenofdemandoftheMRslots.
Table2InclusionCriteria ExclusionCriteria
-WBMS onAlderHeyPACS(studycodeMSKES)-Performedbetween2011-December2016
- IfothersequencesbesidesSTIRwereused- Iftheradiologyreportwasunavailable(usuallybecausescanwasfromanothertrust)
- Ifitwasdoneasapost-mortemscan.
References
1.MentzelHJ,KentoucheK,SaunerD,etal.Comparisonofwhole-bodySTIR-MRIand99mTcmethylene-diphosphonatescintigraphyinchildrenwithsuspectedmultifocalbonelesions. EurRadiol. 2004;14:2297–2302.doi:10.1007/s00330-004-2390-5.2.Whole-BodyMRImagingforDetectionofBoneMetastasesinChildrenandYoungAdul,HeikeE.Daldrup-Link, ChristianeFranzius, ThomasM.Link, DanielaLaukamp, JoachimSciuk, HeribertJürgens, OtmarSchober,and ErnstJ.Rummeny,AmericanJournalofRoentgenology 2001 177:1, 229-2363.FastSTIRWhole-BodyMRImaginginChildren,ChristianJ.Kellenberger, MonicaEpelman, StephenF.Miller,and PaulS.Babyn,RadioGraphics 2004 24:5, 1317-13304.SmetsAM,DeurlooEE,SlagerTJE,StokerJ,BipatS.Whole-bodymagneticresonanceimagingfordetectionofskeletalmetastasesinchildrenandyoungpeoplewithprimarysolidtumors- systematicreview. PediatricRadiology.2018;48(2):241-252.doi:10.1007/s00247-017-4013-8.
Oncology 34%(43)
Rheumatology =30%(38)
Infection24%(31)
11%Miscellaneous• Hemihypertrophy• Complexidiopathicosteolytic
syndrome,• LCH
• 30%Rhuematology• DiagnosisorfollowupofJIA,• SAPHO• Jointpain/jointswelling• Sarcoidosis, Vasculitis
• 24%Infection:• DiagnosisandfollowupofCRMO• Diagnosisandfollowupofosteomyelitis• Pyrexiaofunknownorigin
• 34%Oncology• Bonytumours,softtissuetumours,
neuroblastoma,rhabdomyosarcoma(diagnosis,stagingandfollow–up)
PIECHART1
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Fig.2a Fig.2b Fig.2c
Fig.3a
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Fig3b Fig.3c
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Fig.5a Fig.5b Fig.5c
