{"paper_id":"93417574-8c22-4849-9afc-4ab3cdecb952","body_text":"The Use of Imaging in Endometriosis \nAuthors: Dr Lara Ann Saliba B.Sc (Hons .), MD . & Miss Jeannine Marie Dalli \nAbstract \nEndometriosis is a complex and often painful condition characterised by the presence of endometrial tissue \noutside the uterus . This may lead to inflammation, scarring and symptoms such as pelvic pain and infertility. \nIt may manifest itself as superficial or deep disease as well as ovarian disease with the presence of \nendometriomas . \nThis study came to fruition in order to emphasise the importance of imaging with respect to the diagnosis of \nendometriosis. Whereas previously a surgical approach was the gold standard, imaging has now become the \nbenchmark for diagnosis . The aim of this paper is to highlight the importance of imaging in endometriosis by \nreviewing literature on various databases such as PubMed and combining the most salient and relevant \npoints . The goal is to underscore the previous points even further . \nThis literature review revealed that techniques such as ultrasound, magnetic resonance imaging (MRI) and \ncomputed tomography (CT) are utilised to visualise endometrial lesions, cysts and associated pelvic anatomy \nvariations . Ultrasound, in particular transvaginal, is often the first-line imaging tool primarily because of its \naccessibility and non-invasiveness . MRI however is considered the gold standard for evaluating deep \ninfiltrating endometriosis and is able to provide a detailed image of soft tissue structures . It is therefore the \nmainstay investigation prior to management planning and surgical intervention . \nIn conclusion, the use of imaging does not simply aid with management planning however, is able to assist in \nmonitoring disease progression and response to treatment \nKeywords: Endometriosis, imaging, MRI, ultrasound \nIntroduction \nEndometriosis 1s a gynecological disorder \ncharacterised by the presence and growth of tissue \nwhich when viewed under a microscope, is similar \nto endometrial tissue, outside of the uterus . The \nprime age of diagnosis is between the ages of 30 and \n45 however lesions may occur in 1-20% of all \nwomen, most often asymptomatically . These lesions \ncan be found throughout the pelvis, most notably in \nthe uterosacral ligaments and surrounding the \novaries where it may form endometriomas or \n\"chocolate cysts\" . It may also occasionally affect \nabdominal wound scars, the vagina, bladder, \nrectum and sometimes even the lungs. \nEndometriosis, like normal endometrium within the \nuterus, responds to oestrogen. This explains why it \nis known to regress during the menopause as well as \npregnancy, and is seen to have fluctuating \nsymptomatology during the menstrual cycle. In \nsevere cases, endometriosis has been seen to cause \nwhat is known as a \"frozen pelvis\" secondary to \n9B \n\nprogressive fibrosis and the formation of adhesions . \nClinically, a patient may present in a number of \nvarious ways ranging from cyclical chronic pelvic \npain to dysmenorrhea prior to the onset of \nmenstruation, deep dyspareunia, infertility as well \nas dyschezia. More acute cases may be characterised \nby sudden onset abdominal pain secondary to \nrupture or torsion of an endometrioma. Vaginal \nexamination may reveal thickening in the adnexa, \nan immobile or retroverted uterus , or may also be \ncompletely normal! \nWhereby the previous gold standard to diagnosis \nwas via laparoscopy, imaging has slowly taken over \nmainly because it is less invasive and patients are \ntherefore more likely to comply, however also \nbecause of its sensitivity with respect to diagnosing \nendometriotic lesions. \nLiterature Review \nMoradi et al wrote that there is an average delay of \n7-12 years in the diagnosis of endometriosis (1 ). \nThis delay in diagnosis results in delays of \ninterventions that relieve pain and discomfort \nassociated with this condition, which in some \nwomen can be so severe causing them to harm \nthemselves. For this reason, it is imperative to \ninvest in women 's health since delays in diagnosis \nresult in significant psychological burden (2). \nNICE guidelines recommends ultrasound, which is \nusually trans-vaginal or trans-abdominal as the \nprimary imaging modality, however, transvaginal \nultrasound is preferred. Other guidelines such as \nESHRE also include MRI as being one of the \nprimary imaging modalities (3). Patients tend to \nprefer ultrasound due to its quick and easy process, \nas well as being relatively cheap, however the use \nand accuracy of results depends greatly on the \noperator 's skill and experience, as well as the \nseverity of the disease. \nUltrasound \nOvarian endometriomas are arguably the most \ncommon forms of endometriosis found on \nultrasound . It is generally described as unilocular or \nmultilocular cystic lesions with a ground-glass \nappearance measuring [X] x [Y] x [Z] with no \ninternal vascularity noted on Doppler imaging . \nInternal vascularity would prompt investigations \nfor more sinister causes for the ovarian mass. \nAdditional findings may include finding free fluid in \nthe pouch of Douglas as well as tenderness on \ntransvaginal probe pressure correlating with the \nlesion location . The ultrasound operator may also \nfind endometrial glands within the myometrium, \nmeaning that there is co-existing adenomyosis . \nAdenomyosis and endometriosis are closely related \nhowever may be distinguished since endometriosis is \nfound outside the uterus while adenomyosis is \nfound within the myometrium. To assess the \nextremity of ovarian endometriosis, the operator \nmay elicit the \"sliding sign\" using the application of \npressure to the trans-vaginal probe to measure the \ndegree of mobility of the pelvic structures . A \npositive sliding sign is normal; meaning that the \nanterior rectum glides freely over the posterior \nuterus . A negative sliding sign is a bad prognostic \nindicator since it denotes the presence of deep \ninfiltrating endometriosis, meaning that there is \ninvolvement of uterosacral ligaments, bladder, \nbowel, vagina and any part of the peritoneum. \nMRI \nWith MRI, soft tissue can be seen in much greater \ndetail, than with ultrasound, thus it is good to \ndistinguish lesions when the diagnosis is in doubt. \nHowever, patients may be reluctant since there is a \nneed to be in a closed space for a long period of \ntime. It is important to mention that even though \nhigh-resolution pictures are obtained through MRI, \na diagnosis of endometriosis cannot be ruled out if \nthere are no findings on imaging, and further \ninvestigations are required when there is a high \nclinical index of suspicion . MRI uses T 1 and T2 \n99 \n\nweighted images, therefore it is important to \ndistinguish that endometriosis is hyperintense on Tl \nimages and hypointense on T2 images. There will \nalso be shading signs showing layering of blood \nwithin the lesion. MRI is useful when a diagnosis of \nendometriosis is made on ultrasound, but the degree \nof disease needs to be further quantified . An \nexample of advanced disease seen on MRI is \ndistorted pelvic anatomy due to adhesions and \nfibrosis associated with deep infiltrating \nendometriosis . \nDespite the many signs and clues seen on \nultrasound and MRI which help us in our \ndiagnosis, smaller and more superficial lesions are \nusually missed ( 4), thus, this is where laparoscopy \nstarts to play an important role in the imaging­\nnegative patient with a high index of suspicion. \nUnfortunately, a clinical exam is of little use in most \ncases of endometriosis since only about half of the \nlarger lesions are thought to be palpable . One main \ndisadvantage of imaging is that in some cases, it is \nunable to differentiate between ovarian cancer and \novarian endometriosis . In addition, both conditions \nconstitute a rise in Ca125 which does not help in \ndifferentiating the two diagnoses . This is especially \nan issue in older postmenopausal women, who \nmight have had endometriosis for years but never \nsought help, or got a proper diagnosis, and thus \nfurther warrants surgical exploration via \nlaparoscopy (5). \nKoninckx et al. describe the inaccuracy of imaging \nvia calculations alleging that a test with 99% \nsensitivity and specificity still results in 50% false \npositive results. They also mention the possible \nintegration of artificial intelligence in the future to \nstrengthen the reliability of imaging techniques and \nslowly start moving away from surgical techniques. \nWhen there is uncertainty, surgical options can be \nparticularly damaging especially to the younger \npatient. This is because endometriosis tends to be a \nrecurring condition, thus adhesion formation from \nsurgery may cause recurrence of endometrial \nlesions, possibly even in the adhesion or surgical \nscar! It also poses a threat to the young female's \nfertility and affects family planning (5). For this \nreason, many doctors and patients take the \ncollective decision to commence medical therapy \nwithout a definite diagnosis, thus contributing to \nthe delay in diagnosis as explained earlier by \nMoradi et al. \nPET-CT \nPositron em1ss1on tomography- computed \ntomography (PET-CT) has a wide range of use in \noncology, but it is being applied outside of the \noncological field in various novel studies overseas to \nassess its ability to aid in other possibly benign \ndiagnoses, such as that of endometriosis . Since \nendometriosis may mimic ovarian cancer, it can be \napplied to identify endometrial lesions and \nendometriomas (6). It is a promising diagnostic \ntechnique smce PET involves mJection of \nradiolabeled tracers intravenously to highlight parts \nof the body that take up that specific tracer, for \nexample, in areas that are more metabolically \nactive. There are many tracers that can be used for \nthis purpose . Initially, studies used F­\nfluorodeoxyglucose as the radiolabeled substance­\nwhich showed promising results (7), however \nstudies are shifting their focus towards the \nassessment of F-flouroestradiol and F­\nflourofuranylnorprogesterone as well as the \nintegration of PET-CT with other imaging \nmodalities to improve early-stage diagnoses (8). \nMRE \nMagnetic resonance elastography (MRE) is used to \nadd an extra dimension to the image formed to \ndetermine the tissue's character (mechanical and \nphysical properties such as stiffness and viscosity). \nIt allows the surgeon to know the lesion's \ncharacteristics beforehand to be better prepared \nabout what is most likely to be found during \nsurgery, since the lesion's characteristics and \n100 \n\ncomposition influence decisions for removal (8). \nMRE also overcomes MRI's limitation of not being \nable to identify the difference between ovarian \ncancer and ovarian endometriomas in some cases. \nThe downsides of this technique are that it is very \nexpensive, requires investigation for a long time like \nMRI, and it is not yet available in Malta. \nConclusion \nPatients suffering from this chronic, relapsing \ncondition experience reduced quality of life, time off \nwork and overall increased suffering . It is our duty \nas medical professionals to enhance their quality of \nlife, make sure that our patients feel heard, listen to \ntheir concerns and follow them up on any issues \nthey might have . With the advancements in modern \nmedicine, as well as the increase in awareness of the \ncondition, more and more women are being \ndiagnosed and treated accordingly. As physicians, \nwe must always take pelvic and menstrual pain \nseriously , as they may be dismissed as normal, \ntherefore instead of fixing the problem, we would be \ncontributing to the worsening of the problem . In \naddition, we must also be aware to find and treat \nthe problem, with the least invasive procedures \npossible . A management plan in line with the \nlifestyle and wants of the patient should be devised \nkeeping the patient informed, included, and at the \ncenter of all decisions taken . \nDeclarations \nNone to declare . \nReferences \n1. Moradi M, Parker M, Sneddon A, Lopez V, \nEllwood D . Impact of endometriosis on \nwomen 's lives: a qualitative study . BMC \nWomens Health [Internet] . 2014 Dec [cited 2025 \n2. \n3. \n4. \n5. \n6. \n7. \nFeb 26];14(1):123. Available from: 1. Moradi \nM, Parker M, Sneddon A, Lor-ez V, Ellwood D . \nImr-act of endometriosis on women's lives: a \ngualitative studY.. BMC Womens Health \n[Internet]. 2014 Dec [cited 2025 \nCrump J, Suker A, White L. Endometriosis: A \nreview of recent evidence and guidelines . Aust J \nGen Pract [Internet] . 2024 Feb 1 [cited 2025 Jan \n31];53(1-2):11-8 . Available from : 1. Moradi \nM , Parker M , Sneddon A, Lor-ez V, Ellwood D . \nImr-act of endometriosis on women 's lives: a \ngualitative studY.. BMC Womens Health \n[Internet]. 2014 Dec [cited 2025 \nLei Y, Du X, Chen D, Gao Y, Lian H. Quality \nevaluation of endometriosis guidelines using \nAGREE II. Medicine (Baltimore) . 2022 Oct \n28; 101( 43):e3133 l. \nKoninckx PR, Ussia A, Adamyan L, Wattiez A, \nDonnez J. Deep endometriosis: definition, \ndiagnosis, and treatment. Fertil Steril. 2012 \nSep;98(3):564-71 . \nKoninckx PR, Fernandes R, Ussia A, Schindler \nL, Wattiez A, Al-Suwaidi S, et al. Pathogenesis \nBased Diagnosis and Treatment of \nEndometriosis . \n2021;12:745548. \nFront Endocrinol. \nSaunders PTK, Whitaker LHR, Horne AW. \nEndometriosis : Improvements and challenges in \ndiagnosis and symptom management. Cell Rep \nMed . 2024 Jun 18;5(6):101596. \nBalogova S, DaraI E, Noskovicova L, Lukac L, \nTalbot JN, Montravers F . Interference of \nKnown or Suspected Endometriosis m \nReporting FDG PET/CT Performed in Another \nIndication . Clin Nucl Med . 2022 Apr \n1;47(4):305-13. \n8. Griffiths MJ, Horne AW, Gibson DA, Roberts \nN, Saunders PTK . Endometriosis: recent \nadvances that could accelerate diagnosis and \nimprove care . Trends Mol Med . 2024 \nSep;30(9):875-89. \n101","source_license":"CC0","license_restricted":false}