{"paper_id":"1339347e-f0a8-4aec-beb8-1bc22ac64055","body_text":"GIUSEPPE LO MONTE, MD\nDepartment of Morphology, Surgery \nand Experimental Medicine, University \nof Ferrara, Ferrara, Italy\nJEAN MARIE WENGER, MD\nDepartment of Gynecology and Obstet-\nrics, Division of Gynecology, Geneva \nUniversity Hospitals, Geneva, Switzerland\nPATRICK PETIGNAT, MD\nDepartment of Gynecology and Obstet-\nrics, Division of Gynecology, Geneva \nUniversity Hospitals, Geneva, Switzerland\nROBERTO MARCI, PhD\nDepartment of Morphology, Surgery \nand Experimental Medicine, University \nof Ferrara, Ferrara, Italy\nImaging in Practice\nRole of imaging in endometriosis\nABSTRACT\nEndometriosis—the presence of endometrial tissue \noutside the uterine cavity—is first suspected on the basis \nof its signs and symptoms. The diagnosis is confirmed by \nimaging and surgery. Imaging, particularly transvaginal \nultrasonography and magnetic resonance imaging, is \nessential to confirm the diagnosis and guide surgical \ntreatment. \nKEY POINTS\nThe diagnostic evaluation should always start with trans-\nvaginal ultrasonography of the pelvic structures followed \nby magnetic resonance imaging, especially if deeply \ninfiltrating endometriosis is suspected. \nAn inaccurate imaging evaluation may lead to an incom-\nplete excision of lesions if the patient undergoes surgery. \nTransvaginal ultrasonography and magnetic resonance \nimaging allow the assessment of the size, location, and \nextent of the lesions.\nGiven the multifocal nature of the disease, a thorough \nevaluation of all pelvic structures, including the bowel, \nthe bladder, and the ureters, is always recommended.\nCLEVELAND CLINIC JOURNAL OF MEDICINE  VOLUME 81  • NUMBER 6  JUNE 2014  361\nA \n32-year-old woman presents with a his-\ntory of pelvic pain, dysmenorrhea, dys-\npareunia, dyschezia, and dysuria, with exacer -\nbation of the symptoms during her menstrual \ncycles. Her menarche occurred at the age of \n13 and her menses are regular. She has never \nundergone surgery and has no relevant patho-\nlogic processes. She also reports that for the \npast 18 months she has been unsuccessfully \ntrying to conceive. \n T wo months ago, she went to the emergen-\ncy department because of an acute episode of \nsevere pelvic pain associated with abdominal \ncramps, vomiting, and dyschezia, occurring at \nthe beginning of her menstrual cycle. At that \ntime, her vital signs were within normal limits, \nbut deep palpation of the right iliac fossa was \npainful. On that occasion, acute abdomen and \nbowel obstruction were excluded. \n Now, vaginal examination reveals a bluish, \npainful, bulky induration in the posterior for -\nnix. Digital rectal examination reveals a circu-\nlar infiltrated area in the anterior rectal wall. \nHer cancer antigen 125 (CA 125) level is 230 \nU/mL (normal range 0–35 U/mL). \n ■ MENSES-RELATED SYMPTOMS \nAND THE DIAGNOSIS OF ENDOMETRIOSIS\nThe diagnosis of endometriosis should be con-\nsidered in the patient described above. Many \nof her signs and symptoms can be associated \nwith several diseases. However, the diagnostic \nhypothesis points strongly toward endometrio-\nsis, since her symptoms recur at the beginning \nof every menstrual cycle.\n1 \n Endometriosis is the presence of endome-\ntrial tissue outside the uterine cavity. The af-\nfected organs usually include the ovaries, fallo-\npian tubes,\n2 peritoneal surface, vagina, cervix, \nIMAGING IN PRACTICE\ndoi:10.3949/ccjm.81a.13032\nEDUCATIONAL OBJECTIVE: Readers will order appropriate imaging if patients present with symptoms \nthat suggest endometriosisCREDIT\nCME\n\n362 CLEVELAND CLINIC JOURNAL OF MEDICINE  VOLUME 81  • NUMBER 6  JUNE 2014\nIMAGING IN ENDOMETRIOSIS\nabdominal wall,3 scar tissue, pouch of Douglas, \nurinary tract, and bowel. However, any organ \ncan be involved. \n So-called deeply infiltrating endometriosis is \nan endometriotic lesion penetrating into the \nretroperitoneal space (most often affecting \nthe uterosacral ligaments and the rectovaginal \nseptum) or the pelvic-organ wall to a depth of \nat least 5 mm and involving structures such as \nthe rectum, vagina, ureters, and bladder.\n4 Its \nclinical presentation is highly variable, rang-\ning from no symptoms to severe pain and dys-\nfunction of pelvic organs. \n Endometriosis can be diagnosed with cer -\ntainty only when the endometriotic lesions \nare observed by laparoscopy or laparotomy \nand after the histologic examination of sur -\ngically resected lesions ( FIGURE 1 ).1 However, \na presumptive diagnosis can be made on the \nbasis of imaging findings, which can be useful \nin the differential diagnostic process (TABLE 1).\n ■ EXAMINATION AND BLOOD MARKERS \nPROVIDE LIMITED INFORMATION\nKnowing the history of the patient, along with \na physical examination that includes speculum \nand bimanual vaginal and rectal examination, \ncan be helpful in the diagnostic process even \nif nothing abnormal is found. \n Pelvic examination has a poor predictive \nvalue, as demonstrated in a study conducted \nby Nezhat et al\n5 in 91 patients with surgically \nconfirmed endometriosis, 47% of whom had a \nnormal bimanual examination. \n CA 125 is the serologic marker most often \nused for diagnosing endometriosis. Levels are \nusually high in the sera of patients with endo-\nmetriosis, especially in the advanced stages.\n6 \nHowever, levels increase both in the physi-\nologic menstrual cycle and in epithelial ovar -\nian cancers.7 Thus, the diagnostic value of CA \n125 is limited in terms of both sensitivity and \nspecificity.\n ■ INCLUDE IMAGING \nIN THE DIAGNOSTIC WORKUP\nSurgical treatment is frequently offered to pa-\ntients who have severe pelvic pain that does \nnot respond to medical treatment, or in cases \nof infertility. Imaging investigations are man-\ndatory both to ascertain the diagnosis and to \nassess involvement of internal organs before \nsurgery. Moreover, imaging helps minimize \nthe surgical risks.\n The primary aim of the radiologic exami-\nnation is to describe the precise location, the \ndepth, and the number of pelvic endometri-\notic lesions. Furthermore, imaging is useful to \ncheck for endometriotic foci in pelvic organs \nsuch as the bowel, ureters, and bladder, which \nare often involved in the pathologic process. \n Transvaginal ultrasonography and magnet-\nic resonance imaging (MRI) can accurately \ndelineate deeply infiltrating lesions of endo-\nmetriosis that are not easily accessible laparo-\nscopically.\nTransvaginal ultrasonography\nTransvaginal ultrasonography is the first-line \nimaging study when endometriosis is suspect-\ned: it is powerful, simple, widely available, \nand cost-effective. In particular, it is recom-\nmended for diagnosing endometriotic ovarian \ncysts (endometriomas)\n8,9 and endometriosis of \nthe bladder.10 However, its value for the assess-\nment of superficial peritoneal lesions, ovarian \nfoci, and deeply infiltrating endometriosis is \nquestionable. \n Although uncomfortable for the patient, \ntransvaginal ultrasonography should be per -\nformed during menses, or when the pain \nreaches its highest level. In fact, during men-\nstrual bleeding the endometrial implants grow \nand become easier to detect. \nEndometriosis \ncan involve \nany organ\nMedical history \nPhysical examination \nSerologic markers  \n  (eg, cancer antigen 125)\nPresumptive diagnosis  \nof pelvic endometriosis\nTransvaginal ultrasonography Symptoms or radiologic signs \nsuggesting concomitant bowel \nor bladder endometriosis\nMagnetic resonance imaging Double-contrast barium enema \nMultislice computed tomography \nCystoscopy \nTransrectal ultrasonography\nLaparoscopy and biopsy Definitive diagnosis  \nof endometriosis\nFIGURE 1. Diagnostic algorithm for endometriosis.\n\nCLEVELAND CLINIC JOURNAL OF MEDICINE  VOLUME 81  • NUMBER 6  JUNE 2014  363\nLO MONTE AND COLLEAGUES\n Mais et al 8 reported that transvaginal ul-\ntrasonography has a sensitivity of 88% in dif-\nferentiating endometriomas from other ovar -\nian masses, and a specificity of 90% (FIGURE 2). \nFurthermore, its specificity is as high as that of \nMRI.\n8,9 \n Endometriotic nodules detected in the \nuterosacral ligaments, rectovaginal sep-\ntum, vagina, vesicouterine pouch, bladder \n(FIGURE 3 ), and ureters can be signs of deeply \ninfiltrating endometriosis. Pelvic adhesions \ncan be suspected when pelvic organs appear \nfixed to each other, when hyperechogenic \nplaques are found between the serosal sur -\nfaces of the different organs, and when the \npouch of Douglas is partially or completely \nobliterated. \n The accuracy of transvaginal ultrasonogra-\nphy strongly depends on the operator’s skill. \nFurthermore, lesions of the sigmoid colon \nare impossible to visualize by transvaginal \nultrasonography; hence, further diagnostic \nprocedures are required. Transvaginal ultra-\nsonography is the most accurate technique in \ndetecting endometriotic nodules of the blad-\nder wall in patients with urinary symptoms. \n Transvaginal ultrasonography combined \nwith color Doppler can also demonstrate the \nflow of urine through the ureters to the blad-\nder, thereby ascertaining the patency of the \nureters and clarifying the anatomic relation-\nship between the ureters and any endometri-\notic lesions in the detrusors.\n10 Hydronephrosis \ncan arise from ureteral restriction caused by \nTABLE 1\nDifferential diagnosis of endometriotic lesions  \ndetected at imaging according to location\nLocation Differential diagnosis Additional information\nBladder Urachal remnant \nEpithelial tumor \nMesenchymal tumor\nCystoscopic evaluation may provide  \nadditional information\nPerimetrium and round \nligaments\nSubserosal leiomyoma \nOther neoplasm\nAt laparoscopy, endometriosis appears as  \n  red/black/white scarred lesions associated  \n  or not with adhesions\nRetrocervical region Peritoneal metastasis  \n  (ie, gastrointestinal cancer) \nOvarian malignancy\nAscites and tumor mass detected elsewhere \n  in the abdominal cavity guide the diagnosis \n  to metastatic malignancies \nAt laparoscopy, retrocervical deeply infiltrating  \n  endometriosis is easily recognized\nRectovaginal space Bladder cancer \nVaginal cancer \nAnorectal cancer\nThe region is not easily accessible  \n  for endoscopic viewing \nRectosigmoid colon Bowel-constricting neoplasm \nMetastatic implants to the bowel\nColonoscopy easily detects epithelial colon  \n  cancers; unlike colon cancer, deeply  \n  infiltrating endometriosis starts at the serosal \n  layer and rarely affects the mucosa\nUreters Ureteral cancer \nExtrinsic ureteral obstruction due to  \n  gastrointestinal or gynecologic  \n  malignancies \nCorrect diagnosis requires detection of the \n  epicenter of the mass \nRenal ultrasonography is useful to reveal \n  hydronephrosis\nOvaries Hemorrhagic corpus luteum \nDermoid cyst \nOvarian cancer\nTransvaginal ultrasonography, magnetic  \n  resonance imaging, or computed tomography  \n  usually provides sufficient information\n\n364 CLEVELAND CLINIC JOURNAL OF MEDICINE  VOLUME 81  • NUMBER 6  JUNE 2014\nIMAGING IN ENDOMETRIOSIS\nendometriotic nodules. Thus, transabdominal \nultrasonography of the kidneys is always rec-\nommended when deeply infiltrating endome-\ntriosis is suspected. \n Some centers use a bowel-preparation pro-\ntocol consisting of a laxative taken 24 hours be-\nfore the procedure, combined with a low-residue \ndiet and an enema 1 hour before the examina-\ntion to cleanse the rectosigmoid colon of fecal \ncontent and gas, which can interfere with the \nvisual examination of the pelvic structures.\n11 \nTransabdominal ultrasonography\nTransabdominal ultrasonography can be used \ninstead of transvaginal ultrasonography, eg, in \nyoung girls and women who have never been \nsexually active. When transabdominal ultra-\nsonography is selected, the patient should \nhave a full bladder to maximize the visualiza-\ntion of the pelvic structures. However, trans-\nvaginal ultrasonography is generally more \nsensitive than transabdominal in detecting \nadnexal masses and pelvic nodules.\n12\nMagnetic resonance imaging\nMRI has been recently introduced in the di-\nagnosis of endometriosis. MRI is less operator-\ndependent than transvaginal ultrasonography \nand is more sensitive for detecting foci of \ndeeply infiltrating endometriosis, because of its \nability to completely survey the anterior and \nposterior compartments of the pelvis. How-\never, its diagnostic value in cases of bladder \nendometriosis, superficial peritoneal lesions, \nand ovarian foci is still controversial.\n13–16 \n On MRI, lesions of deeply infiltrating en-\ndometriosis mainly appear as areas or nodules \nwith regular, irregular, indistinct, or stellate \nmargins. A distortion of the normal pelvic \nanatomy or the detection of a loculated fluid \ncollection can indirectly signal the presence \nof adhesions. \n MRI has high specificity for the diagnosis \nof endometriomas as a result of its ability to \ndetect aged hemorrhagic content (\nFIGURE 4).17 \nDespite the many studies that point to the \nlimits of MRI in detecting small endometri-\notic lesions, recent studies demonstrated that \nMRI also has good sensitivity for small peri-\ntoneal implants and adhesions.\n18,19 The injec-\ntion of gadolinium contrast is still a debatable \nmeasure, because contrast-enhanced imaging \ncannot differentiate infiltrating lesions from \nother normal fibromuscular pelvic anatomic \nstructures.\n15,20 \n Bowel preparation can be done with an \noral laxative the day before imaging, comple-\nmented by a low-residue diet. A single dose \nof a ready-to-use enema is given 30 minutes \nbefore the examination to cleanse the termi-\nnal section of the intestinal tract. To avoid \nmotion artifacts caused by bowel peristalsis, \nimages are obtained after intramuscular injec-\ntions of a myorelaxant are given, if there is no \ncontraindication. Bowel preparation is useful \nto eliminate fecal residue and gas, thereby al-\nlowing proper visualization of lesions of deeply \ninfiltrating endometriosis, but it is not rou-\ntinely prescribed in all centers.\n11 \nFIGURE 2. Endometriotic ovarian cysts (endometriomas) (ar-\nrow) on transvaginal ultrasonography.\nFIGURE 3. Transvaginal ultrasonography in the sagittal \nplane shows an endometriotic nodule in the posterior wall \nof the bladder (arrow).\n\nCLEVELAND CLINIC JOURNAL OF MEDICINE  VOLUME 81  • NUMBER 6  JUNE 2014  365\nLO MONTE AND COLLEAGUES\n In most cases, endometriotic lesions have \nan MRI signal intensity that comes very close \nto that of the surrounding fibromuscular struc-\ntures. In this regard, vaginal and rectal disten-\ntion and opacification using ultrasonographic \ngel clearly help to delineate the cervix, vagi-\nnal fornices, and vaginal wall, as well as the \nrectum and wall of the rectosigmoid junction \n(\nFIGURE 5).20\n ■ PRESURGICAL IMAGING\nRectal endoscopic ultrasonography\nEven though it should not be included in the \nroutine diagnostic workup, rectal endoscopic ul-\ntrasonography, using a flexible echoendoscope, \nis suitable in certain presurgical cases. The aim \nof this imaging technique is to assess the depth \nof bowel wall infiltration thanks to the visual-\nization of the different layers.\n21\nDouble-contrast barium enema \nand multislice computed tomography\nDouble-contrast barium enema is extensively \nused for the diagnosis of bowel endometriosis, \nonce the decision to perform surgery has been \nmade. It allows evaluation of the degree and \nlength of the bowel occlusion at the level of \nthe sigmoid or high rectosigmoid tract, but it \ndoes not permit differentiation of bowel en-\ndometriosis from other pathologies. \n Multislice computed tomography offers \nthe opportunity to evaluate the depth of the \nlesions with excellent precision. \n22 \n The most relevant disadvantage of both \nprocedures is the exposure of women of repro-\nductive age to ionizing radiation. In addition, \nmultislice computed tomography requires the \nadministration of an intravenous iodinated \ncontrast medium and a retrograde colonic dis-\ntention with about 2 L of water.\n\t ■\n ■ REFERENCES\n 1. Attaran M, Falcone T, Goldberg J. Endometriosis: still tough to diag-\nnose and treat. Cleve Clin J Med 2002; 69:647–653.\n 2. Wenger JM, Soave I, Lo Monte G, Petignat P , Marci R. Tubal en-\ndometrioma within a twisted fallopian tube: a clinically complex \ndiagnosis. J Pediatr Adolesc Gynecol 2013; 26:e1–e4.\n 3. Marci R, Lo Monte G, Soave I, Bianchi A, Patella A, Wenger JM. \nRectus abdominis muscle endometriotic mass in a woman affected \nby multiple sclerosis. J Obstet Gynaecol Res 2013; 39:462–465.\n 4. Vercellini P , Frontino G, Pietropaolo G, Gattei U, Daguati R, Crosig-\nnani PG. Deep endometriosis: definition, pathogenesis, and clinical \nmanagement. J Am Assoc Gynecol Laparosc 2004; 11:153–161.\n 5. Nezhat C, Santolaya J, Nezhat FR. 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(A) On a fat-saturation transverse T1-weighted \nimage, the endometrioma has high signal intensity. \n(B) On transverse T2-weighted image, blood-degraded \nproduct content has intermediate to low signal intensity.\nFIGURE 5. Posterior deep infiltrating endometriotic nodule \non magnetic resonance imaging. (A) On a T2- weighted \nimage with no opacification of the vagina and rectum with \nultrasonographic gel, a retrocervical endometriotic nodule \n(white oval) has a signal intensity very close to that of the \nsurrounding fibromuscular anatomic structures such as the \nrectal wall (arrow), vagina, and cervical stroma (asterisk). \n(B) A T2- weighted image shows the endometriotic nodule \n(oval) extending downward to the vaginal fornix, which \nappears obliterated. Only the right vaginal fornix (asterisk) \nis distended. 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Gynecol Obstet \nInvest 1996; 41:203–206.\n 20. Loubeyre P , Copercini M, Frossard JL, Wenger JM, Petignat P. Pictori-\nal review: rectosigmoid endometriosis on MRI with gel opacification \nafter rectosigmoid colon cleansing. Clin Imaging 2012; 36:295–300.\n 21. Bahr A, de Parades V, Gadonneix P , et al. Endorectal ultrasonogra-\nphy in predicting rectal wall infiltration in patients with deep pelvic \nendometriosis: a modern tool for an ancient disease. Dis Colon \nRectum 2006; 49:869–875.\n 22. Biscaldi E, Ferrero S, Remorgida V, Rollandi GA. Bowel endometrio-\nsis: CT-enteroclysis. Abdom Imaging 2007; 32:441–450.\nADDRESS: Roberto Marci, PhD, Department of Morphology, Surgery and \nExperimental Medicine, University of Ferrara, Corso Giovecca 183, 44100, \nFerrara, Italy;  \ne-mail: roberto.marci@unife.it","source_license":"public-domain-us","license_restricted":false}