they may have similar presentations but possibly different treatment modalities , ie , hysterectomy for adenomyosis versus conservative management or hysterectomy for leiomyomas , or both . however , only limited studies have been performed on the efficacy of conservative treatment of adenomyosis , and these typically do not improve or preserve fertility . . mri provides better tissue contrast and may be superior to other imaging modalities in certain pelvic pathologies , such as congenital uterine anomalies , leiomyoma , adenomyosis , and endometriomas . some reports suggest mri is a reliable preoperative tool available to physicians to assist in differentiating between fibroids and adenomyoma / adenomyosis . in this study , we evaluated the predictive value of the pre - operative mri in differentiating between leiomyoma and adenomyosis compared with pathologic findings . a 5-year retrospective chart review was performed from january 1999 to december 2004 in a university - based hospital among patients who were admitted to undergo hysterectomy , myomectomy , or both . although 1517 charts were reviewed , only 153 patients who underwent a preoperative mri were selected for this study . patients ranged in age from 21 to 69 with a mean age of 41 and a median age of 39 . the presenting symptoms were as follows : 73(48% ) had menorrhagia , 34(22% ) had dysmenorrhea , 31(20% ) had pelvic pain , 40(26% ) had a pelvic mass , 16(10% ) had irregular bleeding , 14(9% ) had infertility , and 2(1.3% ) had postmenopausal bleeding . of these patients , 50 had a hysterectomy and the other 103 had a myomectomy . mri studies were performed in axial , sagittal , and coronal planes with various t1-weighted spin - echo and t2-weighted turbo spin - echo or spin - echo on a 1.5 tesla system ( gyro scan , phillips medical systems , bothell , washington , usa or ge open magnet mri scanners , general electric company , fairfield , connecticut , usa ) in different centers . contrast enhanced gadolinium was used as an additive technique in 50 cases to achieve better tissue contrast in the patients suspicious for leiomyoma . leiomyoma appeared as low - signal intensity in t2-weighted images and intermediate- to high - signal intensity in t1-weighted images . adenomyosis was described as a focal or diffuse widening of junctional zone above 12 mm , uterine enlargement , or both , with focal or diffuse low - signal intensity myometrial area in t2-weighted images . also on contrast enhanced t1-weighted images , ( gadolinium scan ) small hypointense myometrial spots mri interpretation was performed by different observers in different centers including private radiology centers , community and university hospitals . mri studies were performed in axial , sagittal , and coronal planes with various t1-weighted spin - echo and t2-weighted turbo spin - echo or spin - echo on a 1.5 tesla system ( gyro scan , phillips medical systems , bothell , washington , usa or ge open magnet mri scanners , general electric company , fairfield , connecticut , usa ) in different centers . contrast enhanced gadolinium was used as an additive technique in 50 cases to achieve better tissue contrast in the patients suspicious for leiomyoma . leiomyoma appeared as low - signal intensity in t2-weighted images and intermediate- to high - signal intensity in t1-weighted images . adenomyosis was described as a focal or diffuse widening of junctional zone above 12 mm , uterine enlargement , or both , with focal or diffuse low - signal intensity myometrial area in t2-weighted images . also on contrast enhanced t1-weighted images , ( gadolinium scan ) small hypointense myometrial spots were indicative of adenomyosis . mri interpretation was performed by different observers in different centers including private radiology centers , community and university hospitals . the results were used to confirm the mri findings for the presence of leiomyoma and adenomyosis . according to the pathology reports , 120 had only leiomyoma , 23 had leiomyoma with coexisting adenomyosis , and 9 had adenomyosis . one patient in the hysterectomy group had a normal mri and pathology report that revealed no myoma or adenomyosis . fifteen patients had other pelvic pathologies coexisting with leiomyoma or adenomyosis , or coexisting with both . mri studies correctly diagnosed 136 of 144 patients with leiomyoma . in the remaining 8 patients with leiomyoma data analyses were as follows : sensitivity 94% , specificity 33% , positive predictive value 95% , and negative predictive value 27% . for adenomyosis , in 31 patients , mri revealed true positive , false - positive , and false - negative results in 12 , 11 , and 19 patients , respectively . the positive and negative predictive values of mri for adenomyosis were 52% , 85% , respectively , with 38% sensitivity and 91% specificity . as mentioned previously mri revealed correct diagnoses in only 9/23 patients , in 12/23 it revealed only myoma , and in 2/23 it diagnosed only adenomyosis . adenomyosis and leiomyoma are 2 benign uterine conditions with similar clinical presentations and different pathogeneses . adenomyosis or internal endometriosis is a disease of parous women with the peak incidence between 40 to 50 years of age . it is characterized by the presence of endometrial glands and stroma inside the uterine myometrium . according to different histological interpretations of the hysterectomy specimens , frequency of adenomyosis uterine involvement may be focal or diffuse , and the size of the lesion ranges from a gross macroscopic well - defined lesion ( adenomyoma that mimics myoma ) to a microscopic lesion . uterine leiomyoma is a benign smooth muscle tumor with 25% prevalence in women of reproductive age with a predominance among african american women . furthermore , pathology examination of surgical specimens revealed an incidence of leiomyoma as high as 77% . a definitive diagnosis for both categories is possible based on histological examination of surgical specimens , but imaging techniques are increasingly used for preoperative evaluation and diagnosis . transvaginal ultrasound and pelvic mri are increasingly used as a preoperative diagnostic tool for adenomyosis . although both techniques have been reported to have almost the same sensitivity ( 68% versus 70% ) , the specificity is greater for mri ( 86% versus 65% ) . pelvic mri is also used in the diagnosis of leiomyoma when a patient 's obesity or extreme uterine retroversion , or both , hinder pelvic ultrasound performance . pelvic mri is highly specific in the diagnosis of adenomyosis ( 91% ) and highly sensitive for leiomyoma ( 94% ) according to our findings . currently , pelvic ultrasound , a relatively affordable and effective method , is widely used as an office procedure in the diagnosis of leiomyoma . it is more efficacious to limit the use of mri for specific conditions when uterine preservation is the goal of therapy , such as localization of leiomyoma in an infertile patient or when the patient is a candidate for uterine artery embolization . our results are different from the results in previously published reports that indicated a higher sensitivity ( 70% vs. 38% ) of mri for adenomyosis and higher specificity ( 100% vs. 33% ) for leiomyoma . this can possibly be explained because our study was influenced by selection bias . because the study was performed on a diseased population with a previous diagnosis of myoma or adenomyosis , or both , where ultrasound alone was thought by the physician to be inadequate . therefore , there were very few patients in our study with negative findings , leading to a low specificity . however , it was not possible to select another population , because of the retrospective nature of the study . also , mri studies were done in different centers and interpreted by different radiologists , which may produce interobserver bias . like other radiological studies , mri is highly operator dependent , and the results may be influenced by technical and observer interpretation . however , this may be a strength of the study in the sense that in reality there will not always be the same specialist reviewing all the studies . of 153 patients who had mri as a preoperative diagnostic tool , 103 underwent myomectomies , so there may be an inherent bias against identifying false - negative adenomyosis . at the present time , pelvic ultrasound is used as a first line for the diagnosis of uterine pathology . however , it may be helpful for diagnosis of pelvic pathologies that are not well defined with ultrasound studies . we suggest mri be used as a complementary diagnostic tool in patients whose ultrasound examination does not clarify the diagnosis , such as in extreme uterine retroversion or obesity , or both , and in patients whose ultrasound examination is indicative of adenomyosis and there is a desire for conservative management . if the preoperative mri shows no adenomyosis , patients can be counseled of the low likelihood of having adenomyosis ( 15% ) and therefore conservative management can be offered .