A case of eosinophilic cholecystitis: Radiologic-pathologic correlation.

Eosinophilic cholecystitis (EC) is a rare condition that is characterized by eosinophilic infiltration in the gallbladder wall. We report the case of a 35-year-old woman who presented with unremitting right upper quadrant pain for 1 month. Computed tomography showed a strongly enhanced inner layer of the gallbladder wall. Magnetic resonance imaging of the same area showed low signal intensity on T2-weighted imaging. Cholecystectomy was performed, and histological examination of the surgical specimen revealed >100 eosinophils per high-power field in the inner subserosal layer. The area of these histological findings corresponded to the strongly enhanced inner layer of the gallbladder wall identified on computed tomography.

Double Microballoon-occluded Ethanol Embolization for Pelvic Arteriovenous Malformation: A Case Report.

A 40-year-old man was incidentally found to have right-sided pelvic arteriovenous malformation (AVM) with an aneurysmal dominant outflow vein (DOV). The AVM had two main feeding arteries forming a cluster of fine vessels shunt to the DOV. As transvenous approach was impossible due to anatomical difficulty, transarterial ethanol embolization was performed under simultaneous double microballoon occlusion of the two feeding arteries in combination with protective coil embolization of the prostatic branches. Ethanol (13 mL) was intermittently injected from both microballoon catheters until the AV shunt was completely occluded. At 1-year follow-up, contrast-enhanced CT revealed shrinkage of the thrombosed DOV without any symptom. Our case demonstrated the usefulness of simultaneous double microballoon-occluded ethanol embolization for treating a localized pelvic AVM with a few feeding arteries.

A case of renomedullary interstitial cell tumor: Radiologic-pathologic correlation.

Renomedullary interstitial cell tumor (RMICT), referred to as a medullary fibroma, is almost always asymptomatic and incidentally identified either at autopsy or upon resection of the kidney for other reasons. Although a few cases of RMICTs that are large in size and clinically symptomatic have been reported, there are few reports of RMICTs contrasting imaging findings with pathological findings. In this report, we describe a relatively large RMICT case of 3 cm in size, focusing on the radiologic-pathologic correlation.

Endovascular and Percutaneous Embolotherapy for the Body and Extremity Arteriovenous Malformations.

Arteriovenous malformations (AVMs) consist of abnormal communications between the arteries and veins. They can involve any part of the body and extremity and grow in proportion to age and in response to hormonal influence or trauma. When symptoms progress from Schöbinger clinical stage II to III, transcatheter and/or direct puncture embolization are less-invasive and repeatable options for symptom palliation. The goal of embolization is to obliterate the AV shunt, and the choice of lesion access and embolic agents is based on the individual anatomy and flow. Embolization can be technically challenging due to complex vascular anatomy and morbidity risks. Therefore, a multidisciplinary management is essential for the diagnosis and therapeutic intervention of AVMs.

Detection of the Vesical Arteries Using Three-dimensional Digital Subtraction Angiography Relevant to Intra-arterial Infusion Chemotherapy for Bladder Cancer Using Double-balloon Catheters.

Purpose: This study aims to assess and measure the origin of the superior vesical artery and its distance from the anterior trunk of the internal iliac artery, to which the anticancer drug is infused via double-balloon-occluded arterial infusion bladder-preserving therapy for locally invasive bladder cancer. Material and Methods: The 160 pelvic sides of 80 patients were analyzed. Double-balloon catheters were bilaterally introduced into the contralateral superior gluteal artery via the internal iliac arteries using a bilateral transfemoral approach. The proximal balloon is placed at the internal iliac artery, proximally from superior gluteal artery bifurcation, whereas the distal balloon at the origin of the superior gluteal artery to isolate the anterior trunk of the internal iliac artery discharging to the targeted vesical arteries between the balloons. The side hole between the distal and proximal balloons was adjusted at the origin of the anterior trunk of the internal iliac artery to allow clear visualization of the angiographic flow into the bladder. After the distal and proximal balloons were inflated, three-dimensional rotational digital subtraction angiography was performed by simultaneous contrast injection from one extension tube connected to bilateral catheters. The distance (X) between the origins of anterior trunk of the internal iliac artery and superior vesical artery was measured on three-dimensional digital subtraction angiography images, and the origin of the inferior vesical artery was investigated. Results: All superior vesical artery originated from anterior trunk of the internal iliac artery. The mean x was 7.2 mm (range 1.0-22.0 mm). All inferior vesical arterys branched from anterior trunk of the internal iliac artery or its branches. Conclusions: Superior vesical artery commonly originates from the proximal portion of anterior trunk of the internal iliac artery close to superior gluteal artery bifurcation.

Comparison of reduced field-of-view DWI and full field-of view DWI for the differentiation between non-muscle invasive bladder cancer and muscle invasive bladder cancer using VI-RADS.

PURPOSE: To evaluate whether reduced field-of-view (rFOV) DWI sequence improves the differentiation between non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) using VI-RADS. MATERIAL AND METHODS: Eighty-nine patients underwent bladder MRI with full field-of-view (fFOV) DWI and rFOV DWI sequence. Images were independently evaluated by 2 radiologists. The sensitivities, specificities, accuracies, and areas under the curve (AUCs) for the differentiation between NMIBC and MIBC with fFOV DWI and with rFOV DWI sequence were calculated using VI-RADS. Apparent diffusion coefficients (ADC) values were measured for each patient and averaged. RESULTS: The sensitivity, specificity, accuracy, and AUC by reader 1 were 92%, 78%, 82% and 0.905 with fFOV DWI, and 92%, 86%, 88% and 0.916 with rFOV DWI sequence, respectively. The sensitivity, specificity, accuracy and AUC by reader 2 were 96%, 76%, 82% and 0.900 with conventional DWI, and 96%, 81%, 85% and 0.907 with rFOV DWI sequence, respectively. The specificity and accuracy of reader 1 were significantly better with rFOV DWI sequence than with fFOV DWI, in contrast there was no significant difference for the others. The average of ADC values of fFOV DWI and rFOV DWI sequence were 1.004×10-6 mm2/s and 1.003×10-6 mm2/s, respectively. CONCLUSION: The diagnostic ability of rFOV DWI sequence may be better than that of fFOV DWI using VI-RADS for the differentiation between NMIBC and MIBC regardless of image-reading experience, it is controversial.

Catecholamine-secreting adrenal lipomatous ganglioneuroma: A case study.

Ganglioneuroma, which arise from neural crest cells, typically occurs in adolescents and young adults. Most ganglioneuromas are clinically asymptomatic and hormonally silent, therefore may be diagnosed incidentally during imaging studies. Ganglioneuroma containing fat (lipomatous ganglioneuroma) is a rare variant of ganglioneuroma that is histologically characterized by a mature adipocytic component admixed with a conventional ganglioneuroma. Herein, we report the case of adrenal lipomatous ganglioneuroma with elevated urinary catecholamine level.

Hemorrhage of MRI and Immunohistochemical Panels Distinguish Secretory Carcinoma From Acinic Cell Carcinoma.

OBJECTIVES: Secretory carcinoma (SC, mammary analogue secretory carcinoma) is a salivary gland tumor with ETV6-NTRK3 gene fusion, and its differential diagnosis includes acinic cell carcinoma (ACC). As hemorrhage is often seen in SC, we hypothesized that magnetic resonance imaging (MRI) and immunohistochemical analyses could distinguish SC from ACC. STUDY DESIGN: Retrospective study. METHODS: We used ETV6-NTRK3 gene fusion analyses to reclassify 19 parotid gland tumors that had previously been diagnosed as SC or ACC, and then investigated hemorrhage in both hematoxylin-eosin (H&E)-stained sections and MRIs, and immunohistochemical expression of S-100, mammaglobin, DOG1, and α-amylase. RESULTS: The 19 tumors were genetically reclassified into 11 (58%) SC and 8 (42%) ACC. Combined S-100 and mammaglobin were specific for SC; whereas DOG1 was specific for ACC, and α-amylase was expressed only in 4 ACC cases (50%). H&E staining showed hemorrhage with hemosiderin deposition in all SC cases, and T2-weighted MRI showed hypointense areas in all investigated SC cases, but not in ACC. CONCLUSION: Hemorrhage with hemosiderin deposition is frequently present in SC, and hemorrhage findings in MRI and an immunohistochemical panels for S-100, mammaglobin and DOG1 can distinguish SC from ACC. LEVEL OF EVIDENCE: 3b.

Reduction of the radiation dose and the amount of contrast material in hepatic dynamic CT using low tube voltage and adaptive iterative dose reduction 3-dimensional.

The purpose of this study was to prospectively evaluate the image quality and the diagnostic ability of low tube voltage and reduced contrast material dose hepatic dynamic computed tomography (CT) reconstructed with adaptive iterative dose reduction 3-dimensional (AIDR 3D).Eighty-nine patients underwent hepatic dynamic CT using one of the 2 protocols: tube voltage of 120 kVp, contrast dose of 600 mgI/kg, and filtered back projection in Protocol A (n = 46), and tube voltage of 100 kVp, contrast dose of 500 mgI/kg, and AIDR 3D in Protocol B (n = 43). The volume CT dose index (CTDIvol) and size-specific dose estimates (SSDEs) were compared between the 2 groups. Objective image noise and tumor to liver contrast-to-noise ratio (CNR) were also compared. Three radiologists independently reviewed image quality. The jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed to compare diagnostic performance.The mean CTDIvol and SSDE of Protocol B (14.3 and 20.2, respectively) were significantly lower than those of Protocol A (22.1 and 31.4, P < .001). There were no significant differences in either objective image noise or CNR. In the qualitative analysis, 2 readers assigned significant lower scores to images of Protocol B for at least one of the 3 phases regarding overall image quality (P < .05). There was no significant difference in the JAFROC1 figure of merit between protocols.Low tube voltage CT with AIDR 3D yielded a reduction in radiation dose and in the amount of contrast material while maintaining diagnostic performance.

Can bladder preservation therapy come to the center stage?

Decision-making in urological cancer care requires a multidisciplinary approach for refinement, but its impact on urothelial carcinoma of the bladder has not been fully addressed for the past three decades, except for the latest immunological checkpoint inhibitor approved by the U.S. Food and Drug Administration for metastatic muscle-invasive bladder cancer that is resistant to platinum-based chemotherapy. For the time being, radical cystectomy is the gold standard of curative therapy for muscle-invasive bladder cancer. Trimodal therapy that combines chemotherapy for the purpose of radiation sensitization, external beam radiotherapy and transurethral resection of bladder tumor has emerged as a potential alternative treatment option that preserves the bladder. In lack of randomized studies for bladder preservation therapy compared with surgery, the principles of management of urothelial carcinoma of the bladder have evolved in recent times, with an emphasis on bladder preservation. A number of bladder preservation techniques are available to the surgeon; however, appropriately selected patients with muscle-invasive bladder cancer should be offered the opportunity to discuss various treatment options, including organ-sparing trimodal therapy. The aim of the present study was to compare the primary outcomes of the available treatment methods and identify the sources of variance among studies. A review of various bladder preservation techniques in vogue for the management of urothelial carcinoma of the bladder is discussed.

Assessment of the ability of CT urography with low-dose multi-phasic excretory phases for opacification of the urinary system.

OBJECTIVE: To prospectively evaluate the ability of CT urography with a low-dose multi-phasic excretory phase for opacification of the urinary system. MATERIALS AND METHODS: Thirty-two patients underwent CT urography with low-dose multi-phasic s using adaptive iterative dose reduction 3D acquired at 5-, 10-, and 15-minute delays. Opacification scores of the upper urinary tracts and the urinary bladder were assigned for each excretory phase by two radiologists, who recorded whether adequate (>75%) or complete (100%) opacification of the upper urinary tract and urinary bladder was achieved in each patient. Adequate and complete opacification rates of the upper urinary tracts and the urinary bladder were compared among three excretory phases and among combined multi-phasic excretory phases using Cochran's Q test. RESULTS: There was no significant difference among three excretory phases with 5-, 10-, and 15-minute delays in adequate (56.3, 43.8, and 63.5%, respectively; P = 0.174) and complete opacification rates (9.3, 15.6, and 18.7%, respectively; P = 0.417) of the upper urinary tracts. Combined tri-phasic excretory phases significantly improved adequate and complete opacification rates to 84.4% and 43.8%, respectively (P = 0.002). In contrast, there were significant differences among three excretory phases for the rate of adequate (31.3, 84.4, and 93.8%, respectively; P<0.001) and complete opacification (21.9, 53.1, and 81.3%, respectively; P<0.001) of the urinary bladder. Multi-phasic excretory phases did not improve these rates because opacification was always better with a longer delay. CONCLUSION: Although multi-phasic acquisition of excretory phases is effective at improving opacification of the upper urinary tracts, complete opacification is difficult even with tri-phasic acquisition.

Pathological findings of uterine tumors preoperatively diagnosed as red degeneration of leiomyoma by MRI.

PURPOSE: Venous infarction of a leiomyoma is known as red degeneration of leiomyoma (RDL) and can be a cause of acute abdomen. Although magnetic resonance imaging (MRI) is the only modality that can depict the inner condition of a leiomyoma, the typical MR findings of RDL are sometimes identified incidentally even in asymptomatic patients. The purpose of this study is to clarify common pathological findings of uterine tumors preoperatively diagnosed as RDL by MRI. METHODS: We diagnosed 28 cases of RDL by MRI from March 2007 to April 2015. The ten lesions subjected to pathological analysis after resection were included in the study and reviewed by a gynecological pathologist. The average time from MRI to operation was 4.7 months. RESULTS: The typical beefy-red color was not observed on the cut surface of the tumor except in one tumor resected during the acute phase. All lesions diagnosed as RDL by MRI had common pathological findings consistent with red degeneration of leiomyoma, including coagulative necrosis. Other common pathological features of RDL besides extensive coagulative necrosis appear to be a lack of inflammatory cell infiltrate or hemorrhage in the entire lesion. CONCLUSIONS: Although RDL is known to cause acute abdomen, its typical MR findings can be observed even in asymptomatic patients in a condition that manifests long after red degeneration. The characteristic pathological findings in both the acute phase and the chronic phase that we found in this study, along with radiology reports, will be helpful references for gynecologists and pathologists in suspecting a history of red degeneration and confirming the diagnosis.

[Early and Mid-term Outcomes of Surgical Treatment with Conservative Approach Using Adventitial Inversion Technique for an Acute Type A Aortic Dissection].

OBJECTIVE: This study was performed to assess the early and mid-term outcomes of surgical treatment with adventitial inversion technique for an acute type A aortic dissection. METHODS: From June 2008 to June 2015, 48 patients underwent emergent surgery for acute type A aortic dissection. Ascending aorta/hemiarch replacement was performed in 44/48(91.7%)patients, and total arch replacement in 4/48(8.3%)patients. The adventitial inversion technique was used for both proximal and distal stump constructions of the dissected aortic wall without the reinforcement of Teflon felt. Aortic regurgitation was treated with resuspention of aortic commissures. RESULTS: The operative mortality was 8.3%(4/48). There was no re-exploration in all patients. Postoperative computed tomography showed the obliteration of false lumen in aortic root in all of patients, and aortic arch and/or descending thoracic aorta in 80.9%(38/47)of patients. The actuarial survival rates at 5 years were 74.7%.The freedom from aortic or aortic valve event rate and reoperation rate at 5 year were 90.9% and 95.2%, respectively. CONCLUSION: The adventitial inversion technique provides excellent early and mid-term outcomes for the repair of acute type A aortic dissection.

Postoperative Outcomes of Hybrid Repair in the Treatment of Aortic Arch Aneurysms.

BACKGROUND: The advent of thoracic endovascular aneurysm repair (TEVAR) has bought about a tremendous revolution in the treatment strategy for aortic arch aneurysms. We reviewed our experience using TEVAR with the hybrid approach in the treatment of aortic arch aneurysms to evaluate its feasibility, safety, and effectiveness. METHODS: Between October 2008 and July 2014, 61 consecutive patients (51 men; mean age 75.8 ± 7.7 years; range, 43-85 years) underwent elective treatment for aortic arch aneurysms with the hybrid approach. The 61 patients were separated into 2 groups. Thirty-five patients underwent total debranching TEVAR for zone 0 (debranching TEVAR group), 26 patients underwent long elephant trunk (ET) followed by secondary retrograde TEVAR (ET group). Preoperative, perioperative, and follow-up data were collected retrospectively in the database. RESULTS: The technical success rate was 100%. The paraplegia rates in total debranching TEVAR and long ET TEVAR and were 2.9% and 3.8%, respectively. The stroke rates in total debranching TEVAR and long ET TEVAR were 11.4% and 7.7%, respectively. The overall 30-day mortality and in-hospital mortality rates for all 61 patients were 0% and 3.4% (n = 2; both were in the total debranching TEVAR group), respectively. There were no perioperative type 1 or 3 endoleaks that required secondary intervention. The mean hospital stay was 15.8 days. The median follow-up was 309 ± 303 days. No aneurysm-related deaths occurred during follow-up. CONCLUSIONS: The hybrid approach can be safely performed with good technical success and good midterm results. In future, new alternative devices for aortic arch pathologies, such as a branched stent graft that eliminates extra-anatomic bypass, should be developed.

Real-time in vitro intravascular reconstruction and navigation for endovascular aortic stent grafting.

BACKGROUND: Trans-catheter endovascular stent grafting minimizes trauma and increases the benefitting patient population. However, the alignment between stent graft branches and vasculature branches remains time-consuming and challenging, and such techniques require a significant amount of contrast agent for imaging. METHODS: A new framework for intravascular reconstruction based on sensor fusion between intravascular ultrasound (IVUS) imaging and electromagnetic (EM) tracking was proposed. A new image processing method was presented to realize fully automatic processing of IVUS imaging and 3D reconstruction in real time, as well as branch detection for alignment and deployment. Complementary navigation using CT data allows for efficient catheter advancement and assistant clinical judgement. RESULTS: The reconstruction of an in vitro descending aorta phantom with branches was realized at 35 Hz, with cross-section radius average error of 0.64 mm. CONCLUSION: The proposed method demonstrates significant potential for clinical applications, enables navigation for precise alignment and placement for stent grafting to reduce surgical time, and decreases hemorrhagic collisions and the use of contrast agent. Copyright © 2016 John Wiley & Sons, Ltd.

Novel Software-Assisted Hemodynamic Evaluation of Pelvic Flow During Chemoperfusion of Pelvic Arteries for Bladder Cancer: Double- Versus Single-Balloon Technique.

PURPOSE: Approximately 83 % of patients with bladder cancer have achieved a complete response after undergoing a novel bladder preservation therapy involving balloon-occluded intra-arterial infusion chemotherapy (BOAI) using a four-lumen double-balloon catheter, known as the Osaka Medical College regimen. This study aimed to show the quantitative difference in hemodynamics of the bladder arteries using syngo iFlow (Siemens Healthcare, Erlangen, Germany), which provides an automatic tool for quantitative blood flow analysis between double BOAI (D-BOAI) and conventional single BOAI (S-BOAI). MATERIALS AND METHODS: Fifty patients were included. The catheters were introduced into both posterior trunks of the internal iliac arteries via contralateral femoral artery access. A side hole between the distal and proximal balloons was placed at the origin of each bladder artery to allow clear visualization of angiographic flow of the injected agent into the urinary bladder. Digital subtraction angiography was used during analysis with the syngo iFlow to evaluate the hemodynamics of the contrast medium in the pelvic arteries during BOAI. The comparative change in the amount of contrast medium in the bladder arteries between D-BOAI and S-BOAI was assessed using syngo iFlow. RESULTS: One-hundred pelvic sides were analyzed. The amount of contrast medium in the bladder arteries using D-BOAI was more than twice that using S-BOAI (right, 3.03-fold; left, 2.81-fold). CONCLUSION: The amount of contrast medium in the bladder arteries using D-BOAI was higher than that using conventional S-BOAI. This may increase the anticancer drug concentration in the affected bladder, leading to a good clinical response.

A 'through-and-through bowing technique' for antegrade thoracic endovascular aneurysm repair with total arch debranching: a technical note and the initial results.

OBJECTIVES: The aim of this study was to evaluate the deployment accuracy of a new 'through-and-through bowing technique' that involves the deployment of the stent graft with total arch debranching via median sternotomy. METHODS: The migration distance, patients' demographic characteristics, operative values and the postoperative complications were examined retrospectively. From November 2012 to February 2013, 5 patients with an aortic arch aneurysm underwent total debranching and antegrade thoracic endovascular aneurysm repair (TEVAR) (control group). Fifteen patients underwent placement using the 'through-and-through bowing technique' (bowing group) from March to November 2013. The device was deployed as follows. A stiff guide wire was passed through the debranching prosthesis via the femoral artery. By pushing the bilateral ends of the wire against the aortic arch, the device was located along the greater curvature and bent like a bow. The migration distance, defined as the distance between the pre- and post-deployment positions of the distal end of the stent graft, was measured using fluoroscopic images. RESULTS: There were no significant differences with respect to the patients' demographics or the operative variables between the two groups. The mean migration distance in the control group (9.4 ± 8.7 mm) was significantly longer than that in the bowing group (1.3 ± 1.5 mm). Although one major stroke occurred in the bowing group, there was no operative mortality in either group. CONCLUSIONS: The present paper demonstrated the precise positioning of a GORE TAG deployment using a 'through-and-through bowing technique' with total arch debranching.

Relationship between the distal migration and length of the distal landing zone after endovascular aneurysm repair (EVAR).

BACKGROUND AND PURPOSE: Endovascular aneurysm repair (EVAR) is the main treatment for patients with abdominal aortic aneurysms. This study examines the relationship between the migration of the distal landing zone and the length of the landing zone. MATERIALS AND METHODS: The subjects of this study were 36 patients who underwent contrast-enhanced computed tomography 1 year after EVAR. We constructed curved multi-planar reconstruction imaging and measured the length of migration, the angle of the common iliac artery, and the diameter of the distal landing zone. RESULTS: The mean length of migration was 1.2 ± 1.7 mm. Fifty-four legs had a distal landing zone of over 15 mm and 18 legs had a distal landing zone of less than 15 mm. Four (7.4 %) of the 54 legs with a landing zone of over 15 mm and 3 (16.7 %) of the 18 legs with a landing zone of less than 15 mm had migration of over 3 mm. This difference was significant (P = 0.05). CONCLUSION: The rate of migration on the distal landing zone 1 year after EVAR was reasonable when the length of the landing zone was about 15 mm. It is possible that significant migration can occur in patients with distal landing zones less than 10 mm in length.

Risk factors for adverse outcomes after endovascular therapy for critical limb ischemia with tissue loss due to infrainguinal artery disease.

BACKGROUND: The purpose of this study was to analyze the risk factors for an adverse outcome after endovascular therapy (EVT) for critical limb ischemia (CLI) with tissue loss due to infrainguinal artery disease. METHODS: We retrospectively reviewed the charts of patients with tissue loss (Rutherford class 5 and 6) due to infrainguinal artery disease who were managed with endovascular therapy (EVT) between January 2006 and December 2013. The primary endpoint was amputation-free survival (AFS), while the secondary endpoints were freedom from a major adverse limb event (MALE) plus perioperative (30 days) death (POD), limb salvage, and survival rates at one year. Multivariable perioperative predictors of AFS were identified using the stepwise Cox proportional hazards regression model. RESULTS: A total of 65 patients underwent EVT for infrainguinal artery disease on 72 limbs. The technical success rate was 94% (68/72), while the clinical success was attained in 54 of 72 limbs (72%). The AFS, MALE + POD, limb salvage, and survival rates at one year were 76%, 86%, 91%, and 81%, respectively. The multivariate analysis demonstrated that major tissue loss classified as Rutherford class 6 (HR, 5.68; 95% CI, 2.29-14.13; P<0.05) was negatively associated with decreased AFS, while clinical success (HR, 0.25; 95% CI, 0.11-0.60; P<0.05) was positively associated with increased AFS. CONCLUSIONS: EVT resulted in an acceptable rate of AFS, MALE+POD, limb salvage, and survival. However, we must keep in mind that there are significant limitations to be considered for EVT in patients with major tissue loss, and that, even if revascularization could be successfully performed, a significant number of the treated limbs are still in a critical situation, such as major amputation or death.

A Case of Bilateral Decidualized Endometriomas during Pregnancy: Radiologic-pathologic Correlation.

Clinical differentiation between decidualized endometrioma and malignant transformation still poses difficulties as both are intracystic vascularized excrescences of an endometrial cyst and exhibit similar characteristics on color-flow Doppler sonography. This is a characteristic sonographic finding associated with ovarian cancer, but MRI can provide further information about mural excrescences that can aid in their differential diagnosis; for example, the signal of decidualized endometriomas is isointense with the placenta within the uterus on all sequences and the apparent diffusion coefficient is higher than that of malignant mural nodules. Thus, MRI should be an aid in deciding whether to intervene during pregnancy. However, considering that it is not yet possible to clearly differentiate decidualized endometriomas from ovarian cancer, surgery or watchful observation may still be needed to exclude the possibility of malignancy.