A case of pancreatic body cancer with disappearance of the dilated pancreatic duct on the tail side during preoperative treatment.

This is a case of a 67-year-old woman diagnosed with a 35-mm pancreatic body cancer with a chief complaint of epigastric discomfort. Computed tomography demonstrated invasion of the common hepatic artery, portal vein, and stomach, and chemotherapy was initiated for locally advanced pancreatic cancer. After 9 months of chemotherapy, the tumor remained stable on imaging, and the tumor markers were within the normal range. After additional chemoradiotherapy, the patient underwent a conversion surgery, a pancreaticoduodenectomy. Magnetic resonance cholangiopancreatography (MRCP) at the time of diagnosis demonstrated main pancreatic duct (MPD) dilatation on the tail side of the tumor; however, most of the MPD signal disappeared on MRCP after chemotherapy. Surgical findings failed to identify MPD on the first pancreatic resection plane, and additional resection was conducted; however, no MPD was found. As a pancreatic duct anastomosis was not available, pancreatic reconstruction was selected for pancreaticogastric anastomosis using the invagination method. Pathologically, the pancreatic tissue on the tail side of the tumor was replaced by fibrotic tissue, and MPD could not be identified. To the best of our knowledge, this is the first case report of the disappearance of a dilated pancreatic duct on the tail side accompanied by exocrine tissue loss during preoperative treatment for pancreatic cancer.

Neoadjuvant therapy with intensity-modulated radiotherapy combined with S-1 for borderline-resectable pancreatic cancer.

AIM: We evaluated the efficacy of neoadjuvant chemotherapy with intensity-modulated radiotherapy (NAC-IMRT) in patients with borderline-resectable pancreatic cancer (BRPC). METHODS: BRPC patients were treated with IMRT (45 Gy/15fr) combined with two courses of S-1 (40 mg/m2 bid) before surgery. Outcomes after NAC-IMRT, surgery, and survival were then evaluated. This single-center retrospective study assessed 26 consecutive patients. RESULTS: Twenty-six patients (BR-PV: 7, BR-A: 19) with a median age of 73 years were enrolled from 2016 to 2021. Ten (38%) patients were 75-years-old and above. Twenty-three patients completed NAC-IMRT treatment. The median reductions in tumor size and cancer antigen 19-9 level were 13.6% and 69%, respectively. All 26 patients underwent resection within a median time of 71 days after NAC-IMRT initiation. R0 resection was achieved in 24 patients (92%). The median overall survival (OS) was 28.0 months, and the 1- and 3-year OS rates were 100% and 34%, respectively. The median progression-free survival (PFS) was 12.5 months, and the 1- and 3-year PFS rates were 50% and 32%, respectively. No significant differences were observed in OS between the patients under and over the age of 75 (29 vs. 20 months, p = 0.86). The 12 patients who completed NAC-IMRT, resection, and subsequent adjuvant chemotherapy (AC) exhibited a 3-year survival rate of 73%, which was significantly better than that of the patients who did not receive or complete AC (median OS, not reached vs. 19 months, p < 0.001). CONCLUSION: NAC-IMRT showed outstanding clinical efficacy with acceptable tolerability in patients with BRPC, including geriatric patients.

Multiple portal veins in the hepatoduodenal ligament: Evidence of "duodenal reverse rotation" hypothesis?

Duplication of the portal vein is a rare variation, and reports of this condition are quite limited. The present report describes a woman of advanced age who was incidentally diagnosed with duplicated portal veins. The portal vein from the splenic vein distributed to the left lobe of the liver, and that from the superior mesenteric vein ran between the pancreas and duodenum to distribute to the right lobe. The former portal vein connected with the round ligament, and its presumptive origin was the left vitelline vein. The latter was presumably from the right vitelline vein. Between the 2 portal veins, 2 anastomotic veins were identified; one anastomosis was posterior to the pancreatic head, and the other was intrahepatic. The common bile duct was located posterolateral to the portal veins. The relationships of these veins to the round ligament and common bile duct support the reverse rotation hypothesis of the duodenum in the development of portal vein variations.

Artificial intelligence in coronary artery calcium measurement: Barriers and solutions for implementation into daily practice.

Coronary artery calcification (CAC) measurement is a valuable predictor of cardiovascular risk. However, its measurement can be time-consuming and complex, thus driving the desire for artificial intelligence (AI)-based approaches. The aim of this review is to explore the current status of CAC volume measurement using AI-based systems for the automated prediction of cardiovascular events. We also make proposals for the implementation of these systems into clinical practice. Research to date on applying AI to CAC scoring has shown the potential for automation and risk stratification, and, overall, efficacy and a high level of agreement with categorisation by trained clinicians have been demonstrated. However, research in this field has not been uniform or directed. One contributing factor may be a lack of integration and communication between computer scientists and cardiologists. Clinicians, institutions, and organisations should work together towards applying this technology to improve processes, preserve healthcare resources, and improve patient outcomes.

Appropriate Patient Status for Ra-223 Treatment in the Treatment Sequence for Castration-resistant Prostate Cancer.

BACKGROUND/AIM: Radium (Ra)-223 is widely used for treating castration-resistant prostate cancer (CRPC) with bone metastasis based on evidence of increased survival and decreased skeletal-related events. However, the timing of Ra-223 use in the treatment sequence of CRPC remains controversial. Therefore, this study aimed to explore the appropriate patient status for Ra-223 use in the CRPC treatment sequence by examining patients treated with Ra-223 from the time of CRPC diagnosis until death. PATIENTS AND METHODS: The medical records of 67 CRPC patients with bone metastasis who were treated with Ra-223 at two institutes were retrospectively analysed. The impact of 13 factors from the time of CRPC diagnosis until death was analysed using univariate and multivariate Cox hazard ratio models to evaluate the appropriate patient status for Ra-223 treatment. RESULTS: The median survival time following CRPC diagnosis for all the patient groups was 3.82 years. Univariate analysis identified a higher-than-normal alkaline phosphatase (ALP) level, bone scan indexes ≥2, and prostate-specific antigen (PSA) doubling time <3 months before Ra-223 treatment as predominant adverse prognostic factors. Ra-223 therapy discontinuation was not a significant factor. The survival of CRPC patients with these factors was significantly worse than that of patients without these factors. In the multivariate analysis, a higher-than-normal ALP level at the start of treatment was identified as a poor prognostic factor for mortality. CONCLUSION: The appropriate patient status for Ra-223 use includes low bone metastasis burden and well-controlled PSA levels.

Long-term efficacy and risk factors for stent occlusion in portal vein stent placement: a multi-institutional retrospective study.

BACKGROUND: Surgical treatment for PV (portal vein) stenosis/occlusion can pose a fatal risk of massive bleeding from severe adhesions and collateral vessel formation. PV stents placement is a minimally invasive and effective procedure for PV stenosis/occlusion, but PV stents sometimes occlude. The relationship between post-stent PV hemodynamics and stent occlusion has not been thoroughly investigated. Certain precautions during PV stent placement may reduce the risk of stent occlusion. This study aimed to evaluate long-term outcomes of PV stent patency and investigate factors including PV hemodynamics associated with stent occlusion. MATERIALS AND METHODS: Thirty-four consecutive patients with PV stenosis/occlusion who underwent PV stent placement in four institutions between December 2006 and February 2021 were retrospectively examined. The primary study endpoints were technical success, clinical success, and cumulative stent patency rate. The secondary endpoints were risk factors of stent occlusion. A univariable Cox proportional hazards model with sixteen variables was used to determine predictors of stent occlusion. Factors with p-value ≤ 0.1 in univariable analysis were included in the multivariable analysis. Alpha was set at 0.05. RESULTS: Technical and clinical success rates were 88.2% and 79.4%, respectively. Six patients (17.7%) experienced stent occlusion. The cumulative stent patency rate at six months, one year, and three years was 79.1%, 79.1%, and 65.9%, respectively. In the univariate analysis, the variables with p-value ≤ 0.1 were lesion length > 4 cm, hepatofugal collateral vein visualization after stent placement, and residual stenosis > 30% after stent placement. In the multivariate analysis, residual stenosis > 30% after stent placement was significantly associated with stent occlusion (hazard ratio, 10.80; 95% confidence interval, 1.08-108.44; p = 0.04). CONCLUSION: PV stent placement was technically feasible and effective in improving portal hypertension. However, stent occlusion was not uncommon. Residual stenosis > 30% after stent placement was significantly associated with stent occlusion. We should pay attention to correctly assess the range of stenosis and release the stenosis as much as possible.

Risk Scoring System for Ra-223 Discontinuation and Its Effect on Prognosis: A Retrospective Study.

Background/Aim: Radium-223 therapy prolongs overall survival in castration-resistant prostate cancer (CRPC) patients with bone metastasis. Patients who are unable to complete six courses of radium-223 therapy reportedly have a poor prognosis. This study aimed to develop a risk score using the discontinuation factors of the above therapy modality. Patients and Methods: Seventy patients who received radium-223 therapy for metastatic CRPC at two Japanese Institutions were evaluated. Univariate and multivariate analyses were performed to identify the discontinuation factors and determine the risk scores. Results: The median survival time was 24.3 and 9.5 months in patients who did and did not complete the therapy, respectively. Multivariate analysis revealed haemoglobin and prostate-specific antigen as key factors. A risk score was developed using these factors, and patients were stratified into three groups. The discontinuation rate and survival after radium-223 therapy were significantly different. Conclusion: Our risk score may help evaluate the suitability of radium-223 in CRPC patients.

[Prediction of pancreatitis following endoscopic retrograde cholangiopancreatography].

OBJECTIVE: The aim of this study was to determine if the difference in serum amylase levels prior to, and two hours following, an endoscopic retrograde cholangiopancreatography (ERCP), or the ratio of the two-hour post-ERCP amylase level to the pre-ERCP amylase level was a better predictor of post-ERCP pancreatitis (PEP). METHODS: This was a retrospective, single-center study of consecutive patients, who underwent ERCP between April 2015 and August 2018. Serum amylase was measured before and two hours following ERCP. We compared the difference and the ratio of the two levels in predicting PEP using a receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 1029 patients underwent ERCP, with PEP occurring in 118 (11.5%). Multivariate analysis revealed that an elevated two-hour post-ERCP serum amylase level was a significant predictor of PEP. ROC analysis of the difference and the ratio of the two levels found good performance for both parameters, with an area under the curve (AUC) of 0.861 (95% confidence interval [CI], 0.823-0.900) and 0.847 (95% CI, 0.809-0.886), respectively. The difference between the values was a significantly more effective predictor of PEP, based on the AUC analysis (P = 0.011). CONCLUSION: The difference between pre and two-hour post-ERCP amylase levels is a better predictor of PEP than the ratio of the two.

Four "fine" messages from four kinds of "fine" forgotten ligaments of the anterior abdominal wall: have you heard their voices?

On the posterior aspect of the anterior abdominal wall, there are four kinds of "fine" ligaments. They are: the round ligament of the liver, median umbilical ligament (UL), a pair of medial ULs, and a pair of lateral ULs. Four of them (the round ligament, median UL, and paired medial ULs) meet at the umbilicus because they originate from the contents of the umbilical cord. The round ligament of the liver originates from the umbilical vein, the medial ULs from the umbilical arteries, and the median UL from the urachus. These structures help radiologists identify right-sided round ligament (RSRL) (a rare, but surgically important normal variant), as well as to differentiate groin hernias. The ligaments can be involved in inflammation; moreover, tumors can arise from them. Unique symptoms such as umbilical discharge and/or location of pathologies relating to their embryology are important in diagnosing their pathologies. In this article, we comprehensively review the anatomy, embryology, and pathology of the "fine" abdominal ligaments and highlight representative cases with emphasis on clinical significance.

Can the "pine-needle sign" on computed tomography be used to differentiate pulmonary arteriovenous malformation from its mimics? Analysis based on dynamic contrast-enhanced chest computed tomography in adults.

OBJECTIVES/PURPOSE: To determine the diagnostic value of morphological features on computed tomography (CT) in the differentiation of pulmonary arteriovenous malformation (pAVM) and its mimics. MATERIALS AND METHODS: We retrospectively examined 59 consecutive patients (109 lesions) with initially suspected or occult pAVM who underwent contrast-enhanced chest CT from January 2006 to June 2016. All lesions were divided into two groups based on their diagnosis: AVM (n=93) and non-AVM (n=16). The non-AVM group comprised patients with an anomalous unilateral single pulmonary vein and congenital pulmonary venous atresia. Two board-certified radiologists reviewed the CT images and achieved consensus. Paired abnormal vessels were assessed with respect to their configuration, direction and continuity with the hilum, location, angle between them, and dilation ratio. RESULTS: All pAVM lesions had parallel, straight-running, paired abnormal vessels; most of the vessels ran through the identical segment. Conversely, in the non-AVM group, paired abnormal vessels did not run in parallel but detoured to the hilum through different segments from each other (i.e., the configuration, direction and continuity with the hilum and the location of the vessels were all significantly different between the two groups). The angle between the paired abnormal vessels was significantly narrower in the AVM group. The dilation ratio was not significantly different between the two groups. CONCLUSION: Morphological features can be useful in the differentiation of pAVM and its mimics without contrast-enhanced CT to directly visualize the connection between the abnormal and normal pulmonary vessels. Pulmonary AVMs characteristically had a narrow angle between the two vessels, appearing like a pair of pine-needle leaves.

Portal vein branching order helps in the recognition of anomalous right-sided round ligament: common features and variations in portal vein anatomy.

PURPOSE: This study aimed to evaluate the common features and variations of portal vein anatomy in right-sided round ligament (RSRL), which can help propose a method to detect and diagnose this anomaly. METHODS: In this retrospective study of 14 patients with RSRL, the branching order of the portal tree was analyzed, with special focus on the relationship between the dorsal branch of the right anterior segmental portal vein (PA-D) and the lateral segmental portal vein (PLL), to determine the common features. The configuration of the portal vein from the main portal trunk to the right umbilical portion (RUP), the inclination of the RUP, and the number and thickness of the ramifications branching from the right anterior segmental portal vein (PA) were evaluated for variations. RESULTS: In all subjects, the diverging point of the PA-D was constantly distal to that of the PLL. The portal vein configuration was I- and Z-shaped in nine and five subjects, respectively. The RUP was tilted to the right in all subjects. In Z-shaped subjects, the portal trunk between the branching point of the right posterior segmental portal vein and that of the PLL was tilted to the left in one subject and was almost parallel to the vertical plane in four subjects. Multiple ramifications were radially distributed from the PA in eight subjects, whereas one predominant PA-D branched from the PA in six subjects. CONCLUSIONS: Based on the diverging points of the PA-D and PLL, we proposed a three-step method for the detection and diagnosis of RSRL.

Biliary architecture of livers exhibiting right-sided ligamentum teres: an indication for preoperative cholangiography prior to major hepatectomy.

OBJECTIVE: To obtain information about the basic biliary anatomy of livers with right-sided ligamentum teres (RSLT). SUMMARY OF BACKGROUND DATA: RSLT is a relatively rare anomaly with a reported incidence of 0.2-1.2%. Although the portal/hepatic venous and arterial anatomy of livers with RSLT has already been established, the biliary architecture of such livers remains unclear. METHODS: RSLT was detected in 48 patients during 12,071 consecutive image readings (0.4%). Of these patients, the cholangiograms of 46 patients were analyzed, and their intrahepatic biliary tree confluence patterns were classified. RESULTS: The following four unique biliary confluence patterns were identified in livers with RSLT: the symmetrical type (23/46), independent right lateral type (13/46), total left type (6/46), and total right type (1/46). Analyses of the portal and arterial branching patterns of these livers showed that there were no correlations between their biliary confluence patterns and their portal or arterial ramification patterns. CONCLUSION: The basic biliary architecture of livers with RSLT was clarified. As the RSLT patients' anomalous biliary confluences differed from those seen in normal livers and were difficult to predict, preoperative cholangiography should be performed prior to complex hepatobiliary surgery involving livers with RSLT to ensure patient safety.

MR imaging findings of ovarian torsion correlate with pathological hemorrhagic infarction.

AIM: The aim of this study was to clarify the magnetic resonance (MR) imaging findings, including diffusion-weighted imaging (DWI), of hemorrhagic infarction of ovarian torsion. MATERIAL AND METHODS: Twelve patients presenting surgically confirmed ovarian masses with torsion were independently evaluated by two radiologists about the following MR findings: presence of ascites, uterine deviation, wall thickening on T2 weighted image (WI), recognition of twisted pedicle on T1/T2WI, and presence of wall enhancement of ovarian lesions on Gd-T1WI. The signal intensities on T1WI and DWI were compared with those of the iliopsoas muscle and the nerve root, respectively. These MR findings were statistically compared between cases of ovarian torsion with histopathologically proven hemorrhagic infarction and those without. RESULTS: Pathologically, hemorrhagic infarction of the wall was confirmed in six of twelve cases. Ascites, uterine deviation and twisted pedicle were detected in most cases whether with or without hemorrhagic infarction. The complete absence of wall enhancement was observed in only one case with necrosis. A higher signal intensity of the wall compared to controls was observed in 4/6 and 5/6 cases with infarction on T1WI/DWI, respectively. This was not observed in any cases without infarction. Three out of five cystic lesions with hemorrhagic infarction showed irregular wall thickening on T2WI, and no cystic lesion without hemorrhagic infarction did. Smooth wall thickening was observed in 2/6 cases without hemorrhagic infarction. CONCLUSION: Pathological hemorrhagic infarction of ovarian torsion was associated with several MR imaging findings, including high signal intensity on T1WI/DWI, and irregular wall thickening on T2WI.

CT and MR imaging findings of systemic complications occurring during pregnancy and puerperal period, adversely affected by natural changes.

Dynamic physiological and anatomical changes for delivery may adversely induce various specific non-obstetric complications during pregnancy and puerperal period. These complications can be fatal to both the mother and the fetus, thus a precise and early diagnosis ensued by an early treatment is essential. Along with ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) have assumed an increasing role in the diagnosis. This article aims to discuss the pathophysiology of these complications, the indications for CT and MRI, and the imaging findings.

Massive subchorionic thrombosis followed by magnetic resonance imaging.

Massive subchorionic thrombosis is a rare condition, defined as a large thrombus confined to the subchorionic space. It is associated with poor perinatal prognosis. However, prenatal diagnosis by ultrasonography is often difficult. We report a case of massive subchorionic thrombosis developing dermatomyositis after the delivery, followed by magnetic resonance imaging. Moreover, we review other 4 cases assessed with magnetic resonance imaging. Magnetic resonance imaging is very useful for confirmation of diagnosis and follow-up in combination with ultrasonography.

Posterior cul-de-sac obliteration associated with endometriosis: MR imaging evaluation.

PURPOSE: To retrospectively evaluate the accuracy of magnetic resonance (MR) imaging in depicting posterior cul-de-sac obliteration in patients with endometriosis. MATERIALS AND METHODS: Institutional review board approval was not required for this retrospective study, but informed consent was obtained from all patients. MR images obtained between January 1989 and December 2000 in 57 women (mean age, 39 years; age range, 26-52 years) with histologically confirmed endometriosis were retrospectively evaluated by four radiologists independently. All patients underwent laparotomy or laparoscopy less than 1 month after MR imaging. MR images were evaluated for the presence and location of endometrial implants and adhesions. MR images were also scored for the presence of five findings: retroflexed uterus, elevated posterior vaginal fornix, intestinal tethering or tethered appearance of rectum in direction of uterus, faint strands between uterus and intestine, and fibrotic plaque or nodule covering serosal surface of the uterus. Interobserver agreement for each of the five findings and for the overall diagnosis of cul-de-sac obliteration was calculated. Sensitivity, specificity, accuracy, positive and negative predictive values, and kappa statistics were determined. RESULTS: Laparotomy or laparoscopy revealed posterior cul-de-sac obliteration in 30 patients. Overall, the four radiologists had mean accuracies of 89.0% and 76.3% for diagnosing endometrial implants and adhesions, respectively, at MR imaging. Overall, the radiologists achieved mean sensitivity, specificity, accuracy, and positive and negative predictive values of 68.4%, 76.0%, 71.9%, 76.6%, and 68.5%, respectively, in diagnosing posterior cul-de-sac obliteration. The best accuracy (mean value, 64.5%) was obtained with the finding of fibrotic plaque in the uterine serosal surface. Readers agreed on the observations 63.2%-91.2% of the time. For the impression of the presence or absence of posterior cul-de-sac obliteration, interobserver agreement varied between substantial and moderate: Mean interobserver agreement was 78.4% (range, 70.2%-84.2%), and mean kappa was 0.57 (range, 0.40-0.67). Mean accuracy of MR imaging for diagnosing posterior cul-de-sac obliteration was 71.9%. CONCLUSION: These results suggest that use of the described MR imaging findings may enable diagnosis of posterior cul-de-sac obliteration.

Kinematics of the uterus: cine mode MR imaging.

Cine mode magnetic resonance (MR) imaging has allowed evaluation of kinematics of the pelvis. Visualization of dynamic changes under strain facilitates evaluation of prolapses and adhesions between organs. The uterus, an organ of smooth muscle, has an inherent contractility that characterizes it as different from other visceral organs. This sustained contraction has occasionally been shown on static images as a finding masquerading as a leiomyoma or as adenomyosis. Cine mode MR imaging clearly shows the configuration of the myometrium during these dynamic changes, as well as its signal intensity during contractions. Uterine peristalsis, the subtle and rhythmic contractions of the inner myometrium, is also clearly identifiable on cine mode images as a wavy movement of the endometrium and/or inner myometrium. The direction and frequency of uterine peristalsis are different in each of the menstrual cycle phases and are thought to have important roles in uterine function, such as in fertility and menstrual blood discharge. Elucidation of these kinematics of the uterus will help in the evaluation of static MR images and study of the physiology of the uterus. Cine MR imaging is a novel technique for diagnosis and evaluation of the pelvic organs, especially the uterus.

Diffusely enlarged uterus: evaluation with MR imaging.

Diffuse uterine enlargement is a common clinical finding. Because this abnormality can represent a physiologic manifestation, benign tumor, or malignancy, the diagnostic dilemma of a diffusely enlarged uterus can be challenging. Clinical findings can provide valuable information in regard to physiologic effects, pregnancy-related changes, and hormonal causes. Cytologic examination is essential for identification of cervical and endometrial malignancies. However, since preoperative histologic examination of myometrial lesions is not possible, preoperative distinction between benign and malignant conditions is frequently difficult. Imaging thus plays an important role in evaluation of myometrial lesions. In particular, magnetic resonance (MR) imaging allows specific diagnosis of several different lesions. Signal voids and prominent vessels at MR imaging are characteristic of vascular lesions. Adenomyosis and leiomyomas can be distinguished from other lesions with MR imaging, although a variety of unusual manifestations can be seen. MR imaging findings that allow distinction between leiomyoma and leiomyosarcoma have yet to be clearly established; however, invasion, hemorrhagic necrosis, or rapid growth is suggestive of malignancy. Endometrial stromal sarcoma tends to have distinct MR imaging features that allow differentiation from benign lesions.

Uterine peristalsis shown on cine MR imaging using ultrafast sequence.

PURPOSE: To demonstrate and evaluate uterine peristalsis on cine magnetic resonance imaging (MRI) using ultrafast imaging. MATERIALS AND METHODS: Serial MR uterine images (300) were obtained from 15 normal volunteers over four menstrual phases using true fast imaging with steady-state precession (true FISP) technique over 117 seconds and videotaped. Three radiologists independently evaluated videotapes of 59 studies. Uterine peristalsis was defined as wavy movements of subendometrial myometrium or endometrium. Interobserver reliability was evaluated using a Kappa coefficient. Fifty-four studies obtained in appropriate phases were analyzed. RESULTS: Cine MRI displayed uterine peristalsis in 30 of 59 studies; consensus reading showed direction in 23 studies. Reliability between the final consensus of the recognition of uterine peristalsis and those of the three readers was extremely concordant, with a Kappa coefficient of 0.908. Wave direction was cervico-fundal in follicular and periovulatory phases, with frequency of contraction waves being 1.2-2.3 per minute in positive studies. CONCLUSION: Uterine peristalsis was demonstrated on cine MR using ultrafast MRI. Direction and frequency of peristaltic waves are closely related to menstrual cycle phases. Supplementary material for this article can be found on the JMRI website at http://www.interscience.wiley.com/jpages/1053-1807/suppmat/index.html.

Immature teratoma of the ovary: correlation of MR imaging and pathologic findings.

The objectives of this study were to describe MR imaging findings of immature teratoma and to correlate imaging findings with histopathologic findings. The MR findings of ten patients (age range 12-29 years, mean age 19.0 years) with pathologically proven immature teratoma were retrospectively reviewed for tumor size, presence and characteristics of fatty content, presence and characteristics of solid components, and presence of ascites and implants. The MR findings were compared with gross (n=3) and microscopic (n=10) findings. Comparisons between relative amounts of solid components and histologic grades were evaluated by Spearman rank-order correlation. On MR images all lesions appeared to be fat-containing tumors with solid components consisting of numerous cysts of various sizes. Solid tissue exhibited a wide variety of signal intensities on T2-weighted images. Punctate foci of fat were identified in all lesions, whereas fatty fluid was observed only in two. Predominant fluid content exhibited signal intensities similar to simple fluid in nine lesions. Ascites was observed in six lesions, and peritoneal dissemination in three. Pathologic studies confirmed scattered foci of adipose tissue in the solid portions of all cases, and revealed numerous cystic structure formations in these solid components. The correlation coefficient between the amount of solid tissue and the tumor grade was not significant (r(s)=0.266). The MR images of immature teratoma tended to show aqueous fluids and the solid components consisting of numerous cysts with punctate foci of adipose tissue, whereas predominant fluid is sebaceous fluid in the vast majority of mature cystic teratomas.