Hypointense Rim Research Articles

Morphology-Specific Discrimination between MS White Matter Lesions and Benign White Matter Hyperintensities Using Ultra-High-Field MRI.

Recently published North American Imaging in Multiple Sclerosis guidelines call for derivation of a specific radiologic definition of MS WM lesions and mimics. The purpose of this study was to use SWI and magnetization-prepared FLAIR images for sensitive differentiation of MS from benign WM lesions using the morphologic characteristics of WM lesions. Seventeen patients with relapsing-remitting MS and 18 healthy control subjects were enrolled retrospectively. For each subject, FLAIR and multiecho gradient-echo images were acquired using 7T MR imaging. Optimized postprocessing was used to generate single-slice SWI of cerebral veins. SWI/FLAIR images were registered, and 3 trained readers performed lesion assessment. Morphology, location of lesions, and the time required for assessment were recorded. Analyses were performed on 3 different pools: 1) lesions of >3 mm, 2) nonconfluent lesions of >3 mm, and 3) nonconfluent lesions of >3 mm with no or a single central vein. The SWI/FLAIR acquisition and processing protocol enabled effective assessment of central veins and hypointense rims in WM lesions. Assessment of nonconfluent lesions with ≥1 central vein enabled the most specific and sensitive differentiation of patients with MS from controls. A threshold of 67% perivenous WM lesions separated patients with MS from controls with a sensitivity of 94% and specificity of 100%. Lesion assessment took an average of 12 minutes 10 seconds and 4 minutes 33 seconds for patients with MS and control subjects, respectively. Nonconfluent lesions of >3 mm with ≥1 central vein were the most sensitive and specific differentiators between patients with MS and control subjects.

LI-RADS v2014 categorization of hepatocellular carcinoma: Intraindividual comparison between gadopentetate dimeglumine-enhanced MRI and gadoxetic acid-enhanced MRI.

To use Liver Imaging Reporting and Data System (LI-RADS) categorization and features of hepatocellular carcinomas (HCCs) to intraindividually compare gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI) and gadoxetic acid-enhanced MRI (Gd-EOB-MRI), before and after applying modified major features. Of 77 HCCs in 64 patients analysed, 17 HCCs were confirmed histopathologically and 46 patients had cirrhosis. Gd-EOB-MRI and Gd-DTPA-MRI were evaluated for the presence of major and ancillary features by two radiologists. LI-RADS categorization was done for Gd-DTPA-MRI (LI-RADS-DTPA) and for Gd-EOB-MRI before and after applying modified major features (hepatobiliary phase [HBP] hypointensity as an additional major feature, LI-RADS-EOBm1; HBP hypointense rim as capsule appearance, LI-RADS-EOBm2; and transitional phase [TP] hypointensity as washout appearance, LI-RADS-EOBm3). Sensitivities of LR-5 categorization for the diagnosis of HCC were compared. Washout (p=0.012) and capsule appearance (p<0.001) were less frequently observed on Gd-EOB-MRI. Sensitivity for LR-5 categorization was significantly higher with LI-RADS-DTPA compared with LI-RADS-EOB (p=0.001) and LI-RADS-EOBm2 (p=0.004), while sensitivity for LR-5 categorization with LI-RADS-EOBm1 (p=0.210) and LI-RADS-EOBm3 (p=0.727) was comparable. Modifying LI-RADS for use with Gd-EOB-MRI, such as applying HBP hypointensity as an additional major feature or using TP hypointensity as washout appearance, can improve the sensitivity for the detection of HCC. • Adding HBP hypointensity as additional major feature improved sensitivity of LR-5 categorization. • Adding TP hypointensity as modified washout appearance improved sensitivity of LR-5 categorization. • Sensitivities for LR-5 classification were comparable between LI-RADS-DTPA, LI-RADS-EOBm1, and LI-RADS-EOBm3.

The capsule appearance of hepatocellular carcinoma in gadoxetic acid-enhanced MR imaging: Correlation with pathology and dynamic CT.

This study aimed to evaluate the capability of gadoxetic acid-enhanced MR (GAeMR) to detect presence of capsule appearance in hepatocellular carcinoma (HCC), and to correlate it with dynamic computed tomography (CT) and pathological features.Sixty-three patients (54: 9 = M: F, mean age 55.8) surgically confirmed HCCs with preoperative CT and GAeMR were included in this retrospective study. Two readers evaluated presence of capsule appearances on CT and GAeMR images in each phase including precontrast (Pre), portal phase (PP), delayed phase (DP), transitional phase (TP), and hepatobiliary phase (HBP). Histologic capsule was compared with CT and GAeMR. Diagnostic performance of CT and GAeMR of each phase for histologic capsule was evaluated and compared by receiver operating characteristic curve. Interobserver agreement was assessed with kappa statistics.Histologically the capsule was complete in 12.7% (8/63) and incomplete in 60.3% (38/63). Four cases (6.3%) were pseudocapsule. Interobserver agreement for capsule appearance on GAeMR was good in Pre (κ = 0.684), moderate in PP (κ = 0.434), poor in TP (κ = 0.187), fair in HBP (κ = 0.395), and moderate on CT in PP (κ = 0.476) and DP (κ = 0.485). Diagnostic performance and sensitivity for the histologic capsule in DP on CT was highest among PP on CT and other phases on GAeMR. DP on CT images showed a higher Az value than PP on CT images with statistical significance (P < .001). PP on MR images revealed higher Az value than PP on CT images.The capsule appearance was most frequently observed in the DP on CT with highest diagnostic performance, and so DP images should be obtained on CT study for liver mass categorization. GAeMR yielded comparable capsule appearance to CT with moderate interobserver agreement. Considering hypointense rim on the HBP as fibrous capsule on pathology should be refrained, and so further study is warranted to correlate HBP hypointense rim with pathologic findings.

Percutaneous Endoscopic Lumbar Surgery via the Transfacet Approach for Lumbar Synovial Cyst

There are currently no high-quality studies on the optimal therapeutic approach for juxtafacet cyst, as treatment guidelines have not been developed. Herein, a novel technique in which we used an endoscopic transfacet approach to treat a patient with symptomatic lumbar synovial cyst is presented. An 87-year-old man presented with severe dull pain in the right anterior thigh. Lumbar magnetic resonance imaging revealed disc extrusion over the central canal zone at the L2-L3 and L4-L5 levels and an ovoid lesion with a hyperintense center plus a hypointense rim on the T2-weighted image. The lesion was located over the medial side of the right juxtafacet region at the L2-L3 level, causing thecal sac compression. After the operation, the visual analog pain scale improved with a value of 0-1/10, and straight leg raise test was negative. Microscopically, cystic fibrous tissue with focal myxoid degeneration, fibrin exudate, and scant synovial-like lining was observed. These findings were consistent with clinical synovial cyst. Three months later, lumbar magnetic resonance imaging was performed, and no evidence of cyst was disclosed. Lumbar computed tomography revealed the upper part of left L2-L3 facet joint was removed. The patient did not report any radicular pain during the 6-month follow-up period. Percutaneous endoscopic lumbar surgery could be a new option for the management of lumbar synovial cysts, especially when general anesthesia is not appropriate for the patient.

Pleomorphic adenoma of salivary glands: common and uncommon CT and MR imaging features.

Pleomorphic adenoma (PA) is the most common salivary gland tumor and is characterized by cytomorphological and architectural diversity. On CT and MR images, PAs are shown as well-defined lesions occasionally accompanied by characteristic lobulated contours. On T2-weighted images, typical PAs show marked hyperintensity, which reflects the abundant myxochondroid stroma, with a hypointense rim indicating the fibrous capsule. However, intratumoral signal intensity varies according to the cellular density, proportion of epithelial and stromal components, and type of stromal components. In addition, a variety of secondary histological changes, including fibrosis, lipometaplasia, ossification, cystic degeneration, and infarction, occur rarely in PAs; therefore, they are associated with difficulty in differential diagnosis from other salivary gland tumors. This review article describes the common and uncommon CT and MR imaging features of PA of the salivary glands.

T2-hypointense rim of breast mass lesions on magnetic resonance images: Radiologic-pathologic correlation

We investigated the radiologic-pathologic correlation of a strong hypointense rim on T2-weighted images (T2-hypo-rim) surrounding breast mass lesions and evaluated its clinical significance. We retrospectively reviewed 3503 consecutive breast magnetic resonance imaging (MRI) examinations. The T2-hypo-rim was defined as a border of strong hypointensity compared with the fat signal on fat-suppressed T2-weighted images. Detected lesions with T2-hypo-rim were classified as a solid or cystic mass with MRI and correlated with histopathologic findings. Sixty-two masses (2%; 34 solid, 28 cystic) with T2-hypo-rim were detected [44 breast cancers, 18 benign lesions, including 15 (24%) papillary tumors]. Patients with cancer were significantly older than those with benign lesions (P=.002). Breast cancers were significantly larger than benign masses (P=.023). In 49 of 62 lesions (24 solid and 16 cystic cancers; three solid and six cystic benign masses), the rims were accurately correlated with the histopathologic findings. All malignant and benign cystic masses exhibited hemosiderin deposits in the cyst walls. However, 22 of 24 solid cancers and no solid benign masses exhibited hemosiderin at the tumor periphery (92% and 0%, respectively, P<.001). In addition, a thick fibrous capsule was present in nine (38%) of 24 solid cancers and none of the solid benign lesions. Strong T2-hypo-rims mostly correlated with hemosiderin deposits and/or sometimes fibrous capsules. Although the rims could not distinguish malignant from benign cystic lesions, they indicated malignancy in solid mass lesions on MRI. Additionally, the rims often indicated papillary tumors.

Uterine smooth muscle tumours with hyperintense area on T1weighted images: differentiation between leiomyosarcomas and leiomyomas.

Hyperintense area on T1weighted images (T1 HIA) have been reported as suggestive features of uterine leiomyosarcoma (LMS), but differentiating LMS from leiomyoma (LM) is often difficult. This study aimed to evaluate the differences between uterine LMS and LM demonstrating intratumoral T1 HIA. MRI was performed in 509 patients with 1137 uterine smooth muscle tumours [14 LMSs, 5 smooth muscle tumours of uncertain malignant potential , and 1118 LMs] which exceeded 3 cm in diameter. LM with red degeneration and lipoleiomyoma were excluded from the study. We retrospectively reviewed the images and assessed T1 HIA within tumours. Results T1 HIAs were observed in 11/14 (78.6%) LMSs, 0/5 (0%) smooth muscle tumours of uncertain malignant potential, and 15/1118 (1.3%) LMs. T1 HIAs were more homogenous (53 vs 0%, p < 0.01) and more well-demarcated (60 vs 9%, p < 0.05) in LMs than in LMSs. T2 hypointense rim within T1 HIA (53 vs 9%, p < 0.05) was more frequently observed in LMs than in LMSs. The occupying rate of T1 HIA (0.20 ± 0.24 vs 0.42 ± 0.27, p < 0.05) was smaller in LMs than in LMSs. The signal intensity ratio of T1 HIA (1.83 ± 0.36 vs 1.38 ± 0.23, p < 0.01) was greater in LMs than in LMSs. T1 HIA within LM showed more homogeneity, better demarcation, smaller occupying rate, and higher signal intensity than T1 HIA within LMS. Advances in knowledge: The differences in T1 HIA within tumours may be useful for differentiating between LMS and LM.

3.0T MRI for long-term observation of lung nodules post cryoablation: a pilot study

BackgroundThe purpose of this study was to use serial magnetic resonance imaging (MRI) examinations to observe changes in malignant lung tumors over time post-cryoablation.MethodsThe study protocol was approved by Institutional Review Board, and written informed consent was obtained from each participant in accordance with the Declaration of Helsinki. Patients with primary or metastatic lung tumors eligible for cryoablation were included in this prospective study. Cryoablation was performed according to standard procedures. Unenhanced and dynamic contrast-enhanced MRI scans were performed pre-cryoablation and at 1 day, 1 week, and 3-, 6-, and 12 months after cryoablation. At each time point, the signal intensity of the ablated zone on both T1WI and T2WI images, and volume and characteristics of the ablation zone were examined, and changes over time analyzed.ResultsA total of 26 nodules in 23 patients were included in the study. The mean patient age was 53.7 ± 13.6 years, and 57.7% were males. Ablation zone volume increased to 1 week after the procedure, and then returned to baseline by 3 months. Cavitation post-cryoablation was found in 34.6% (9/26) of the nodules 1 month after treatment. Two types of time-signal intensity curves post-cryoablation were found: a straight line representing no definite enhancement from 1-day to 1-month, and an inflow curve representing mild delayed enhancement from month 3 to month 12. Local progression was associated with an incomplete hypointense rim around the ablation zone and absence of cavitation post-treatment.ConclusionsCharacteristic changes are present on MRI after cryoablation of lung tumors. A complete hypointense rim and cavitation may be signs of adequate treatment and that local tumor progression is less likely.

Radiologic and histologic features of the T2 hyperintensity rim of meningiomas on magnetic resonance images.

A hyperintensity rim is often seen at the brain-tumor interface of meningiomas upon T2-weighted (T2WI) magnetic resonance imaging (MRI), and it is referred to as the cerebrospinal fluid (CSF) space; however, the true nature of the rim remains unclear. We surveyed the MRI findings and the histopathologic characteristics of such rims. Our study population consisted of 53 consecutive patients who underwent meningioma removal at our hospital. The intensity of the rim on MRI scans obtained with different imaging sequences was assessed in all patients. We used 22 tumors for histopathologic investigation: tissue samples were acquired from both the tumor surface and from a deep intratumoral site. Of the 53 meningiomas, 37 (69.8%) manifested a hyperintensity rim on T2WI (T2-rim). The other 16 showed neither a hyperintense nor a hypointense rim on their T2WI. An enhancement effect corresponding to the rim was observed in 28 of the 37 (75.7%) T2-rim positive tumors. While 9 among the 37 tumors with a T2-rim (24.3%) did not show rim enhancement, they showed low intensity on fluid-attenuated inversion recovery (FLAIR) images. The microvascular density in the tumor capsule was significantly greater in the 12 T2-rim and rim enhancement positive tumors than in 10 tumors that were T2-rim negative or T2-rim positive, but rim enhancement-negative ( p < 0.001, Mann-Whitney U test). We found that 75.7% of T2 hyperintense rims that were detected at the brain-meningioma interface reflected a microvascular-rich capsule layer, rather than the CSF space.

Signal changes in standing magnetic resonance imaging of osseous injury at the origin of the suspensory ligament in four Thoroughbred racehorses under tiludronic acid treatment.

ABSTRACTProblems associated with the proximal metacarpal region, such as an osseous injury associated with tearing of Sharpey’s fibers or an avulsion fracture of the origin of the suspensory ligament (OISL), are important causes of lameness in racehorses. In the present study, four Thoroughbred racehorses (age range, 2–4 years) were diagnosed as having forelimb OISL and assessed over time by using standing magnetic resonance imaging (sMRI). At the first sMRI examination, all horses had 3 characteristic findings, including low signal intensity within the trabecular bone of the third metacarpus on T1-weighted images, intermediate-to-high signal intensity surrounded by a hypointense rim on T2*-weighted images, and high signal intensity on fat-suppressed images. Following the sMRI examination, all horses received 50 mg of tiludronic acid by intravenous regional limb perfusion once weekly for 3 weeks. Attenuation of the high signal intensity on T2*-weighted and fat-suppressed images was observed on follow-up sMRI in 3 horses. Following rest and rehabilitation, these 3 horses successfully returned to racing. In contrast, the other horse that did not show attenuation of the high signal intensity failed to return to racing. To our knowledge, this is the first report of OISL in Thoroughbred racehorses assessed over time by sMRI under tiludronic acid treatment. Our findings support the use of sMRI for examining lameness originating from the proximal metacarpal region to refine the timing of returning to exercise based on follow-up examinations during the recuperation period.

Chapter 24 - Radiology and imaging for cavernous malformations

Cavernous malformations are low-flow vascular malformations that are histologically characterized by the lack of mural elements of mature vascular structures and intervening parenchymal neural tissue. They are often clinically quiescent, and may grow, bleed, and regress, but can also manifest clinically as neurologic deficits or seizures in the setting of an acute hemorrhage. The low-flow nature of cavernous malformations renders them inherently occult on cerebral angiography. Magnetic resonance imaging has become the mainstay imaging modality in evaluating cavernous malformations, producing characteristic imaging features that usually provide a straightforward diagnosis. Features on magnetic resonance imaging include a reticulated pattern of mixed hyper- and hypointensity on T1- and T2-weighted imaging, with a characteristic hypointense rim best appreciated on T2-weighted imaging or gradient-echo sequences. Contrast enhancement is useful for revealing coexisting developmental venous anomalies that are frequently associated with sporadic cavernous malformations, and may further support the diagnosis. Susceptibility-weighted imaging is highly sensitive for cavernous malformations and accompanying developmental venous anomalies, and is superior to gradient-echo sequences in screening for multifocal, familial cavernous malformations.

MRI of ovarian torsion: Correlation of imaging features with the presence of perifollicular hemorrhage and ovarian viability

PurposeThe purpose of our study is to test for: (a) correlation between the presence of a perifollicular T2-hypointense rim on MRI with the presence of perifollicular hemorrhage on histology; and (b) correlation between this finding and diminished ovarian viability after intra-operative detorsion. Methods and materialsOur IRB-approved, retrospective study evaluated 780 patients between August 2012 and February 2016 with ovarian torsion as a diagnostic consideration on the emergency department note. Patients were included if they had preoperative MRI and intraoperatively confirmed case of ovarian torsion. MRIs were retrospectively reviewed for presence of perifollicular T2 hypointense rim in the torsed ovary. Two arms of analysis were performed: (a) assessment of perifollicular hemorrhage on histological exam; and (b) assessment of ovarian viability after intra-operative detorsion. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI for predicting ovarian viability in the setting of torsion was performed. κ test assessed level of agreement between readers. Results24 patients included in one of the two arms; 20 in viability analysis and 12 in perifollicular hemorrhage analysis (8 in both). The presence of T2-hypointense rim on MRI demonstrated 88.9% sensitivity and 66.7% specificity for the diagnosis of perifollicular hemorrhage on histology, and 91.7% sensitivity and 100% specificity for predicting intraoperative viability. ConclusionThe presence of a perifollicular T2 hypointense rim on MRI in the setting of ovarian torsion correlates with perifollicular hemorrhage on histopathologic exam, and may also be a useful predictor of ovarian viability in patients presenting with ovarian torsion.

Using 3.0 T MR to dynamically observe ablated lung tumors after percutaneous cryotherapy therapy

Objective: To initially explore MRI features and its changing trends including of lung tumors after Argon-Helium cryoablation therapy, and enhance the recognition of MR findings of lung tumors postcryoablation. Methods: Twenty-three cases of patients with twenty six nodules of pulmonary malignance who received Argon-Helium cryoablation therapy in Henan Cancer Hospital from July 2014 to January 2016 were enrolled.All patients underwent unenhanced and dynamic contrast-enhanced MRI scans at pre-and 1-day, 1-week, 1-, 3-, 6-, 12-month postcryoablation. Two radiologists independently reviewed MRI images, signal intensity in the ablated zone on T1WI and T2WI were assessed by a 5-point scale.The changing trends of size and signal intensity with time were showed by time-maximum diameter and time-score curve.Time-signal intensity curves based on dynamic enhanced sequence were also performed. Results: Typical MRI findings includes: heterogeneous signal intensity on both T1WI and T2WI at 1-day postcryoablation(26/26, 100%). Hyper-intense on T1WI(22/26, 84.6%) and T2WI(17/26, 65.4%) with a hypo-intense rim at 1-week postcryoablation.Decreasing signal intensity on T1WI(17/26, 65.4%) and increasing signal intensity on T2WI(22/26, 84.6%) at 1-month.Signal intensity declined to the level of muscle on both T1WI(18/26, 69.2%) and T2WI(19/26, 73.1%) at 3-month, nineteen ablated zone turned into patchy shape(19/26, 73.1%). The maximum diameter was largest at 1-day and gradually shrunk with time. The mean score value toped at 1-week and gradually decreased. A straight line type without definite enhancement was found from 1-day to 1-month postcryoablation, an inflow curve with a mild delayed enhancement was seen from 3- to 12- month. Totally 4 recurrence (4/26, 15.4%) all occurred at 3-month and were lack of a complete hypo-intense rim at 1-week postcryoablation. Conclusion: MRI findings of lung tumors postcryoablation are characteristic, a complete hypo-intense rim at 1-week is helpful to determine further recurrence, 1-week to 3-month is an important period to observe significant change of the ablation zone, MRI is valuable in identifying the ablation zone and can reflect its evolution with time.

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.

The clinicopathological features of sinonasal angiomatous polyps.

BackgroundSinonasal angiomatous polyp (SAP) is a rare subtype of sinonasal polyp that might be misdiagnosed as a malignant lesion due to its clinical symptoms.MethodsWe retrospectively enrolled the patients who were diagnosed with SAP in our hospital during 2008–2015. We analyzed the clinical symptoms, radiological findings, and pathological features of all patients diagnosed with SAP.ResultsUnilateral nasal obstruction, rhinorrhea, and epistaxis were the common symptoms. SAPs all originated from maxillary sinus and extended to nasal cavity with or without involving the nasopharynx. Expansile mass with surrounding bony destruction is typical on computed tomography imaging but specific for SAPs. The magnetic resonance revealed high signal intensity on T1-weighted images and hypointense rim on T2-weighted images.ConclusionComputed tomography and magnetic resonance together might give rise to more accurate diagnosis of SAP. Incisional biopsy does help if the clinician suspects a malignant lesion. To treat SAP, complete removal is the optimal choice.

In vivo MR guided boiling histotripsy in a mouse tumor model evaluated by MRI and histopathology.

Boiling histotripsy (BH) is a new high intensity focused ultrasound (HIFU) ablation technique to mechanically fragmentize soft tissue into submicrometer fragments. So far, ultrasound has been used for BH treatment guidance and evaluation. The in vivo histopathological effects of this treatment are largely unknown. Here, we report on an MR guided BH method to treat subcutaneous tumors in a mouse model. The treatment effects of BH were evaluated one hour and four days later with MRI and histopathology, and compared with the effects of thermal HIFU (T-HIFU). The lesions caused by BH were easily detected with T2 w imaging as a hyper-intense signal area with a hypo-intense rim. Histopathological evaluation showed that the targeted tissue was completely disintegrated and that a narrow transition zone (<200 µm) containing many apoptotic cells was present between disintegrated and vital tumor tissue. A high level of agreement was found between T2 w imaging and H&E stained sections, making T2 w imaging a suitable method for treatment evaluation during or directly after BH. After T-HIFU, contrast enhanced imaging was required for adequate detection of the ablation zone. On histopathology, an ablation zone with concentric layers was seen after T-HIFU. In line with histopathology, contrast enhanced MRI revealed that after BH or T-HIFU perfusion within the lesion was absent, while after BH in the transition zone some micro-hemorrhaging appeared. Four days after BH, the transition zone with apoptotic cells was histologically no longer detectable, corresponding to the absence of a hypo-intense rim around the lesion in T2 w images. This study demonstrates the first results of in vivo BH on mouse tumor using MRI for treatment guidance and evaluation and opens the way for more detailed investigation of the in vivo effects of BH. Copyright © 2016 John Wiley & Sons, Ltd.

MP78-03 MRI INTENSITY RATIO CURVE ANALYSIS: A NEW OBJECTIVE METHOD FOR CHARACTERIZING SMALL RENAL MASSES

You have accessJournal of UrologyKidney Cancer: Epidemiology & Evaluation/Staging II1 Apr 2016MP78-03 MRI INTENSITY RATIO CURVE ANALYSIS: A NEW OBJECTIVE METHOD FOR CHARACTERIZING SMALL RENAL MASSES Shingo Moriyama, Soichiro Yoshida, Hajime Tanaka, Masaharu Inoue, Masaya Ito, Minato Yokoyama, Junichiro Ishioka, Yoh Matsuoka, Noboru Numao, Kazutaka Saito, Yoshihisa Fujii, and Kazunori Kihara Shingo MoriyamaShingo Moriyama More articles by this author , Soichiro YoshidaSoichiro Yoshida More articles by this author , Hajime TanakaHajime Tanaka More articles by this author , Masaharu InoueMasaharu Inoue More articles by this author , Masaya ItoMasaya Ito More articles by this author , Minato YokoyamaMinato Yokoyama More articles by this author , Junichiro IshiokaJunichiro Ishioka More articles by this author , Yoh MatsuokaYoh Matsuoka More articles by this author , Noboru NumaoNoboru Numao More articles by this author , Kazutaka SaitoKazutaka Saito More articles by this author , Yoshihisa FujiiYoshihisa Fujii More articles by this author , and Kazunori KiharaKazunori Kihara More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1959AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Radiological evaluation is a key step in managing small renal mass (SRMs), and pretreatment characterization of fat poor angiomyolipoma (fpAML) is a major concern. MRI is a non-invasive and useful modality in addition to CT for characterizing SRM. Absence of a pseudocapsule (hypointense rim surrounding tumors), intratumor homogeneity, and low tumor intensity on T2WI are key features of fpAML to consider in the differential diagnosis, however, all of which have been studied only subjectively. Here, we developed an objective method to evaluate the MRI characteristics of SRM using a pixel intensity-based analysis. METHODS Between 2009 and 2013, a total of 121 solid renal tumors (<4 cm) surgically removed or biopsied after receiving MRI were evaluated in this study. Those showing apparent fat components on unenhanced CT were excluded. We set an analyte line across the tumor on T2WI upon which the pixel intensity was scored. The pixel intensity was standardized using the intensity ratio (IR) of the ipsilateral renal cortex. The IR curve was drawn along the analyte line (Fig.). Thus, a notch in the IR curve at the tumor border indicated a pseudocapsule, a quartile range of the IRs >0.1 within the tumor indicated heterogeneity, and median IRs within the tumor >1.2 and <0.8 indicated high and low tumor intensity, respectively. IR curves were classified as follows: fpAML type, pseudocapsule (-) & heterogeneity (-) & low-isointensity; clear cell RCC (ccRCC) type, pseudocapsule (+) & heterogeneity (+) & high-isointensity; and other type. We assessed the ability of the IR curves to indicate the pathological diagnosis. RESULTS The eligible SRMs were pathologically diagnosed as fpAML (n=14), ccRCC (n=92), and non-ccRCC (n=15). The median pixel size was 0.74 mm, and the median number of pixels at the analyte line was 48. The fpAML, ccRCC, and non-ccRCC were characterized as fpAML type/ccRCC type/other in 13/0/1, 1/72/19, and 5/4/6 cases, respectively. The sensitivity/specificity/accuracy of the fpAML type against fpAML and ccRCC type against ccRCC was 93%/94%/94% and 80%/86%/80%, respectively. CONCLUSIONS IR curve analysis on T2WI could be a non-invasive, quantitative method in characterizing SRM. This objective method may contribute to the differential diagnosis of fpAML. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1024-e1025 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Shingo Moriyama More articles by this author Soichiro Yoshida More articles by this author Hajime Tanaka More articles by this author Masaharu Inoue More articles by this author Masaya Ito More articles by this author Minato Yokoyama More articles by this author Junichiro Ishioka More articles by this author Yoh Matsuoka More articles by this author Noboru Numao More articles by this author Kazutaka Saito More articles by this author Yoshihisa Fujii More articles by this author Kazunori Kihara More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Organized Hematoma: An Analysis of 84 Cases with Emphasis on Difficult Prediction and Favorable Management.

To characterize features of organized hematoma (OH) that may cause considerable diagnostic difficulties. Case series with chart review. Tertiary medical center. Eighty-four patients with pathologically confirmed OH over a 10-year period were retrospectively reviewed for clinical features, imaging findings, pathologic characteristics, and treatment modalities. This study included 39 males and 45 females who presented with frequent epistaxis and nasal obstruction. There were 62 (74%) patients >40 years old (mean, 50; range, 9-81). OH mainly originated in the maxillary sinus (n = 82) or nasal cavity (n = 2) unilaterally, and most were expansile masses (n = 73) that extended into nasal cavity (n = 71) or choanae (n = 17). Several lesions were locally aggressive and simulated a malignant process that involved the ethmoid sinus (n = 22), orbit (n = 11), pterygopalatine fossa (n = 16), infratemporal fossa (n = 9), cheek (n = 3), and hard palate (n = 3). Internal architecture on computed tomography (CT) scans showed OH with expansile remodeling of the maxillary wall (82.1%) and smooth bony destruction (70.2%), whereas T2-weighted magnetic resonance (MR) images showed inhomogeneity with a notable hypointense peripheral rim in all lesions. CT and MR contrast-enhanced images revealed patchy heterogeneous enhancement that could be interpreted according to histopathologic findings of hemorrhage and neovascularization. OH was successfully removed with endoscopic surgery, although 5 cases recurred. OH can be successfully treated by endoscopic surgery. CT and MR examination provide characteristic findings for prediction and careful surgical planning.

Intravascular papillary endothelial hyperplasia: magnetic resonance imaging of finger lesions.

To describe magnetic resonance imaging (MRI) features of intravascular papillary endothelial hyperplasia (IPEH), to identify findings differentiating IPEH of the finger from that of other locations, and to correlate these with pathology. Nineteen patients with 20 I.E. masses of the finger (n = 13) and other locations (n = 7) were evaluated. All patients underwent MRI, and the results were correlated with pathology. Seventeen IPEHs, including all IPEHs of the finger, were located in the subcutis, the three other lesions in the muscle layer. On T1WI, all masses were isointense or slightly hyperintense. IPEHs of the finger (n = 13) revealed focal hyperintense nodules (n = 2) or central hypointensity (n = 2) on T1WI, hypointensity with a hyperintense rim (n = 7), hyperintensity with hypointense nodules (n = 5), or isointensity with a hypointense rim (n = 1) on T2WI, and rim enhancement (n = 5), heterogeneous enhancement with nodular nonenhanced areas (n = 6), peripheral nodular enhancement (n = 1), or no enhancement (n = 1) on gadolinium-enhanced T1WI. IPEHs of other locations (n = 7) demonstrated focal hyperintense nodules (n = 5) on T1WI, hyperintensity with hypointense nodules (n = 5) or heterogeneous signal intensity (n = 2) on T2WI, and rim or rim and septal enhancement (n = 6) or peripheral nodular enhancement (n = 1). Microscopically, IPEHs were composed of thrombi that were hypointense on T2WI and papillary endothelial proliferations that showed T2 hyperintensity and enhancement. MRI of finger IPEH reveals well-demarcated subcutaneous masses with hypointensity or hypointense nodules with peripheral hyperintensity on T2WI, as well as peripheral enhancement. T1 hyperintense nodules, internal heterogeneity on T2WI, and septal enhancement are more common in IPEH of other locations.

OSTEOID OSTEOMA AS AN ATYPICAL SOLITARY LUCENT EPIPHYSEAL LESION IN A CHILD

A previously healthy 5-year-old boy was admitted to the hospital with a nine-month history of diurnal and nocturnal pain in lower legs, particularly in the right knee, partially relieved by NSAIDs. Routine laboratory tests and an initial radiographic evaluation six months ago were normal. Due to persistent pain and limping repeated radiographs identified subtle lytic lesion with diffuse medullary sclerosis of the medial femoral condyle epiphysis (Fig1). MRI of the knee presented T2 hyperintense lesion with a thin hypointense rim consistent with sclerosis and perilesional bone marrow edema. After paramagnetic contrast application the lesion revealed a ring of enhancement (Fig. 2 a, b). A bone scan showed no focal uptake. Imaging char-