Isointense Signal Research Articles

Fibroma of tendon sheath of the hand in a 3-year-old boy: a case report

BackgroundFibroma of tendon sheath (FTS) is a rare benign soft tissue tumor that often occurs in the upper extremities. It manifests as a slow-growing mass, often without tenderness or spontaneous pain. FTS occurs most commonly in people aged 20–40 years and is extremely rare in young children. Because FTS presents with atypical physical and imaging findings, it might be misdiagnosed as another soft tissue tumor such as a ganglion cyst or tenosynovial giant cell tumor (TSGCT). Although marginal resection is usually performed, a high rate of local recurrence is reported.Case presentationA boy aged 3 years and 1 month visited our outpatient clinic with a complaint of a mass of the left hand. An elastic hard mass approximately 20 mm in diameter could be palpated on the volar side of his left little finger. This mass was initially diagnosed as a ganglion cyst at another hospital. Ultrasonography revealed a well-circumscribed hypoechoic mass with internal heterogeneity on the flexor tendon. On magnetic resonance imaging (MRI), the mass showed iso signal intensity to muscle on T1-weighted images, and homogeneously low signal intensity to muscle on T2-weighted images. The mass was peripherally enhanced after contrast administration. FTS was initially suspected as the diagnosis on the basis of these imaging features. Because of the limited range of motion of his little finger, surgery was performed when he was 4 years old. Histopathological findings indicated the mass was well-circumscribed and contained scattered spindle cells embedded in a prominent collagenous matrix. The spindle cells contained elongated and cytologically bland nuclei with a fine chromatin pattern. Nuclear pleomorphism and multinucleated giant cells were not observed. On the basis of these findings, we made a diagnosis of FTS. One year after surgery, no signs of local recurrence were observed.ConclusionsWe experienced an extremely rare case of FTS in the hand of a 3-year-old child. We especially recommend ultrasonography for hand tumors of young children to diagnose or eliminate ganglion cysts. MRI helped differentially diagnose FTS from TSGCT. Although marginal resection can be performed as a treatment, great care should be taken postoperatively because FTS has a high possibility of local recurrence.

Pediatric atypical choroid plexus papilloma: Clinical features and diagnosis

ObjectiveAtypical choroid plexus papilloma (aCPP) is a newly introduced subtype of choroid plexus tumors (CPTs) defined by the World Health Organization (WHO) in 2007 and is characterized by intermediate characteristics between choroid plexus papilloma (CPP) and choroid plexus carcinoma (CPC). Currently, the available data describing the clinical features of aCPP in children are limited. MethodsWe performed a retrospective review of 24 pediatric patients with CPTs in our institute and focused on the clinical, radiological and histopathological features of 9 patients with aCPP. ResultsThe median age of aCPP patients was 12 (3−144) months, which was younger than the age of CPP patients (36 (5−132) months, P < 0.05). Of the 9 aCPPs, there were 4 cases of giant masses in the cerebral hemisphere, which was significantly higher than that in CPPs (44.4 % vs 0.0 %, P < 0.05). According to MRI analysis, cysts and necrosis (66.7 % vs 16.7 %, P < 0.05), peritumoral edema (55.6 % vs 8.3 %, P < 0.05) and blurred borders (55.6 % vs 8.3 %, P < 0.05) were more common in aCPPs than in CPPs. T1WI isointense signals were mainly observed in aCPPs and CPPs (aCPP66.7 % vs CPP58.3 %, P >0.05), while T2WI slightly low signals were more common in CPPs (CPP41.7 % vs aCPP0%, P < 0.05); moreover, the tumor volume of aCPPs was significantly larger than that of CPPs (aCPP78.3 cm3 vs 8.4 cm3, P < 0.05). For the DWI sequence scans, isointense signals were more common in aCPPs (aCPP77.8 %>CPP25.0 %, P < 0.05), while slightly low signals were more common in CPPs (CPP58.3 %>aCPP0%, P < 0.05). Both aCPPs and CPPs mainly showed homogeneously strong enhancement (aCPP66.7 % vs CPP91.7 %, P > 0.05). Interestingly, 1 aCPP showed annular enhancement. For the pathological and immunohistochemical studies, the Ki67 proliferation index was significantly higher in aCPPs than in CPPs (13 % vs 6%, P < 0.05), and the S-100(+)/Vim(+)/Syn(+) positive rate was higher in aCPPs (58.3 % vs 11.1 %, P < 0.05). ConclusionsaCPP shows some distinctive clinical features compared with CPP, such as younger age, larger tumor size, more frequent necrosis and peritumoral edema, blurred borders, slightly low signals on T2WI and isointense signals on DWI, and a higher S-100(+)/Vim(+)/Syn(+) positive rate, which may provide more valuable evidence for differential diagnosis and clinical decisions surrounding aCPP.

High Signal Intensity on Diffusion-Weighted Images Reflects Acute Phase of Deep Vein Thrombus

The effects of antithrombotic therapy on deep vein thrombosis (DVT) can be affected by thrombus age, which cannot be reliably determined by noninvasive imaging modalities. We investigated whether magnetic resonance (MR) diffusion-weighted imaging (DWI) can localize and determine the age of venous thrombus in patients with DVT, animal models, and human blood in vitro. Signal intensity (SI) on DWI and the apparent diffusion coefficient (ADC) of thrombi were assessed in eight patients with DVT using a 1.5-T MR imaging (MRI) system. We assessed the organizing processes as venous thrombus developed in the rabbit jugular vein using a 3.0-T MRI system over time. We also assessed MRI signals of human blood in vitro using the 1.5-T MRI system. Venous thrombi were detected by DWI as areas of high or mixed high and iso SI in all patients. The ADCs were lower in the proximal, than in the distal portion of the thrombi. The thrombi of rabbit jugular veins histologically organized in a time-dependent manner, with high SI on DWI at 4 hours, mixed high and iso SI at 1 and 2 weeks, and iso SI at 3 weeks. The ADC correlated negatively with erythrocyte content, and positively with smooth muscle cells, macrophages, hemosiderin, and collagen content. MRI signals of human blood in vitro showed that ADCs were affected by erythrocyte content, but not by blood clotting. MR-DWI can detect venous thrombus, and high SI on DWI accompanied by a low ADC might reflect erythrocyte-rich, acute-phase thrombi.

Imaging Features and Floating-Ice Sign of Primary Lymphoma of the Bone

Background: The imaging presentation of primary bone lymphoma is unclear. Objectives: The present study aimed to investigate the imaging presentations of primary bone lymphoma especially a specific “floating-ice” sign. Patients and Methods: Forty one patients with primary bone lymphoma confirmed by pathology with 27 males and 14 females and an age range of 2 - 76 (mean = 40) years were enrolled. The clinical and imaging data were analyzed. Results: The tumor involved long bones in 17 cases, flat bones in 12, spine in eight and irregular bones in four cases. The imaging presentations were divided into five types: infiltrative type in nine cases (22%), osteolytic in 14 cases (34.1%), osteosclerotic in four cases (9.8%), mixed in 11 cases (26.8%) including four cases with a “floating-ice” sign and cystic in three cases (7.3%). In plain radiography, only three of four long bone lesions in children had a varying degree of periosteal reaction. Among 20 cases with CT scanning, sixteen had soft tissue masses, seventeen had ill-defined margins, and three had well-defined margins with sclerotic rims. Among twelve patients with MRI, ten had soft tissue masses with well-defined margins. MRI demonstrated a greater extent of lesion than CT. In MRI T1 weighted image (T1 WI), isointense signal was seen in three cases, hypointense signal in five and mixed signal in four. In T2 WI, isointense and hypointense signal was detected in five cases, hyperintense signal in three and mixed hyperintense signal in four. Conclusion: Primary bone lymphoma occurs most frequently in long and flat bones as infiltrative osteolytic destruction, and combined plain radiographs, CT and MRI help obtain a correct diagnosis.

Analysis of magnetic resonance imaging features of ovarian thecoma.

To investigate the magnetic resonance imaging (MRI) findings in ovarian thecoma and improve preoperative diagnostic accuracy.Retrospective analysis was performed on 45 patients with surgically and pathologically confirmed ovarian thecoma. Patients were grouped into those with maximum lesion diameter ≥5 cm and <5 cm. Diagnostic scores (up to 6 points) were evaluated on the basis of MRI performance.The ≥5 cm group contained 36 cases (cystic necrosis, 32 cases) with the following findings: T1WI: isointense signal, 22 cases; slightly hypointense signal, 14 cases; T2WI: isointense signal, 6 cases; slightly hypointense signal, 21 cases; slightly hyperintense signal, 9 cases; Diffusion-weighted imaging (DWI): hyperintense signal, 23 cases; mixed hyperintense signal, 13 cases; slight enhancement on dynamic enhanced scans; pelvic fluid accumulation, 31 cases. The diagnostic score evaluations yielded 6 points in 31 cases, 5 points in 1 case, 4 points in 2 cases, and 3 points in 2 cases. The <5 cm group contained 9 cases (cystic necrosis, 3 cases) with the following findings: T1WI: isointense signal, 3 cases; slightly hypointense signal, 6 cases; T2WI: isointense signal, 2 cases; slightly hypointense signal, 4 cases; slightly hyperintense signal, 3 cases; DWI, hyperintense signal; slight enhancement in 8 cases and significant enhancement in 1 case; pelvic fluid accumulation, 4 cases. The diagnostic score evaluations yielded 6 points in 3 cases, 5 points in 1 case, 4 points in 4 cases, and 3 points in 1 case. (iii) Incidence of pelvic fluid accumulation and cystic necrosis differed depending on the size of the lesion (P = .007, .000).Larger lesions show hyperintense or mixed hyperintense signals on DWI along with pelvic fluid and cystic necrosis; whereas, smaller lesions show a hyperintense signal on DWI, cystic necrosis is rare. MRI characteristics along with the patient age and laboratory findings can improve the accuracy of preoperative diagnosis of these lesions.

Validation of a scoring system to evaluate the risk of rapid growth of intracranial meningiomas in neurofibromatosis type 2 patients.

Intracranial meningiomas occur in about half of neurofibromatosis type 2 (NF2) patients and are very frequently multiple. Thus, estimating individual meningiomas' growth rates is of great interest to tailor therapeutic interventions. The Asan Intracranial Meningioma Scoring System (AIMSS) has recently been published to estimate the risk of tumor growth in sporadic meningiomas. The current study aimed to determine predictors of rapid meningioma growth in NF2 patients and to evaluate the AIMSS score in a specific NF2 cohort. The authors performed a retrospective analysis of 92 NF2 patients with 358 measured intracranial meningiomas that had been observed prospectively between 2012 and 2018. Tumor volumes were measured at diagnosis and at each follow-up visit. The growth rates were determined and evaluated with respect to the clinicoradiological parameters. Predictors of rapid tumor growth (defined as growth ≥ 2 cm3/yr) were analyzed using univariate followed by multivariate logistic regression to build a dedicated predicting model. Receiver operating characteristic (ROC) curves to predict the risk of rapid tumor growth with the AIMSS versus the authors' multivariate model were compared. Sixty tumors (16.76%) showed rapid growth. After multivariate analysis, a larger tumor volume at diagnosis (p < 0.0001), presence of peritumoral edema (p = 0.022), absence of calcifications (p < 0.0001), and hyperintense or isointense signal on T2-weighted MRI (p < 0.005) were statistically significantly associated with rapid tumor growth. It is particularly notable that the genetic severity score did not seem to influence the growth rate of NF2 meningiomas. In comparison with the AIMSS, the authors' multivariate model's prediction did not show a statistically significant difference (area under the curve [AUC] 0.82 [95% CI 0.76-0.88] for the AIMSS vs AUC 0.86 [95% CI 0.81-0.91] for the authors' model, p = 0.1). The AIMSS score is valid in the authors' cohort of NF2-related meningiomas. It adequately predicted risk of rapid meningioma growth and could aid in decision-making in NF2 patients.

Appearance of recurrent adult fibrosarcoma of the soft tissue and loco-regional post-treatment changes on MRI follow-up

BackgroundAdult fibrosarcoma (AFS) is a very rare malignant soft tissue tumor, arising from malignant spindle-shaped fibroblasts. We aim to analyze the appearance of recurrent AFS with a focus on configuration and to assess the occurrence of loco-regional post-treatment changes on MRI follow-up.MethodsOne hundred sixty-eight MRI follow-up scans (1.5 T MRI) of 12 patients with histologically proven AFS were reviewed. The recurrent tumors were examined for configuration, limitation, contrast enhancement, and extent and signal intensity on MRI.ResultsThe mean age of the patients was 50.2 ± 16.7 years. Forty-two percent of the patients presented recurrent AFS (n = 5). Recurrences occurred 12 ± 6.5 months after tumor resection in the mean. Patients over 55 years of age showed a significantly higher risk for recurrences (RR = 5; 95% CI, 1.8 to 31; p = 0.04). Recurrent AFS was ovoid, nodular, streaky, polycyclic, or fascicular configured with homogeneous/heterogeneous contrast enhancement and well- or ill-defined borders. The intensity of contrast enhancement ranged from rim to marked contrast enhancement. Recurrent AFS mostly showed a muscle iso-intense signal in T1-weighted and a hyperintense signal in PD-weighted/TIRM sequences. The most common post-treatment changes were subcutaneous edema (92%; p = 0.03), muscle edema (75%), and postoperative seroma (50%). Patients with the presence of muscle edema after primary tumor resection had a slightly, but not significantly higher risk for recurrences (RR = 1.75; p = 0.08).ConclusionRecurrent AFS shows no common configuration on MRI, as it may appear ovoid, nodular, streaky, polycyclic, or fascicular. Patients with the presence of post-treatment muscle edema have a slightly higher risk for recurrences.Level of evidence: Level III, therapeutic study

A study to find the characteristic imaging findings of various ring-enhancing lesions using MR imaging

Introduction: Multiple ring-enhancing lesions are one of the most commonly encountered neuroimaging abnormalities. A study was conducted to find the characteristic imaging findings of various ring-enhancing lesions on MRI. Materials and methods: It was a prospective study conducted in the department of radiodiagnosis, GSL Medical College. All age groups of both gender with cerebral ring-enhancing lesions detected in contrast MR studies were taken up for spectroscopy. Patients with a history of claustrophobia and individuals with metallic implants insertion, cardiac pacemakers, and metallic foreign body in situ were excluded. The MRI scan was performed MRI PHILIPS ACHIEVA HDxt 1.5 T, the active shielded superconducting magnet of 1.5telsa magnetic field using SENSE coils for the acquisition of images. Results: Out of 30 study participants, under 45 years category metastases was common (15%), 44% were female and 56% were males. Depicts T1 signal intensity showed hypointense signal intensity on T1W sequence in 65 (95.5%) cases. Only 4.6% of cases showed isointense signal intensity on T1W image. T2 signal intensity in 73.5% of cases showed hyperintense signal intensity. Conclusions: MRI is an excellent, non-ionizing imaging modality with multiplanar imaging capabilities for excellent grey-white matter differentiation

Comparison of the Imaging and Pathological Features of Telangiectatic Osteosarcoma and Aneurysmal Bone Cyst of Long Tubular Bones

Background: The clinical, imaging and pathological features of telangiectatic osteosarcoma (TOS) in long bones are helpful for differentiation from aneurysmal bone cysts (ABC). Objectives: To investigate the clinical, imaging and pathological features of TOS in comparison with ABC in long bones. Patients and Methods: Seventeen patients with TOS and 17 patients with ABC in our hospital were analyzed in the clinical, imaging and pathological features for proper diagnosis. Results: For plain radiographs in 17 TOS cases, a soft tissue mass was detected in 14 cases, lytic bone destruction in 13, ill-defined border in 12, periosteal reaction in eight, formation of the Codman triangle in five, pathological fracture in three, and calcification in one. In 17 cases with ABC, an ill-defined border was found in fifteen cases, lytic and expansile destruction in eleven, thinned sclerotic rim in twelve, eccentrically location in ten, coarse septations in eight, a soft tissue mass in three, pathological fracture in three, periosteal reaction in two, and ill-defined border in two cases. In CT imaging of TOS, multiple cysts were in twelve cases, and fluid-fluid levels in three. In ABC, multiple cysts were in eleven cases while fluid-fluid levels in four. In MRI presentations of TOS, low and medium signal was present in the T1-weighted imaging (T1WI), whereas mixed (9/12) or high signal (3/12) was presented in the T2 WI with inhomogeneous signal. Four cases had multiple cysts and fluid-fluid levels in the bone destruction and soft tissues. The cysts had long T1 and long T2 signal with isointense signal in the septations (5/12). Fat inhibition sequence showed clear cystic changes. In ABC, low complete or incomplete signal was demonstrated in all lesions with a higher incidence of fluid-fluid levels (8/11). The lesion was of low and medium inhomogeneous signal in the T1 WI but mixed signal in T2 WI (6/11) including hyperintense signal in the upper part but mixed signal in the lower part in four cases or hyperintense signal (1/11) in T2 WI. The histopathological features of TOS were bleeding inside the lesion, highly atypia tumor cells of malignancy in the septa and tumorous bone tissue. The septa of ABC were composed of proliferative fibroblasts with dispersed polykaryocytes, reactive woven bone but no atypical cells. Conclusion: The clinical, imaging and pathological characteristics should be combined to make a correct differential diagnosis between telangiectatic osteosarcoma and aneurysmal bone cyst.

Added Value of Thoracic Magnetic Resonance Imaging in the Differential Diagnosis Between Peripheral Lung Cancer and Progressive Massive Fibrosis of Coal Silicosis

To compare the thoracic magnetic resonance imaging (TMRI) features between peripheral lung cancer (PLC) and progressive massive fibrosis (PMF) of coal silicosis (CS), and to excavate information of differential diagnostic value. 68 patients with PLC (68 lesions) were selected as lung cancer group (LCG), and 50 patients with PMF of CS (78 lesions) were selected as coal silicosis group (CSG). TMRI was performed in both groups, and T1-weighted imaging (T1WI), T2-weighted imaging (T2WI) and Spectral pre-saturated inversion recovery (SPIR) were used. The differences and characteristics of TMRI between the two groups were analyzed. 55 cases of pulmonary masses (PM) in LCG showed iso-signal intensity on T1WI (80.9%), and 63 cases showed high-signal intensity on T2WI and SPIR (92.6%); 65 cases of PMF in CSG showed iso-signal intensity on T1WI (83.5%), and high-signal intensity on T2WI and SPIR was found in 4 cases (5.1%), but 67 cases showed low-signal intensity (85.9%). PMF in CSG with high-signal intensity on T2WI and SPIR were significantly lower than PM in LCG(P &lt; 0.1). Compared with TMRI of PLC showed high-signal intensity on T2WI and SPIR, PMF in CS showed low-signal intensity on T2WI and SPIR. This feature is of important significance in differential diagnosis.

Longitudinal ultra-high field MRI of brain lesions in neuromyelitis optica spectrum disorders

BackgroundIn neuromyelitis optica spectrum disorder (NMOSD), clinical disability in NMOSD patients is relapse-related and progressive phase is rare. This observation raises the question whether there is any radiographic disease activity. The aim of present study was to determine the longitudinal changes in cerebral lesion number, lesion size, lesion-to-venule relationship, and morphological patterns of lesions in NMOSD using multiparametric 7T MR imaging. We also aimed to assess brain volume changes in NMOSD. MethodsA cohort of 22 patients with NMOSD underwent high-resolution 3D-susceptibility weighted imaging (SWI) and 2D-gradient-echo (GRE-T2*) weighted imaging on 7T MRI of brain at baseline and after ~2.8 years of follow-up. Morphologic imaging characteristics, and signal intensity patterns of lesions were recorded at both time points. Lesions were classified as "iron-laden" if they demonstrated hypointense signal on GRE-T2* images and/or SWI as well as hyperintense signal on quantitative susceptibility mapping (QSM). Lesions were considered "non-iron-laden" if they were hyperintense on GRE-T2*/SWI and isointense or hyperintense on QSM. Additionally, fractional brain parenchymal volume (fBPV) was computed at both time points. ResultsA total of 169 lesions were observed at baseline. At follow-up, 6 new lesions were found in 5 patients. In one patient, a single lesion could not be detected on the follow-up scan. No appreciable change in lesion size and vessel-lesion relationship was observed at follow up. All lesions demonstrated hyperintense signal intensity on GRE-T2* weighted images and isointense signal on QSM at both time points. Therefore, these lesions were considered as non-associated with iron pathology. Additionally, no significant change in brain volume was observed: fBPV 0.78 ± 0.06 at baseline vs. 0.77 ± 0.05 at follow up, p>0.05. ConclusionCerebral lesions in NMOSD patients remain ‘inert’ and do not show any substantial variations in morphological characteristics during a 2–3-year follow-up period.

Association between Pericytes in Intraplaque Neovessels and Magnetic Resonance Angiography Findings.

(1) Background: Pericytes are involved in intraplaque neovascularization of advanced and complicated atherosclerotic lesions. However, the role of pericytes in human carotid plaques is unclear. An unstable carotid plaque that shows high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) is often a cause of ischemic stroke. The aim of the present study is to examine the relationship between the pericytes in intraplaque neovessels and MRA findings. (2) Methods: A total of 46 patients with 49 carotid artery stenoses who underwent carotid endarterectomy at our hospitals were enrolled. The patients with carotid plaques that were histopathologically evaluated were retrospectively analyzed. Intraplaque hemorrhage was evaluated using glycophorin A staining, and intraplaque neovessels were evaluated using CD34 (Cluster of differentiation) stain as an endothelial cell marker or NG2 (Neuron-glial antigen 2) and CD146 stains as pericyte markers. Additionally, the relationships between the TOF-MRA findings and the carotid plaque pathologies were evaluated. (3) Results: Of the 49 stenoses, 28 had high-intensity signals (TOF-HIS group) and 21 had iso-intensity signals (TOF-IIS group) on TOF-MRA. The density of the CD34-positive neovessels was equivalent in both groups. However, the NG2- and CD146-positive neovessels had significantly higher densities in the TOF-HIS group than in the TOF-IIS group. (4) Conclusion: The presence of a high-intensity signal on TOF-MRA in carotid plaques was associated with intraplaque hemorrhage and few pericytes in intraplaque neovessels. These findings may contribute to the development of new therapeutic strategies focusing on pericytes.

Abstract TP333: The Volume of an Acute Intracerebral Hemorrhage May Be Larger Than it Appears on Computed Tomography Scan

Background and Purpose: Computed tomography (CT) scan is difficult to detect early-onset acute intracerebral hemorrhage (ICH) rich in fresh blood correctly. We identified the presence of a perihematomal low-density lesion on CT imaging, which showed a high-intensity signal on T2-weighted imaging and an iso-intensity signal on fluid-attenuated inversion recovery imaging in magnetic resonance imaging (MRI) (Figure. A~C). It located inside of the hypo-intensity rim at the edge of hematoma on gradient recalled echo T2*-weighted imaging (Figure. D). We named it the “CT wall sign” and investigated the association with imaging findings in acute ICH. Methods: Patients with acute ICH within 24 hours from onset who underwent non-contrast head CT and MRI scan at the same time periods were included. The ICH volumes on CT and MRI (cm 3 ) were measured using a three-dimensional slicer and compared. Subjects were divided according to the presence or absence of the CT wall sign and compared the neuroradiological variables. Statistical analyses were performed to evaluate the association between the CT wall sign and other imaging findings. Results: A total of 146 patients were included and the CT wall sign was observed in 42 (29%) patients. The difference in the ICH volume between MRI and CT were significantly larger in the CT wall sign-positive group than in -negative group (6.0 cm 3 versus 0.40 cm 3 , P &lt;0.001). The presence of CT wall sign was significantly associated with putamen hemorrhage ( P =0.049), large hematoma &gt; 11.36 cm 3 ( P =0.005), and niveau formation in the hematoma ( P &lt;0.001). Conclusions: The presence of the CT wall sign suggests that the volume of an acute ICH may be larger than it appears on CT imaging. Key words: Acute intracerebral hemorrhage, Computed tomography, Magnetic resonance imaging, Perihematomal low-density area.

P729 A shocking tumor

Abstract Introduction Primary cardiac tumors are a relatively uncommon condition, which may appear both in asymptomatic patients or in a myriad of clinical presentations. Imaging techniques are crucial for its diagnosis, and a multi-modality approach may be useful in the evaluation of this masses. Case description A 57 year-old man with history of hypertension presented in the emergency department with acute pulmonary edema and cardiogenic shock. He was admitted to the coronary care unit, and on bedside echocardiography a mass on the tricuspid valve was observed. Upon clinical improvement, a cardiac CT and cardiac MRI was performed (figure 1). A solid mass with no calcium content and dependent exclusively on the anterior leaflet of the tricuspid valve was seen on CT-scan (fig 1, A and B). Thrombus on the right atrial appendage could also be appreciated. MRI confirmed the presence of a 18x19 mm mass with isointense signal on T1-turbo spin echo black-blood (fig 1, C) and cine steady-state free precession sequences, whereas an hyperintense signal was evident on T2 weighted images (T2-STIR; fig 1 D). In first pass sequences the central core was hypointense and late gadolinium enhancement showed peripheral enhancement with a non captating central core (fig 1, E). The patient underwent surgery and the anatomopathological results showed a tumor constituted by dense connective tissue, scarce cellular content and an avascular matrix of mucopolysaccharides, elastic fibers and fusiform cells consistent with the diagnosis of papillary fibroelastoma. Discussion The imaging characteristics of papillary fibroelastoma are not commonly reported on MRI. We present an unusually large right-sided fibroelastoma with a characteristic distribution of late gadolinium enhancement, which has not been consistently described on a fibroelastoma. Cardiac tumors are rare, and a non-invasive differential diagnosis is always a challenge. A multi-modality approach (echocardiography, cardiac-CT and cardiac MRI) as well as integration of relevant morphological information, including the location of the lesion and tissue characteristics was essential to the orientate the most plausible diagnosis. The distinctive images are presented. Abstract P729 Figure 1.

Scoring System to Predict Malignancy for MRI-Detected Lesions in Breast Cancer Patients: Diagnostic Performance and Effect on Second-Look Ultrasonography.

PurposeTo design a scoring system to predict malignancy of additional MRI-detected lesions in breast cancer patients.Materials and MethodsEighty-six lesions (64 benign and 22 malignant) detected on preoperative MRI of 68 breast cancer patients were retrospectively included. The clinico-radiologic features were correlated with the histopathologic results using the Student's t-test, Fisher's exact test, and logistic regression analysis. The scoring system was designed based on the significant predictive features of malignancy, and its diagnostic performance was compared with that of the Breast Imaging-Reporting and Data System (BI-RADS) category.ResultsLesion size ≥ 8 mm (p < 0.001), location in the same quadrant as the primary cancer (p = 0.005), delayed plateau kinetics (p = 0.010), T2 isointense (p = 0.034) and hypointense (p = 0.024) signals, and irregular mass shape (p = 0.028) were associated with malignancy. In comparison with the BI-RADS category, the scoring system based on these features with suspicious non-mass internal enhancement increased the diagnostic performance (area under the receiver operating characteristic curve: 0.918 vs. 0.727) and detected three false-negative cases. With this scoring system, 22 second-look ultrasound examinations (22/66, 33.3%) could have been avoided.ConclusionThe scoring system based on the lesion size, location relative to the primary cancer, delayed kinetic features, T2 signal intensity, mass shape, and non-mass internal enhancement can provide a more accurate approach to evaluate MRI-detected lesions in breast cancer patients.

Neuroendocrine tumor of Pancreas: Which modality is better, 320-MDCT or 3T-MRI?

Background: Significant improvement in the spatial and temporal resolution of CT have been made over the past decade, with advent of multidetector row CT (MDCT). Also, the increased spatial resolution of the 3T-MRI allows for high-quality abdominal imaging. Therefore, neuroendocrine tumors of pancreas (PNET) and their metastasis are increasingly diagnosed on imaging studied performed for unrelated purposes. Our purpose of this study is to find out the good modality to detect PNETs. Material and Methods: We selected 11 PNETs. Four of the 11 PNETs were diagnosed as NET G2, and seven of the 11 PNETs were diagnosed as NET G1. We took both 320-MDCT and 3T-MRI for all patients before surgery. We used pancreatic protocol CT with and without intravenous contrast. We made 5 kind of CT image such as non-contrast image, early-arterial phase (25sec), late-arterial phase (40sec), portal phase (70sec) and venous phase(180sec). All CT slices were made of 1mm. About 3T-MRI, we selected 2 kind of images, diffusion-weighted image (DWI) and T2 weighted image (T2WI). Slice thickness of both DWI and T2 weighted image was 3mm. We compared CT image with DWI and T2WI. Results: Seven of the 11 PNETS were diagnosed on both CT, DWI and T2WI. All 7 PNETs showed well-enhanced on late-arterial phase on CT and high signal intensity on both DWI and T2WI. Three of the 11 PNETs were able to detect on CT and DWI. All 3 PNET showed iso-signal intensity as compared to the normal pancreas. One of the 11 PNET was able to detect on DWI and T2WI. The PNET showed the same enhancement as the normal pancreatic parenchyma on all phase CT. Conclusion: DWI was the most sensitive image to detect PNET. High cell density PNETs with moderate vascularity may show atypical PNETs on CT and MRI.

MRI and pathological features of Rathke cleft cysts in the sellar region.

The aim of the present study was to investigate the MRI and pathological features of Rathke cleft cysts (RCC) in the sellar region. A total of 45 RCC cases were retrospectively analyzed. RCC size, location, intracyst nodules and general signals, as well as the posterior pituitary bright spot (PPBS) were analyzed using MRI-T1 weighted images (T1WI) and T2WI. The relationship between the presence of PPBS and histopathological features was additionally evaluated. On T1WI, there were 18 cases of isointense signal, 16 cases of hyperintense signal, 9 cases of hypointense signal, 1 case of heterogeneous signal and 1 case with a stratification effect, with isointense signal in the upper part and hyperintense signal in the lower part. On T2WI, there were 5 cases of isointense signal, 27 cases of hyperintense signal, 11 cases of hypointense signal and 1 case of the stratification effect. There were 10 cases of PPBS+ and 35 cases of PPBS-. There were no significant differences in the age, sex, cyst location and size between PPBS+ and PPBS- cases. However, PPBS+ cases had significantly lower inflammation than PPBS- cases. A total of 20 cases of intracystic nodules were identified on MRI scans, most of which exhibited T2 -hypointense signals. The shape of RCC nodules varied and there were 17 cases where the nodules were non-adherent to the cyst wall. The MRI signals of RCCs varied and most nodules were floating within cysts. Intracystic nodules are characteristic features of RCCs when observed by MRI and thus are of high diagnostic value. Most patients with RCC were also PPBS-, which may be associated with an increased inflammatory response.

Vascular Hyperintensity on Fluid-Attenuated Inversion Recovery Indicates the Severity of Hypoperfusion in Acute Stroke

Background and AimAlthough fluid-attenuated inversion recovery vascular hyperintensities may be frequently seen in acute large-artery ischemic stroke, reports on their prognostic utility had been conflicting due to lack of quantitative evaluation of the perfusion status based on the signal intensity. We hypothesized that greater hyperintensity represents more severe hypoperfusion. MethodsOverall, 27 patients with acute occlusion of the proximal middle cerebral artery were divided into 2 groups, based on their signal intensity in the insular segment of middle cerebral artery on the affected side, relative to that of the insular cortex: the low signal intensity group (hypo- or isointense signals, n = 12) and the high signal intensity group (hyperintense signals, n = 15). Using dynamic susceptibility contrast magnetic resonance imaging, we assessed the time of the maximum value of the residue function and mean transit time, in the entire middle cerebral artery cortical area and diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, including the corona radiata. ResultsThe high signal intensity group had significantly longer time of the maximum value of the residue function in all the diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, except the M3 and M6 regions, and significantly longer mean transit time in the M1 and M4 regions. ConclusionsQuantitative analysis of the perfusion parameters revealed more severely compromised and widely disturbed perfusion status in the high signal intensity group than in the low signal intensity group.

On the selection of endogenous and exogenous signals.

Alerting is one of the three components of attention which involves the eliciting and maintenance of arousal. A seminal study by Posner et al. (Posner MI, Klein R, Summers J, Buggie S. 1973 Mem. Cognit. 1, 2–12 (doi:10.3758/BF03198062)) focused on how changing the interval between an alerting signal and a target would impact the speed and accuracy of responding. Participants indicated whether targets were presented on the left or right side of the fixation point. Auditory warning signals were played at various intervals prior to the target to alert participants and prepare them to make a response. Reaction times revealed a robust, U-shaped, preparation function. Importantly, a clear speed-accuracy trade-off (SAT) was observed. In the current experiment, we replicated the methodological components of this seminal study while implementing a novel auditory warning signal (Lawrence MA, Klein RM. 2013 J. Exp. Psychol. General 142, 560 (doi:10.1037/a0029023)) that was either purely endogenous (change in quality without a change in intensity; analogous to isoluminant colour change in vision) or a combination of endogenous and exogenous (change in both quality and intensity). We expected to replicate the U-shaped preparation function and SAT observed by Posner and colleagues. Based on Lawrence and Klein's findings we also expected the SAT to be more robust with the intense signal in comparison to the isointense signal.

Diagnosis of Postlaminar Optic Nerve Invasion in Retinoblastoma With MRI Features.

Retinoblastomas (RBs) with postlaminar optic nerve invasion (PLONI) increases the risk of local recurrence or systemic metastasis. Most MRI studies on PLONI focused on optic nerve enhancement and tumor size, with reported relatively high specificity (84-98%) but low sensitivity (37-78%), which shows room for improvement, especially with regard to sensitivity. To evaluate the diagnostic performance for detecting PLONI with RB using MRI features. Retrospective. Fifty patients with histopathologic PLONI and 70 patients without PLONI of RB. 1.5T and 3.0T, precontrast axial T1 -weighted and T2 -weighted, postcontrast axial, coronal and oblique-sagittal T1 -weighted. The eyes were histopathologically analyzed and the preoperative MRI features of the eyes were independently evaluated by three observers. MRI features suggesting the presence of PLONI were identified by univariate and multivariable analysis. Receiver operating characteristic curve (ROC) and the area under the curve (AUC) were used to analyze diagnostic performance. Significant independent diagnostic factors for PLONI include: 1: Bilateral tumor (odds ratio [OR], 15.32; 95% confidence interval [CI]: 1.63-143.51); 2: Tumor with total coverage of the optic disk (OR, 6.43; 95% CI: 1.04-39.79); and 3: Optic nerve enhancement (OR, 8.43; 95% CI: 3.50-20.31). On the other hand, isointense signal of tumor on T2 WI (OR, 0.30; 95% CI: 0.12-0.75) was an independent diagnostic factor in excluding PLONI. ROC analysis showed AUC of 0.84 (95% CI: 0.77-0.91, P < 0.0001) for PLONI. Based on the cutoff of maximum Youden index, the sensitivity, specificity, and accuracy were 82%, 73%, and 77%, respectively. MRI features of RB showed a strong association with PLONI. The model of MRI features demonstrated promising diagnostic performance in detecting PLONI. 4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;51:1045-1052.