Parenchymal Contrast Enhancement Research Articles

Abstract 776: Change in background contrast enhancement category on abbreviated breast MRI with administration of 6 months of bazedoxifene and conjugated estrogen vs wait list control

Abstract Background MRI background contrast enhancement (BPE) has found to be a marker of breast cancer risk providing information beyond that provided by assessment of breast density. BPE is qualitatively classified into categories that correspond to BPE estimates as minimal, <25% BPE; mild, 25-50% BPE; moderate, 50-75% BPE; and marked, >75% BPE. We divided minimal into minimal and almost none (≤5%). We conducted a feasibility study of change in BPE after 6 months of the selective estrogen receptor modulator bazedoxifene (BZA) 20 mg + conjugated estrogen (CE) 0.45 mg marketed commercially as Duavee™ for relief of hot flashes and prevention of osteoporosis in postmenopausal women. Methods STUDY00145121 started 5-27-2020 with randomization to 6 months of Duavee™ vs waitlist control but was stopped after 11 entrants because participants were unable to receive follow-up breast MRIs due to COVID and Duavee™ became unavailable. STUDY0014761 was opened in early 2022 when a source of BZA was found. Doses of BZA and CE were the same as Duavee™ but given as two pills instead of one. 16 women have been randomized to 6 months of BZA/CE vs a wait list control between 2-14-2022 and 9-19-2023. Inclusion criteria are postmenopausal women ages 45-65 at increased risk for breast cancer, BMI < 36 kg/m2 and having current vasomotor symptoms. Participants had a blood draw, 3D mammogram, and abbreviated breast MRI at baseline and the studies were repeated at 6 months. Volumetric density was assessed by Volpara™ fully automated software. Research evaluation of abbreviated MRI background parenchymal contrast enhancement (BPE) was assessed by 5 categories as almost none, minimal, mild, moderate, and marked. BPE was evaluated by a single radiologist blinded to treatment assignment and compared to the 4-category clinical assessment. Results A total of 27 women have been entered in these studies. Six were not evaluable from STUDY00145121 because of the inability to perform 6-month MRI. Two women on STUDY0014761 are not endpoint evaluable due to early drop out and 3 have not yet completed study. A total of 16 women have completed the 6-month portion of the study and abbreviated MRI, with median age 55 (range 47-62) and median BMI 26 kg/m2 (20-33 kg/m2). At baseline, BPE were 3 almost none, 4 minimal, 8 mild, 1 moderate, and 0 marked. There was little correlation between absolute baseline mammographic fibroglandular volume and baseline BPE. A shift in BPE category using the 5-category assessment was noted in 6/11 women (all but one decreased) randomized to BZA +CE and 2/5 women (both decreased) on waitlist. The one increase and four categorical decreases would not have been detected without expansion of BPE to a 5-category system. Conclusion Using the 5-category classification, abbreviated MRI BPE may have promise as a response biomarker in prevention trials for postmenopausal high-risk women. Citation Format: Carol J. Fabian, Onilisa Winblad, Amy Kreutzjans, Krystal Pittman, Christy Altman, Kandy R. Powers, Mary McCarthy, Lauren Nye, Bruce F. Kimler. Change in background contrast enhancement category on abbreviated breast MRI with administration of 6 months of bazedoxifene and conjugated estrogen vs wait list control [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 776.

Suspected tick-borne flavivirus meningoencephalomyelitis in dogs from the UK: six cases (2021).

Tick-borne encephalitis virus and louping ill virus are neurotropic flaviviruses transmitted by ticks. Epidemiologically, tick-borne encephalitis is endemic in Europe whereas louping ill's predominant geographical distribution is the UK. Rarely, these flaviviruses affect dogs causing neurological signs. This case series aimed to describe the clinical, clinicopathological, and imaging findings, as well as the outcomes in six dogs with meningoencephalitis and/or meningomyelitis caused by a flavivirus in the UK in 2021. Observational retrospective case-series study. Clinical data were retrieved from medical records of dogs with positive serological or immunohistochemical results from three different institutions from spring to winter 2021. Six dogs were included in the study. All dogs presented an initial phase of pyrexia and/or lethargy followed by progressive signs of spinal cord and/or intracranial disease. Magnetic resonance imaging showed bilateral and symmetrical lesions affecting the grey matter of the thalamus, pons, medulla oblongata, and thoracic or lumbar intumescences with none or mild parenchymal and meningeal contrast enhancement. Serology for tick-borne encephalitis virus was positive in five dogs with the presence of seroconversion in two dogs. The viral distinction between flaviviruses was not achieved. One dog with negative serology presented positive immunohistochemistry at post-mortem examination. Three dogs survived but presented neurological sequelae. Three dogs were euthanased due to the rapid progression of the clinical signs or static neurological signs. These cases raise awareness of the presence of tick-borne encephalitis as an emergent disease or the increased prevalence of louping ill virus affecting dogs in the UK.

Multi‐modality imaging characteristics of a surgically confirmed emphysematous torsion of papillary process of the caudate liver lobe and pneumoperitoneum in a dog

AbstractA 7‐year‐old, female, spayed dog presented with a 1‐week history of vomiting, diarrhoea and lethargy. Abdominal radiographs and ultrasound revealed bicavitary effusion, a large, gas‐cavitated, soft tissue mass in the region of the papillary process of the caudate lobe of the liver, with associated peritonitis and mild pneumoperitoneum. The location of the mass and gas cavitation were confirmed on computed tomography. The absence of vascular and parenchymal contrast enhancement and the distortion of the caudal vena cava was consistent with hilar torsion of the papillary process of the liver. The torsion was surgically confirmed and excised, and ischemic necrosis was histologically confirmed. The patient fully recovered following surgery.

Quantification approaches for magnetic resonance imaging following intravenous gadolinium injection: A window into brain-wide glymphatic function.

The glymphatic system is a brain-wide network of perivascular pathways along which cerebrospinal fluid and interstitial fluid rapidly exchange, facilitating solute and waste clearance from the brain parenchyma. The characterization of this exchange process in humans has relied primarily upon serial magnetic resonance imaging following intrathecal gadolinium-based contrast agent injection. However, less invasive approaches are needed. Here, we administered a gadolinium-based contrast agent intravenously in eight healthy participants and acquired magnetic resonance imaging scans prior to and 30, 90, 180, and 360 min post contrast injection. Using a region-of-interest approach, we observed that peripheral tissues and blood vessels exhibited high enhancement at 30 min after contrast administration, likely reflecting vascular and peripheral interstitial distribution of the gadolinium-based contrast agent. Ventricular, grey matter and white matter enhancement peaked at 90 min, declining thereafter. Using k-means clustering, we identify distinct distribution volumes reflecting the leptomeningeal perivascular network, superficial grey matter and deep grey/white matter that exhibit a sequential enhancement pattern consistent with parenchymal contrast enhancement via the subarachnoid cerebrospinal fluid compartment. We also outline the importance of correcting for (otherwise automatic) autoscaling of signal intensities, which could potentially lead to misinterpretation of gadolinium-based contrast agent distribution kinetics. In summary, we visualize and quantify delayed tissue enhancement following intravenous administration of gadolinium-based contrast agent in healthy human participants.

MRI ischemic and hemorrhagic lesions in arterial and venous territories characterize central nervous system intravascular lymphoma in dogs.

Intravascular lymphoma (IVL) is characterized by the proliferation of large malignant lymphocytes within the lumen of blood vessels. This retrospective, multi-center, case series study aimed to describe the MRI features of confirmed central nervous system IVL in dogs and compare them with histopathological findings. Medical record databases from seven veterinary centers were searched for cases of histologically confirmed IVL. Dogs were included if an MRI was performed. The MRI studies and histopathology samples were reviewed to compare the MRI changes with the histopathological findings. Twelve dogs met the inclusion criteria (12 brains and three spinal cords). Imaging of the brains revealed multifocal T2-weighted/FLAIR hyperintense and T1-weighted iso-hypointense lesions, with variable contrast enhancement; areas of abnormal diffusion both in arterial and venous territories in diffusion-weighted imaging; and meningeal enhancement. On gradient echo images (GRE), the changes comprised tubular susceptibility artifacts, consistent with the "susceptibility vessel sign", and additional variably sized/shaped intraparenchymal susceptibility artifacts. Spinal cord lesions presented as fusiform T2-weighted hyperintensities with scattered susceptibility artifacts on GRE and variable parenchymal and meningeal contrast enhancement. On histopathology, subarachnoid hemorrhages and neuroparenchymal areas of edema and necrosis, with or without hemorrhage, indicating ischemic and hemorrhagic infarctions, were found. These lesions were concurrent with severely dilated meningeal and parenchymal arteries and veins plugged by neoplastic lymphocytes and fibrin. Due to the unique angiocentric distribution of IVL, ischemic and hemorrhagic infarcts of variable chronicity affecting both the arterial and venous territories associated with thrombi formation can be detected on MRI.

A patient-informed approach to predict iodinated-contrast media enhancement in the liver

ObjectiveTo devise a patient-informed time series model that predicts liver contrast enhancement, by integrating clinical data and pharmacokinetics models, and to assess its feasibility to improve enhancement consistency in contrast-enhanced liver CT scans. MethodsThe study included 1577 Chest/Abdomen/Pelvis CT scans, with 70–30% training/validation-testing split. A Gaussian function was used to approximate the early arterial, late arterial, and the portal venous phases of the contrast perfusion curve of each patient using their respective bolus tracking and diagnostic scan data. Machine learning models were built to predict the Gaussian parameters of each patient using the patient attributes (weight, height, age, sex, BMI). Pearson’s coefficient, mean absolute error, and root mean squared error were used to assess the prediction accuracy. ResultsThe integration of the pharmacokinetics model with a two-layered neural network achieved the highest prediction accuracy on the test data (R2 = 0.61), significantly exceeding the performance of the pharmacokinetics model alone (R2 = 0.11). Applying the model demonstrated that adjusting the contrast administration directed by the model may reduce clinical enhancement inconsistency by up to 40 %. ConclusionsA new model using a Gaussian function and supervised machine learning can be used to build liver parenchyma contrast enhancement prediction model. The model can have utility in clinical settings to optimize and improve consistency in contrast-enhanced liver imaging.

Modeling Patient-Informed Liver Contrast Perfusion in Contrast-enhanced Computed Tomography.

To determine the correlation between patient attributes and contrast enhancement in liver parenchyma and demonstrate the potential for patient-informed prediction and optimization of contrast enhancement in liver imaging. The study included 418 chest/abdomen/pelvis computed tomography scans, with 75% to 25% training-testing split. Two regression models were built to predict liver parenchyma contrast enhancement over time: first model (model A) utilized patient attributes (height, weight, sex, age, bolus volume, injection rate, scan times, body mass index, lean body mass) and bolus-tracking data. A second model (model B) only used the patient attributes. Pearson coefficient was used to assess predictive accuracy. Weight- and height-related features were found to be statistically significant predictors (P < 0.05), weight being the strongest. Of the 2 models, model A (r = 0.75) showed greater accuracy than model B (r = 0.42). Patient attributes can be used to build prediction model for liver parenchyma contrast enhancement. The model can have utility in optimization and improved consistency in contrast-enhanced liver imaging.

Pancreatic fistula in proximal pancreas resection: correlation of computed tomography and morphological predictors

Purpose: identification of the possibilities of computer tomography with contrast enhancement in evaluated of the degree of fibrosis and number of acinar structures in the pancreatic parenchyma at the preoperative period to predict the development of postoperative complications.Material and methods: In the department of abdominal surgery in 2016-2019, 196 pancreatoduodenal resections were performed. Retrospectively selected group of patients (49). Patients were divided into 2 groups according with the postoperative period. The postoperative period was uncomplicated in 41 (84%) cases. Сlinically significant pancreatic fistula was in 8 (16%) cases. According to preoperative computed tomography with contrast enhancement, we evaluated: the structure of the pancreas; the density of the pancreas in the native phase of the scan (HU), parenchyma accumulation coefficient; parenchyma accumulation coefficient in the venous phase; parenchyma accumulation coefficient in the excretory phase; coefficient of relative washout of contrast enhancement of parenchyma. According histological we evaluated the number of fibrosis and acinar, fat cells in the section pancreas.Results: "Soft" structure of the pancreas (r=0,747, p=0,000), parenchyma accumulation coefficient (r=0,631, p=0,000), the density of the pancreas in the native phase of the scan (r=0,568, p=0,000) positively correlated with complicated postoperative period and the number of acinar cells. Parenchyma accumulation coefficient in the excretory phase (r=0,562, p=0,000) positively correlated with the fibrosis pancreas and in the negatively correlated with the complicated postoperative period. The risk of developing pancreatic fistula is 3 times higher with values parenchyma accumulation coefficient greater than 1, sensitivity 75%, specificity 73%. The risk of developing pancreatic fistula is 3 times higher with values parenchyma accumulation coefficient in the excretory phase less than 0.45, sensitivity 75%, specificity 63%.Conclusions: computed tomography with contrast enhancement allows the structure pancreas, the number of fibrosis and acinar cell sat the preoperative period to pick out the high-risk patient group to the development of postoperative complications.

CT characteristics of primary splenic torsion in eight dogs.

Splenic torsion is a rare potentially life-threatening condition characterized by rotation of the spleen around the gastrosplenic and phrenosplenic ligaments leading to occlusion of venous drainage and arterial supply. This retrospective study describes the CT characteristics for dogs with surgically confirmed splenic torsion from 2013 to 2018 using the submissions to a large multinational teleradiology database. Eight dogs had the splenic torsion confirmed with surgery. Seven of eight cases had histology confirming congestion, hemorrhage, and necrosis, and one had concurrent myelolipoma infiltration. The CT characteristics included an enlarged (8/8), rounded (7/8), folded C-shaped spleen (8/8) with a difference of median parenchymal attenuation between pre- and postcontrast of +1.15 HU (Hounsfield units). Other common features included a mainly homogeneous parenchyma on pre- and post-contrast images (6/8), lack of subjective and objective vascular and parenchymal contrast enhancement (6/8) and free peritoneal fluid (6/8). A "whirl sign" was seen in the majority of cases (7/8) alongside a strongly hyperattenuating center (95-416HU) on the precontrast images (5/7), which has not been previously described in the veterinary literature. Gastric position was normal in all cases. More variable CT characteristics of the confirmed torsions were attributable to suspected partial torsion and myelolipomatous infiltration. Overall, primary splenic torsion confirmed with surgery showed consistent characteristics on CT.

Preliminary study of presumptive intradural-intramedullary intervertebral disc extrusion in 20 dogs.

BackgroundIntradural-intramedullary intervertebral disc extrusion (IIVDE) is a rare condition of intervertebral disc disease. However, the diagnosis of IIVDE is challenging because the prognosis and imaging characteristics are poorly characterized.ObjectivesWe aimed to describe the clinical and imaging characteristics of tentatively diagnosed IIVDE in dogs to assess the prognostic utility of neurological grade and magnetic resonance imaging (MRI) findings.MethodsTwenty dogs were included in this retrospective cohort study.ResultsNonchondrodystrophic breeds (n = 16) were more predisposed than chondrodystrophic breeds. Most dogs showed acute onset of clinical signs. Neurological examination at admission showed predominant non-ambulatory paraparesis (n = 9); paresis (n = 16) was confirmed more frequently than paralysis (n = 4). Follow-up neurological examination results were only available for 11 dogs, ten of whom showed neurological improvement and 8 showed successful outcomes at 1 month. The characteristic MRI findings include thoracic vertebra (T)2 hyperintense, T1 hypointense, intramedullary linear tracts with reduced disc volume, and cleft of the annulus fibrosus. None of the MRI measurements were significantly correlated with neurological grade at admission. Neurological grade did not differ according to the presence of parenchymal hemorrhage, parenchymal contrast enhancement, and meningeal contrast enhancement. Neurological grades at admission showed a statistical correlation with those observed at the 1-month follow-up (r = 0.814, p = 0.02).ConclusionsIIVDE is a rare form of disc extrusion commonly experienced after physical activity or trauma and most frequently affects the cranial-cervical and thoracolumbar regions of nonchondrodystrophic dog breeds. Neurological score at admission emerged as a more useful prognostic indicator than MRI findings in dogs with suspected IIVDE.

Selective middle cerebral artery occlusion in the rabbit: Technique and characterization with pathologic findings and multimodal MRI

BackgroundA reliable animal model of ischemic stroke is vital for pre-clinical evaluation of stroke therapies. We describe a reproducible middle cerebral artery (MCA) embolic occlusion in the French Lop rabbit characterized with multimodal MRI and histopathologic tissue analysis. New methodFluoroscopic-guided microcatheter placement was performed in five consecutive subjects with angiographic confirmation of MCA occlusion with autologous clot. Multimodal MRI was obtained prior to occlusion and up to six hours post after which repeat angiography confirmed sustained occlusion. The brain was harvested for histopathologic examination. ResultsAngiography confirmed successful MCA catheterization and durable (>6 h) MCA occlusion in all animals. There was increase of ADC volume over time and variable final core volume presumably related to individual variation in collateral flow. FLAIR hyperintensity indicative of cytotoxic edema and parenchymal contrast enhancement reflective of blood brain barrier disruption was observed over time. Tissue staining of the ischemic brain showed edema and structural alterations consistent with infarction. Comparison with existing methodsThis study describes a technique of selective catheterization and embolic occlusion of the MCA in the rabbit with MRI characterization of evolution of ischemia in the model. ConclusionsWe demonstrate the feasibility of a rabbit model of embolic MCA occlusion with angiographic documentation. Serial MR imaging demonstrated changes comparable to those observed in human ischemic stroke, confirmed histopathologically.

Magnetic resonance imaging features of canine gliomatosis cerebri

A retrospective, case series study was undertaken to identify magnetic resonance imaging (MRI) characteristics of gliomatosis cerebri in dogs. Fourteen dogs were included by review of histopathological records and contemporaneous MRI. On MRI, all lesions presented as ill-defined, intraaxial lesions within the left and right forebrain hemispheres with involvement of white and gray matter. Lesions presented as hyperintense areas on T2-weighted and FLAIR sequences and as hypointense or isointense areas on T1-weighted images, with mild parenchymal contrast enhancement in three dogs. Signal changes were noted in three to 10 cerebral lobes. Other most commonly affected structures were the thalamus (13), caudate nucleus (13), interthalamic adhesion (11), hypothalamus (11), callosal commissure (10), hippocampus (9), and quadrigeminal plate (8). Abnormalities within the caudal fossa were noted in 10 dogs. Solid tumor portions were identified in five dogs. The histopathological examination demonstrated in all dogs a widespread diffuse infiltration with neoplastic glial cells in white and gray matter with meningeal infiltration. Comparison between MRI and histopathology showed that all areas with signal changes on MRI corresponded to diffuse and dense infiltration with neoplastic cells. The signal intensity on T2-weighted and FLAIR images reflected the density of neoplastic cells. In all dogs, MRI underestimated lesion extent and meningeal infiltration. Involvement of the caudal fossa was not seen on MRI in three dogs. Despite this, MRI allowed identification of lesions extending into at least three cerebral lobes and therefore satisfying the criteria used for diagnosis of diffuse glioma with gliomatosis cerebri growth pattern in humans.

Subtypes of primary angiitis of the CNS identified by MRI patterns reflect the size of affected vessels

ObjectiveTo describe patterns of diagnostic findings, and identify subgroups of primary angiitis of the central nervous system (PACNS).MethodsWe retrospectively analysed 31 patients with PACNS. Cases were selected by predetermined diagnostic...

Clinical presentation, diagnostic findings and outcome in dogs diagnosed withpresumptive spinal-only meningoen-cephalomyelitis of unknown origin.

ObjectivesTo summarise clinical presentation, diagnostic findings and long‐term outcome for dogs clinically diagnosed with meningoencephalomyelitis of unknown origin affecting the spinal cord alone.MethodsMedical records were reviewed for dogs diagnosed with presumptive spinal‐only meningoencephalomyelitis of unknown origin between 2006 and 2015.Results21 dogs were included; the majority presented with an acute (43%) or chronic (52%) onset of neurological signs. Ambulatory paresis was the most common neurological presentation (67%). Neurological examination most commonly revealed a T3‐L3 myelopathy, and spinal hyperaesthesia was a common finding (71%). A spinal cord lesion was visible in 90% of cases on magnetic resonance imaging. Eighteen lesions (86%) showed parenchymal contrast enhancement and 17 lesions (81%) showed contrast enhancement of overlying meninges. All dogs were treated with immunosuppressive doses of glucocorticosteroids, sometimes combined with cytosine arabinoside. At time of data capture, 10/21 dogs (48%) had died or been euthanased because of the condition. Overall median survival time was 669 days.Clinical SignificanceMeningoencephalomyelitis of unknown origin should be considered in the differential diagnosis of dogs presenting with a progressive myelopathy. Magnetic resonance imaging features can possibly help to distinguish presumptive meningoencephalomyelitis of unknown origin from other more common spinal diseases. Overall, long‐term survival is guarded, approximately 50% of dogs will die or be euthanased despite appropriate therapy.

Direct MRI detection of impending plaque development in multiple sclerosis.

Objectives:To detect and localize MRI signal changes prior to the parenchymal contrast enhancement that classically defines the radiologic onset of the developing white matter lesion in multiple sclerosis (MS).Methods:We reviewed 308 high-resolution (≤1 mm3 voxels) MRI scans at 3T and 7T in 29 patients with active MS. The presence of pre-parenchymal enhancement abnormalities before the appearance of parenchymal enhancement was evaluated in all available scans.Results:Pre-enhancement signal changes were noted in 26 of 162 enhancing lesions (16%) as linear enhancement of the central vein and/or perivenular hyperintense signal on T2 fluid-attenuated inversion recovery or T2* images. They occur up to 2 months before focal enhancement within the parenchyma in 10% of cases.Conclusions:In some lesions, the abrupt opening of the blood-brain barrier, detected by contrast enhancement on MRI, can have directly visible antecedent MRI changes centered on the central vein. We propose that these findings might be the basis for prior reports of subtle pre-parenchymal enhancement changes in quantitative MRI indices. In line with the venulocentric model of lesion development, our findings are consistent with the centrality of early perivenular events in lesion formation in vivo.

The relationship between liver function and liver parenchymal contrast enhancement on Gd-BOPTA-enhanced MR imaging in the hepatocyte phase

ObjectivesTo investigate the relationships between liver function parameters and the degree of hepatic contrast enhancement on gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging in the hepatocyte phase, as well as to clarify whether Gd-BOPTA-enhanced MR imaging in the hepatocyte phase could be used to evaluate liver function and liver function reserve. Materials and methodsIn this study, 150 patients were classified into the following 4 groups: patients with normal liver function without liver cirrhosis (the NLF group) and cirrhosis patients with Child–Pugh Classes A, B, and C (the LCA, LCB, and LCC groups, respectively). The relative enhancement ratio (RE) of the liver parenchyma in the T1-vibe sequence was calculated from measurements of the signal intensity before (SI pre) and 90min after (SI post) the intravenous administration of Gd-BOPTA, using the following formula: RE=(SI post−SI pre)/SI pre. Statistical analysis was used to evaluate the relationship between the REs of the liver parenchyma and liver function parameters, as well as the different REs of the liver parenchyma among the NLF, LCA, LCB, and LCC groups. ResultsIncreased REs of the hepatic parenchyma showed correlations with decreased serum levels of total bilirubin (r=−0.263, P<0.01) and prothrombin time (r=−0.24, P<0.01), and elevated serum levels of albumin (r=0.328, P<0.01) for all of the patients. The REs of the liver parenchyma were significantly higher for the NLF and LCA groups compared with the LCB (P<0.001) and LCC (P<0.001) groups, respectively. ConclusionsThe intracellular uptake of Gd-BOPTA decreased with impaired liver function. Measurement of the degree of the liver parenchymal contrast enhancement on GD-BOPTA-enhanced MR imaging in the hepatocyte phase might be a non-invasive technique for assessing liver function and liver function reserve.

Early Blood Brain Barrier Changes in Acute Ischemic Stroke: A Sequential MRI Study.

We sought to identify MRI factors associated with BBB changes at the acute stage of ischemic stroke. We analyzed BBB changes on admission and within 3 hours after the first scan. BBB changes was defined as the presence of leptomeningeal and parenchymal contrast enhancement on T1-weighted imaging. Tmax , CBV, and DWI lesion volume were assessed on baseline MRI. Clinical and MRI factors associated with BBB changes were assessed by univariate and multivariate logistic regressions analyses. Forty-four patients were included. BBB changes on baseline MRI was observed in 2 of 44 patients (3%). BBB disruption on H3-MRI was present in 19 of 44 patients (43%). Hemodynamic status and baseline ischemic core size were not different between patients with or without BBB changes. BBB alteration on H3 MRI was strongly associated with FLAIR MRI sequence positivity, 16/19 patients (83%) P = .001. BBB changes are exceptional during the first 3 hours after stroke onset. Delayed BBB alteration was associated with FLAIR positivity mainly reflecting vasogenic edema.

English

The Editor, Sir, Haemangiomas were first described by Payne in 1869 (1). In the literature, their coexistence with various diseases of the female genital tract has been reported (2–5). Our case differs in that a postmenopausal woman had a mucinous cystadenoma in one ovary and an incidentally discovered cavernous haemangioma with focal positivity for progesterone receptor (PR) in the other ovary. An 81-year old woman had right lower quadrant pain. Transabdominal sonography revealed a 10 cm right ovarian cystic and septated mass. No left adnexal lesion was reported. There was no sign of ascites. The serum cancer antigen (CA) 125 level of the patient was 144.9 IU/mL (ref 0–35), serum Ca-19–9 level was 24.9 IU/mL (ref 0–39). Magnetic resonance images revealed a well circumscribed, slightly lobulated contoured, T1 SE hypo-, T2 SE hyperintense, multilocular cystic lesion in the right half of the pelvis (Figs. 1A–D). The left ovary measured 34 × 14 × 35 mm with slight spiculations and was isointense to myometrium on T1 SE and T2 SE weighted sequences (Fig. 1A–B). With injection of contrast material, slightly heterogeneous parenchymal contrast enhancement less than the myometrium was observed (Fig. 1A–D). Fig. 1 Magnetic resonance imaging shows right ovarian lesion to be a multilocular cyst; (A) homogeneous hypo-signal intensity on T1-weighted images and (B) high signal intensity on T2-weighted images. Left ovary has slight spiculations isointense on T1 and T2 ... The result of the right ovary was reported as a mucinous cystadenoma on frozen section (Fig. 2). Fig. 2 Histologically, the right ovarian cyst was lined by mucinous epithelium (HE × 20). On the cut surface of the left ovary (4 × 3 × 1.5 cm in size), a haemorrhagic nodular lesion, 2.5 × 1.5 cm in size, was noted. Microscopic sections revealed dilated, thin-walled vascular structures, variable in diameter, and the walls of which were comprised a single layer of endothelial cells not showing atypia (Fig. 3). Fig. 3 Near the ovarian stroma, dilated thin walled vessels were lined by a single layer of endothelial cells, containing red blood cells in their lumen (HE × 4). Based on macroscopic, morphologic and immunohistochemical findings of factor 8 (FVIII), CD 34, smooth muscle actin (SMA) expression, the case was reported as ovarian cavernous haemangioma. Oestrogen receptor (ER) was negative; however, some endothelial cells were positive for PR (Fig. 4). Fig. 4 Immunohistochemical findings; (A): strong positivity for factor 8 and (B): CD 34 in cells lining the cavernous vessels; (C): immunoreactivity for smooth muscle action in the walls of the vessels; (D): focal positivity for progesterone receptor in the ... Ovarian tumour coexisting with an incidental haemangioma has been previously reported (2–5). A review of the literature reveals that the present case was different in terms of capillary haemangioma in a postmenopausal patient with positive PR receptor (Table). Table Clinicopathologic features of patients with ovarian haemangioma and coexistent lesions reported in the literature The ovarian hilus had a histological appearance that is often confused with haemangiomas due to its rich vascular structure. A mass composed of large vascular channels, nodular formation and minimal amounts of stroma might be helpful to distinguish haemangiomas from dilated, hilar vascular structures (6). In the present case, the mass was composed of dilated blood vessels with little stroma and this helped to establish the diagnosis of haemangioma. The pathogenesis of stromal luteinization remains complicated and it is still controversial whether luteinized stromal cells promote the development of haemangiomas (7). Some authors have studied immunohistochemical expression of ER and PR, and they have found different results (3, 7). In the present case, luteinization was not observed. Moreover, endothelial cells were negative for ER, but some endothelial cells were positive for PR. Radiological appearance for the left ovary was inconclusive; the presence of an enlarged ovary (8) and visualization of contrast uptake on preoperative magnetic resonance imaging in a postmenopausal woman supported rich vascular structure. In postmenopausal women, enlarged ovaries with or without contralateral lesions should be evaluated cautiously.

Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy

To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM). A total of 459 female volunteers (mean age 49.1 ± 12.5 years) underwent T1-weighted 3D MRM 1-5 min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n = 69) and HT (n = 24) on CE was studied using random effects models. Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P < 0.001). CE decreased significantly with the use of OC (P = 0.01), while HT had negligible effects (P = 0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P < 0.0001), but was similar in OC users and non-OC users (P = 0.61) as well as HT users and non-HT users (P = 0.77). Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use. Breast parenchymal enhancement at MR mammography is stronger in premenopausal than postmenopausal women. The prevalence of strong enhancing non-mass-like areas is greater before menopause. Such enhancing non-mass-like areas may impair lesion detection in premenopausal women. Breast parenchymal enhancement is only marginally affected by hormone use. Discontinuation of hormone use before MR mammography may be unnecessary.

High concentration (400 mgI/mL) versus low concentration (320 mgI/mL) iodinated contrast media in multi detector computed tomography of the liver: A randomized, single centre, non-inferiority study

ObjectivesTo compare vascular and parenchymal contrast enhancement in multidetector computed tomography of the liver using two contrast media with different iodine concentration (Iodixanol 320mgI/mL and Iomeprol 400mgI/mL) and similar viscosity, using fixed total iodine volume (40gI) and iodine delivery rate (1.6gI/s). Methods110 patients were prospectively randomized into two groups. Group A received 125mL of Iodixanol 320 and group B 100mL of Iomeprol 400.Attenuation values were measured at the level of the aorta, portal vein and liver parenchyma on unenhanced, arterial, portal and equilibrium phases. A non inferiority test was performed on the differences between the two groups. An independent reader evaluated image quality. ResultsThe equivalence of the two CM was demonstrated in all measurements. Higher, but not statistically significant, attenuation values were obtained with Iomeprol 400 in the aorta during the arterial phase (305.3HU versus 288.4HU; P=0.32) and with Iodixanol 320 in the liver parenchyma, during both portal (59.8HU versus 65.5HU; P=0.78) and equilibrium (40.4HU versus 41.8HU; P=0.55) phases. ConclusionsIodixanol 320 and Iomeprol 400 injected at the same iodine delivery rate (1.6gI/s) and total iodine load (40gI) did not provide statistically significant differences in liver parenchymal and vascular contrast enhancement.