T1-weighted Hyperintense Research Articles

The Importance of Flexion MRI in Hirayama Disease with Special Reference to Laminodural Space Measurements

Hirayama disease is a benign focal amyotrophy of the distal upper limbs involving C7, C8, and T1 segmental myotomes with sparing of the brachioradialis and proximal muscles of the upper limb innervated by C5-6 myotomes. The objective of the present study was to study the utility of MR imaging in young patients presenting with weakness and wasting of the distal upper extremity and to evaluate the importance of the laminodural space during flexion cervical MR imaging. This was a prospective cross-sectional study conducted from January 2014 to July 2017 in a tertiary care center from Northeast India. Forty-five patients with clinically definite Hirayama disease underwent electrophysiologic evaluation followed by MR imaging of the cervical spine. The mean age at recruitment was 22.8 ± 5.5 years. Forty patients (88.9%) had unilateral and 5 (11.1%) had bilateral upper extremity involvement. Cervical cord T2-weighted hyperintensities were demonstrated in 16 patients (35.6%), of which 15 (33.3%) had anterior horn cell hyperintensities. Flexion MR imaging showed loss of the posterior dural attachment, forward shifting of the posterior dural sac with postcontrast enhancement, and prominent posterior epidural venous plexus in all patients. The laminodural space at maximum forward shifting of the posterior dural sac ranged from 3 to 9.8 mm, with a mean distance of 5.99 mm (95% confidence interval, 5.42-6.57 mm). Flexion cervical MR imaging is a very useful investigation in diagnosing Hirayama disease. The increase in the laminodural space and the presence of cervical cord flattening during flexion are essential for diagnosis.

Orbital Schwannoma: Radiographic and Histopathologic Correlation in 15 Cases

To evaluate the relationship between radiographic and histopathologic features of orbital schwannoma. Retrospective review of 15 patients with orbital schwannoma managed at an ocular oncology service. The mean patient age at the time of presentation was 42 years old (median 40, range 15-64 years). The orbital schwannoma was found incidentally (n = 2) or with symptoms of proptosis (n = 2), blurred vision (n = 3), pain (n = 3), eyelid swelling (n = 2), diplopia (n = 2), or headache (n = 1). The mean duration of symptoms was 15 months (median, 9; range 1-60 months). The tumor occupied the superior (n = 11) or inferior (n = 4) orbit. Antero-posterior tumor location involved the anterior (n = 2), middle (n = 3), posterior (n = 4), or entire (n = 6) orbit. MRI was performed in 12 patients (80%) and CT was the only form of imaging in 3 patients (20%). The T1-weighted MRI (n = 11) showed the mass as isointense (n = 10) or hyperintense (n = 1) to the extraocular muscles). On T2-weighted MRI (n = 10), the mass demonstrated hyperintensity (n = 9) or hypointensity (n = 1). Histopathologic assessment demonstrated Antoni A (n = 12) and Antoni B (n = 12) patterns. Antoni A pattern correlated with hyperintensity on T1-weighted MRI and hypointensity on T2-weighted MRI. Antoni B pattern correlated with hypointensity on T1-weighted MRI and hyperintensity on T2-weighted MRI. As Antoni B approached >50% of the solid mass (n = 8), both T1- and T2-weighted MRI images were more likely to be heterogeneous (n = 7, 88% and n = 6, 75%, respectively). Orbital schwannomas are nearly always benign, well-encapsulated slowly progressive tumors. Due to the biphasic distribution of Antoni A and Antoni B pattern, the appearance on MRI has a variable degree of heterogeneity. Antoni A pattern correlated with hyperintensity and Antoni B pattern correlated with hypointensity on T1-weighted MRI.

MRI features of primary hepatic lymphoma.

Our retrospective study sought to describe the spectrum of magnetic resonance imaging (MRI) features of primary hepatic lymphoma (PHL) by analyzing its morphological aspects, signal intensity before and after contrast agent (CA) administration, and diffusion-weighted imaging (DwI) with the apparent diffusion coefficient (ADC) values. A retrospective analysis was conducted on 25 patients with pathologically proven PHL who underwent MRI between January 2011 and December 2016. For the evaluation of the ADC, we used a control group of 87 patients (22 with hepatocellular carcinoma, 15 with cholangiocellular carcinoma, 23 with liver metastasis, 22 with focal nodular hyperplasia, and 5 with adenoma). Two radiologists evaluated the morphological features, the signal intensity before and after CA administration, and the DwI. The sensitivity and specificity of the ADC values in distinguishing the PHL lesions from other hepatic lesions were calculated by analyzing the receiver operating characteristic (ROC) curves. Twenty-one patients had non-Hodgkin's lymphoma (18 had diffuse large B-cell lymphoma and three had mucosa-associated lymphoid tissue) and four had Hodgkin's lymphoma (nodular sclerosis). The PHL had a variable morphologic distribution (17 focal mass and eight multiple nodules) and mainly an insinuative growth (24/25). Usually, PHL was usually hypointense on the T1-weighted images (23/25) and hyperintense on the T2-weighted images (21/25); non-specific dynamic enhancement was found after CA administration, but in the hepatobiliary phase, PHL is mainly hypointense (92%). All PHLs showed a signal restriction in the DwI. The sensitivity and specificity in the differential diagnosis between PHL and the other malignant lesions were respectively 81.7% and 100%, with applying an ADC cut-off value of 0.918×10-3mm2/s. Although PHL is a rare disease and biopsy is still required, an MRI could be indicative. In our series, PHL showed an insinuative growth, hypointense signal in the hepatobiliary phase, signal restriction in the DwI, and an ADC value lower than that of the other hepatic lesions analyzed.

Review of hepatobiliary contrast agents: Current applications and challenges.

Review of hepatobiliary contrast agents: Current applications and challenges.

Silent cerebral infarct definitions and full-scale IQ loss in children with sickle cell anemia.

To evaluate whether application of the adult definition of silent cerebral infarct (SCI) (T2-weighted hyperintensity ≥5 mm with corresponding T1-weighted hypointensity on MRI) is associated with full-scale IQ (FSIQ) loss in children with sickle cell anemia (SCA), and if so, whether this loss is greater than that of the reference pediatric definition of SCI (T2-weighted hyperintensity ≥3 mm in children on MRI; change in FSIQ -5.2 points; p = 0.017; 95% confidence interval [CI] -9.48 to -0.93). Among children with SCA screened for SCI in the Silent Cerebral Infarct Transfusion trial, ages 5-14 years, a total of 150 participants (107 with SCIs and 43 without SCIs) were administered the Wechsler Abbreviated Scale of Intelligence. A multivariable linear regression was used to model FSIQ in this population, with varying definitions of SCI independently substituted for the SCI covariate. The adult definition of SCI applied to 27% of the pediatric participants with SCIs and was not associated with a statistically significant change in FSIQ (unstandardized coefficient -3.9 points; p = 0.114; 95% CI -8.75 to 0.95), with predicted mean FSIQ of 92.1 and 96.0, respectively, for those with and without the adult definition of SCI. The adult definition of SCI may be too restrictive and was not associated with significant FSIQ decline in children with SCA. Based on these findings, we find no utility in applying the adult definition of SCI to children with SCA and recommend maintaining the current pediatric definition of SCI in this population.

Imaging Features of Morel-Lavallée Lesions.

Objectives:To review the imaging characteristics of Morel-Lavallée lesions with both ultrasound and magnetic resonance imaging (MRI).Materials and Methods:We retrospectively analyzed 31 patients (mean age = 46 years), diagnosed with a Morel-Lavallée lesion, on ultrasound (n = 15) or MRI (n = 16). On ultrasound the echogenicity, internal septations, hyperechoic fat globules, compressibility and Doppler signal were evaluated. On MRI, T1- and T2-signal intensity, capsule presence, internal septations, enhancement, mass-effect and fluid-fluid levels were assessed. The MR images were classified according to the classification of Mellado and Bencardino.Results:Most of the lesions were situated peritrochanteric, around the knee or the lower leg. The majority of the lesions had a heterogeneous hypoechoic appearance with septations and intralesional fat globules. On MRI, most of the collections were hypointense on T1-weighted images and hyperintense on T2-weighted images. Half of the collections were encapsulated, and most collections demonstrated septations. The collections were classified as seroma (n = 10), subacute hematoma (n = 2) and chronic organizing hematoma (n = 5).Conclusion:Ultrasound is the imaging method of choice to diagnose Morel-Lavallée lesions. MRI can be of use in selected cases (extension in different compartments, large collections, superinfection). Characteristic imaging features include a fusiform fluid collection between the subcutaneous fat and the underlying fascia with internal septations and fat globules. On MRI, six types of ML lesion can be differentiated, with the seroma, the subacute hematoma, and the chronic organizing hematoma being the most frequently observed lesions.

Gadolinium deposition in the paediatric brain: T1-weighted hyperintensity within the dentate nucleus following repeated gadolinium-based contrast agent administration

To determine whether repeated gadolinium-based contrast agent administration (GBCA) in children is associated with the development of increased T1-weighted signal intensity within the cerebellar dentate nucleus. With institutional review board approval for this The Health Insurance Portability and Accountability Act-compliant retrospective study, a cohort of 41 patients under the age of 18 years who underwent at least four contrast-enhanced magnetic resonance imaging (MR) examinations of the brain from 2005 to 2015 were identified. For each examination, both dentate nuclei were manually contoured, and the mean dentate nucleus-to-pons signal intensity (DN-P SI) ratio was calculated. The DN-P SI ratios from the last to first MRI examination were compared, and the correlation between DN-P SI ratio and cumulative gadolinium dose was calculated using a linear mixed effect model to control for potentially confounding variables. For the 41 patients in the cohort, there was a significant increase in the mean DN-P SI ratio from the first MRI to the last MRI examination (1.05 versus 1.11, p=0.004). After controlling for patient diagnosis, history of chemotherapy or radiation, sex, and age, there was a significant positive association between DN-P SI ratio and cumulative gadolinium dose (coefficient=0.401, p=0.032). Repeated GBCA administration in children is associated with increased T1-weighted signal intensity within the dentate nucleus.

Civilian Occult Orbitocranial Penetrating Injury Presenting with Cerebral Abscess in Elderly Patient

AbstractOrbital penetrating injuries are uncommon and occur following accidental entry of objects through orbit. The authors report an interesting case of right frontal abscess resulting from orbitocranial penetrating injury due to accidental penetration of wooden stick into the right eye, which remained undiagnosed. A 70-year-man presented with complaints of headache and vomiting for few days. His computed tomographic (CT) scan of the brain revealed peripheral rim-enhancing cystic lesion in the right frontal lobe with perilesional edema, mass effect, and midline shift. Orbital CT scan revealed hyperdense lesion just lateral to medial orbital wall. Magnetic resonance imaging of the brain showed cystic peripheral rim-enhancing lesion that was homogenous hypointense on T1-weighted images and homogenous hyperintense on T2-weighted images. The patient underwent right frontal craniotomy. Pus was drained out, and abscess wall was excised. Foreign bodies protruding through fractured orbital roof were found and removed. He made good clinical recovery. He has received intravenous antibiotics for 2 weeks followed by 4 weeks of oral antibiotics. He had no visual symptoms. The authors report the case, review the literature, and highlight need for imaging in every case of orbital penetrating injury to prevent the life-threatening cerebral parenchymal complications.

Supplementary Diagnostic Landmarks of Left Ventricular Non-Compaction on Magnetic Resonance Imaging.

PurposeDiagnostic criteria for left ventricular non-compaction (LVNC) are still a matter of dispute. The aim of our present study was to test the diagnostic value of two novel diagnostic cardiac magnetic resonance (CMR) parameters: proof of non-compact (NC) myocardium blood flow using T2 sequences and changes in geometry of the left ventricle.Materials and MethodsThe study included cases with LVNC and controls, from a data base formed in a period of 3.5 years (n=1890 exams), in which CMR protocol included T2 sequences. Measurement of perpendicular maximal and minimal end diastolic dimensions in the region with NC myocardium from short axis plane was recorded, and calculated as a ratio (MaxMinEDDR), while flow through trabecula was proven by intracavital T2-weighted hyperintensity (ICT2HI). LVNC diagnosis met the following three criteria: thickening of compact (C) layer, NC:C>2.3:1 and NC>20%LV.ResultsThe study included 200 patients; 71 with LVNC (35.5%; i.e., 3.76% of CMRs) and 129 (64.5%) controls. MaxMinEDDR in patients with LVNC was significantly different from that in controls (1.17±0.08 vs. 1.06±0.04, respectively; p<0.001). MaxMinEDDR >1.10 had sensitivity of 91.6% [95% confidence intervals (CI) 82.5–96.8], specificity of 85.3% (95% CI 78.0–90.0), and area under curve (AUC) 0.919 (95% CI 0.872–0.953; p<0.001) for LVNC. Existence of ICT2HI had sensitivity of 100.0% (95% CI 94.9–100.0), specificity of 91.5% (95% CI 85.3–95.7), and AUC 0.957 (95% CI 0.919–0.981; p<0.001) for LVNC.ConclusionTwo additional diagnostic parameters for LVNC were identified in this study. ICT2HI and geometric eccentricity of the ventricle both had relatively high sensitivity and specificity for diagnosing LVNC.

Imaging features of rosette-forming glioneuronal tumours

To describe the imaging features of rosette-forming glioneuronal tumours (RGNTs) to enable accurate diagnosis. Image data and clinical findings for seven patients with histopathologically confirmed RGNTs were studied comprehensively. Six neoplasms were located near the midline and all were relatively well circumscribed. Most lesions were hypointense on T1-weighted images and hyperintense on T2-weighted images. Furthermore, five tumours were hypointense on diffusion-weighted imaging (DWI). On computed tomography (CT), the solid tumour portions showed hypo-attenuation compared with brain parenchyma. Obvious calcification was found in two cases, and hydrocephalus was seen in five. Cerebrospinal fluid (CSF) dissemination and multiple satellite lesions were not observed in these cases. Haemorrhage was found in one case. The "green bell pepper sign" was present in five cases on gadolinium-enhanced magnetic resonance imaging (MRI). Each of the patients accepted surgical treatment, and no recurrences occurred during follow-up. RGNTs are very rare mixed glioneuronal tumours and mostly affect young people. They are usually hypointense on T1-weighted images and DWI, hyperintense on T2-weighted images, and hypo-attenuated on CT images. The "green bell pepper sign" after gadolinium enhancement, intratumoural haemorrhage, CSF dissemination, and multiple satellite lesions provide additional clues to the correct diagnosis. A relatively well-demarcated tumour with these features and a midline location should raise suspicion of an RGNT.

Renal clear cell carcinoma metastasis to the breast ten years after nephrectomy: a case report and literature review

BackgroundRenal cell carcinoma most commonly metastasizes to the lungs, skeleton or liver. Metastatic renal cell carcinoma to the breast is very rare, especially for clear cell carcinoma, and few cases regarding this condition have been reported.Case PresentationThe case we presented was a 68-year-old Chinese female with metastatic renal clear cell carcinoma of the left breast 10 years after a nephrectomy. Identification of the metastatic renal clear cell carcinoma in the breast required multiple breast imaging modalities. Imaging showed a single, ovary-shaped, well-defined hypo-echoic mass, with abundant blood flow on ultrasound images. The mass was enhanced early on MRI, and it was hypointense on a T1-weighted image and hyperintense on a fat-saturated T2-weighted image. Following surgical excision of the tumor, a routine immunohistochemistry antibody panel on the tumor cells revealed negative staining for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (Her-2). Strong positive staining for the cluster of differentiation 10 (CD10) and vimentin was present.ConclusionThis case is unusual because of the site of metastatic progression. It is important for physicians to be aware of this progression so early diagnoses can be made, and appropriate therapeutic planning can be initiated.

Lymphadenitis associated with cat-scratch disease simulating a neoplasm: Imaging findings with histopathological associations.

The lymphadenitis associated with cat-scratch disease (CSD) is often confused with neoplasms by a number of radiologists and clinicians, and consequently, unnecessary invasive procedures or surgeries are performed. In the present study, the contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) findings of 10 patients (6 men and 4 women) with clinically and pathologically confirmed lymphadenitis associated with CSD were retrospectively analyzed (CT in 3 patients, MRI in 6 patients, and CT and MRI in 1 patient) at The Second Affiliated Hospital of Zhejiang University School of Medicine (Hangzhou, China) between January 2007 and November 2014. As a result, 17 enlarged lymph nodes were identified in 10 cases. The 5 nodes identified by CT scan exhibited relatively inhomogeneous isodensity to muscle, with patchy low density in the center. All 14 nodes identified by MRI scan exhibited homogeneous or heterogeneous isointensity to muscle or slightly increased intensity compared with that of muscle on T1-weighted images (T1WI), and homogeneous or heterogeneous hyperintensity on fat-suppressed T2WI. Following enhancement, all 17 enlarged lymph nodes associated with CSD demonstrated the following 3 different enhancement patterns: Moderate homogeneous enhancement (n=8), which was associated with histologically identified early disease stage; marked heterogeneous enhancement with no enhancement of the necrotic areas (n=4), and heterogeneous enhancement with progressively ‘spoke-wheel-like’ (defined as radiating enhancement from the center) enhancement of the patchy low-density area (n=1), which was associated with histologically identified intermediate disease stage; and astral low-density/hypointensity with marked enhancement (n=2) or a ‘rose flower’ sign (n=2), which was associated with histologically identified late disease stage. We hypothesized that the CT and MRI results of lymphadenitis in CSD may be associated with the pathological features. It may be suggested that the diagnosis of CSD may be formed when considering the characteristic CT and MRI features of astral low-density/hypointensity with marked enhancement or a ‘rose flower’ sign (defined as marginal petaloid enhancement) in the late disease stage, or the MRI results of homogeneous, moderate enhancement in the early disease stage, or the CT/MRI data of heterogeneous enhancement with non-enhancing area in the center in the intermediate disease stage, in solitary or multiple enlarged lymph nodes associated with general subcutaneous edema in the vicinity of the nodes on CT/MRI and with a history of cat exposure.

Venous Ectasia Mimicking Intraparotid Mass: MRI Findings

Background: Venous ectasias of the parotid region are rarely lesions that mimic mass of the parotid gland. The detection of venous ectasia has significantly increased with the increased use of cross-sectional imaging in the last two decades, especially in asymptomatic patient who scanned for other reasons. We report MRI findings and appropriate radiological investigation of case with venous ectasia in the parotid gland imitated intraparotid mass. Case Report: A 58-year old woman underwent cranial MRI due to the history of headache. Incidentally, was detected well-defined nodular lesion with regular contours in the parotid gland, hypointense on T1-weighted scan and homogeneous hyperintense on T2-weighted scan similar with solid mass. Lesion completely and strongly enhanced after contrast administration. Axial T2-weighted images demonstrates incomplet phase-encoding artefact in the lesion indicating flow. The gray scala and Doppler ultrasonography rule out solid mass and confirm diagnosis of venouse ectasia. Therefore, fine needle aspiration was not performed. Since the absence seriously discomfort of patient advanced invasive procedure as venography or surgery treatment were not done. Conclusion: To know MRI findings of intraparotid venous ectasia important for accurately diagnosis and differential diagnosis of intraparotid masses and can prevent unnecessary invasive procedures. Gray scale and Doppler US combined with clinical examination are sufficient for correct diagnosis.

Subhepatic mass occurrence after using oxidized and regenerated cellulose polymer in laparoscopic cholecystectomy: a case series

Background: Oxidized regenerated cellulose (ORC) is a bioabsorbable surgical hemostatic. We present the first prospective case series of circumscribed mass occurrence after using ORC in laparoscopic cholecystectomy.Methods: Tabotamp (Ethicon, Inc., Somerville, NJ) in the form of tightly woven knitted patches was used to achieve hemostasis in 83 patients submitted to LC.Results: A subhepatic mass was detected in five patients and radiologic characteristics were described. Abdominal contrast enhanced CT showed a heterogeneous soft-tissue mass. NMR was performed in one patient and showed a T2-weighted hyperintense mass.Conclusion: ORC retention after surgery is not uncommon at long-term follow-up. The radiologic characteristics of a suspected ORC retention mass can differentiate it from a neoplastic lesion, so that surgery can be avoided.

Diphtheric encephalitis and brain neuroimaging features

We report a rare case of paediatric diphtheria complicated with encephalitis. A 6-year-old boy who did not receive his scheduled diptheria–tetanus–pertusis vaccination presented with one episode of generalised convulsive seizure. His illness was preceded by a 3day history of fever associated with enlarged exudative tonsils with a pseudomembrane. He was commenced on intravenous penicillin and oral erythromycin. However, he developed progressive encephalopathy with focal neurological deficit which required intubation on day 5 of illness. Throat swab polymerase chain reaction for diphtheria toxin A and B were positive and diphtheria antitoxin was given. Magnetic resonance imaging (MRI) of brain showed T2-weighted hyperintensities over the anterior cingulate gyri, insular cortex and cerebellum. This is the first reported MRI finding of diphtheric encephalitis. Our report highlights the importance of neuroimaging in diagnosing diphtheric encephalitis particularly in cases with unremarkable cerebrospinal findings.

Treatment-Related Noncontiguous Radiologic Changes in Children With Diffuse Intrinsic Pontine Glioma Treated With Expanded Irradiation Fields and Antiangiogenic Therapy

We previously reported the cases of 3 children with diffuse intrinsic pontine glioma (DIPG) in whom noncontiguous treatment-related abnormalities (NCTRAs) developed in the brain after expanded-field radiation therapy (RT). To investigate the occurrence and putative mechanism of NCTRAs, we reviewed brain magnetic resonance imaging studies of patients with DIPG treated in 2 consecutive phase I clinical trials (trials 1 and 2). The 55 children included in these trials received small-molecule inhibitors: vandetanib in trial 1 (n=32; mean age 6.4years) and vandetanib and dasatinib in trial 2 (n=23; mean age 5.8years). The patients also received conformal 3-dimensional RT (cumulative dose 54Gy). For patients enrolled in trial 1, the clinical target volume (CTV) was expanded by 1cm from the gross tumor volume. In trial 2, the expansion to form the CTV was 2 to 3cm. A review of imaging studies was performed from the initial diagnosis through the end of progression-free survival. The imaging findings were grouped into 5 categories according to the presence, absence, location, extent, and putative mechanism of NCTRAs. Statistical analysis was performed to evaluate the association between covariates and NCTRA, cohort characterization, and survival comparisons. Overall survival was similar in both studies (P=.74). NCTRAs developed in 9 patients (39%) treated in trial 2 but in none treated in trial 1. The NCTRAs included T2-weighted hyperintensities with (n=3; radiation necrosis) or without (n=5) contrast uptake, supratentorial leukoencephalopathy (n=2), and ischemic stroke (n=1). All NCTRAs, except for 1, occurred within the CTV. Compared with nonaffected patients, patients with a NCTRA were younger (P=.003) and had had larger relative brain volumes exposed to doses >20Gy. The imaging features of NCTRAs suggest that their development is secondary to synergistic steno-occlusive vascular effects induced by the combination of RT, an expanded CTV, potent antiangiogenic therapy, young age, and, in 1 case, a genetic predisposition.

Analysis of heterogeneity in T2-weighted MR images can differentiate pseudoprogression from progression in glioblastoma.

PurposeTo develop an image analysis technique that distinguishes pseudoprogression from true progression by analyzing tumour heterogeneity in T2-weighted images using topological descriptors of image heterogeneity called Minkowski functionals (MFs).MethodsUsing a retrospective patient cohort (n = 50), and blinded to treatment response outcome, unsupervised feature estimation was performed to investigate MFs for the presence of outliers, potential confounders, and sensitivity to treatment response. The progression and pseudoprogression groups were then unblinded and supervised feature selection was performed using MFs, size and signal intensity features. A support vector machine model was obtained and evaluated using a prospective test cohort.ResultsThe model gave a classification accuracy, using a combination of MFs and size features, of more than 85% in both retrospective and prospective datasets. A different feature selection method (Random Forest) and classifier (Lasso) gave the same results. Although not apparent to the reporting radiologist, the T2-weighted hyperintensity phenotype of those patients with progression was heterogeneous, large and frond-like when compared to those with pseudoprogression.ConclusionAnalysis of heterogeneity, in T2-weighted MR images, which are acquired routinely in the clinic, has the potential to detect an earlier treatment response allowing an early change in treatment strategy. Prospective validation of this technique in larger datasets is required.

Imaging features of primary renal lymphoma.

Background Cases of primary renal lymphoma (PRL) are quite rare and are often mistaken for renal cell carcinoma. Purpose To determine the multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) characteristics of PRL. Materials and Methods Twenty-three patients with PRL were identified by CT and MRI, and their tumor characteristics were assessed. Results Tumors exhibited single or multifocal nodules (n = 19) and diffuse renal enlargement (n = 4). Twenty-two tumors exhibited an infiltrative appearance. There was no evidence of calcification in any of the cases. Twenty-one tumors displaced or wrapped around abdominal vessels rather than encasing them. Enlarged retroperitoneal nodes were observed in three cases. Neither extension into the venous system nor distant metastasis was found. Tumor enhancement was of low attenuation compared with that of normal renal cortex and medulla ( P < 0.05). PRL was isointense on T1-weighted imaging, slightly hypointense on T2-weighted imaging and hyperintense on diffusion-weighted imaging. Twenty-two patients exhibited biopsy-confirmed PRN. There were four, 12, and seven cases of low-grade, intermediate-grade, and high-grade tumors, respectively. Patient were followed up over 16 to 166 months. Six patients died within three years and five patients died within five years. Conclusion Infiltrative appearance and tumor displacement or extension around abdominal vessels rather than vessel encasement are common findings on CT or MRI imaging and may suggest a diagnosis of PRL.

Hepatic segmental atrophy and nodular elastosis: imaging features.

To evaluate the imaging features of hepatic segmental atrophy and nodular elastosis. In this Institutional review board (IRB)-approved, HIPAA-compliant study, we reviewed imaging features in six cases of histologically confirmed hepatic segmental atrophy (HSA) and nodular elastosis (NE). Retrospective review of ultrasound (US) in 2 patients, computed tomography (CT) in 5 patients, magnetic resonance imaging (MRI) in 4 patients, and positron emission tomography (PET) in 2 patients was performed. Location, size, and attenuation/density/signal intensity of these lesions were evaluated. Clinical presentation and coexistent conditions were also recorded. All six patients were females. Mean age of presentation was 58.3years (range 37-80). A single HSA and NE lesion in each patient was found. The mean size of the lesion was 18 mm (range: 3mm to 36mm). Most lesions were detected incidentally (5/6). On contrast-enhanced single-phase (portal venous) CT, most lesions were hypodense (4/5) and one lesion was hyperdense to fatty liver parenchyma. On MRI, the lesions were iso- to hyperintense on T2-weighted images, T1 hypointense, and hyperintense on diffusion-weighted images (DWI). Three lesions were hypointense on arterial, portal venous, and delayed phases. One lesion occurring in fatty liver appeared hyperintense on all three phases. Gd-EOB-DTPA-enhanced images were available in 2 patients and lesions were hypointense on the 20-min hepatobiliary phase. On PET, two lesions were isometabolic to the background hepatic parenchyma. On ultrasound, one lesion appeared hypoechoic and another lesion isoechoic to hepatic parenchyma. Hepatic segmental atrophy and nodular elastosis is an uncommon benign lesion and can simulate metastases due to variable imaging features. Lack of FDG uptake on PET/CT may be a clue to the benign nature of the lesion and may suggest the possibility of HSA and NE.

Muscle Microdialysis to Investigate Inflammatory Biomarkers in Facioscapulohumeral Muscular Dystrophy.

Recent progresses in the understanding of facioscapulohumeral muscular dystrophy (FSHD) genetics opened the way to the development of targeted therapies. However, knowledge about pathophysiology of muscle damage is still limited and there is increasing need to identify biomarkers of disease activity in the perspective of clinical trial readiness.We analyzed inflammatory mediators in the interstitial fluid of muscles with different MRI signal in FSHD patients, comparing muscles displaying early lesions on short-tau inversion recovery (STIR) sequences with normal ones. Patients with one T1-weighted normal and STIR hyperintense (STIR+) and contralateral T1-weighted and STIR normal (STIR-) lower limb muscle were asked to enter the study. Twelve consecutive patients, five controls, and one non-penetrant gene carrier underwent prolonged muscle microdialysis with high cut-off membranes. Microdialysates were analyzed using xMAP technology with a wide panel for cytokines, chemokines, and growth factors. A small number of inflammatory mediators were dysregulated in STIR+ versus STIR- and control muscles: CXCL13, upregulated in STIR+ muscles compared with controls (p<0.01); CXCL5, downregulated in STIR+ compared with STIR- muscles (p<0.05); and G-CSF, downregulated in STIR+ muscles compared with controls (p<0.05). CXCL13 was also upregulated in the STIR+ muscles compared with the contralateral STIR- muscles of the same patient (p<0.01).These results support the evidence of a selective inflammatory process taking place in STIR+ FSHD muscles. The application of microdialysis could provide insights on novel mechanisms involved in muscle damage in FSHD and in other myopathies. Further studies are needed to validate these investigated molecules as tissue and circulating biomarkers.