Basal ganglia hyperintensity on T1-weighted MRI in Rendu-Osler-Weber disease

The purpose of this study was to evaluate possible central nervous system (CNS) involvement in Rendu-Osler-Weber (ROW) disease in magnetic resonance imaging (MRI). Three patients with symptomatic ROW disease underwent brain MRI. Brain MRI depicted in all three of them increased signal intensity on T1-weighted images involving the globus pallidus and cerebral crura bilaterally. Laboratory studies of the two men showed iron deficiency anemia, while all three of them had normal liver function tests and increased manganese blood concentration. Gastroscopy and colonoscopy revealed a gastric and a cecal arteriovenous malformation (AVM) in the first one, while pulmonary and hepatic computed tomography (CT) angiography did not detect any intrahepatic shunts. Liver ultrasound in the second one revealed dilatation of intrahepatic artery branches consistent with intrahepatic shunts, while it was normal in the third patient. Chest radiographs were normal in all three patients. Pallidal T1 hyperintensity on T1-weighted imaging may be a biomarker of manganese overload in ROW disease.     

Gadoxetic acid-enhanced T1-weighted MR cholangiography in primary sclerosing cholangitis

Purpose:

To investigate the value of gadoxetic acid‐enhanced three‐dimensional T1‐weighted MR cholangiography (T1w‐MRC) in comparison to three‐dimensional T2‐weighted MR cholangiopancreaticography (T2w‐MRCP) in patients with primary sclerosing cholangitis (PSC).

Materials and Methods:

Thirty‐four MR exams in 29 patients (46.0 ± 16.1 years; 19 men, 10 women) scanned within a 14‐month period were retrospectively included. Two abdominal radiologists independently evaluated image quality regarding image contrast, image quality degradation due to artifacts, and visualization quality of ducts. The order of biliary tree branches that were visualized and reader preference toward each method were recorded. Helpfulness of T1w‐MRC was scored in consensus. Confirmatory endoscopic retrograde cholangiopancreaticography (ERCP) performed within 3 months of the MR examination was available in 8 patients.

Results:

Image quality of T1w‐MRC and T2w‐MRCP was graded good to excellent in all cases. There were advantages for both T1w‐MRC (functional information, less degradation due to artifacts) and T2w‐MRCP (higher order of visualized branches, better branch depiction). Both readers showed preference for T2w‐MRCP; however, both readers found gadoxetic acid–enhanced T1w‐MRC helpful in the majority of cases.

Conclusion:

Gadoxetic acid‐enhanced T1w‐MRC is complementary to, but should not replace, T2w‐MRCP. T1w‐MRC is a useful adjunct to T2w‐MRCP for morphologic evaluation and provides additional diagnostic information. J. Magn. Reson. Imaging 2012;36:632–640. © 2012 Wiley Periodicals, Inc.     

7 Tesla imaging of cerebral radiation necrosis after arteriovenous malformations treatment using amide proton transfer (APT) imaging

Arteriovenous malformations (AVM) can be treated with stereotactic radiosurgery. An infrequent, but important complication of this treatment is radionecrosis, which can be detected by MRI. However, the imaging characteristics of necrosis are unspecific in conventional MRI. Here, we report a case of necrosis after radiotherapy of an AVM to illustrate the potential of 7 Tesla MRI including amide proton transfer (APT) for necrosis imaging.     

Radiological findings of primary localized amyloidosis of the ureter

Localized amyloidosis is a rare condition, especially that involving the ureter. Because of its rarity and the difficulty in differentiating this condition from urothelial carcinoma by intravenous urography and computed tomography, nephroureterectomy has often been performed unnecessarily for this disease. The authors encountered two cases of this disease, both of which showed a negative urine cytology, no obvious mass effect, and a hypointensity on T2-weighted imaging. Because these findings are very rare in urothelial carcinoma, ureteroscopy-guided biopsy was performed, which yielded the diagnosis of amyloidosis. The patients were then treated and followed up at our institute. Primary localized amyloidosis of the ureter should be considered when evaluating ureteric lesions visualized as hypointensities on T2-weighted images that do not show an obvious mass effect, which could help in the avoidance of unnecessary surgery.     

Thyroid hormone concentrations and inhibition of thyroid stimulating hormone secretion in euthyroid subjects with autonomous thyroid nodules

Abstract. Sixty-four euthyroid patients with autonomous thyroid nodules and normal thyroxine (T₄) concentrations and tri-iodothyronine resin uptake have been studied. The serum tri-iodothyronine (T₃) concentration of the patients was 2.24 (±0.67) ng/ml, significantly higher than in a group of fifty-seven euthyroid control subjects (1.58 ± 0.30 ng/ml). When no extranodular tissue was visible on the basal thyroid scan, the T₃ was 2.31 (±0.63) ng/ml, significantly higher than in patients with some extranodular uptake on the basal scan (1.91 ± 0.42 ng/ml). There was no significant difference in the serum T₄ concentrations of the patients (7.37 ± 2.10 μg/100 ml) compared to the control group (6.88 ± 1.89 μg/100 ml). The T₄ concentrations were not correlated with total or partial inhibition of the extranodular tissue. The thyroid hormone concentrations were not directly correlated to the size of the nodule assessed by scan imaging. The thyroid stimulating hormone (TSH) concentration of the patients (1.52 ± 0.38 μU/ml) was significantly lower than in normals (2.49 ± 0.96 μU/ml). No significant difference was found in the TSH concentrations of patients with partial or total inhibition of extranodular tissue irrespective of the T₃ concentration. A thyrotrophin releasing hormone stimulation test in twelve patients did not increase the serum TSH, irrespectively of the T₃ concentration.
These data show the high frequency of elevated serum T₃ concentrations despite normal serum T₄ concentration in euthyroid patients with autonomous thyroid nodules. They confirm that inhibition of TSH secretion can occur when thyroid hormone concentrations are in the normal range.     

Monocytic Myeloid-Derived Suppressor Cells Underpin Resistance to Adoptive T Cell Therapy in Nasopharyngeal Carcinoma

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Clinica chimica acta notice board

In order to study the three regulator enzymes of glycolysis, hexokinase (HK). phosphofructokinase (PFK) and pyruvate kinase (PK), in relation to lymphocyte maturation, lymphocytes of different origin were investigated. Lymphocytes from bone marrow, thymus, cord blood, adult peripheral blood and mitogen-stimulated lymphocytes were investigated. The enzyme activities were determined and the isozyme patterns were studied by means of electrophoresis, kinetic measurements and immunoprecipitation.The young lymphocytes from bone marrow and the mitogen-stimulated lymphocytes could be distinguished from the other lymphocytes by a higher residual HK activity in the presence of the inhibitor glucose-1,6-diphosphate.Peripheral blood T lymphocytes differed from non-T lymphocytes in the PK isozymes distribution. All the cells contained PK type K4 and the hybrid K₃M. In T cells a smaller amount of the K isozyme was seen than in non-T cells. The PK residual activity in the presence of alanine was significantly higher in peripheral blood T cells than in non-T cells.Thymocytes are characterised by a larger amount of PFK M-subunits than peripheral blood T and non-T lymphocytes. The stimulation of PFK by the positive effector glucose-1,6-diphosphate was higher in thymocytes than in the peripheral blood lymphocytes.     

CD28-independent,TRAF2-dependent Costimulation of Resting T Cells by 4-1BB Ligand

4-1BB ligand (4-1BBL) is a member of the tumor necrosis factor (TNF) family expressed on activated antigen-presenting cells. Its receptor, 4-1BB, is a member of the TNF receptor family expressed on activated CD4 and CD8 T cells. We have produced a soluble form of 4-1BBL using the baculovirus expression system. When coimmobilized on plastic with anti-CD3, soluble 4-1BBL induces interleukin (IL)-2 production by resting CD28⁺ or CD28⁻ T cells, indicating that 4-1BBL can function independently of other cell surface molecules, including CD28, in costimulation of resting T cell activation. At low concentrations of anti-CD3, 4-1BBL is inferior to anti-CD28 in T cell activation. However, when 4-1BB ligand is provided together with strong TCR signals, then 4-1BBL and anti-CD28 are equally potent in stimulation of IL-2 production by resting T cells. We find that TNF receptor–associated factor (TRAF)1 or TRAF2 associate with a glutathione S-transferase–4-1BB cytoplasmic domain fusion protein in vitro. In T cells, we find that association of TRAF1 and TRAF2 with 4-1BB requires 4-1BB cross-linking. In support of a functional role for TRAF2 in 4-1BB signaling, we find that resting T cells isolated from TRAF2-deficient mice or from mice expressing a dominant negative form of TRAF2 fail to augment IL-2 production in response to soluble 4-1BBL. Thus 4-1BB, via the TRAF2 molecule, can provide CD28-independent costimulatory signals to resting T cells.