Subcapsular beaded appearance of the kidney on contrast-enhanced CT: indicative of dilated subcapsular lymphatics?

AIM: To assess the renal subcapsular beaded appearance (RSBA) seen on contrast-enhanced multidetector-row computed tomography (CT). MATERIALS AND METHODS: In total, 2,020 consecutive MDCT examinations with both non-contrast-enhanced and contrast-enhanced procedures were assessed retrospectively to identify interconnecting lobular structures in the renal subcapsular area that created a beaded appearance on contrast-enhanced CT. Positive cases were investigated for CT attenuation on unenhanced CT and were then compared with fat-suppressed heavily T2-weighted magnetic resonance imaging (MRI) and follow-up CT if available. The degree of RSBA occupying the renal periphery was evaluated using a three-grade system (Grade I: <25%, Grade II: 25-75%, Grade III: >75% of surface involvement). Only Grades II and III were defined as a positive RSBA. Possible associated findings such as hypertension, chronic kidney disease (CKD), renal atrophy, and liver cirrhosis were also evaluated. RESULTS: The RSBA was positive in 33 (1.63%) of patients and was more commonly found in patients in their seventies (39.4%) with male predominance (male:female ratio, 7:3; p=0.005). Of 33 positive cases, five showed low CT attenuation predominance, 25 showed iso-attenuation, and three showed high attenuation on unenhanced CT. In five positive cases, T2-weighted MRI showed markedly high signal intensity, suggesting prominent capsular lymphatic structures. The RSBA was associated with hypertension (p=0.001) and CKD (p=0.011). CONCLUSION: The MRI findings suggested that the RSBA probably reflects dilated subcapsular lymphatics. Knowledge of this CT finding is clinically important because it might be misinterpreted as other pathological findings.

Thoracic duct and cisterna chyli: evaluation with multidetector row CT.

OBJECTIVES: The aim of this study was to evaluate the normal anatomy of the thoracic duct and cisterna chyli obtained by axial and multiplanar reformation (MPR) images of 1 mm slice thickness using multidetector row CT (MDCT). METHODS: We evaluated the ability of MDCT to examine the normal anatomy of the thoracic duct and cisterna chyli. The axial and coronal images of thoracoabdominal MDCT images obtained in 50 patients (20 females and 30 males; mean age, 63.5 years; range, 32-81 years) were reviewed between January and October 2005. We excluded patients with malignant neoplasms, inflammation or vascular diseases (e.g. aortic aneurysm, aortic dissection) and those with a history of thoracoabdominal surgery. The thoracic duct was divided into three anatomical sections: the upper, middle and lower. We evaluated the degree of visualisation and the maximum size of the thoracic duct. We also evaluated the degree of visualisation, maximum size, configuration and location of the cisterna chyli. RESULTS: Visualisation of the thoracic duct and cisterna chyli was almost 100% on axial and coronal images. The lower section of the thoracic duct was most clearly visualised among the three sections. There was little difference in the maximum size of the thoracic duct among the three sections. The cisterna chyli was most frequently located at the Th12 or L1 level, and the most common type was the "straight thin tube type". CONCLUSION: Axial and MPR images of 1 mm slice thickness using MDCT can clearly depict the thoracic duct and cisterna chyli.

A sensitive, direct colorimetric assay of serum iron using the chromogen, nitro-PAPS.

A direct colorimetric method is presented for the determination of serum iron in 0.1-ml sized samples, using a new, water-soluble, reagent, 2-(5-Nitro-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol Na salt (epsilon 585 nm = 9.4 X 10(4) l/mol per cm). Interference of copper and zinc in sera can be eliminated entirely by forming copper- and zinc-thioglycollate complexes immediately upon the dissociation of the protein-bound iron, copper and zinc by thioglycollate and sodium dodecyl sulfate. The serum blank was minimized by the use of sodium dodecyl sulfate as a protein denaturant. Within-run and between-run precision (CV) were in the range of 0.7-2.9% and 1.1-3.6%, respectively, depending on the serum iron content. A good correlation (r = 0.995) was obtained between this method and the reference method proposed by the International Committee for Standardization in Hematology.