Early prediction of urinary tract infection with urinary neutrophil gelatinase associated lipocalin

Neutrophil gelatinase associated lipocalin (NGAL) is a protein identified in human neutrophil granules. The aim of the study was to assess whether urine level of NGAL (uNGAL) could represent a novel, reliable marker of urinary tract infection (UTI) and to determine the optimal cutoff level for uNGAL to predict UTI in children. Sixty patients with symptomatic UTI and 29 healthy controls were enrolled the study. Urine NGAL was measured by enzyme-linked immunosorbent assay. A dimercaptosuccinic acid (DMSA) radionuclide scan was performed within 7 days in the patients with UTI in an attempt to distinguish pyelonephritis from cystitis. Mean uNGAL level was significantly higher in the UTI group than in the controls (91.02 ng/ml vs 14.29 ng/ml, p = 0.0001) and using a cutoff 20 ng/ml for uNGAL for diagnosis of UTI, sensitivity, and specificity were 97% and 76%, respectively [area under the curve (AUC): 0.979]. Mean uNGAL/creatinine ratio (uNGAL/Cr) was also significantly higher in the UTI group [201.81 ng/mg creatinine (Cr) vs 18.08 ng/mg Cr; p = 0.0001], and using a cutoff 30 ng/mg Cr for uNGAL/Cr for diagnosis of UTI, sensitivity and specificity were 98% and 76%, respectively (AUC: 0.992). In conclusion, both uNGAL and uNGAL/Cr can be used as a novel, sensitive marker for early prediction of UTI in the absence of acute kidney injury and chronic kidney disease, and the optimal cutoff value for prediction of UTI is lower than the values determined for acute kidney injury. Further investigations with larger patient groups are required to confirm our results.     

Can we use CT pulmonary angiography as an alternative to echocardiography in determining right ventricular dysfunction and its severity in patients with acute pulmonary thromboembolism?

Purpose

Our aim was to investigate the role of computed tomography pulmonary angiography (CTPA) in the diagnosis of right ventricular dysfunction (RVD) and massive pulmonary thromboembolism (PTE).

Materials and methods

We retrospectively involved a total of 61 patients. In CTPAs, pulmonary arterial obstruction index (PAOI), right ventricular/left ventricular diameter ratio (RV/LV), and superior vena cava (SVC) diameters were calculated, followed by echocardiography (ECHO), and clinical results were evaluated based on the reports available.

Results

CTPA findings that included PAOI, RV/LV ratio, and SVC diameter were, respectively, 54.9 ± 22.7 %, 1.58 ± 0.51, and 20.3 ± 0.2 mm in patients with RVD on ECHO, whereas corresponding values were, respectively, 37.8 ± 24.2 %, 1.32 ± 0.47, and 18.4 ± 3.3 mm in those without RVD (respectively, p = 0.006, p = 0.038, and p = 0.026). PAOI was 63.3 ± 22.0 % in patients among whom massive PTE was detected and 43.1 ± 23.9 % in the group without massive PTE (p = 0.01). As for mortality; given an RV/LV ratio >1.0, this ratio had 100 % sensitivity and 35.6 % specificity, whereas given a PAOI of ≥50 %, sensitivity and specificity were 83.3 % and 57.8 %, respectively.

Conclusion

We concluded that in the patients with PTE, PAOI ≥50 % and RV/LV >1.0 in CTPA could be helpful to demonstrate RVD.     

Diagnostic value of color Doppler ultrasonography and MDCT angiography in complications of hemodialysis fistulas and grafts

Purpose

The purpose of the study was to compare the diagnostic value of color Doppler ultrasonography (CDUS) and multidetector computed tomography (MDCT) angiography against that of digital subtraction angiography (DSA) or surgery in the evaluation of failing hemodialysis arteriovenous fistulas (AVFs).

Materials and methods

CDUS and MDCT angiography were performed with 41 patients (24 men, 17 women; mean age 55.8) with dysfunctional hemodialysis fistulas. The presence of stenosis, thrombosis, aneurysm, pseudoaneurysm and seroma were recorded. The sensitivity, specificity, positive and negative predictive values (PPV and NPV) and accuracy of CDUS and MDCT angiography were calculated both individually and in combination for the detection of vascular segments with significant stenosis, thrombosis, aneurysms, pseudoaneurysms, perivascular complications and stenosis subgroups.

Results

Sixty-four segmental lesions were diagnosed by DSA or surgery. Sensitivity, specificity, PPV, NPV and accuracy of CDUS for all vascular tree lesions were 85.9%, 99.2%, 96.4%, 96.7% and 94.5%, respectively. For MDCT angiography the figures were 96.8%, 99.6%, 98.4%, 99.2% and 98.5%, respectively. When both tests were used in combination, sensitivity, specificity, PPV, NPV and accuracy for all vascular tree lesions rose to 100%.

Conclusion

Combined use of MDCT and CDUS for diagnosis of AVF dysfunctions is of equivalent value to surgery or DSA, a gold standard technique.     

Initial experience of 3 tesla apparent diffusion coefficient values in differentiating benign and malignant thyroid nodules

Purpose:

To evaluate the role of diffusion‐weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner.

Materials and Methods:

Twenty‐eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses.

Results:

The mean ADC value of the benign nodules was 1548 ± 353.4 (×10^?6 mm²/s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10^?6 mm²/s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10^?6 mm²/s (958–1689 × 10^?6 mm²/s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10^?6 mm²/s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5–98.3) sensitivity and 100% (81.3–100.0) specificity.

Conclusion:

This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules. J. Magn. Reson. Imaging 2013;37:1077–1082. © 2012 Wiley Periodicals, Inc.

     

Evaluation of Tc-99m(V) DMSA for imaging inflammatory lesions: An experimental study

The present study evaluated^99mTc(V) DMSA as an agent for the visualization of inflammatory lesions in comparison to^99mTc(HI) DMSA and^99mTc-HIG. All three radiopharmaceuticals were prepared with commercial kits.^99mTc(V) DMSA was prepared at neutral pH by the addition of first bicarbonate and then pertechnetate to the kit contents. The labeling efficiency was 99% as determined by ITLC. Abscesses were induced by i.m. injection of 50 μl turpentine into the right thighs of 36 Swiss albino mice. Six days later 3.7 MBq of each radiopharmaceutical was i.v. administered to 12 mice. The mice were sacrificed at 1,3,6 and 24 h later. Scintigrams were obtained with a gamma camera. The abscesses were better visualized on scintigrams with^99mTc(V) DMSA compared to^99mTc(III) DMSA, starting at 1 h. The animals were dissected and the organs were removed, weighed and the radioactivity determined with a gamma counter. The abscess to other tissue ratios were higher with^99mTc(V) DMSA than the other radiopharmaceuticals. The max. abscess/muscle ratios were 9.46 ± 3.20 (24 h), 4.19 ± 1.39 (6 h) and 5.98 ± 1.17 (24 h) and max. abscess/blood ratios were 6.22 ± 1.41, 4.09 ± 0.84 and 0.914 ± 0.351 all at 24 h for^99mTc(V) DMSA,^99mTc(III) DMSA and^99mTc-HIG, respectively. Experimental arthritis was produced in 6 New Zealand white rabbits by intra-articular injection of ovalbumin. Four days later 37 MBq of^99mTc(V) DMSA and^99mTc-HIG were each i.v. administered to 3 rabbits. Scintigrams obtained at 1, 3, 6, and 24 h clearly demonstrated arthritic joints. ROFs over arthritic joints were compared to contralateral normal joints (A/C). The max. A/C ratios were 2.10 ± 0.31 (3 h) and 2.92 ± 0.99 (24 h) for^99mTc(V) DMSA and^99mTc-HIG, respectively. Our results indicated the feasibility of imaging inflammatory lesions with^99mTc(V) DMSA.     

MR fluoroscopy-guided transthoracic fine-needle aspiration biopsy: feasibility

The purpose of this study was to evaluate the feasibility of using an open-configuration magnetic resonance (MR) imaging system with MR fluoroscopic guidance to perform percutaneous transthoracic fine-needle aspiration biopsy in patients with lung masses. Percutaneous transthoracic aspiration biopsies were performed with MR fluoroscopic guidance in 14 patients. The masses were 2-7 cm in diameter (mean, 4.1 cm). The needle was positioned by using a free-hand technique with MR fluoroscopic guidance. The needle tip reached the target lesion, and biopsy was performed. Analysis of the biopsy specimens facilitated a specific diagnosis in all patients. Pneumothorax was noted in two patients (14%) with chronic obstructive pulmonary disease. Study results showed that the described MR fluoroscopy-guided transthoracic biopsy technique can be used safely and successfully for lung masses. MR fluoroscopy can be used to reach the target lesion easily and accurately.     

Changes in vascularity of cartilage endplate of degenerated intervertebral discs in response to melatonin administration in rats

We carried out an experimental investigation of cartilage endplate vascularity of degenerated intervertebral discs produced by exogenous melatonin (MEL) treatment. Adult Swiss albino rats were divided into three groups: control, operated degeneration, and MEL treatment. There were five rats in each group and, using a posterior approach, cuts were made parallel to the endplates in the posterior annulus fibrosus in five consecutive intervertebral discs between the 5th and 10th vertebral segments of the rats' tails. At 8 weeks, five of these animals were treated with exogenous MEL (s.c. injection of 30 μg/100 g body weight daily for 4 weeks). In each experimental group, one animal was examined using CT scanner to study the density of the cartilage endplate of the disc. To evaluate the bone growth and vascularity of the cartilage endplate region, the animals were killed for subsequent histopathological evaluation. We found that the vascular channel counts and percentage areas from animals treated with MEL were significantly lower than from the operated degeneration animals. Accordingly, the density histogram in the MEL group showed a spike profile for both the vertebral body and the cartilage endplate, indicating an increase in the amount of higher density tissues in these regions. Our results demonstrate that the use of MEL reduces the cartilage endplate vascularity of degenerated intervertebral discs, suggesting that it may have an osteoinductive effect on bone formation. Further studies are needed to characterize fully the relevance of our findings for the treatment of disorders such as postmenopausal osteoporosis.