Lumbosacral Transitional Vertebrae amongst the Individuals Undergoing Magnetic Resonance Imaging of the Whole Spine in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

INTRODUCTION: Lumbosacral transitional vertebrae is a common congenital anomalous condition of the spine. Recent advances in magnetic resonance imaging have made it possible to acquire images of the whole spine. This study aimed to find out the prevalence of lumbosacral transitional vertebrae amongst the individuals undergoing magnetic resonance imaging of the whole spine in a tertiary care hospital. METHODS: A descriptive cross-sectional study was conducted in 750 patients of all age groups who underwent magnetic resonance imaging of the whole spine in the Department of Radiodiagnosis and Imaging, Kathmandu University School of Medical Sciences from 7th November, 2019 to 6th November, 2020. Convenience sampling technique was used. Ethical approval was taken from the Institutional Review Committee (Reference number 207/19). Data was analysed using Statistical Package for Social Sciences version 22. Point estimate at 95% Confidence Interval was calculated along with frequency and percentage. RESULTS: Lumbosacral transitional vertebra was seen in 98 (13.10%) (95% Confidence Interval= 10.61-15.51) of the total 750 individuals. Out of the 98 patients who had lumbosacral transitional vertebra, 31 (4.10%) had lumbarization of S1 vertebra and 67 (8.94%) had sacralization of L5 vertebra. CONCLUSIONS: Prevalence of lumbosacral transitional vertebrae amongst the individuals undergoing magnetic resonance imaging of the whole spine in our hospital was similar to other study done in similar settings. Lumbosacral transitional vertebrae are a common congenital anomalous condition of the spine that is identified incidentally. Enumeration of vertebrae from the first cervical vertebra using whole spine magnetic resonance imaging can confirm the presence of the lumbosacral transitional vertebrae with much accuracy.

MRI contrast agents: Classification and application (Review).

Magnetic resonance imaging (MRI) contrast agents are categorised according to the following specific features: chemical composition including the presence or absence of metal atoms, route of administration, magnetic properties, effect on the magnetic resonance image, biodistribution and imaging applications. The majority of these agents are either paramagnetic ion complexes or superparamagnetic magnetite particles and contain lanthanide elements such as gadolinium (Gd3+) or transition metal manganese (Mn2+). These elements shorten the T1 or T2 relaxation time, thereby causing increased signal intensity on T1-weighted images or reduced signal intensity on T2-weighted images. Most paramagnetic contrast agents are positive agents. These agents shorten the T1, so the enhanced parts appear bright on T1-weighted images. Dysprosium, superparamagnetic agents and ferromagnetic agents are negative contrast agents. The enhanced parts appear darker on T2-weighted images. MRI contrast agents incorporating chelating agents reduces storage in the human body, enhances excretion and reduces toxicity. MRI contrast agents may be administered orally or intravenously. According to biodistribution and applications, MRI contrast agents may be categorised into three types: extracellular fluid, blood pool and target/organ-specific agents. A number of contrast agents have been developed to selectively distinguish liver pathologies. Some agents are also capable of targeting other organs, inflammation as well as specific tumors.

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging: A potential utility for the evaluation of regional liver function impairment following transcatheter arterial chemoembolization.

The present study aimed to evaluate regional liver function impairment following transcatheter arterial chemoembolization (TACE), assessed by magnetic resonance imaging (MRI) enhanced by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Additionally, this study evaluated the associations between signal intensity and various clinical factors. A prospective study was conducted between March 2012 and May 2013 with a total of 35 patients. Gd-EOB-DTPA-enhanced MRI was performed 3-5 days after TACE therapy. The signal to noise ratio (SNR) was subsequently calculated for healthy liver tissue regions and peritumoral regions, prior to and 20 min after Gd-EOB-DTPA administration. The correlation between clinical factors and relative SNR was assessed using Pearson's correlation coefficient or Spearman's rank correlation coefficient. Prior to Gd-EOB-DTPA administration, the SNR values showed no significant difference (t=1.341, P=0.191) in healthy liver tissue regions (50.53±15.99; range, 11.25-83.46) compared with peritumoral regions (49.81±15.85; range, 12.34-81.53). On measuring at 20 min following Gd-EOB-DTPA administration, the SNR in healthy liver tissue regions (82.55±33.33; range, 31.45-153.02) was significantly higher (t=3.732, P<0.001) compared with that in peritumoral regions (75.77±27.41; range, 31.42-144.49). The relative SNR in peritumoral regions correlated only with the quantity of iodized oil used during TACE therapy (r=0.528, P=0.003); the age, gender, diameter and blood supply of the tumor, or Child-Pugh class of the patient did not correlate with relative SNR. Gd-EOB-DTPA-enhanced MRI may be an effective way to evaluate regional liver function impairment following TACE therapy.

Magnetic resonance imaging of intracranial hemangiopericytoma and correlation with pathological findings.

The present study aimed to evaluate the radiological and pathological features of intracranial hemangiopericytoma, and improve the understanding of this tumor. A retrospective analysis of radiological and pathological features of five cases of intracranial hemangiopericytoma was conducted between 2006 and 2012 in the Second Xiangya Hospital of Central South University. A total of five cases (three males and two females; aged 37-60 years) were enrolled. Magnetic resonance imaging revealed that the lesions were lobulated with iso-intensity T1-weighted image signals and slightly long T2-weighted image signals. Cystic degeneration, necrosis and flow void were observed. The case with the lesion located under the tentorium cerebelli exhibited compression of the fourth ventricle with lateral ventricle dilatation hydrocephalus. In all cases, the solid section of the lesion was markedly enhanced following injection of the contrast agent, and intratumoral vessels were observed. No case exhibited the dural tail sign. Immunohistochemical examination revealed positive expression of cluster of differentiation 34(CD34), vimentin and CD99, and negative expression of epithelial membrane antigen, S100 and glial fibrillary acidic protein. Proliferating cell nuclear antigen Ki-67 immunohistochemical staining revealed that <5% of cells expressed Ki-67 in two cases and 5-10% of cells expressed Ki-67 in three cases. In conclusion, intracranial hemangiopericytoma exhibits certain distinctive characteristics in radiological examination, allowing for improved diagnosis. However, pathological examination is required for confirmation.