Hounsfield Unit Data Research Articles

The Comparative Evaluation of Hospitalized Elderly Patients with COVID-19 from the Onset of the Disease to Recovery and Death in Iran

Background & Objectives: Numerous studies have shown that the risk of death is higher in elderly patients with COVID-19. In Iran, due to the growth of the elderly population and the prevalence of underlying diseases, it is necessary to pay attention to this age group of patients. In this study, clinical, radiological, PCR, and laboratory data of elderly patients with COVID-19 were collected and analyzed in two groups of recovered and dead patients.Materials & Methods: This is a retrospective study of 196 consecutive elderly patients with COVID-19 hospitalized from March 21, 2020, to April 3, 2020, and their follow-up until April 23, 2021. Clinical characteristics, laboratory results, PCR, chest CT scans and Hounsfield Unit data were collected and analyzed in two groups of recovered and dead patients. Obtained Data were analyzed using SPSSv22.0 and MATLAB-R2017 software.Results: The results showed that there were no specific symptoms to distinguish the death group from the recovery group. Significant differences were observed between the two groups for red blood cell counts, hemoglobin, MCHC and MCV levels, bilirubin, aminotransferase levels, CRP, white blood cells, serum BNU, creatinine and PT coagulation index. The concentrations of VBG (HCO3) and VBG (PCO2) in the deceased patients suggest compensated respiratory alkalosis. CT sensitivity is 100% for patients in advanced and severe stages of the disease.Conclusion: The patients in the death group had more underlying diseases than the recovered group. COVID-19 patients are more likely to die when they have both diabetes and cardiovascular disease.

Redefining the Limits of Flexible Ureterorenoscopy

Flexible ureterorenoscopic holmium laser lithotripsy allows retrograde management of renal calculi that previously needed alternative strategies. This study assesses the influences of stone size, density, and location on treatment outcomes from a large series. Data concerning patients who presented for ureterorenoscopic laser lithotripsy between May 2005 and September 2008 were retrospectively analyzed. Single-treatment success was defined as satisfactory visual clearance of stone bulk, radiopacities less than 2 mm on noncontrast CT, and no further treatment. One hundred and eighty-five patients had 236 treatments (median=51 years; range 18-83 years). Overall success rate was 90.7%. The mean ± standard deviation (SD) stone size was 13.1 ± 8.5 mm with significant differences between the successful (11.6 ± 6.7 mm) and nonsuccessful (27.8 ± 10.0 mm) outcome groups (P<0.0001, unpaired t test). Of treatments for stone size ≤ 20 mm, 96.5% were successful. Of 36 patients with stone size >20 mm, 21 (58.3%) were stone free after one treatment and 31 (86.1%) after two treatments. Hounsfield unit data did not differ significantly between the groups (mean ± SD 858 ± 388 vs 1115 ± 643, P=0.146, unpaired t test). Stone locations were: Renal pelvis, caliceal diverticula, and upper pole, midpolar, and lower pole in 61, 9, 24, 27, and 115 cases with success rates of 85%, 100%, 83%, 93%, and 94%, respectively (P=0.899, chi-square test). Clearance rates of >90% can be achieved for stones up to 20 mm with flexible ureterorenoscopy and holmium laser lithotripsy, but with larger stones, the stone-free rates reduce significantly. Therefore, 20 mm should be regarded as the upper limit of stone size that can be cleared in a single procedure. Stone density and location do not influence outcome.