Comparison of Glomerular Filtration Rate Measurement Methods between Radionuclide in vivo Scintigraphic Gates’ and Plasma Sampling

AIM: To correlate between the radionuclide in vitro plasma sampling method (using single and dual blood samples) and Gates’ GFR measurement using Tc-99m diethylene triamine penta-acetic acid (Tc-99m DTPA) renal scintigraphy (in vivo method). METHODS: This study included 40 renal donors (group 1) and 40 patients with obstructive uropathy (group 2). Group 1 included 22 males and 18 females with an age range from 22 to 65 years, while group 2 included 24 males and 16 females with age range 27 to 64 years. Both groups subjected to renal Scintigraphy after administration of 5 mCi 99m-Tc DTPA, GFR was calculated using Gates’ method (in vivo method), then plasma sampling was acquired at 60 mins and 180 mins post-injection of the tracer, samples were counted in well counter and GFR was calculated using in vitro technique either using single plasma sample (SPSM 60 mins) or dual sample (DPSM 60 & 180 min). Additionally, GFR was measured by estimated equations based on serum creatinine. RESULTS: In group 1, the mean GFR using in vivo Gates’ method was 115.7 ± 29 ml/min, while using the SPSM was 100.1 ± 16.1 ml/min, and the DPSM was 100.3 ± 20.1 ml/min. In group 2, mean GFR using in vivo method was 74.1 ± 14.5 ml/min, while using in vitro SPSM it was 77.5 ± 24.9 ml/min and DPSM was 76.8 ± 24.8 ml/min. There was no significant difference between mean GFR values using in vivo and in vitro methods (single or dual samples) in group 1 and 2 (p > 0.05). There is high significant correlation between SPSM and DPSM in groups 1 and 2 (r = 0.90, r = 0.91 respectively), moderate significant correlation was found between in vivo Gates’ method and in vitro SPSM in group 1 and 2 (r = 0.46 and 0.57 respectively) and moderate correlation was evident between in vivo and in vitro DPSM in both groups (r = 0.42 and 0.68 respectively). By using the DPSM as the reference standard significant high correlation was found with SPSM and significant-high moderate correlation with in vivo Gates’ scintigraphic method. Conclusion: In vitro plasma sampling considered as a reliable, accurate |method for GFR calculation yet it considered relatively complex, both single and dual sample in vitro techniques showed a very high correlation, and hence SPSM can replace DPSM. CONCLUSION: Renal scintigraphy and GFR estimation using Gates’ in vivo method is considered inaccurate, yet given its simplicity in performance it can still be used if corrected GFR is standardised for Egyptian population-based on studies with large numbers of patients from multiple centres

Renal duplex doppler ultrasonography in patients with recurrent urinary tract infection

Renal hemodynamics were studied using duplex Doppler ultrasonography in forty (33 females and 7 males; mean age: 12.1 ± 5.3 years) normotensive patients with recurrent urinary tract infection and with no evidence of obstructive uropathy and age matched control group of 24 healthy children and adolescents. Resistivity index (RI) and pulsatility index (PI) in both arcuate (AA) and interlobar (IA) arteries were significantly higher in patients as compared to controls (P= 0.001, 0.01 respectively). Diastolic/systolic ratio (D/S) at the same levels of renal vasculature (AA and IA) was significantly lower in study patients as compared to their controls (P= 0.01, 0.001 respectively). Moreover, scarred renal units had higher RI and PI values as well as lower D/S ratio as compared to non scarred units (p= 0.01, 0.001, 0.001 respectively).). In conclusion, intra renal vascular resistivity is significantly increased in recurrent UTI patients particularly in those sus-taining renal scarring. Further follow up studies are recommended to determine if duplex assess-ment of intrarenal vasculature could be useful as an ancillary diagnostic and/or prognostic technique in the evaluation and follow up of recurrent UTI

Diagnostic & prognostic impact of 18F-NaF PET/CT versus 99mTc-MDP bone scan in detection of bone metastases: Initial and follow up assessment

Purpose: To assess the role of 18F-NaF PET/CT in the detection of metastatic bone disease compared to 99mTc-MDP bone scan (+/-SPECT/CT). Methods: 64 adult patients with locally advanced primary tumor were enrolled in this study. All patients underwent pretherapy 18F-NaF PET/CT and 99mTc-MDP bone scan. Results: Among the 64 patients 18F-NaF PET/CT revealed positive bone metastases in 26 patients, only 19 of them have positive results in 99mTc-MDP bone scan, while the remaining 7 patients were falsely negative in 99mTc-MDP bone scan. On the other hand 18F-NaF PET/CT diagnosed 38 patients free of osseous metastases, 5 patients of them were falsely diagnosed having osseous metastases by 99mTc-MDP bone scan. None of patient has positive bone metastases by 99mTc-MDP & negative 18F-NaF PET/CT for bone metastases in our study group. The overall results revealed significant higher sensitivity for 18F-NaF PET/CT (100%) compared to 99mTc-MDP bone scan (73.08%) (P<0.05) as well as higher specificity for 18F-NaF PET/CT (100%) compared to 99mTc-MDP bone scan (86.8%) (P<0.05). Conclusion: 18F-NaF PET/CT is a high-quality skeletal imaging with convenient diagnostic performance in either lytic or sclerotic bone lesions surpassing that of Tc99m MDP, with lower equivocal interpretations

Could Myocardial 99mTc-MIBI Washout rate be the savior in patients with Ischemic Cardiomyopathy in limited resources countries?!

Background: proper assessment of patients with ischemic cardiomyopathy is a key determinant for management with other investigations, improving the patient’s quality of life and reducing future cardiac events. This study was conducted to evaluate the value of myocardial MIBI washout rate using delayed resting myocardial perfusion imaging in patients with ischemic cardiomyopathy in limited resources countries. Patients and Methods: this prospective study included 86 patients (64 males (74.4%) &    22 females (25.6%) with ejection fraction less than 35%. The mean age was 56.7 ± 9.4 years, all patients underwent ECG-gated single-photon emission computed tomography (SPECT) technetium-99m MIBI myocardial perfusion imaging (99mTc MIBI).&nbsp