Differentiation of dementia with Lewy bodies, Alzheimer's disease and vascular dementia by cardiac 131I-meta-iodobenzylguanidine (MIBG) uptake (preliminary report).

OBJECTIVE: Differentiation of dementia with Lewy bodies (DLB), vascular dementia (VAD), and Alzheimer's disease (AD) is difficult in clinical practice. Several new techniques have been used for differentiation of various types of dementia. Among these techniques 123I-meta-iodobenzylguanidine (MIBG) uptake was reported to have benefit in distinguishing DLB from AD. The authors study the role of MIBG as a tool for differentiation of DLB, AD and VAD. METHOD: Patients with dementia were recruited to the study by DSMIIIR criteria. Diagnosis of each dementia type was made by standard clinical criteria. Brain imagings and 131I-MIBG uptake were performed in all the studied patients. RESULTS: Five DLB, 3 AD and 3 VAD patients were clinically diagnosed. The heart/mediastinum (H/M) ratio in 4 out of 5 in DLB was significantly lower than H/M ratio in patients with AD and VAD. AD patients had the highest uptake of MIBG MIBG uptake of VAD patients was in the range between AD and DLB but the values were close to the AD group. CONCLUSIONS: 131I-MIBG is helpful in differentiating DLB from AD.

The incidence of deep vein thrombosis and pulmonary embolism after total knee arthroplasty: the screening study by radionuclide venography.

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are considered uncommon in Asian populations and thrombo-prophylaxis is rarely indicated. The objective of this study was to investigate the incidence of DVT and PE after total knee replacement in an Asian population. MATERIAL AND METHOD: There were 100 patients who underwent total knee replacement enrolled in this study. No thrombo-prophylaxis was given to these patients. The possible risk factors such as age, sex, body mass index (BMI), operative time and the post-operative blood loss were recorded. RESULTS: The duplex ultrasonography (controlled) showed no evidence of DVT in all cases. There were 67 patients who completed radionuclide venography in this study. The incidence of DVT from positive radionuclide venography was 24% (16/67 patients) and PE was 12% (8/67 patients). All patients with positive imaging studies were asymptomatic. The risk factors were similar in both groups. CONCLUSION: The incidence of DVT and PE in post-operative total knee replacement surgery, although lower than the incidence in Western populations, is higher than previously assumed. The radionuclide venography is less invasive and a useful diagnostic method for both DVT and PE. Because all patients with DVT and PE are asymptomatic, the use of thrombo-prophylaxis should be considered for risk and benefit.

Comparative study of renal function between standard and modified anatrophic nephrolithotomy by radionuclide renal scans.

OBJECTIVE: To compare the changes in renal function after surgery between standard and modified anatrophic nephrolithotomy using the technetium 99m-DTPA renal scan in patients with complex staghorn calculi. MATERIAL AND METHOD: From July 2001 to March 2002, standard anatrophic nephrolithotomy (sANL) was performed in 7 patients with complex staghorn calculi and modified anatrophic nephrolithotomy (mANL) was performed in another group of 8 patients with the same condition. Preoperative and postoperative renal function were assessed by technetium 99m-DTPA renal scan. RESULTS: Mean patient age was 41 years in the sANL group and 45 years in the mANL group. Male to female ratio was 4:3 in the sANL group and 5:3 in the mANL group. Median operative time was 205 minutes in the sANL group compare with 180 minutes in the mANL group (P = 0.03). Median estimated blood loss was 300 ml. in the sANL group and 275 ml. in the mANL group (P = 0.17). Median percent reduction of GFR on the operated kidney was 9.13 (-30.03 to -3.15) in the sANL group and 27.25 (-41.81 to -1.55) in the mANL group (P = 0.13). Residual small stone was seen in one patient of the sANL group and ESWL was performed for stone fragmentation. There were no serious short-term complications. CONCLUSION: The average operative time of sANL was longer than mANL however, sANL preserved more renal function than mANL. This study suggested that sANL should be the procedure of choice in patients who have compromised renal function.