Preoperative localization of parathyroid adenoma with sonography and 99mTc-sestamibi scintigraphy in primary hyperparathyroidism.

PURPOSE: To evaluate the sensitivity, specificity, and usefulness of dual-phase 99mTc-Sestamibi scintigraphy (SS) and sonography (US) of the neck, alone and in combination, as noninvasive adenoma localizing procedures in patients with primary hyperparathyroidism prior to parathyroidectomy. METHODS: We retrospectively analyzed the charts of 79 patients with parathyroid (PT) adenomas and confirmed diagnosis of hyperparathyroidism who were evaluated with SS and US prior to successful parathyroidectomy. RESULTS: Ninety-three adenomas were removed during bilateral neck exploration. SS alone showed a sensitivity of 76% and a specificity of 79% compared with 89% and 75%, respectively, for US performed after SS on the same day. Combination of the 2 procedures yielded a sensitivity of 89% and a specificity of 90%, with 22% discordant results. The differences in sensitivity and specificity between the 2 techniques alone or in combination were not statistically significant. CONCLUSIONS: No benefit was gained from using both SS and US for the preoperative localization of PT adenomas in patients with primary hyperparathyroidism. Each technique can be negatively affected by thyroid enlargement and nodularity. US, when performed by a skilled operator, is a reliable tool for PT adenoma localization. If the US findings are inconclusive, SS should be used.

Cholesterol emboli syndrome in type 2 diabetes: the disease history of a case evaluated with renal scintigraphy.

BACKGROUND: Cholesterol crystal emboli syndrome (CCE) is an emerging disease, whose progression reflects the currently observed increase in cardiovascular diseases. Diagnostic criteria shifted from pathological to clinical criteria: creatinine increase, skin lesions, recent endovascular interventions and severe vasculopathy). Diabetes, hypertension and diffuse vascular disease are inter-linked, major risk factors. The role of imaging techniques in the diagnosis and treatment of the disease has been little investigated thus far. The AIM of this report is to describe a case exemplifying the potentials for renal scintigraphy in CCE, an emerging disease in type 2 diabetic patients. THE CASE: A 75 year-old, type 2 diabetic for over 15 years, obese, hypertensive white man was referred to the Nephrology Unit after an acute coronary syndrome. Stenosis of the left renal artery was diagnosed from the angiography. Serum creatinine (baseline: 1.9 mg/dl) increased after multiple angioplasties to 3.3 mg/dl, then slowly returned towards baseline (2.2 mg/dl), but rose, on referral, to 3.9 mg/dl, with an increase in acute phase reactants and peripheral livedo reticularis, a picture highly suggestive of CCE. The first renal scintiscan showed a reduction of the parenchymal phase, and a non-homogeneous parenchymal pattern in the right dominant kidney. The patient was started on corticosteroid therapy with a prompt decrease in creatinine; four days later (creatinine 2.5 mg/dl) a second scintiscan showed an improvement of the peak time and of the radionuclide parenchymal transit, and was further confirmed two months later (creatinine 2.2 mg/dl). No modification was detected in the left kidney, presumably mechanically "protected" from the cholesterol shedding by the stenosis. CONCLUSIONS: This is the first description of an imaging demonstration of the morpho-functional substratum to the rapid clinical response of corticosteroid therapy in a case of CCE and type 2 diabetes, underlining the potential of 99mTc-MAG3 dynamic scintiscan in this disease.

The grafted kidney takes over: disappearance of the nephrotic syndrome after preemptive pancreas-kidney and kidney transplantation in diabetic nephropathy.

This report describes the rapid and complete reversal of proteinuria after preemptive transplantation in diabetic nephropathy. Case 1 was a 42-year-old woman with type 1 diabetes (before pancreas-kidney graft: serum creatinine 1.6 mg/dL and proteinuria 9.1 g/day; 1 month after pancreas-kidney graft: proteinuria 0.3 g/day and creatinine 1.3 mg/dL). Case 2 was a 48-year-old man with type 2 diabetes (before kidney graft: creatinine 2 mg/dL and proteinuria 5.9 g/day; 1 month after: proteinuria 0.7 g/day and creatinine 1.1 mg/dL). The proteinuria pattern changed (pre: glomerular nonselective, tubular complete; post: physiologic). Renal scintiscan (99mTC-MAG3) demonstrated functional exclusion of the native kidneys, despite high pretransplant clearance (> 50 mL/min). The effect was not linked to euglycemia or readily explainable by pharmacologic effects (no difference in renal parameters after pancreas transplantation with the same protocols). These data confirm the efficacy of preemptive kidney and kidney-pancreas transplantation in diabetic nephrotic syndrome and indicate that a regulatory hemodynamic effect should be investigated.

Reliability of captopril renography in patients under chronic therapy with angiotensin II (AT1) receptor antagonists.

UNLABELLED: Captopril renography is a reliable, widely used test for the functional diagnosis of renovascular hypertension. Well-recognized drawbacks of the procedure include reduced accuracy in patients with bilateral disease or renal impairment as well as the possible interference from concurrent antihypertensive medication (diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers). Currently, no data exist regarding the reliability of captopril renography in patients with renovascular hypertension evaluated while they are under chronic treatment with angiotensin II (AT1) receptor antagonists (Sartans). Moreover, the renographic response of the kidney with renal artery stenosis to prolonged therapy with angiotensin II receptor antagonists has not yet been evaluated. METHODS: We investigated the diagnostic effectiveness of (99m)Tc-mercaptoacetyltriglycine captopril renography performed after acute addition of 25 mg of captopril to the daily dose of AT1 receptor antagonist in 13 patients with unilateral renal artery stenosis and subsequent evidence of renovascular hypertension, based on short-term (3 mo) blood pressure outcome after revascularization. The renographic evaluation was first performed after ingestion of the daily therapy of angiotensin II receptor antagonist alone (Sartan renography) and was repeated within 7 d after the acute addition of 25 mg of captopril to chronic treatment with angiotensin II receptor antagonist (captopril-Sartan renography). A cohort of 13 patients with a final diagnosis of essential hypertension was chosen as the control subjects. RESULTS: Twelve of 13 patients were correctly detected by captopril-Sartan renography (92% sensitivity), and 3 subjects were also identified without the addition of captopril. Adding captopril to Sartan therapy resulted in a slight reduction in mean arterial blood pressure, while significant side effects were never observed. No false-positive results were found in the 13 patients with essential hypertension. CONCLUSION: We conclude that performing captopril renography with the acute addition of 25 mg of captopril to the chronic monotherapy with Sartans has the same diagnostic effectiveness as performing captopril renography alone. Interrupting the vasoactive action of angiotensin II alone on the efferent glomerular arteries, which can also be selectively achieved by chronic administration of angiotensin II receptor antagonists, does not fully explain the effectiveness of captopril renography in detecting renovascular hypertensive patients.