ماهنامه پوپک
سال هفدهم شماره 4 (پیاپی 192، تیر 1389)

Renal artery stenosis (RAS) is the most common cause of secondary hypertension. Preliminary data indicate that aspirin renography with hippurate may be more sensitive for detection RAS. In this study 20 patients with known or suspected RAS underwent aspirin renography (20 mg/kg orally 1 hour before injection of radiotracer) and captopril renography (50 mg orally) with 99mTc-DTPA. Renal angiography was performed in all patients. Of the 20 patients enrolled, 11 had unilateral RAS on angiography. Captopril renography was positive in 10 patients (91% sensitivity and 90% specificity). Aspirin renogram showed 9 patients with RAS correctly (81.8% sensitivity and 100% specificity). Our data suggest that aspirin renography with 99mTc-DTPA has comparable sensitivity with captopril in detection of unilateral RAS.

Since 3D medical images such as SPECT and MRI are taken under different patients positioning and imaging parameters, interpretation of them, as reconstructed originally, does not provide an easy and accurate understanding of similarities and differences between them. The problem becomes more crucial where a clinician would like to map accurately region of interest from one study to the other, by which some surgical or therapeutical planning may be based. The research presented here is an investigation into the problems of the registration and display of brain images obtained by different imaging modalities. Following the introduction of an efficient method some clinical useful application of the registration and superimposition were also defined. The various widely used registration algorithms were first studied and their advantages and disadvantages of each method were evaluated. In this approach, an edge-based algorithm (Called surface fitting), which are based on a least-square-distance matching, were suggested for registering of brain images. This algorithm minimizes the sum of square-distances between the two surfaces obtained from two modalities. The minimization is performed to find a set of six geometrical transformation parameters (3 shifts and 3 rotations) which indicate how one surface should be transformed in order to match with the other surface.

Coronary heart disease (CAD) is the leading cause of death specially among elderly. Coronary angiography is the best diagnostic method in the patients, but is unfortunately an invasive procedure with its inherent risks. Myocardial perfusion scan is a noninvasive and sensitive method for evaluation of CAD and is suggested by many investigators in recent years. In this study, 64 patients who had a Tc-99m MIBI SPECT myocardial perfusion study at our department, underwent coronary angiography within 4 months. Correlation of the methods revealed that SPECT Tc-99m-MIBI had a high sensitivity and specificity in our hand, which is comparable with international findings.

Tc-99m MIBI has recently been used in the functional imaging of various tumors. This prospective study was performed to evaluate the role of Tc-99m MIBI imaging at the time of the initial staging, assessment of treatment response, follow-up studies and survaillance in Hodgkin’s and non-Hodgkin’s Iymphoma. 25 patients (14 with Hodgkin’s and 11 with non-Hodgkin’s Iymphoma) underwent 32 studies. The patient’s age range wa 19-73 years, with a mean age of 41.7 years. All patients underwent whole body planar imaging following intravenous injection of 20-25 mCi Tc-99m MIBI. Comparative imaging with 3 mCi Tl-201 and 10 mCi Ga-67 injection was done. Clinical, radiographic and biopsy correlation was obtained in all cases.

The primary treatment of thyroid carcinoma is surgery and the outcome depends on its extent. The post-operative management alternatives in thyroid carcinoma include thyroid hormone, radio-iodine ablation (I-131 Na), external beam radiation therapy (EBRT) and occasionally adjuvant chemotherapy. This retrospective study analyzes the managements of 153 patients (102, 51), age range 10-96 years, mean age 50.2 years treated for thyroid carcinoma. The range of follow-up was 1.0-294 months with median follow-up for 60.4 months. Twenty patients without therapy were excluded. Group A included 87 patients treated with I-131. Group B consisted of 13 patients received EBRT. Group C included both therapies in 33 patients. The therapies in all different stages of thyroid carcinoma and with various histopathologies were reviewed.