PATIENT DOSES IN WHOLE-BODY PET/CT EXAMINATIONS IN THE LARGEST TERTIARY HOSPITAL IN GREECE.

The purpose of this study was to determine the patient radiation dose in combined whole-body positron emission tomography/computed tomography (PET/CT) examinations performed in the largest tertiary hospital in Greece. Computed tomography dose index (CTDIvol), dose length product (DLP), weight, height and administered activity of 2-[18F] fluoro-2-deoxy-D-glucose values for PET/CT examinations were recorded in a sample of 1014 randomly selected patients. The mean (±standard deviation) and median (interquartile) CTDIvol values were equal to 5.5 ± 2.4 and 4.8 (2.5) mGy, respectively. The respective DLP values were 483.3 ± 212.4 and 426 (234.6) mGy·cm. For the administered activity, mean and median were equal to 363.9 ± 68.3 and 361.6 (85.6) MBq. The mean administered activity per body weight was 4.8 ± 0.6 and the median 4.8 (0.6) MBq/kg. The results of this survey are within the range of values reported in the literature and can be used as a standard of reference until national diagnostic reference levels are established for whole-body PET/CT procedures.

Focal vitreomacular traction: a prospective study of the evolution to macular hole: the mathematical approach.

UNLABELLED: PURPORSE: To determine the associated balance of forces of the vitreofoveal interface in focal vitreomacular traction evolving to full-thickness macular hole (FTMH) and to link/explain the observed changes in the context of mathematical and physics models. PATIENTS AND METHODS: This is a multicenter, prospective, and observational case series conducted at the Vitreoretinal Department of three different referral centers. Fellow eyes of patients with unilateral idiopathic FTMH were included. Eighty-nine patients were included in the analysis. The fellow normal eye of the study patients was imaged with spectral-domain optical coherence tomography. The main outcome measure was the optical-coherence-tomography-defined characteristics of the vitreofoveal interface and their analysis with mathematical and physics models at the end of follow-up period. RESULTS: Of the included 89 patients (66 women and 23 men; mean age±SD, 68.5 years±9.8), 10 (11.2%) developed FTMH at the fellow eye at the end of the follow-up period. We observed two types of vitreofoveal attachment. A V-shaped (cord-like) configuration and a U-shaped configuration. The eyes with the V-shaped attachment demonstrated initial structural changes in the outer foveal layers and the eyes with the U-shaped attachment showed inner morphological changes. CONCLUSION: We hypothesize that the type (V- or U-shaped) of the vitreofoveal attachment may affect the type and location of the initial structural change leading to the formation of FTMH from the stage of the focal vitreomacular traction.

Contribution of (99m)Tc-depreotide (Neospect) scintigraphy in lung cancer staging.

PURPOSE: The aim of this study was to evaluate the usefulness of scintigraphy with (99m)Tc-depreotide in the staging of lung cancer, especially in cases where CT findings are doubtful. METHODS: 53 patients with suspected lung cancer were investigated with whole body planar acquisition and single photon emission computed tomography (SPECT) of the thorax after i.v. injection of 740 MBq (99m)Tc-depreotide (Neospect). The results were compared with CT and correlated with histological findings. RESULTS: In 50 of 53 patients the biopsy was positive for bronchogenic carcinoma (31 patients with non small cell lung cancer [NSCLC], 18 with small cell lung cancer (SCLC), and 1 patient with neuroendocrine cancer). In the remaining 3, biopsy revealed no bronchogenic carcinoma (3 patients with inflammation). In 2/31 patients with NSCLC and doubtful CT findings, uptake of (99m)Tc-depreotide was the only non invasive reliable staging method. CONCLUSION: It seems that scintigraphy with (99m)Tc-depreotide in patients with SCLC does not change the tumor stage, whereas in NSCLC the contribution of Neospect in lung cancer staging may be a helpful tool, especially in cases where CT alone is unable to distinguish between IIIA and IIIB stages (operable from non operable status).

Imaging of myeloma bone disease--implications for staging, prognosis and follow-up.

Among all imaging modalities, magnetic resonance imaging provides the most useful information about the accurate staging of solitary bone plasmacytoma, the prediction of progression of asymptomatic multiple myeloma and the prognosis of symptomatic multiple myeloma. Furthermore, magnetic resonance imaging contributes to the differential diagnosis of compression fractures in patients with myeloma and can be used for assessment of response to treatment.

Predictive value of captopril transit renography in essential hypertension and diabetic nephropathy.

Captopril renography was utilized to assess the presence of angiotensin II dependent renovascular dysfunction in (1) 28 patients with mild to moderate essential hypertension (EH) with unimpaired renal function, and (2) 25 hypertensive patients with diabetic nephropathy (HDN). These studies were classified according to the diagnostic criteria outlined by the Working Party on Diagnostic Criteria of Renovascular Hypertension with Captopril Renography and the mean parenchymal transit time (MPTT) was used as an index for detecting the presence of angiotensin II dependent renal haemodynamic change. Patients with EH showed non-significant or non-specific alterations in the MPTT. Four patients in the HDN group showed a significant prolongation of MPTT in the presence of renin-angiotensin-aldosterone activation due to renal artery stenosis, and the other patients in this group showed a significant decrease in MPTT after captopril, consistent with increased blood flow and improved tubular transport function in the presence of microangiopathy only. We conclude that addition of MPTT to the standard diagnostic criteria of captopril renography may be helpful in predicting the beneficial or detrimental impact of angiotensin II inhibition treatment in HDN and in limiting the test protocol in EH to one post-captopril study.

Captopril renal scintigraphy in patients with hypertension and chronic renal failure.

UNLABELLED: The aim of this prospective study was to determine the ability of the captopril renogram to reveal the presence of angiotensin II-dependent renovascular disorder in hypertensive patients with chronic renal failure and to assess the possibility of predicting beneficial effect of angiotensin-converting enzyme (ACE) inhibitors on renal function. METHODS: Forty-one patients were evaluated. Baseline renal scintigraphy was performed with 80 MBq of 99mTc-mercaptoacetyltriglycine (MAG3) injected intravenously. Scintigraphy was repeated within a week with 25 mg of oral captopril given 60 min prior to the test. Using the measurements outlined by the Working Party on Diagnostic Criteria of Renovascular Hypertension with Captopril Renography, the patients were categorized into high (7 patients), indeterminate (19 patients) and low (15 patients) probability for renal artery stenosis (RAS). RESULTS: In five of the seven patients with high probability, the presence of RAS was confirmed angiographically and corrective surgical procedure performed in two. In patients with GFR of 10 ml/min/1.73 m2 and/or split renal function of 10% or less, all qualitative and semiquantitative scintigraphic parameters were nonspecific. Mean parenchymal transit time of tracer was a useful parameter to predict the beneficial effect of ACE inhibition therapy in 23 patients (14 low and 9 indeterminate probability of RAS). CONCLUSION: In hypertensive patients with renal failure, captopril renal scintigraphy can be utilized to identify the presence of angiotensin II-dependent renal dysfunction and possibly help to predict the beneficial effect of ACE inhibitor therapy.