Single photon emission computed tomography (SPECT) imaging with (123)I-FP-CIT is of great value in differentiating patients suffering from Parkinson's disease (PD) from those suffering from essential tremor (ET). Moreover, SPECT with (123)I-IBZM can differentiate PD from Parkinson's "plus" syndromes. Diagnosis is still mainly based on experienced observers' visual assessment of the resulting images while many quantitative methods have been developed in order to assist diagnosis since the early days of neuroimaging. The aim of this work is to attempt to categorize, briefly present and comment on a number of semi-quantification methods used in nuclear medicine neuroimaging. Various arithmetic indices have been introduced with region of interest (ROI) manual drawing methods giving their place to automated procedures, while advancing computer technology has allowed automated image registration, fusion and segmentation to bring quantification closer to the final diagnosis based on the whole of the patient's examinations results, clinical condition and response to therapy. The search for absolute quantification has passed through neuroreceptor quantification models, which are invasive methods that involve tracer kinetic modelling and arterial blood sampling, a practice that is not commonly used in a clinical environment. On the other hand, semi-quantification methods relying on computers and dedicated software try to elicit numerical information out of SPECT images. The application of semi-quantification methods aims at separating the different patient categories solving the main problem of finding the uptake in the structures of interest. The semi-quantification methods which were studied fall roughly into three categories, which are described as classic methods, advanced automated methods and pixel-based statistical analysis methods. All these methods can be further divided into various subcategories. The plethora of the existing semi-quantitative methods reinforces the feeling that visual assessment is still the base of image interpretation and that the unambiguous numerical results that will allow the absolute differentiation between the known diseases have not been standardized yet. Switching to a commonly agreed-ideally PC-based-automated software that may take raw or mildly processed data (checked for consistency and maybe corrected for attenuation and/or scatter and septal penetration) as input, work with basic operator's inference and produce validated numerical results that will support the diagnosis is in our view the aim towards which efforts should be directed. After all, semi-quantification can improve sensitivity, strengthen diagnosis, aid patient's follow-up and assess the response to therapy. Objective diagnosis, altered diagnosis in marginal cases and a common approach to multicentre trials are other benefits and future applications of semi-quantification.

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OBJECTIVE -To investigate the relation between diabetic autonomic neuropathy (DAN) and left ventricular (LV) function in type 1 diabetic patients. RESEARCH DESIGN AND METHODS-A total of 57 type 1 diabetic patients free of coronary artery disease and arterial hypertension were studied. Diagnosis of DAN was established by autonomic nervous function (ANF) tests, and LV systolic and diastolic functions were assessed by radionuclide ventriculography at rest.RESULTS -There were 24 patients who had definite DAN, established by the presence of two or more abnormal ANF tests, and 33 subjects were without DAN. DAN patients had impaired LV filling pattern, obvious by a reduced peak filling rate (3.1 Ϯ 1.1 vs. 3.7 Ϯ 0.7 end-diastolic volume [EDV]/s, P ϭ 0.011) and first third filling fraction (35.3 Ϯ 19.5 vs. 50.8 Ϯ 16%, P ϭ 0.002) as well as an increased time to peak filling (159.4 Ϯ 45.1 vs. 134.2 Ϯ 33.4 ms, P ϭ 0.02) after correction for age and heart rate. There were no differences between the two groups with regard to ejection fraction, cardiac output, and cardiac index, whereas the peak emptying rate was greater in DAN patients (4.1 Ϯ 0.8 vs. 3.6 Ϯ 0.8 EDV/s, P ϭ 0.019), suggesting LV hypercontractility. DAN patients had an increased heart rate (83.4 Ϯ 11.9 vs. 72.7 Ϯ 9.3 bpm, P ϭ 0.001) and slightly higher systolic blood pressure. As a result, LV working load at rest was higher in DAN patients (11,109 vs. 9,096 bpm ϫ mmHg, P Ͻ 0.001). Moreover, a correlation was found between abnormal LV systolic and diastolic indexes and the number of abnormal ANF tests.CONCLUSIONS -At rest, DAN patients have impaired LV filling pattern, slightly increased LV systolic function, and a higher LV working load, in comparison to non-DAN type 1 diabetic patients. Diabetes Care 26:1955-1960, 2003C linical and epidemiological studies have confirmed that patients with diabetes appear susceptible to heart failure, which is the leading cause of death in these patients (1). Impairment of left ventricular (LV) function is frequent in patients with type 1 diabetes, even in the absence of ischemic, hypertensive, or valvular heart disease (2). Possible mechanisms for a specific diabetic cardiomyopathy include abnormalities of small intramural coronary vessels, deposition of collagen, and lipids and metabolic derangements that alter actomyosin and myosin adenosine triphosphatase activities (3). Although histopathologic and biochemical evidence for a distinct diabetic cardiomyopathy is available, it remains unclear whether these pathologic processes may cause significant LV systolic or diastolic dysfunction. Numerous studies have reported normal LV systolic function at rest in most type 1 diabetic patients (4), whereas others have suggested increased LV systolic function (5,6). Several investigators have shown abnormal LV diastolic function in the majority of type 1 diabetic patients (7-11), whereas others (12) found no evidence of LV diastolic dysfunction at rest in longterm type 1 diabetic patients. It has been suggested that LV dysfunction in type...

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