The symptoms asymmetry of drug-induced parkinsonism is not related to nigrostriatal cell degeneration: a SPECT-DaTSCAN study.

AIM: Drug-induced parkinsonism (DIP) is the most common form of parkinsonism after Parkinson's disease (PD) itself. It has been widely believed that DIP is characterised by symmetry of symptoms. Studies of patients with DIP in whom PD had been ruled out by SPECT-DaTSCAN have shown that symptom asymmetry is a common element of DIP clinical presentation. The aim of our study was to determine whether the asymmetry of symptoms in DIP is related to any abnormality within the presynaptic part of the nigrostriatal dopaminergic system. MATERIALS AND METHODS: Eleven patients with the diagnosis of DIP and asymmetric symptoms were studied. Their individual SPECT-DaTSCANs were normal. Indices calculated for the whole group of radiotracer uptake in the whole striatum, putamen and caudate contralateral to more severe DIP symptoms were compared to values obtained in the opposite hemisphere. RESULTS: We did not find significant differences in radiotracer uptake in structures contralateral to more severe clinical symptoms when compared to the homolateral hemisphere. CONCLUSIONS: Our results have not confirmed the presence of a presynaptic nigrostriatal deficit which could be related to asymmetry of DIP. The factors responsible for the asymmetry of DIP symptoms should be sought in the postsynaptic part of the nigrostriatal dopaminergic system.

Should non-movement specialists refer patients for SPECT-DaTSCAN?

BACKGROUND: SPECT with radioligand DaTSCAN (SPECT-DaTSCAN) is a sensitive tool used for assessing the functional integrity of the presynaptic part of the nigrostriatal dopaminergic system. The procedure is useful whenever there is a need to distinguish between neurodegenerative parkinsonism and other parkinsonian syndromes in subjects with equivocal signs and symptoms. It can be assumed that the neurologist's decision to perform SPECT-DaTSCAN depends on his or her experience and skill in the diagnosis of parkinsonian and tremor syndromes. AIMS: To assess the accuracy of referrals to SPECT-DATSCAN made by non-movement disorders specialists. MATERIAL AND METHODS: Sixty seven patients referred for SPECT-DaTSCAN by a general neurologist were studied. In all subjects, a movement disorder specialist performed the neurological examination, collected medical history, and analysed previous treatments and the results of diagnostic tests. RESULTS: Evaluation carried out by a movement disorder specialist did not confirm an indication for SPECT-DaTSCAN in 31 patients (46.3%). General neurologists needed support for clinical diagnosis with SPECT-DaTSCAN most frequently in subjects with parkinsonism even though they were presenting a full-blown disease manifestation and even though the patients met the diagnostic criteria for Parkinson's disease or one of the atypical parkinsonian syndromes. CONCLUSIONS: Our presented results probably reflect the limited experience of general neurologists in the evaluation of parkinsonian syndromes and tremor. The use of SPECT-DaTSCAN by non-movement disorders specialists is associated with a significant risk of overuse of this tool. To minimise this risk, the skills of general neurologists in diagnosing parkinsonian and tremor syndromes should be improved. Moreover, patients should be provided with access to movement disorders specialists.

Is nigrostriatal dopaminergic deficit necessary for Holmes tremor to develop? The DaTSCAN and IBZM SPECT study.

Holmes's tremor (HT) is assumed to be the result of coexistence of nigrostriatal dopaminergic system impairment and the lesion of cerebello-thalamic pathways. It was suggested that dopaminergic deficiency is responsible for rest tremor, and lack of compensatory cerebellar function leads to spill of tremor into voluntary movements. Cases of HT with and without abnormalities of the presynaptic part of dopaminergic nigrostriatal were published and these findings raised the question of possibility of the postsynaptic lesion. Three patients with HT diagnosed according to criteria of Consensus Statement on Tremor were studied. In all of them SPECT imaging with ligands of presynaptic (I 123-FP CIT-DaTSCAN) and postsynaptic (I 123-iodobenzamide-IBZM) nigrostriatal dopaminergic neurons was performed. Indices of uptake in caudate and putamen normalized to nonspecific uptake in occipital cortex and indices of asymmetry for each whole striatum as well as for putamen and caudate separately were calculated. SPECT studies did not reveal asymmetry of DaTSCAN and IBZM binding in striatum in all studied subjects. The current clinical diagnostic criteria of HT are presumably insufficiently specific and when using them we identify patients both with and without the involvement of dopaminergic system. These two groups may represent tremor disorders of similar phenomenology but of different pathomechanism.

Myocardial perfusion GSPECT imaging in patients with myocardial bridging.

BACKGROUND: The aim of this study was to investigate the incidence, reversibility, and severity of LV perfusion abnormalities in patients with isolated myocardial bridges using a gated myocardial perfusion SPECT study (GSPECT). METHODS: A retrospective study involved 42 patients without history of myocardial infarction, with isolated myocardial bridges detected in coronary angiography and no substantial evidence of atherosclerotic changes in coronary arteries. In all patients a gated SPECT study was performed at both rest and stress, after intravenous administration of (99m)Tc MIBI. Reconstructed slices were analyzed using a 20-segment model of the left ventricle. RESULTS: Incidence and severity of stress-induced ischemia were related to degree of artery constriction (P = .002 and .00014, respectively). Perfusion abnormalities were detected only in patients with critical narrowing (≥ 50%) of artery (in 12 out of 28, i.e., 43% of patients). Summed stress scores (SSS) ranged from 4 to 11 (mean 7), indicating slight or moderate defect intensity. Only 1 patient presented with a SSS value of 31 (severe defect). Perfusion defects were stress induced in 70 out of 72 (97%) segments with abnormal perfusion. CONCLUSION: Perfusion abnormalities were observed in ab. 40% of patients with critical (≥ 50%) narrowing of artery affected by bridging and were mild, stress induced.

Mask-Related Motion Artifact on 99mTc-MIBI SPECT: Unexpected Pitfalls of SARS-CoV-2 Countermeasures.

A 61-year-old man was referred for myocardial perfusion scintigraphy (MPS) by an occupational physician to exclude coronary artery disease (CAD). The patient had a complete left bundle branch block (LBBB) that rendered the routine exercise stress test non-diagnostic, but otherwise had no history of heart diseases, good stress tolerance with no symptoms of angina, and no abnormalities in transthoracic echocardiogram, apart from contraction patterns typical for LBBB. Initial MPS, performed using technetium-labeled Sestamibi on a Discovery NM 530c camera equipped with solid-state semiconductor detectors, revealed a significant stress-induced ischemia that did not match the good overall condition of the patient. A motion detection procedure revealed significant heart motion in Z-axis during the stress study. Upon inquiry, the patient reported breathing difficulties caused by the mandatory mask, which slipped into an uncomfortable position during the study. Repeated acquisition, without motion artifacts, revealed no features of ischemia.

Assessment of Renal Function Based on Dynamic Scintigraphy Parameters in the Diagnosis of Obstructive Uro/Nephropathy.

This study evaluates the usefulness of parameters allowing assessment of renal function in absolute values in dynamic renal scintigraphy (DRS) with 99mTc-ethylenedicysteine (99mTc-EC) uptake constant (K), mean transit time (MTT), and parenchymal transit time (PTT) in the diagnosis of obstructive uro/nephropathy. The study included 226 people: 20 healthy volunteers, for whom normative values of assessed parameters were determined, and 206 patients. Reproducibility of results obtained by two independent operators, specificity, correlation with estimated GFR (eGFR), and Cohen's kappa were used to evaluate reliability of assessed parameters. Normative values were as follows: K ≥ 1.6, MTT ≤ 250 s, and PTT ≤ 225 s. Reproducibility of determination of K (rs = 0.99) and MTT (rs = 0.98) was significantly higher than that of PTT (rs = 0.95) (p = 0.001). Specificity was 100% for K, 81% for MTT, and 91% for PTT. Correlation of eGFR with K (rs = 0.89) was significantly higher than with PTT (rs = 0.53) and with split function (SF) (rs = 0.66) (p < 0.0001). Cohen's kappa was κ = 0.89 for K, κ = 0.88 for MTT, and κ = 0.77 for PTT. In a group of patients where standard DRS parameters are unreliable (bilateral obstructive uro/nephropathy or single functioning kidney), the use of K (the most effective among assessed parameters) changed the classification of 23/79 kidneys (29%). K enables reproducible assessment of absolute, individual kidney function without modifying routine DRS protocol. Diagnostic value of MTT and PTT is limited.

Inter- and Intraobserver Repeatability of Myocardial Flow Reserve Values Determined with SPECT Study Using a Discovery NM530c Camera and Corridor 4DM Software.

BACKGROUND: Myocardial blood flow (MBF) and flow reserve (MFR) examination, especially useful in the diagnosis of multivessel coronary artery disease (CAD), can be assessed with a cadmium-zinc-telluride (CZT) SPECT gamma camera, as an alternative to the expensive and less available PET. However, study processing is not free from subjective factors. Therefore, this paper aims to evaluate intra- and interobserver repeatability of MBF and MFR values obtained by the same operator and two independent operators. METHODS: This study included 57 adult patients. MBF and MFR were assessed using a Discovery NM530c camera in a two-day, rest/dipyridamople protocol, using 99mTc-MIBI. Data were processed using Corridor4DM software, twice by one operator and once by another operator. RESULTS: The repeatability of the assessed values was quite good in the whole myocardium, LAD and LCX vascular territories, but was poor in the RCA territory. CONCLUSIONS: The poor repeatability of MBF and MFR in RCA vascular territory can be explained by poor automatic orientation of the heart axis during post-processing and a so-called "cardiac creep" phenomenon. Better automatic heart orientation and introduction of automatic motion correction is likely to drastically improve this repeatability. In the present state of the software, PET is better for patients requiring assessment of MFR in the RCA territory.

Assessment of clinical usefulness of parametric clearance images in diagnosis of kidney cicatrisation in children with chronic infections of the urinary tract.

BACKGROUND: Cicatrisation of the renal cortex is closely related to chronic infections of the urinary system. Static renal scintigraphy is used as the method enabling detection of local defects of radiopharmaceutical uptake, and is treated as the "gold standard" in the diagnosis of renal scars. The aim of the reported investigation was a comparison of the diagnostic efficacy of parametric clearance images and the conventional summation images - obtained from dynamic scintigraphy - in the detection of local defects of renal function. As the "gold standard" for the above comparison, the static scintigraphy of kidneys was accepted. MATERIAL AND METHODS: Forty-one patients (age 4-19 years), 28 girls and 13 boys, participated in the study. Altogether, 73 kidneys were analyzed (in 9 patients, only one kidney). In each patient dynamic renal scintigraphy was performed after IV administration of 99mTc EC (ethylenedicysteine) and static planar renal scintigraphy using 99mTc-DMSA (dimercaptosuccinic acid) as a reference method. From the dynamic study, summation and parametric clearance images were generated. Each kidney was divided into 3 segments (upper, middle, lower); altogether 219 segments were evaluated by modified Howard's scale. Planar and oblique projection images were compared with corresponding summation and parametric clearance images. RESULTS AND CONCLUSIONS: Parametric clearance imaging has a higher sensitivity and accuracy for detection of regional post-inflammatory changes in the kidneys than conventional summation images (p < 0.05) and shows parenchymal changes similarly to static scintigraphy (high Cohen's kappa index).

Kidney efficiency index quantitative parameter of a dynamic renal scintigraphy. II. usefulness in the diagnosis of obstructive nephropathy.

BACKGROUND: One of the main indications for DRS is a diagnosis of obstructive uro-/nephropathy. In standard practice, this study includes the assessment of sequential scintigraphic images, renographic curves and such quantitative parameters as TMAX, T1/2 and split function of each kidney (SF). Due to the relative nature of SF and limitations of diagnostic capabilities of TMAX and T1/2, DRS was expanded to include new quantitative parameters describing kidney function in absolute values. This study aims to evaluate the usefulness of kidney efficiency index (KEi) - new, in-house developed parameter proportional to the average clearance function of the kidney. MATERIAL AND METHODS: The study included 156 people aged 18-84 (average 51) years. The first group, from which normative values of new parameters were determined, consisted of 20 healthy volunteers. The second group consisted of 136 patients selected retrospectively, based on archived scintigraphic data. "Normalcy rate" (percentage of normal results among selected 62 patients with a low likelihood of obstructive uro-/nephropathy) was used to evaluate the reliability of KEi. A comparative differential analysis of obstructive uro-/nephropathy, based on standard and new DRS parameters, was performed on selected 74 patients (92 kidneys) with single functioning kidney or bilateral obstructive uropathy, where SF is unreliable. RESULTS: Normative values: KEi ≥ 8; Normalcy rate for KEi: 95%. In comparison with standard DRS evaluation, application of KEi changed the diagnosis in 1/3 of assessed kidneys (from uropathy to nephropathy in 27/92 kidneys and vice versa in 4 kidneys). CONCLUSIONS: KEi enables reproducible, quantitative assessment of absolute kidney function without any modifications of the standard DRS protocol. Its values can be compared between independent studies (e.g. follow-up examinations). KEi corrected the diagnosis of obstructive uro-/nephropathy in cases of single functioning kidney or bilateral obstructive uropathy.

Kidney Efficiency Index - quantitative parameter of a dynamic renal scintigraphy. I. Theory and preliminary verification.

BACKGROUND: One of the basic clinical indications for dynamic renal scintigraphy (DRS) is a diagnosis of obstructive uropathy and/or nephropathy. Currently, a basic quantitative criterion for diagnosing nephropathy is the percentage of individual kidney's contribution in the global uptake of a radiopharmaceutical from the blood (so-called Split Function - SF). From a clinical point of view, a parameter evaluating a radiopharmaceutical uptake and reflecting the efficiency of a specific kidney, determined independently of the total uptake of both kidneys, would be much more useful. Based on a Rutland theory, a kidney uptake constant K proportional to a radiotracer uptake by individual kidney was introduced and applied to DRS with 99mTc-ethylene-1-dicysteine (99mTc-EC). In addition, a kidney efficiency index (KEi) was also worked out as a new parameter obtained by dividing the uptake constant K by the surface of the ROI of a given kidney, which can be interpreted as the average "efficiency" of clearance of a kidney. MATERIAL AND METHODS: K and KEi values were verified in 72 studies selected retrospectively from patients referred routinely for DRS, with available current level of blood creatinine, used for calculation of estimated GFR (eGFR) according to a CKD-EPI formula. After splitting of eGFR values into individual kidneys according to SF, single kidney eGFR values (SKeGFR) were obtained and then used as a verification method for SF, K and KEi values. RESULTS: Correlation between SF and SKeGFR values, rsp = 0.64, was significantly weaker (p < 0.0022) than the correlation of SKeGFR values with K uptake constants and KEi indices: 0.90 and 0.84, respectively. CONCLUSIONS: Uptake constant K and KEi, as quantitative parameters, give the opportunity to analyze a function of each kidney separately and in an absolute way. KEi also allows for a reliable assessment of kidneys of atypical sizes (larger or smaller than average). It also gives the opportunity to create normative values for this parameter and may be useful in a number of clinical situations where the diagnostic effectiveness of such a relative parameter as SF, is severely limited, e.g. in assessing a large kidney with hydronephrosis or while differing a cirrhotic from hypoplastic (i.e. a small but properly functioning) kidney.

Impact of intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction on left ventricular perfusion and function: a 6-month follow-up gated 99mTc-MIBI single-photon emission computed tomography study.

PURPOSE: We investigated the impact of intracoronary injection of autologous mononuclear bone marrow cells (BMC) in patients with acute ST elevation myocardial infarction (STEMI) on left ventricular volumes, global and regional systolic function and myocardial perfusion. METHODS: The study included 39 patients with first anterior STEMI treated successfully with primary percutaneous coronary intervention. They were randomly assigned to the treatment group or the control group in a 2:1 ratio. The patients underwent baseline gated single-photon emission computed tomography (G-SPECT) 3-10 days after STEMI with quantitative and qualitative analysis of left ventricular perfusion and systolic function. On the following day, patients from the BMC treatment group were subjected to bone marrow aspiration, mononuclear BMC isolation and intracoronary injection. No placebo procedure was performed in the control group. G-SPECT was repeated 6 months after STEMI. RESULTS: Baseline and follow-up G-SPECT studies were available for 36 patients. At 6 months in the BMC group we observed a significantly enhanced improvement in the mean extent of the perfusion defect, the left ventricular perfusion score index, the infarct area perfusion score and the infarct area wall motion score index compared to the control group (p = 0.01-0.04). However, the changes in left ventricular volume, ejection fraction and the left ventricular wall motion score index as well as the relative changes in the infarct area wall motion score index did not differ significantly between the groups. CONCLUSION: Intracoronary injection of autologous mononuclear BMC in patients with STEMI improves myocardial perfusion at 6 months. The benefit in infarct area systolic function is less pronounced and there is no apparent improvement of global left ventricular systolic function.

Comparison of (99m)Tc-HEPIDA and (99m)Tc-MBrIDA from the standpoint of hepatic clearance determination-- preliminary communication.

BACKGROUND. In order to evaluate the functional capacity of the liver by means of clearance determination, the derivative of iminodiacetic acid ((99m)Tc-HEPIDA) has been used in recent decades. Because of recent problems with manufacturing and delivery of (99m)Tc-HEPIDA, an investigation was undertaken with the aim of testing whether a more widely available (99m)Tc-MBrIDA could be used for clearance determination and whether hepatic clearance measured with the use of this compound provides a similarly useful test of hepatic function. MATERIAL AND METHODS. Comparative investigations were performed in 73 patients of both sexes. The state of the efficiency of liver parenchyma was determined based on seven widely used biochemical tests, i.e. levels of: bilirubin, albumin, and gamma globulin; activity of AST, ALT, GGTP, and prothrombin index. The clearances of both radiopharmaceuticals, (99m)Tc-HEPIDA and (99m)Tc-MBrIDA, were determined by means of multisample technique. The results of determination were correlated among themselves and with the results of biochemical tests. The set of results of all estimations allowed a factorial analysis to be performed to find a common factor and to compute the values of factor loadings in particular tests. RESULTS. Obvious correlation between plasma and hepatic clearances of both radiopharmaceuticals was obtained and between plasma clearance of (99m)Tc-MBrIDA and hepatic clearance of (99m)Tc-HEPIDA. Correlation coefficients of (99m)Tc-MBrIDA clearance and the biochemical test results attained somewhat lower values than for (99m)Tc-HEPIDA clearance. Similarly, values of chi(2) test of independence of (99m)Tc-MBrIDA clearances and test results were also less close than for (99m)Tc-HEPIDA clearances. Factorial analysis showed that common factor loading is greatest for hepatic clearance of (99m)Tc-HEPIDA; the values of two loadings of (99m)Tc-MBrIDA clearances are very close, but somewhat lower than those for (99m)Tc-HEPIDA. CONCLUSIONS. From the performed investigations it is possible to conclude that (99m)Tc-MBrIDA clearances may be used for the evaluation of liver parenchyma performance, even if the results may not be as certain as those obtained using (99m)Tc-HEPIDA.

A contribution of Józef Rotblat, a winner of the Nobel Peace Prize, to the development of nuclear medicine.

Józef Rotblat, a nuclear physicist born and educated in Poland, is the only laureate of the Nobel Peace Prize, who made a significant contribution to the development of nuclear medicine. In 1948 he went down in the annals of nuclear medicine by obtaining, with extarnal measurements, the first "image " of a function of an internal organ - thyroid gland, by registering gamma rays with a collimated Geiger counter at many points of the patient's neck and chest. He was awarded the Nobel Prize in Rotblat in 1995 for organizing, together with the a British philosopher Bertrand Russell, the international, peaceful movement of scholars for the eradication of weapons of mass destruction (Pugwash) and multi-annual activity in this movement.

Application of stress-only myocardial perfusion imaging.

BACKGROUND: Single-photon emission computed tomography myocardial perfusion study is usually a sequence of stress and rest part. In case of a normal stress study rest part can be given up. The objective of this study was to examine factors affecting concordance of results of stress-only (SO) and stress-rest (SR) studies. MATERIAL AND METHODS: SO and SR studies without and with attenuation correction (AC) of 212 selected patients (without cardiomyopathy, history of myocardial infarction or coronary artery bypass grafting) were analyzed visually. Influence of percutaneous coronary intervention (PCI) in the past, type of stress (physical/pharmacological) and application of AC (in form of combined method of non-corrected and corrected images - CM), patient body mass index (BMI) and gender on concordance rates of SO and SR studies were examined. RESULTS: Neither a history of PCI, nor a type of stress affected concordance rate. AC (in form of CM) improved concordance rate significantly, from 60% to 68% (p = 0.018). Patient BMI affected concordance rates - 72% in non-obese and 59% in obese patients (p = 0.05). In the whole group, risk of overlooking patients with abnormal perfusion in SO study was small (< 2%), but it grew significantly with patient BMI. Rest study was necessary in about 20% of non-obese and in about 50% of obese patients. CONCLUSION: MPS can be limited to stress part in appropriately selected, especially non-obese, patients provided that AC is applied, due to a low risk of overlooking patients with abnormal perfusion. In case of obese patients, careful analysis of exercise images for their normality is particularly important.

Lung perfusion scintigraphy in the assessment of pulmonary circulation after completion of surgical treatment of a hypoplastic left heart syndrome (HLHS).

INTRODUCTION: Hypoplastic left heart syndrome (HLHS) is an inborn complex heart malformation. A multi-stage treatment is initiated in a neonatal period with a Norwood surgery. The next step is Glenn surgery - a bidirectional superior cavo-pulmonary anastomosis. At the last stage anastomosis of inferior vena cava (IVC) with the right pulmonary artery (RPA) is formed as a result of a Fontan surgery. The aim of this study was to assess lung perfusion in patients with HLHS after completion of a surgical therapy, using a scintigraphic method. MATERIAL AND METHODS: In 92 patients with HLHS a planar lung scintigraphy in anterior and posterior projections after administration of 99mTc-macroaggregates in activity 18-111MBq was carried out twice (in several day intervals). At first, a radiopharmaceutical was administered to the right extremity in order to assess the lung distribution of blood flowing through the anastomosis of superior vena cava (SVC) with RPA. In the next study, after administration of the tracer to the right lower extremity, the distribution of blood flowing through the anastomosis of IVC with RPA was assessed. The relative percentage of each lung in the total lung perfusion was calculated on a Xeleris workstation using the "Lung perfusion analysis" program. Lung perfusion was considered close to symmetrical when the proportion was in the range of 40-60%. RESULTS: In spite of the fact that mean relative values of distribution of blood flowing through the anastomosis of SVC with RPA to the left lung (LL) and right lung (RL) in the entire study group did not differ significantly: LLmean = 47%; RLmean = 53%, p = 0.14, relative values of perfusion of both lungs were differentiated - in 26% of patients LL was better perfused, in 38% RL was better perfused and in 36% a perfusion of both lungs was similar. The analysis of blood distribution by anastomosis of IVC with RPA showed that the mean relative perfusion of RL was significantly higher than that of LL (70% vs. 30%, p < 0.0000001). No signs of pulmonary emboli were detected. In 13% of studied patients, uptake of the radiopharmaceutical in kidneys was shown indicating the presence of shunt "from right to left". CONCLUSIONS: After completion of surgical treatment of patients with HLHS, differentiated blood supply of the lungs was observed through SVC with RPA anastomosis and a tendency to higher blood supply of RL than LL by anastomosis of IVC with RPA. No signs of pulmonary embolism were detected. The study revealed a "right to left" shunt in some patients.

Gated 99mTc-MIBI single-photon emission computed tomography for the evaluation of left ventricular ejection fraction: comparison with three-dimensional echocardiography.

OBJECTIVE: Parameters of left ventricular systolic function directly influence the management of patients with suspected coronary artery disease (CAD). Quantitative gated single-photon emission computed tomography (QGS; Cedars-Sinai Medical Center, Los Angeles, CA, USA) allows the computation of left ventricular ejection fraction (LVEF) from myocardial perfusion imaging studies which are frequently performed on patients with suspected CAD. Three-dimensional (3D) echocardiography is considered to be the echocardiographic "gold standard" for the quantification of LVEF. We sought to compare QGS with 3D echocardiography in the evaluation of EF in patients with suspected CAD. METHODS: Ninety-one consecutive patients with suspected CAD, scheduled for coronary angiography, underwent rest electrocardiographic-gated technetium-99m methoxyisobutylisonitrile SPECT (G-SPECT) with measurement of LVEF by QGS and transthoracic 3D echocardiography with off-line measurement of LVEF (Tomtec 4D LV Analysis 1.1). The diagnosis of CAD was based on coronary angiography, performed on every patient. RESULTS: Nine patients were excluded from the analysis owing to unsuitability for 3D echocardiography (8 patients) or G-SPECT (1 patient). In the remaining group of 82 patients, 71 (87%) had significant CAD, 34 (42%) had a history of myocardial infarction, and 50 (61%) had perfusion defects at rest G-SPECT images. The mean LVEF measured by QGS and 3D echocardiography was 53+/-13% and 53+/-10%, respectively. The mean difference in LVEF between 3D echocardiography and QGS was 0.1+/-6.0% (P=0.87), and the correlation between the values obtained by both methods was high (r=0.88, P<0.001). The largest discrepancies were observed in patients with small ventricular volumes. CONCLUSIONS: In patients undergoing diagnostic work-up for CAD, the measurement of LVEF by QGS algorithm provides high correlation and satisfactory agreement with the results of reference ultrasound method--3D echocardiography.

Optimized lymphoscintigraphy and diagnostics of lymphatic oedema of the lower extremities.

BACKGROUND: The elementary diagnostic method for the detection of lymph circulation abnormalities in extremities is lymphoscintigraphy. This method provides information on the morphology and function of the lymphatic system. However, there are no generally acceptable standards for lymphoscintigraphy, which makes judgment of its clinical usefulness very difficult. MATERIAL AND METHODS: In this work, a discussion is presented on the usefulness of static qualitative scintigraphy of the lymphatic system of lower extremities as well as of its quantitative interpretation, depending upon: (1) time measurement of radiopharmaceutical transport in the system, and (2) assessment of its regional uptake in lymph nodes. The effectiveness of visual assessment combined with each of the quantitative evaluations mentioned is also presented. RESULTS/CONCLUSIONS: Combination of visual evaluation of static scintigraphy with each of the listed quantitative procedures improves the sensitivity of lymphoscintigraphy in the diagnosis of lymphatic oedema of lower extremities without affecting the specificity of visual evaluation. Both combined methods are characterized by similar indices of diagnostic efficacy. This enables limitation of the quantitative evaluation of lymphatic scintigraphy to the measurement of the final uptake of RPh in the inguinal lymphatic nodes.

Conventional and parametric kidney scintigrams - reproducibility of semiquantitative image evaluation.

BACKGROUND: Parametric kidney scintigraphy gives the possibility of regional function distribution assessment of these organs; the clinical application of the method has thus far been limited. The usefulness of the method for the assessment of postinflammatory scars and diabetic nephropathy has been demonstrated. Preliminary data also indicate that this type of imaging allows the assessment of kidney function after extracorporeal shock wave lithotripsy. The aim of this study was the evaluation of the reproducibility of semiquantitative parametric kidney image evaluation. MATERIAL AND METHODS: The results of 98 dynamic kidney scintigraphic series were evaluated, obtained from examination of 44 patients (20 males, 24 females) with nephrolithiasis, who had been treated by means of lithotripsy. The semiquantitative assessment involved conventional renoscintigraphic images obtained from summation of scintigraphic serial records in the secretory phase, and parametric clearance images. A 5-level score was applied for assessment of both types of images, based upon numbers of detected defects of the regional function (0 - no defects; 1, 2, 3 - for 1, 2 or 3 defects, and 4 for higher numbers). Altogether, 196 kidney images were evaluated. The assessment was performed independently by 2 observers: A - an experienced specialist in nuclear medicine, who evaluated the images twice, and B - a resident physician with limited experience in the field. RESULTS: The agreement between the two evaluations by the specialist (intra-observer test) reached a level of 96% for conventional images and 90% for the parametric ones. In the inter-observer test, full agreement reached the levels of 84% and 71% for conventional and parametric images, respectively. If +/- 1 degree of the image score was taken as factual agreement, the intra-observer concordance reached 100%, and for inter-observer comparison, the agreement reached 99% and 97% for conventional and parametric images, respectively. CONCLUSIONS: The concordance of image assessment for conventional and parametric images is very good. In observations by two physicians, a somewhat closer agreement was reached for conventional than for parametric images; the difference between the two series of image assessments was small.

Biodistribution of two (131)I-IMBA preparations, differently labelled, in mice with experimental B16 melanoma tumours.

BACKGROUND: Numerous reports indicate that some iodinated compounds of benzamide derivatives display a strong affinity to the cells of melanoma. In the present report, a compound [N-(2-diethylaminoethyl)-3-iodo-4metyoxybenzamide ((131)I-IMBA)] has been prepared by two different labelling methods. Biodistribution of the injected compound was followed in mice with experimentally induced B16 melanoma tumours, and tumour/ tissue ratios were studied as a function of time post administration. MATERIAL AND METHODS: The iodinated (131)I-IMBA was obtained by means of (131)I exchange for nonradioactive iodine atoms (method I) and by means of (131)I substitution for a metalorganic group (method II). The last preparation was purified by chloroform extraction. The chemical purity was assessed by means of ascending thin layer chromatography (TLC). The biodistribution of (131)I-IMBA in C57 Black mice was studied in animals with experimentally induced B16 mice melanoma tumours. RESULTS: The mean labelling efficiency exceeded 95 and 80 % for methods I and II, respectively, at radiochemical purity > 95% in both cases. (131)I-IMBA was vividly cumulated by melanoma tumours in mice. At 24-hours post (131)I-IMBA administration the values of tumour /non-tumour ratios for the compound labelled by method II reached the following values: tumour/liver 10 +/- 3, tumour/lung 15 +/- 12, tumour/blood 153 +/- 39, tumour/intestines 176 +/- 26, tumour/kidneys 270 +/- 107, and tumour/muscle 448 +/- 82. These values exceeded, by an order of magnitude, the corresponding ratios for the same compound labelled by method I. CONCLUSIONS: High values of tumour/non-tumour ratios indicate that (131)I-IMBA could be a promising radiopharmaceutical for clinical diagnosis (staging) of melanomas in humans.

Effect of attenuation correction on normal (99)mTc-MIBI myocardial perfusion scintigrams acquired with a hybrid SPECT/CT camera.

The aim of this study was to evaluate the effect of the CT-derived attenuation correction on (99m)Tc-MIBI normal myocardial perfusion scintigrams. Rest perfusion scintigrams of patients in whom coronary artery disease was suspected, without a history or any signs in ECG of a myocardial infarction, were analysed. Patients were included in the material if their rest perfusion scintigrams were normal. This criterion was fulfilled by 61 patients (29 men and 32 women) aged between 40 and 74 (mean value 57) years, with body mass between 50 and 120 (mean value 70) kg. Tomographic reconstruction of a radionuclide study was performed with an iterative OSEM method (10 subsets, 2 iterations) sequentially without and with attenuation and scatter corrections on a dedicated Xeleris workstation, applying an ACQC tool to enable manual realignment of SPECT and CT images. SPECT studies were evaluated visually and semiquantitatively. Visual analysis of tomograms was performed with the aim of finding sites of significantly lower counts in comparison with the maximal level (in the lateral wall). Semiquantitative analysis was based on counts in 20 segments of a polar map. Attenuation correction caused a complete (in 32 of 40 - 80% of patients) or partial (in 8 of 40 - 20% of patients) filling out of all areas of lower counts in the inferior wall. However, although in the anterior wall attenuation correction caused a complete (in 11 of 35 - 31% of cases) or partial (10 of 35 - 29% of cases) filling of areas of lower counts, in 14 cases (40%) those areas remained unchanged or increased, and in 8 cases (13% of all patients) new areas of decreased counts appeared. The same was true for the apical region, in which areas of decreased counts were detected in 14 of 61 (23%) cases without attenuation correction, but after application of the correction number of apical defects, this figure grew to 22 (36%) patients. Altogether, attenuation correction reduced the total number of lower count areas from 104 to 66. Semi-quantitative analysis revealed that attenuation correction reduced nonuniformity in counts in the whole myocardium - the mean difference between segment with maximum counts and values in all segments was reduced from 17.5 +/- +/- 12% to 11.0 +/- 10.3% (p < 0.0001) in male patients, and in female patients, from 11.5 +/- 9% to 10.5 +/- 8.6%, thus equalling non-uniformities in myocardial scintigrams of both sexes. Misalignment of CT and SPECT studies was observed in 17 (28%) patients but only in 2 (3% of all patients) patients did CT realignment evidently change the attenuation corrected scintigrams. Although attenuation correction can cause artefacts, its use is justified by the reduction of the total number of areas of lower counts and the improvement of uniformity of images of normally perfused myocardium.