B. L. F. Van Eck-Smit

Reproducibility of left ventricular size, shape and mass with echocardiography, magnetic resonance imaging and radionuclide angiography in patients with anterior wall infarction : A plea for core laboratories

After myocardial infarction, left ventricular volume and ejection fraction can be assessed by echocardiography, magnetic resonance imaging and radionuclide angiography to guide therapy and determine prognosis. Whether a measured parameter gives the same results irrespective of the method used and the observer who performs the analysis is only partly known. Intra-observer and inter-observer variability were determined for echo and magnetic resonance imaging. Left ventricular ejection fraction measured by these techniques was related to radionuclide angiograms performed in the same period. Intra-observer variability for both echo and MRI was low and in most instances below 5%. Inter-observer variability for the echo and MRI measurements were substantially higher than intra-observer variability. Comparison of the three imaging modalities revealed systematic differences. Therefore, in clinical studies, left ventricular volume and function parameters have to be measured with the same technique and by the same observer in qualified core laboratories.

Quantitative scintigraphic parameters for the assessment of renal transplant patients

Radionuclide renal diagnostic studies play an important role in assessing renal allograft function especially in the early post transplant period. In the last two decades various quantitative parameters have been derived from the radionuclide renogram to facilitate and confirm the changes in perfusion and/or function of the kidney allograft. In this review article we discuss the quantitative parameters that have been used to assess graft condition with emphasis on the early post-operative period. These quantitative methods were divided into parameters used for assessing renal graft perfusion and parameters used for evaluating parenchymal function. The blood flow in renal transplants can be quantified by measuring (a) the rate of activity appearance in the kidney graft; (b) the ratio of the integral activity under the transplanted kidney and arterial curves e.g. Hilsons perfusion index and Kirchers kidney/aortic ratio; (c) calculating the renal vascular transit time by deconvolution analysis. The literature overview on these parameters showed us that they have some practical disadvantages of requiring high quality bolus injection and numerical variations related to changes in the site and size of regions of interest. In addition, the perfusion parameter values suffer from significant overlap when various graft pathologies coexist. Quantitative evaluation of the graft parenchymal extraction and excretion was assessed by parameters derived from 123I/131I-OIH, 99mTc-DTPA or 99mTc-MAG3 renograms. We review in this article a number of parenchymal parameters which include (1) plasma clearance methods like glomerular filtration rate (GFR) and effective renal plasma flow (ERPF); (2) renal transit times such as parenchymal mean transit time, Tmax, T1/2; (3) parenchymal uptake and excretion indices as the accumulation index, graft uptake capacity at 2 and 10 min, excretion index and elimination index. These indices, however, are non-specific and far from defining a specific cause for graft parenchymal dysfunction. In conclusion, despite that the literature is replete with mathematical strategies for quantitating perfusion and parenchymal functions, none of these have enough diagnostic power for specific diagnosis of graft dysfunction. In addition, no universal agreement on the use of certain quantitation parameters in transplant patients has been reached.

The value of quantitative gallium-67 single-photon emission tomography in the clinical management of malignant external otitis

Abstract.Malignant external otitis (MEO) is a severe infectious disorder usually caused by Pseudomonas aeruginosa, which most frequently affects diabetic patients. Due to its rarity, the diagnosis of MEO is often not made promptly. Extension into deeper structures or chronic osteomyelitis may occur without signs of infection on local clinical examination. Of the imaging techniques, magnetic resonance imaging provides a fairly adequate picture of the spread of the disease, but, as with computed tomography (CT) scanning and bone scintigraphy, the images remain unchanged for a long time after disease regression. The objective of this study was to establish whether quantitative gallium-67 single-photon emission tomography (SPET) represents an accurate method for the assessment of infection and, moreover, for the monitoring of therapeutic effect. Eight patients (five males, three females) with the clinical diagnosis of MEO were studied. In three patients antibiotic treatment was prolonged for several weeks because visual analysis of gallium scintigraphy still showed slightly increased uptake in the affected area on the first follow-up scan. In one patient, it was decided to stop antibiotic treatment despite a slight increase in uptake on the second follow-up scan. Lesion to non-lesion (L/NL) ratios obtained from 67Ga SPET images at initial diagnosis and during follow-up were assessed in correlation with clinical and biochemical data and with the results of CT scans. In addition to a raised erythrocyte sedimentation rate (ESR), all patients showed increased uptake on the affected side, with L/NL ratios ranging from 1.4 to 3.6 at the time of diagnosis. CT scans failed to demonstrate abnormalities in four patients. Including four scans demonstrating slightly increased uptake in the affected area, L/NL ratios after 6–8 weeks of antibiotic treatment were 1.0±0.1. Despite a persistently elevated ESR in the majority of patients, none of them demonstrated local recurrence or complications during follow-up. In all patients, leucocyte count was within the normal range throughout the course. No relation was found between the slightly increased uptake on the follow-up scans and surgical treatment. It is concluded that in addition to the visual analysis of 67Ga SPET imaging, L/NL ratios should be calculated for a more accurate assessment of disease activity in MEO. Despite visually slightly increased uptake, L/NL ratios of 1.0±0.1 during follow-up are highly indicative of complete recovery, regardless of ESR values or leucocytosis. CT scans are of little value for diagnosis or for monitoring of therapeutic effect.

Assessment of tissue viability : clinical demand and problems

Pregnancy in women with rheumatic disorders is known to be associated with risks for both the mother and fetus; however, these risks can be minimized with proper planning and careful management of the disease. In the Middle East, there are specific cultural challenges that may have a negative impact on the care that women with rheumatic disorders receive. There is a need for cross-collaboration between specialist physicians, improved awareness of rheumatic disorders among the general public and more open discussion with patients about the potential complications of pregnancy. Women in the region are often unwilling to discuss their disease with their partner and are even less likely to seek advice regarding family planning from their physician. The objective of this review is to highlight the specific challenges of pregnancy management and to discuss why establishing specialist pregnancy clinics for women with rheumatic disorders could be an effective solution. Such clinics can provide high quality care before, during and after pregnancy as shown in several European and US centers. Additionally, such clinics could be useful for the collection of pregnancy outcomes data from the Middle East, which may currently be lacking in the region, in order to highlight where further improvements can be made. With specialist care and analysis of pregnancy outcomes, the standard of care for women with rheumatic disorders in this area could be significantly improved.

Pretreatment serum lactate dehydrogenase as additional staging parameter in patients with small-cell lung carcinoma

Purpose: At present the standard staging procedure in patients with small-cell lung cancer (SCLC) is extensive, expensive and time-consuming. Furthermore, the predictive and prognostic value of the current staging system is poor. To determine the value of pretreatment clinical and biochemical parameters to predict tumour stage and to assess prognosis, a retrospective study was performed of 121 consecutive patients with newly diagnosed SCLC. Methods: On the basis of routine diagnostic procedures, 51 patients were staged as having limited disease and 70 patients as having extensive disease. During follow-up, data on tumour progression and survival were gathered. These data and the tumour stage were correlated with lactate dehydrogenase (LDH), alkaline phosphatase, liver enzymes, leucocyte count, protein, albumin, calcium, age and gender. Results: Follow-up ranged from 1 week to 96 months, during which 110 patients died. In all patients with LDH levels above 400 U/l (n = 31), metastases were found at the initial stage, whereas all patients initially staged as having limited disease and LDH levels above 240 U/l showed tumour progression. Bone and liver were found to be the most commonly involved sites, whereas the incidence of brain metastases increased during follow-up. In patients initially staged as having limited disease, no differences in survival were found between those showing local recurrence and those developing metastases during follow-up (P = 0.67). Compared to the patients initially staged as having extensive disease, the survival of both groups was significantly better (P < 0.001). Significant independent variables of survival were LDH, albumin, initial stage and gender, but LDH was the best overall predictor (P < 0.001). Conclusion: These results suggest that pretreatment LDH may be used as an additional staging parameter in SCLC, which can identify prognostic subgroups before treatment.

Myocardial SPET imaging with 99Tcm-tetrofosmin in clinical practice : Comparison of a 1 day and a 2 day imaging protocol

99Tcm-tetrofosmin is a new myocardial perfusion agent with the advantage that it can be reconstituted at room temperature. Because two separate injections are required for rest and stress images, a separate-day imaging protocol with one injection each day would be optimal in terms of image quality. From the logistical point of view, a 1 day protocol may be more convenient for the majority of those referred as outpatients. The main aim of this study was to determine whether the detection of myocardial ischaemia would be impeded by the use of a 1 day protocol instead of a 2 day protocol. A secondary aim was to establish the relative diagnostic accuracy of the two imaging strategies. 99Tcm-tetrofosmin SPET imaging was performed in 157 patients. Sixty-nine (44%) patients were administered 250 MBq (7 mCi) 99Tcm-tetrofosmin at rest followed 4 h later by 750 MBq (21 mCi) during stress (the 1 day protocol), whereas 88 (56%) patients had rest and stress imaging studies on two separate days, receiving a 500 MBq (14 mCi) dose of 99Tcm-tetrofosmin on each occasion (the 2 day protocol). With the 1 day protocol, 135 of 621 (22%) abnormal segments (i.e. both reversible and persistent defects) were observed, compared with 195 of 792 (25%) segments with the 2 day protocol. Also, the occurrence of reversible defects only did not differ between the two protocols (both 9%). The sensitivity for the detection of coronary artery disease was 83 and 90% for the 1 and 2 day protocols respectively. We conclude that the 1 and 2 day protocols provide similar scintigraphic information and are equally sensitive and specific for the detection of coronary artery disease. Therefore, the imaging protocol can be adjusted as appropriate for the patient in question.

Quantitative analysis of 99tcm-sestamibi myocardial perfusion Spect using a three-dimensional reference heart: a comparison with experienced observers

Background Quantification of myocardial perfusion single photon emission computed tomography (SPECT) may improve scintigraphic analysis. Recently, a fully operator independent technique for the quantification of myocardial perfusion SPECT was described, based on a normal three-dimensional averaged reference heart. The purpose of this study was to compare the automated SPECT quantification technique with experienced observers. Methods A total of 43 patients, 36 with one-vessel coronary artery disease (CAD) and seven with a low likelihood of CAD, underwent 99Tcm-sestamibi SPECT (99Tcm-MIBI SPECT). Three experienced observers and a panel (composed of the three observers), blinded to the clinical and angiographic data, analysed the size and severity of perfusion defects and the relation to the distribution areas of the coronary arteries. Inter-observer agreement was calculated by using kappa (κ) statistics. Results The inter-observer agreement between the human observers and the automated quantitative analysis, for severity and size of perfusion abnormality, was moderate (κ range 0.38-0.68), while this was fair between three individual observers (κ range 0.36-0.87) and good between the individual observers and the panel (κ range 0.63-0.89). There were no differences between the quantitative analysis and the panel in the allocation of perfusion abnormalities to the affected coronary artery. Conclusions The operator independent quantification method showed a moderate agreement with individual observers and a panel analysis for size and severity of perfusion abnormalities. The automatic quantification has a similar ability to assign perfusion abnormalities to the diseased coronary artery as compared to an expert panel.

Cardiac 123 I-MIBG imaging and clinical variables in risk stratification in patients with heart failure treated with beta blockers.

Both myocardial m-[123I]iodobenzylguanidine (123I-MIBG) uptake and plasma norepinephrine are markers of sympathetic activation in heart failure and have been shown to portend a poorer prognosis. However, these observations were noted before treatment with beta blockers became part of standard clinical practice. Fifty-eight patients with chronic heart failure (New York Heart Association functional class II and III, ejection fraction <35%; 53% ischaemic cardiomyopathy) were prospectively studied with a mean follow-up of 36 months. During the observational period, 17 patients (29.3%) had a predefined event (death and heart transplantation). All prognostic parameters were obtained before beta blocker therapy was initiated. In both uni- and multivariate analysis, the heart-mediastinum ratio of 123I-MIBG uptake did not correlate with cardiovascular mortality. In the multivariate Cox regression analysis, plasma norepinephrine, peak oxygen consumption, end-diastolic volume as measured by echocardiography and exercise performance during bicycling and walking had prognostic significance in patients with heart failure treated with beta blockers in addition to angiotensin-converting enzyme inhibitors.

Tc-99m tetrofosmin myocardial SPECT perfusion imaging: comparison of rest-stress and stress-rest protocols

Aim. The purpose of this study was to evaluate the diagnostic value of Tc-99m tetrofosmin SPECT myocardial perfusion scintigraphy rest/stress and stress/rest protocols for the assessment of coronary artery disease (CAD). Methods. 65 patients underwent both rest and stress SPECT imaging in a one-day protocol and coronary angiography within 2 months before or after scintigraphy. Scintigraphic data was obtained according to two different protocols; 1) rest-stress (n=18) and 2) stress-rest (n=47). Results. Scintigraphic evidence for myocardial ischaemia was found in 36 patients (55%). The overall sensitivity to detect CAD (>50% luminal stenosis) was 94% (34/36), specificity 66% (19/24), positive predictive value 77%, negative predictive value 90%. The sensitivity to detect CAD for protocols 1 and 2 were 100% and 93%, specificity 56% and 70%, positive predictive value 69% and 81% and negative predictive value 100% and 88%, respectively. The left anterior descending coronary artery showed a sensitivity (overall, protocol 1 & 2) of 78%, 75% (3/4) and 79% (15/19) and a specificity of 71%, 64% (9/14) and 75% (21/28). The right coronary artery showed a sensitivity (overall, protocol 1 & 2) of 91%, 100% (6/6) and 88% (14/16) and a specificity of 70%, 92% (11/12) and 61% (19/31). The left circumflex coronary artery showed a sensitivity (overall, protocol 1 & 2) of 50%, 67% (2/3) and 46% (6/13) and a specificity of 94%, 100% (15/15) and 91% (31/34). Conclusion. Tc-99m tetrofosmin appears to be a valuable tool in predicting significant CAD. The sensitivity and the positive predictive value are high, making this test highly appropriate for the diagnosis of CAD. The diagnostic value of the individual coronary arteries is high to moderate. No significant differences were found between both protocols.

Pretreatment serum LDH as additional staging parameter in small-cell lung carcinoma.

BACKGROUND In patients with limited disease staged small-cell lung cancer (SCLC), overall survival is still poor. Therefore, a retrospective study was carried out of 48 patients with limited disease staged SCLC to select a parameter which can identify prognostic subgroups at the time of diagnosis. MATERIALS AND METHODS Follow-up varied from 3 to 96 months during which 38 patients died. Based on clinical outcome, patients were clustered into three groups: complete remission (CR) (n = 16); local recurrence (LOC) (n = 7); and distant recurrence (DIS) (n = 25). Age, gender and pretreatment biochemical parameters were correlated with clinical outcome and survival. RESULTS No differences in survival were found in patients with LOC (14% 2-year survival) and DIS (16% 2-year survival) (P = 0.67). Patients with complete remission demonstrated a significantly better survival (75% 2-year survival). LDH was found to be the only significant correlate of both tumour progression and survival. All patients with pretreatment LDH levels > 240 IU/l (n = 13) demonstrated tumour recurrence. The survival rate of patients with LDH levels < 240 IU/l (41% 2-year survival) was much better than that of patients with LDH levels > 240 IU/l (8% 2-year survival) (P = 0.0001). CONCLUSION LDH may be used for the identification of prognostic subgroups in limited disease SCLC. Patients showing pretreatment LDH levels > 240 IU/l have an extremely high risk of tumour recurrence, whereas survival is poor. In patients with LDH levels, < 240 IU/l survival is significantly better.