Assessment of successful incorporation of cages after cervical or lumbar intercorporal fusion with [(18)F]fluoride positron-emission tomography/computed tomography.

The purpose of this study is to assess the successful incorporation of cages in patients after cervical or lumbar intercorporal fusion with positron-emission tomography/computed tomography (PET/CT). Twenty patients (14 female and 6 male; mean age 58 years, age range 38-73 years) with 30 cervical (n = 13) or lumbar (n = 17) intercorporal fusions were prospectively enrolled in this study. Time interval between last intercorporal intervention and PET/CT ranged from 2 to 116 months (mean 63; median 77 months). IRB approval was obtained for all patients, and written informed consent was obtained from all patients. About 30 min prior to PET/CT scanning, 97-217 MBq (mean 161 MBq) 18F-fluoride were administered intravenously. Patients were imaged in supine position on a combined PET/CT system (Discovery RX/STE, 16/64 slice CT, GE Healthcare). 3D-PET emission data were acquired for 1.5 and 2 min/bed position, respectively, and reconstructed by a fully 3D iterative algorithm (VUE Point HD) using low-dose CT data for attenuation correction. A dedicated diagnostic thin-slice CT was optionally acquired covering the fused region. Areas of increased 18F-fluoride uptake around cages were determined by one double-board certified radiologist/nuclear physician and one board certified radiologist in consensus. In 12/20 (60%) patients, increased 18F-fluoride uptake around cages was observed. Of the 30 intercorporal fusions, 15 (50%) showed increased 18F-fluoride uptake. Median time between intervention and PET/CT examination in cages with increased uptake was 37 months (2-116 months), median time between intervention and PET/CT examination in those cages without increased uptake was 91 months (19-112 months), p (Wilcoxon) = 0.01 (one-sided). 14/29 (48%) cages with a time interval > 1 year between intervention and PET/CT scan showed an increased uptake. In conclusion, PET/CT frequently shows increased 18F-fluoride uptake in cervical and lumbar cages older than 1 year (up to almost 8 years in cervical cages and 10 years in lumbar cages) possibly indicating unsuccessful fusion due to increased stress/microinstability.

The additional value of CT images interpretation in the differential diagnosis of benign vs. malignant primary bone lesions with 18F-FDG-PET/CT.

OBJECTIVE: To evaluate the value of a dedicated interpretation of the CT images in the differential diagnosis of benign vs. malignant primary bone lesions with 18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT). MATERIALS AND METHODS: In 50 consecutive patients (21 women, 29 men, mean age 36.9, age range 11-72) with suspected primary bone neoplasm conventional radiographs and 18F-FDG-PET/CT were performed. Differentiation of benign and malignant lesions was separately performed on conventional radiographs, PET alone (PET), and PET/CT with specific evaluation of the CT part. Histology served as the standard of reference in 46 cases, clinical, and imaging follow-up in four cases. RESULTS: According to the standard of reference, conventional 17 lesions were benign and 33 malignant. Sensitivity, specificity, and accuracy in assessment of malignancy was 85%, 65% and 78% for conventional radiographs, 85%, 35% and 68% for PET alone and 91%, 77% and 86% for combined PET/CT. Median SUV(max) was 3.5 for benign lesions (range 1.6-8.0) and 5.7 (range 0.8-41.7) for malignant lesions. In eight patients with bone lesions with high FDG-uptake (SUV(max) >or= 2.5) dedicated CT interpretation led to the correct diagnosis of a benign lesion (three fibrous dysplasias, two osteomyelitis, one aneurysmatic bone cyst, one fibrous cortical defect, 1 phosphaturic mesenchymal tumor). In four patients with lesions with low FDG-uptake (SUV(max) < 2.5) dedicated CT interpretation led to the correct diagnosis of a malignant lesion (three chondrosarcomas and one leiomyosarcoma). Combined PET/CT was significantly more accurate in the differentiation of benign and malignant lesions than PET alone (p = .039). There was no significant difference between PET/CT and conventional radiographs (p = .625). CONCLUSION: Dedicated interpretation of the CT part significantly improved the performance of FDG-PET/CT in differentiation of benign and malignant primary bone lesions compared to PET alone. PET/CT more commonly differentiated benign from malignant primary bone lesions compared with conventional radiographs, but this difference was not significant.

Unsuspected osteomyelitis is frequent in persistent diabetic foot ulcer and better diagnosed by MRI than by 18F-FDG PET or 99mTc-MOAB.

AIM: Prevalence, optimal diagnostic approach and consequences of clinically unsuspected osteomyelitis in diabetic foot ulcers are unclear. Early diagnosis of this infection may be crucial to ensure correct management. METHODS: We conducted a prospective study in 20 diabetic patients with a chronic foot ulcer (>8 weeks) without antibiotic pretreatment and without clinical signs for osteomyelitis to assess the prevalence of clinically unsuspected osteomyelitis and to compare the value of magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and 99mTc-labelled monoclonal antigranulocyte antibody scintigraphy (99mTc-MOAB). Those with suggestive scans underwent bone biopsy for histology (n = 7). RESULTS: Osteomyelitis was confirmed by biopsy in seven of the 20 clinically unsuspected foot ulcers. Presence of osteomyelitis was not related to age, ulcer size, ulcer duration, duration of diabetes or HbA1c. C-reactive protein was slightly elevated in patients with osteomyelitis (35.1 +/- 16.0 mg L(-1) vs. 12.2 +/- 2.6 mg L(-1) in patients with and without osteomyelitis respectively; P = 0.07). MRI was positive in six of the seven patients with proven osteomyelitis, whereas 18F-FDG PET and 99mTc-MOAB were positive only in (the same) two patients. Of the seven patients with osteomyelitis, five had lower limb amputation and in one patient the ulcer was persisting after 24 months of follow-up. In contrast, of the 13 patients without detectable signs of osteomyelitis on imaging modalities only two had lower limb amputation and two persisting ulcers. CONCLUSIONS: Clinically unsuspected osteomyelitis is frequent in persisting foot ulcers and is a high risk factor for adverse outcome. MRI appears superior to 18F-FDG PET and 99mTc-MOAB in detecting foot ulcer-associated osteomyelitis and might be the preferred imaging modality in patients with nonhealing diabetic foot ulcers.

F-18-fluorodeoxyglucose (FDG) positron-emission tomography of Echinococcus multilocularis liver lesions: prospective evaluation of its value for diagnosis and follow-up during benzimidazole therapy.

BACKGROUND: Long-term benzimidazole therapy benefits patients with non-resectable alveolar echinococcosis (AE). Methods to assess early therapeutic efficacy are lacking. Recently, AE liver lesions were reported to exhibit increased F-18-fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET). To assess the value of FDG-PET for diagnosis and follow-up of AE patients. PATIENTS/METHODS: Twenty-six consecutive patients with newly diagnosed AE were enrolled. Baseline evaluation included CT and FDG-PET. Thirteen patients (11 women; median age 50 years, range 40-76) were resected, the remaining 13 (8 women; median age 60 years, range 39-72) had non-resectable disease, were started on benzimidazoles, and CT and FDG-PET were repeated at 6, 12 and 24 months of therapy. Twelve consecutive patients with newly diagnosed cystic echinococcosis (CE) of the liver were also subjected to baseline FDG-PET. RESULTS: In 21/26 AE patients, baseline PET scans showed multifocally increased FDG uptake in the hepatic lesions' periphery, while liver lesions were FDG negative in 11/12 CE patients. Thus, sensitivity and specificity of FDG-PET for AE vs. CE were 81% and 92%, respectively. In 5 of 10 non-resectable patients with increased baseline FDG uptake, the intensity of uptake decreased (or disappeared) during benzimidazole therapy, in 3 by >or=2 grades within the initial 6 months. CONCLUSIONS: FDG-PET is a sensitive and specific adjunct in the diagnosis of suspected AE and can help in differentiating AE from CE. The rapid improvement of positive PET scans with benzimidazole therapy in some patients indicates that absent FDG uptake does not necessarily reflect parasite viability.

18F FDG-PET imaging in musculoskeletal infection.

(18)F Fluorodeoxyglucose-positron emission tomography (FDG-PET) has become an encouraging imaging modality in musculoskeletal infection. This application has an incremental value in the assessment of both acute and chronic infection and has shown to be more accurate in detecting chronic osteomyelitis than conventional radionuclide imaging. Whether FDG-PET has the potential to replace conventional scintigraphy completely depends on a number of factors, including cost and availability. Conventional radionuclide studies have represented imaging methods of choice in the diagnosis of implant-associated infection in patients with trauma so far. However, nonspecific tissue uptake of imaging agents and limited spatial resolution restrict their usefulness. Magnetic resonance imaging (MRI) and computed tomography (CT) image quality is degraded in the presence of metallic implants due to susceptibility and beam-hardening artifacts, respectively. Although its role is still evolving, FDG-PET imaging will have increased importance in patients with metallic implants used for trauma surgery because FDG uptake is not hampered by metallic artifacts. In contrast to patients with metallic implants, PET may not be as useful in the diagnosis of infection in patients with failed total joint replacements. In this situation, combined 111Indium-labeled leucocyte/(99m)Tc-sulfur colloid marrow imaging still remains the gold standard. This article reviews the currently available literature on FDG-PET and PET/CT in the diagnosis of musculoskeletal infection.

[Intima media thickness of the carotid arteries: early pointer to arteriosclerosis and therapeutic endpoint]. / Intima-Media-Dicke der Karotisarterien: Früher Indikator für Arteriosklerose und therapeutischer Endpunkt.

An early sign of atherosclerosis is hypertrophy of the arterial wall. Increased intima-media thickness (IMT) is a non-invasive marker of arterial wall alteration, which can easily be assessed in the carotid arteries by high-resolution B-mode ultrasound. There are important differences in B-mode measurements of carotid IMT between laboratories. These might concern on IMT image acquisition (in relation to the segment and/or the wall of measure) as well as determination of the echo boundary defining the IMT interfaces and the difference in relationship between anatomic and sonographic structures of the near and far arterial wall. Measurements derived from the near wall reflect thickness of a part of media and intima influenced by sonographic artefacts, rather than that of the total intima-media complex. Two main approaches are used for measuring IMT: 1) manual measurement at multiple extracranial carotid sites in near and far walls, and 2) automated computerized measurement, restricted to the far wall of the distal common carotid artery. Intra- and inter-observer variabilities have been found to vary in manual measurements between 0.09 to 0.13 mm and 0.12 to 0.18 mm (absolute differences). The best reproducibility of manual IMT-measurements is found at the far wall of the common carotid artery 1 cm from the bulb in the site of two parallel wall contours without local thickening. For automated measurements lower intra- and inter-observer variabilities have been reported. IMT of the common carotid artery is strongly influenced by age. For younger age groups (20 to 30 years) mean IMT values of 0.5 mm have been reported, while IMT values of 0.9 mm have been found for older subjects (60 to 70 years). Carotid IMT correlates with other risk factors such as systolic blood pressure, serum lipids and smoking, as well as being positively linked to the presence and extend of coronary artery disease in both women and men. The demonstration of a correlation between IMT and cardiovascular events such as stroke and myocardial infarction in clinical studies of atherosclerosis progression and cardiovascular outcomes have led to FDA accepting 2D ultrasound as a valid technique in clinical studies of atherosclerosis. Regression or slowing of progression of increased carotid IMT by various antihypertensive and lipid-lowering drugs agents have been reported. In addition to carotid IMT measurement as a predictive value of future vascular events the presence of plaques or stenosis in the carotid artery tree increases drastically the risk for cardiovascular events. Therefore the authors of this article propose the use of high resolution Duplex-Sonography for the assessment IMT of the common carotid artery as well as the detection of plaques and stenosis in clinical practice. In conclusion, high-resolution Duplex-sonography seems promising for the detection, quantification and serial investigations of structural alterations of the arterial wall. The method is sensitive enough to be applied in clinical studies of the progression and regression of early preintrusive atherosclerotic lesions in extracranial carotid arteries. Moreover IMT of the common carotid artery can be used as a therapeutic endpoint.

Antihypertensive efficacy of olmesartan compared with other antihypertensive drugs.

The therapeutic profile of olmesartan medoxomil, which is a recently developed angiotensin II (A II) receptor blocker, has been compared with four commonly used antihypertensive therapeutic drugs (atenolol, captopril, felodipine and losartan) in five separate multicentre, randomised, double-blind, parallel-group, phase III trials. The trials were designed to compare the efficacy of individually optimised dosages of olmesartan medoxomil and the comparator agent. The primary efficacy variable in all trials was the mean change from baseline to week 12 in trough mean sitting diastolic blood pressure (DBP). Olmesartan medoxomil (10-20 mg once daily (o.d.)) showed similar efficacy to atenolol (50-100 mg o.d.), both in patients with mild-to-moderate hypertension and, when given together with hydrochlorothiazide (HCTZ) 25 mg o.d., in patients with moderate-to-severe hypertension. Olmesartan medoxomil (20-40 mg o.d.) was also similar in efficacy to felodipine (5-10 mg o.d.) in reducing BP in patients with mild-to-moderate hypertension. Compared with captopril (12.5-50 mg twice daily (b.i.d.)) and losartan (50-100 mg o.d.), in patients with mild-to-moderate hypertension, olmesartan medoxomil (5-20 mg o.d. and 10-20 mg o.d., respectively) was significantly superior in terms of lowering DBP from baseline to week 12. In terms of the secondary efficacy variable, which was mean change from baseline to week 12 in trough mean sitting systolic BP, olmesartan showed significant superiority to atenolol, captopril and losartan in patients with mild-to-moderate hypertension. In the longer term, compared with losartan, a lower percentage of olmesartan-treated patients required concomitant HCTZ after 12 weeks of therapy. Olmesartan was well tolerated in all studies.

Blood pressure response, but not adverse event incidence, correlates with dose of angiotensin II antagonist.

OBJECTIVE: To assess the efficacy and safety of the novel angiotensin II antagonist olmesartan medoxomil in patients with mild to moderate essential hypertension, using a meta-analysis of the combined database from seven US and European clinical trials. DESIGN: Studies were randomized, double-blind, placebo-controlled and dose-finding (2.5-80 mg), with treatment duration of 6-52 weeks. SETTING: Hospital outpatient clinics. PATIENT POPULATION: A total of 3,095 patients in the safety population and 3,055 patients in the intent-to-treat (efficacy) population. METHODS: All studies used conventional sphygmomanometry for blood pressure measurements at trough (end of the dosing interval). Three studies also used 24-h ambulatory blood pressure monitoring for the principal efficacy evaluations. MAIN OUTCOME MEASURES: Percentage of patients achieving diastolic blood pressure (DBP) < or = 90 mmHg or decrease > or = 10 mmHg (responder rate), percentage of patients achieving a target DBP < or = 90 mmHg or target systolic blood pressure (SBP) < or = 140 mmHg (normalization rate), and mean decrease in DBP from baseline to last visit. RESULTS: Efficacy variables tended to be dose related up to the 40 mg dose level. All olmesartan medoxomil doses were statistically significantly more effective than placebo for responder rate, DBP and SBP normalization rates, and mean decrease in DBP. A clinically relevant decrease of > or = 5 mmHg from baseline in sitting DBP was also observed at doses of 20 mg and above after correction for placebo effect The safety profile of olmesartan medoxomil was similar to that of placebo and was not dose related. CONCLUSIONS: Olmesartan medoxomil was safe and highly effective in lowering blood pressure in patients with mild to moderate essential hypertension in these studies.

Relative efficacy of an angiotensin II antagonist compared with other antihypertensive agents. Olmesartan medoxomil versus antihypertensives.

OBJECTIVE: To compare the relative efficacy and safety of olmesartan medoxomil (OM) with atenolol, captopril and losartan in phase III trials on mild to severely hypertensive patients. DESIGN: Multi-centre, randomized, double-blind, parallel group, with dose-titration studies lasting 12 or 24 weeks. METHODS: Two studies respectively compared 10 mg OM once daily (o.d.) with: (1) 50 mg atenolol o.d. in moderate to severe hypertensives receiving 25 mg hydrochlorothiazide o.d. over 12 weeks; and (2) 50 mg losartan o.d. in mild to moderate hypertensives over 24 weeks, both with dose doubling at week4 if required. Study 3 compared 5 mg OM o.d. plus placebo o.d.with 12.5 mg captopril twice daily in mild to moderate hypertensives over 12 weeks, with dose doubling at weeks 4 and 8 if required. The primary outcome measure for all studies was the change from baseline to week 12 in trough mean sitting diastolic blood pressure (DBP). Safety was monitored throughout all studies. RESULTS: (1) Atenolol and OM both reduced BP effectively in moderate to severe hypertensives. OM was significantly superior to: (2) losartan (95% confidence interval for baseline to week 12 change in DBP < 0, lower limit < -3.6 mmHg); and (3) captopril (95% confidence interval for baseline to week 12 change in DBP < 0, lower limit < -4.8 mmHg) in BP reduction for mild to moderate hypertensives. Treatment with OM was safe and well tolerated. CONCLUSION: At the doses tested, olmesartan medoxomil o.d. is as effective as atenolol, and more effective than both losartan and captopril in reducing blood pressure in the hypertensive population.

Joint accumulations of FDG in whole body PET scans.

PURPOSE: To retrospectively evaluate FDG accumulations in major joints in a large series of non-absorption corrected partial body and whole body FDG-PET scans, and to determine the frequency and intensity of accumulation. MATERIALS AND METHODS: 354 consecutive PET partial- and whole body non-transmission corrected scans of patients obtained for tumor staging were examined with respect to FDG accumulations in the acromio-clavicular (AC)-, gleno-humeral-, hip-, knee- and talo-tibial joints. FDG-uptake was graded using a semi-quantitative scale from 0 (no accumulation) to 4 (very strong accumulation comparable to brain uptake). RESULTS: Joint activity of grade 1-2 was noted frequently, while grade 3 was rare, occurring only in the knee and shoulder joints, and grade 4 was inexistent. The 43 patients with grade 3 accumulations or with at least 4 joints showing grade 2 uptake were interviewed, but all denied pain specifically referred to a joint. Joint accumulations were seen in 50% of the acromio-clavicular-, 80% in the glenohumeral-, 50% in the hip-, 90% in the knee and 80% in the talo-tibial joints. The intensities of joint accumulations correlated positively and significantly with patient age, ranging from r = 0.7 and p < 0.05 in the knee to r = 0.96 and p < 0.0001 in the AC joint. CONCLUSIONS: FDG accumulations in the joints in whole body FDG-PET scans are frequent and are very likely not related to symptoms. As there is a strong age correlation, and FDG is known to accumulate in inflammatory lesions, the findings are most likely a result of sub-clinical inflammatory synovial proliferation or other chronic inflammatory processes occurring in aging joints.

Infection imaging using whole-body FDG-PET.

The purpose of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) for the detection of soft tissue and bone infections. Forty-five PET examinations in 39 patients (26 male, 13 female, age range 27-86 years) with suspected infectious foci were examined with whole- or partial-body PET scans using FDG. Twenty-seven scans were done in patients with soft tissue and 18 in patients with bone infections. Corrected and uncorrected transaxial PET images were acquired. Seven hundred and twelve body regions in these 45 PET scans were evaluated. Pathological findings were graded using a confidence scale from A to E (A, definitive infection; E, no infection). Disease status was defined in all patients by culture, biopsy or surgery and clinical follow-up. In 45 PET scans there were 40 true-positive, four false-positive and one false-negative findings. Twelve foci suspected to be infectious in nature on the basis of other imaging examinations were identified as negative by PET, thus representing true-negative findings. Sensitivities for the patients with soft tissue (STI) and bone infections (BI) and for the pooled data were 96%, 100% and 98%, respectively. As the calculation of specificity is not straightforward, it was calculated on a per lesion as well as on a per body region basis to permit estimation of an upper and a lower limit. On a per lesion basis, specificities were 70% (STI), 83% (BI) and 75% for the pooled data and on a per body region basis (dividing the body into 22 regions) they were 99% (STI), 99% (BI) and 99% for the pooled data. One false-negative result was found in a patient with cholangitis. It is concluded that PET appears to be a highly sensitive method to detect infectious foci. Specificity is more difficult to estimate, but is probably in the range from 70% to above 90%.

Magnetic resonance-based assessment of global coronary flow and flow reserve and its relation to left ventricular functional parameters: a comparison with positron emission tomography.

BACKGROUND: Measurement of coronary sinus blood flow (CSF) by phase-contrast magnetic resonance (PC-MR) imaging at rest and during hyperemia may allow noninvasive assessment of global coronary hemodynamics. METHODS AND RESULTS: Sixteen healthy volunteers (age, 22 to 32 years) were examined with MR and PET in random order within 1 to 2 days. At rest and during hyperemia (dipyridamole 0.56 mg/kg), CSF was measured by a cine PC-MR technique (temporal resolution, 40 ms; spatial resolution, 1.25x0.8 mm(2)), and myocardial blood flow (MBF) was measured by [(13)N]NH(3) PET. PET and MR agreed closely for coronary flow reserve (CFR; mean difference, 2.2+/-14.7%; Bland-Altman method). CSF divided by either total left ventricular mass or an estimate of drained myocardium (LVM(drain)) correlated highly with PET flow data (r=0.93 and 0.95, respectively) and with measures of oxygen demand, ie, heart rate, afterload-corrected fiber shortening, and peak systolic stress determined by MR (overall correlation coefficients, 0.81 and 0.87, respectively, multivariate analysis). CSF/LVM(drain) did not differ significantly from PET-derived MBF (difference, 3.6+/-16.6%). In orthotopic heart transplant recipients (n=9), CFR was reduced and blood supply-demand relationships at rest were shifted toward higher flows (P<0.0001). CONCLUSIONS: This integrated MR approach allows comprehensive assessment of autoregulated and hyperemic coronary flow and is suitable for serial measurements in patients. In transplanted hearts, elevated resting flow is the major cause of reduced CFR.

Chronic osteomyelitis of the femur: value of PET imaging.

The purpose of this report is to discuss FDG-PET as a potentially new imaging tool in the diagnosis of infections of osteosynthetic material. We present a patient with a poly-trauma who developed a chronic osteomyelitis and ostitis after repeated osteosynthesis in a fibular transplant to the left femur. Work up included MRI, antigranulocyte antibody scintigraphy and positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG). Infection of the fibular transplant was demonstrated clearly by PET but not by the other methods. Positron emission tomography may become an important indication in the diagnosis and follow-up of bone infection.

High-normal serum homocysteine concentrations are associated with an increased risk of early atherosclerotic carotid artery wall lesions in healthy subjects.

OBJECTIVE: Moderate hyperhomocysteinaemia is common in the general population and has been linked with systemic atherosclerotic vascular disease. We studied the relation of sonographically determined carotid intima-media wall thickness to serum homocysteine concentrations in asymptomatic, healthy subjects. METHODS AND RESULTS: Seventy-five male and female untreated subjects (mean age 49 years, range 22-75) with normal serum folate concentrations were included. High-resolution duplex sonography was used to determine intima-media thickness of the common carotid artery. Serum homocysteine concentration was measured by high-performance liquid chromotography with fluorescence detection. Mean intima-media thickness (+/- SD) was 0.78 +/- 0.19 mm (range 0.5-1.35) and mean serum homocysteine concentration was 10.5 +/- 2.81 micromol/l (range 5.7-19.6). In stepwise regression models, statistically significant predictors of intima-media thickness included age, body mass index, LDL cholesterol and homocysteine (R2 = 0.51). Homocysteine concentration was independently associated with intima-media thickness after adjustment for the other variables (P < 0.001) and explained an additional 18% of the variation of intima-media thickness. CONCLUSIONS: In healthy subjects, high-normal serum homocysteine concentrations are associated with an increased prevalence of carotid artery wall thickening. The significance of the contribution of homocysteine to the variation of carotid intima-media thickness, even at concentrations previously believed to be normal, suggests a role for homocysteine as an independent risk factor for early carotid artery atherosclerosis in the asymptomatic subjects.

Practicability and safety of dipyridamole cardiac imaging in patients with severe chronic obstructive pulmonary disease.

We tested the practicability of dipyridamole myocardial nitrogen-13 ammonia positron emission tomography (dipyridamole (13)NH(3 )PET) for the perioperative risk assessment of coronary artery disease (CAD) in a cohort of patients with severe chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS). Twenty consecutive LVRS candidates, 13 men and 7 women (mean age 57+/-2 years), without symptoms of CAD were prospectively studied by dipyridamole (13)NH(3 )PET. Side-effects and overall tolerance were assessed by a questionnaire and visual analogue scale. Repeated pulmonary function tests were performed before and 4, 12, 16 and 30 minutes after dipyridamole injection. All dipyridamole (13)NH(3 )PET studies were negative for CAD. Seventeen patients underwent LVRS without cardiac complications; three patients did not undergo LVRS for other reasons. Nine patients suffered intolerable dyspnoea requiring i.v. aminophylline. Mean FEV(1) decreased significantly after dipyridamole infusion: in nine patients the reduction in FEV(1)exceeded 15% from baseline. We found that dipyridamole is not well tolerated and causes significant bronchoconstriction in patients with severe COPD. Although all dipyridamole-induced side effects can be promptly reversed by aminophylline, dipyridamole cannot be recommended as a pharmacological stress in this setting.

Radiographically negative stress related bone injury. MR imaging versus two-phase bone scintigraphy.

PURPOSE: To assess the diagnostic value of MR imaging relative to two-phase bone scintigraphy in radiographically negative stress-related injuries. MATERIAL AND METHODS: Sixteen consecutive patients presenting with stress-related bone injuries and normal standard radiographs were examined with two-phase bone scans and MR imaging. MR imaging protocols varied according to the region to be examined. The MR and scintigraphic images were evaluated blindly and separately by respectively two radiologists and two nuclear medicine physicians. The standard of reference was represented by a combination of clinical and scintigraphic findings as well as clinical follow-up. RESULTS: For MR imaging, sensitivity, specificity, and positive and negative predictive values for the presence of stress-related injuries for the two readers were 69/63%, 100/80%, 100/91%, and 50/40%, respectively. Interobserver agreement was good (kappa = 0.62). For scintigraphy, all abnormal and normal findings were correctly identified. CONCLUSION: For patients with clinically suspected stress-related injuries and a low probability of other active bone diseases (such as infection or neoplasm), bone scintigraphy should be the initial imaging modality.

Whole-body positron emission tomography using fluorodeoxyglucose for staging of lymphoma: effectiveness and comparison with computed tomography.

The purpose of this study was to evaluate whole-body positron emission tomography (WB-PET) as a staging modality in Hodgkin's disease (HD) and non-Hodgkin lymphoma (NHL) and to compare it with computed tomography (CT) in a retrospective study. Seventy-one WB-PET studies using fluorodeoxyglucose (FDG) and 49 CT examinations were performed in 19 women and 31 men. Transaxial images were acquired and reformatted coronally and sagittally in PET. CT sections were obtained from the skull base to the pelvic floor. The written reports of the imaging data were compared with a reference standard constructed on the basis of all the data on the individual patients, including clinical follow-up of at least 6 months. The sensitivity and specificity of PET were, respectively, 86% and 96% for HD (n=53), and 89% and 100% for NHL (n=18). For CT sensitivity and specificity were 81% and 41% for HD (n=33) and 86% and 67% for NHL (n=16). Differences between PET and CT sensitivities were not significant, while in HD there was a significant difference in the specificity of PET and CT examinations, mainly because CT was unable to distinguish between active or recurrent disease and residual scar tissue after therapy. FDG tumour uptake was found in high- as well as low-grade NHL patients. In conclusion, PET appears to be highly sensitive and specific for staging of lymphoma. It is at least as sensitive as CT, and more specific, particularly in patients undergoing restaging, where a well-recognized diagnostic dilemma in CT is the presence of a post-therapeutic residual mass.

Comparison of the angiotensin II receptor antagonist irbesartan with atenolol for treatment of hypertension.

In this multicenter, double-blind study, the antihypertensive efficacy and safety of irbesartan were compared with those of atenolol in patients with mild-to-moderate hypertension. Following a 4- to 5-week placebo lead-in period, 231 patients with seated diastolic blood pressure (SeDBP) 95-110 mmHg were randomized to irbesartan 75 mg or atenolol 50 mg once daily for 24 weeks. Doses were doubled at Week 6 for SeDBP > or = 90 mmHg. At Week 12, or anytime thereafter, doses were doubled for SeDBP > or = 90 mmHg if not done at Week 6, and hydrochlorothiazide and then nifedipine were added. Efficacy was determined by change from baseline in blood pressure and by therapeutic response rates. Safety was assessed by monitoring adverse events (AEs). Both treatments significantly lowered blood pressure from baseline. There were no significant differences between treatment groups with respect to blood pressure changes or therapeutic response. Atenolol significantly reduced seated heart rate compared with irbesartan at Week 12. The incidences of serious AEs and discontinuations due to AEs were approximately twice as high in the atenolol group compared with the irbesartan group. Thus, in comparison to atenolol, irbesartan < or = 150 mg provided at least equivalent blood pressure control while demonstrating an excellent safety and tolerability profile.

Effects of bunazosin and atenolol on serum lipids and apolipoproteins in a randomised trial.

The effects of bunazosin and atenolol on serum lipids and lipoproteins after 6 months of treatment were compared in this multicentric, double-blind, randomised trial. A total of 174 patients with mild to moderate essential hypertension from 15 hospitals in Germany and Poland was included in the study. Eighty-seven were treated with the alpha-receptor blocker bunazosin and the same number with the beta-blocker atenolol. Systolic and diastolic blood pressure decreased significantly in both groups, whereas only atenolol decreased pulse rate. In the bunazosin group HDL-cholesterol was significantly increased after 6 months of treatment, whereas all other analysed parameters remained unchanged. In the atenolol group total cholesterol, LDL-cholesterol, total triglycerides, apolipoprotein E, VLDL-cholesterol and VLDL-triglycerides were significantly increased after 6 months of therapy. There was a significant difference between bunazosin and atenolol for total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, triglycerides, VLDL-triglycerides and apolipoprotein B levels. As a consequence, there was a significant difference in the atherogenic index of both groups. We conclude that bunazosin is favorable in the treatment of high blood pressure, because the coronary risk is not negatively influenced as shown for atenolol.