[Results of myocardial scintigraphy with 99mTc-tetrofosmin and dipyridamole administration in patients diagnosed of microvascular angina]. / Resultados de la gammagrafía de perfusión miocárdica con 99mTc-tetrofosmina y estímulo con dipiridamol en pacientes diagnosticados de angina microvascular.

The objective of the study was to evaluate the results of the myocardial scintigraphy with 99mTc-tetrofosmin (Tc-Tf) and pharmacological stimulation with dipyridamole in patients diagnosed of microvascular angina. The study population is made up of 50 patients discharged with the diagnosis of microvascular angina who had undergone Tc-Tf-dipyridamole. Clinical and electrical positivity appeared in 40% and 12% of the patients, respectively. Myocardial perfusion defects were found in 35 patients (70%), and were reversible in 21 (60%), fixed in 11 (21%), and combined in 3 (9%). Abnormalities were inferior, anteroseptal and lateral in 21, 18, and 2 patients, respectively. Patients with a positive exercise treadmill test, compared with those with a negative one, had more frequent perfusion abnormalities (91% vs 50%, p = 0.0327) and myocardial ischemia (64% vs 20%, p = 0.392). Women, in comparison with men, had angina (56% vs 22%, p = 0.013), and anteroseptal perfusion abnormalities (26% vs 4%, p = 0.028) more frequently. On the contrary, men had inferior perfusion abnormalities more frequently (57% vs 30%, p = 0.057). Thus, Tc-Tf-dipyridamole shows perfusion abnormalities in 70% of patients with microvascular angina (91% in patients with a positive exercise treadmill test). Scintigraphic pattern may be partially conditioned by gender in these patients.

[Usefulness of spect with 99mTc-tetrofosmin and stimulus with dipyridamole in patients with left bundle branch block of His]. / Utilidad del SPECT con 99mTc-tetrofosmin y estímulo con dipiridamol en pacientes con bloqueo completo de rama izquierda del haz de His.

BACKGROUND: In patients with left bundle branch block, the 201Tl scintigraphic studies show high sensitivity, but with low specificity, in the diagnosis of coronary artery disease. OBJECTIVE: [corrected] To assess the value of 99mTc-tetrofosmin Single Photon Emission Computed Tomography (SPECT) and dipyridamole administration in patients with left bundle branch block. METHODS: 22 patients with angina and left bundle branch block were retrospectively studied by cardiac catheterization and Tc-Tf after dipyridamole administration (0,142 mg/kg/min. i.v.) and at rest. RESULTS: The mean number of territories with perfusion defects was 1.5+/-1.0, and the average number of diseased vessels in the coronariographic study was 1.6+/-1.3 (r = 0.77, p<0.001). Sensitivity, specificity, positive predictive value, negative predictive value, total predictive value and Kappa index in the diagnosis of multivessel disease were 92%, 90%, 92%, 90%, 91% and 0.82, respectively. In the diagnosis of anterior descending artery disease, these values were 83%, 70%, 77%, 78%, 77%, and 0.54, respectively. CONCLUSION: In patients with angina and left bundle branch block, SPECT with Tc-Tf-dipyridamole is of great value in the study of coronary artery disease extension. Sensitivity and specificity for the diagnosis of anterior descending artery disease were similar to that shown in series with thallium-dipyridamole.

[Scintigraphy diagnosis of renovascular hypertension in renal transplanted patients]. / Diagnóstico gammagráfico de hipertensión renovascular en trasplantados renales.

UNLABELLED: Captopril renography (CR) has been shown to be a useful technique in the diagnosis of renovascular hypertension (RVH). This disease is a significant complication of the kidney transplanted patient so that early diagnosis would be extremely useful to preserve renal function and prevent graft loss. This work evaluates the role of CR, together with arteriography and doppler-ultrasound, in the diagnosis of RVH. MATERIALS: A total of 19 transplanted patients with clinical suspicion of RVH underwent an isotopic study, a doppler-ultrasound study and an arteriography. Scintigraphy was performed 1 hour after a 50 mg dose of captopril, with oral hydration and i.v. administration of approximately 111 MBq of 99mTc-MAG3 and 20 mg of furosemide. If abnormal, a subsequent renography in baseline conditions was performed for comparison. RESULTS: Overall, 11 patients had renovascular hypertension. Sensitivity and specificity of CR were 91% and 80% respectively, 100% and 60% for US and 91% and 100% for arteriography. The CR yielded one false positive result and 2 false negatives cases: one with 50% stenosis and one polar artery stenosis. Six patients were successfully dilated or operated. CONCLUSION: CR seems to be a reliable diagnostic tool for the diagnosis of renovascular hypertension in kidney transplanted patients.

PET evaluation of therapeutic limb perfusion in Merkel's cell carcinoma.

An 87-yr-old woman diagnosed with recurrent Merkel's cell carcinoma was treated with therapeutic limb perfusion and underwent PET scanning with 18F-fluorodeoxyglucose (FDG). PET studies were obtained before and after treatment to determine the response to the intervention. A baseline whole-body study was obtained to assess the extent and degree of disease activity. This was followed by a repeat PET scan 2 mo. later after treatment with isolated limb chemotherapy with high-dose melphalan and tumor necrosis factor-alpha. The initial scan demonstrated multiple foci of high FDG uptake in the left calf, a left supraclavicular lesion and also detected concurrent keratinizing squamous cell metastasis in the right axilla. A repeat PET study showed complete metabolic resolution of the lesions in the left calf after treatment. FDG PET may be a useful technique for staging Merkel cell carcinoma and for assessing the tumor response after therapy of this rare tumor.

Renal artery stenosis after kidney transplantation: diagnostic and therapeutic approach.

Transplant renal artery stenosis (TRAS) is a common complication after transplantation and an important cause of graft dysfunction. Many factors have been implicated as possible causes of TRAS, such as damage from trauma and atherosclerosis. We reviewed all 286 patients transplanted in our unit from January 1990 to July 1997 to study the prevalence, clinical features, and diagnostic and therapeutic approach. Thirteen patients with TRAS were identified, and their mean age was 40 +/- 15 years. The detected incidence was 4.5%. They were treated with triple therapy (prednisone, azathioprine and cyclosporine A). The mean age of the donors was 28 +/- 27 years. TRAS was diagnosed within nine months after transplant. All patients were studied with Doppler ultrasound, renography with captopril and angiography. The preferred initial therapy was percutaneous transluminal balloon renal angioplasty. Angioplasty was performed in four patients with good results. Two patients underwent surgery because angioplasty was not possible. Blood pressure control could be achieved with less antihypertensive medication after angioplasty. Transplantectomy was performed in one patient because of surgical complications. In conclusion, most patients with TRAS can be treated successfully with percutaneous transluminal angioplasty as the initial interventional treatment of choice for high-grade renal artery stenosis, and surgical revascularization is indicated when percutaneous transluminal angioplasty cannot be done or is unsuccessful.

[Integration of multimodal medical images]. / Integración de imágenes médicas multimodalidad.

Multimodality analysis is becoming a required tool in medical practice due to the development of different image techniques and new imaging processing tools. This paper is a review of the basis of medical image integration, image fusion techniques, and their clinical applications, especially addressing our experience with brain tomographic studies in nuclear medicine and radiology.

Technetium-99m-HMPAO in Tourette's syndrome on neuroleptic therapy and after withdrawal.

UNLABELLED: Both decreased and increased perfusion and metabolism have been described with PET and SPECT in different areas of the brain in patients with Gilles de la Tourette's syndrome. The aim of this study was to define the regional cerebral perfusion pattern in drug-free patients and the changes in perfusion with the usual neuroleptic treatment. METHODS: A group of 13 normal control subjects and 15 unmedicated Gilles de la Tourette's syndrome patients were studied with 99mTc-HMPAO brain SPECT. Thirteen of the initial group of patients were retested on neuroleptic treatment. A semiquantitative analysis of the images was performed. RESULTS: Decreased perfusion in orbital and anterior medial regions of both frontal lobes as well as in both temporal lobes was observed in the nontreated group compared with control subjects. With treatment, a perfusion increase in these frontal regions and in the left medial temporal cortex was observed. CONCLUSION: Neuroleptic treatment could decrease the hyperactivity of the dopaminergic system leading to improvement of the clinical symptoms and reperfusion of some previously hypoperfused regions.

[Neuroimaging techniques in the Gilles de la Tourette syndrome]. / Técnicas de neuroimagen en el síndrome de Gilles de la Tourette.

Tourette's syndrome (GdT) is a chronic neuropsychiatric disorder of unclear etiology characterized clinically by the presence of motor and phonic tics as well as a variety of behavioral and cognitive abnormalities such as Obsessive-Compulsive Disorder (TOC) and Attention Deficit Hyperactivity Disorder (ADHD). Dopaminergic pathway and movement control related structures may have some implications for pathogenesis. Neuroimaging techniques may yield relevant data for a better understanding of the symptoms and physiopathology of this disease. Among them, functional isotopic techniques such as PET and SPECT and other like quantitative EEG are the most remarkable. In this article we intend to perform a thorough review of the most recent literature, contributing with our own experience and discuss the pathogenesis of GdT.

Abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes in patients with seronegative spondylarthropathies without clinical evidence of inflammatory bowel disease.

Abdominal scintigraphy with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes is an excellent tool for evaluating disease extent and activity of intestinal lesions in patients with inflammatory bowel disease (IBD). In some cases of seronegative spondylarthropathies (SSp), IBD may remain subclinical. The aim of this study was to evaluate the presence of positive abdominal scintigraphy in patients with SSp and without clinical symptoms or signs of IBD. To this end we studied 32 patients with active SSp (European Spondylarthropathy Study Group 1991 criteria) without clinical evidence of IBD (eight had ankylosing spondylitis, four psoriatic arthritis, three reactive arthritis an 17 undifferentiated SSp) and 11 controls without SSp. All SSp and control patients received similar doses of non-steroidal anti-inflammatory drugs (NSAIDs). Abdominal scintigraphic images were obtained at 30 and 120 min after re-injection of 99mTc-HMPAO-labelled leucocytes. The 99mTc-HMPAO-labelled leucocyte scan was positive in 17 patients with SSp (53.1%) (six with ankylosing spondylitis, three with psoriatic arthritis, two with reactive arthritis and six with undifferentiated SSp). Fourteen patients scored from 2 to 4 on the intensity of uptake scale. The colon and terminal ileum were predominantly involved. Axial involvement was more frequent in patients with a positive scan than in patients with negative results (P<0.05) (64.7% vs 26.6%; odds ratio: 5). No control patient showed a positive scan. It is concluded that 99mTc-HMPAO-labelled leucocyte scan shows increased uptake among patients with SSp without evidence of IBD. These findings provide new evidence linking SSp with intestinal inflammation and suggest that in some cases a bowel-related process could contribute to the development of SSp. Long-term follow-up studies with more patients are necessary to evaluate the diagnostic and therapeutic implications of these results.

Different abdominal scintigraphy pattern in patients with ulcerative colitis, Crohn's disease and seronegative spondylarthropathies.

The aim was to analyse the abdominal scintigraphy pattern in patients with seronegative spondylarthropathy (SSp), ulcerative colitis (UC) and Crohn's disease (CD). A total of 117 patients with defined histological lesions of inflammatory bowel disease (IBD) (68 UC and 49 CD), 32 patients with active SSp [European Spondylarthropathy Study Group (ESSG) 1991 criteria] without clinical evidence of IBD and 21 controls without IBD or SSp were studied. All patients with SSp and controls received similar doses of non-steroidal anti-inflammatory drugs. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of 99m-technetium hexamethyl propylene amine oxime (99mTc-HMPAO)-labelled leucocytes. The 99mTc-HMPAO-labelled leucocyte scan was positive in 17 patients with SSp (53.1%), 45 patients with UC (66.1%) and 33 patients with CD (67.3%). Rectum and sigma involvement was more frequent in patients with UC (68.8%) than in patients with SSp (23.5%) or CD (33.3%) (P < 0.05) [odds ratios (OR): 7.1 and 4.4, respectively]. Terminal ileum involvement was more frequent in patients with CD (63.6%) than in patients with SSp (23.5%) or UC (8.8%) (P < 0.05) (OR: 5.6 and 17.9, respectively). The 99mTc-HMPAO-labelled leucocyte scan shows an increased uptake in patients with SSp without evidence of IBD. Perhaps these patients represent one end of the spectrum of IBD, but rectal and terminal ileum involvement were less frequent in patients with SSp than in patients with UC or CD.