[Incidental diagnosis of lymph node tuberculosis in an 111-indium-octreotide scintigraphy during a study of acromegaly]. / Diagnóstico casual de tuberculosis ganglionar activa en una gammagrafía con octreótido-Indio 111 durante el estudio de una acromegalia.

A patient with clinical suspicion of acromegaly and no radiologic visualization of pituitary adenoma is presented. (111)In-DTPAOC scintigraphy was performed in order to localize an ectopic foci of GH production. Scintigraphy showed uptake in right paratracheal and hiliar lymph nodes that seemed residual in CT. Biopsy through mediastinoscopy showed tuberculous granulomas. After treatment, scintigraphy normalized. This case illustrate that (111)In-DTPAOC can be positive not only in tumoral but in benign pathology and, in specific cases, it can be a marker of inflammatory activity and useful for treatment monitoring.

Diagnóstico casual de tuberculosis ganglionar activa en una gammagrafía con octreótido-Indio 111 durante el estudio de una acromegalia / Causal diagnosis of lymph node tuberculosis in an 111 Indium-octreotide scintigraphy during a study of an acromegaly

Presentamos a un paciente con sospecha de acromegalia y ausencia radiológica de adenoma hipofisario al que se realizó una gammagrafía con 111In-DTPAOC para localizar un posible foco ectópico productor de hormona de crecimiento (GH). La gammagrafía mostró la existencia de adenopatías captantes paratraqueales e hiliares derechas que en la tomografía computarizada (TC) parecían residuales. La biopsia por mediastinoscopia de las adenopatías mostró la existencia de granulomas tuberculosos. Tras tratamiento tuberculostático la gammagrafía se normalizó. Este caso ilustra el hecho de que la gammagrafía con 111In-DTPAOC puede ser positiva no sólo en patología de origen tumoral, sino también en patología benigna y que en ocasiones puede ser un marcador de actividad inflamatoria y útil en la monitorización del tratamiento

A patient with clinical suspicion of acromegaly and no radiologic visualization of pituitary adenoma is presented. 111In-DTPAOC scintigraphy was performed in order to localize an ectopic foci of GH production. Scintigraphy showed uptake in right paratracheal and hiliar lymph nodes that seemed residual in CT. Biopsy through mediastinoscopy showed tuberculous granulomas. After treatment, scintigraphy normalized. This case illustrate that 111In-DTPAOC can be positive not only in tumoral but in benign pathology and, in specific cases, it can be a marker of inflammatory activity and useful for treatment monitoring

[Does brain blood flow HMPAO SPECT withhold the vascular etiopathogenic theory of transient global amnesia?]. / Apoya el SPECT de perfusión cerebral la teoría etiopatogénica vascular de la amnesia global transitoria?

INTRODUCTION: Transient global amnesia (TGA) is a neurological disorder that consists in a sudden loss of anterograd memory and temporospatial disorientation during less than 24 hours. Several precipitating factors have been reported. Conventional neuroimaging scans usually are negative. Different etiopathogenic theories have been postulated but the vascular etiology is the most commonly accepted. CASE REPORTS: Three patients with a typical presentation of TGA are studied. In all of them two brain blood flow HMPAO SPECT were performed, within the first 48 hours from the onset and three months after as an evolutive control. The first patient showed a left temporal perfusion defect and temporoparietal hypoperfusion. The second showed frontotemporal hypoperfusion, temporal mesial defect and hypoperfusion in basal ganglia, all in the left side. The third patient showed thalamic hyperperfusion and cerebellum hypoperfusion, both in the left. In all of them, control SPECT normalized. CONCLUSION: Three etiopatogenic theories about TGA have been reported: epilepsy, migraine and blood flow impairment. In TGA neuroanatomic image and neurophysiologic studies usually do not show significative alterations. Conversely, functional studies as brain blood flow HMPAO SPECT, do show changes being the most common bilateral temporobasal hypoperfusion, although this is not the only pattern described. Causes of this variable behaviour remain unclear but can be related to different clinic expressions and, over all, to time of evolution from onset. The three cases in this study show three different perfusion patterns reported in TGA and all of them withhold the vascular etiopathogenic theory.

¿Apoya el SPECT de perfusión cerebral la teoría etiopatogénica vascular de la amnesia global transitoria? / Does brain blood flow hmpao spect withhold the vascular etiopathogenic theory of transient global amnesia?

Introducción. La amnesia global transitoria (AGT) es un desorden neurológico consistente en una pérdida brusca de memoria anterógrada predominantemente y una desorientación temporoespacial cuya duración es inferior a 24 horas. Se han definido múltiples factores desencadenantes. Las pruebas de imagen convencionales suelen ser negativas. Existen varias teorías etiopatogénicas, de las que la más aceptada es la de origen vascular. Casos clínicos. Se presentan tres pacientes con cuadro típico de AGT a los que se realizó un SPECT de perfusión con HMPAO dentro de las primeras 48 del inicio del episodio y un control evolutivo a los tres meses. El primero mostró un defecto de perfusión temporal izquierdo e hipoperfusión temporoparietal ipsilateral. El segundo, una hipoperfusión frontotemporal, un defecto temporal mesial e hipoperfusión de los ganglios basales, todos ellos izquierdos. El tercer paciente mostró una hiperperfusión talámica e hipoperfusión cerebelosa, ambos izquierdos. En todos ellos, el SPECT de control mostró la normalización de los hallazgos. Conclusión. Las tres teorías etiopatogénicas de la AGT postulan un origen epileptógeno, migrañoso o vascular. En la AGT, las pruebas de imagen neuroanatómica y neurofisiológicas no suelen aportar datos significativos, pero las pruebas funcionales del SPECT de perfusión sí suelen mostrar alteraciones, la más frecuente de las cuales es la hipoperfusión temporobasal bilateral, aunque no es el único patrón descrito. Las causas del patrón variable de hipoperfusión no están claras, aunque pueden estar relacionadas con cambios en la expresividad clínica y, sobre todo, en el tiempo de evolución desde el inicio de la clínica. Los tres casos mostrados ilustran tres patrones de perfusión diferentes descritos en la AGT, y todos ellos apoyan la teoría etiopatogénica vascular (AU)

Introduction. Transient global amnesia (TGA) is a neurological disorder that consists in a sudden loss of anterograd memory and temporoespatial disorientation during less than 24 hours. Several precipitating factors have been reported. Conventional neuroimaging scans usually are negative. Different etiopathogenic theories have been postulated but the vascular etiology is the most commonly accepted. Case reports. Three patients with a typical presentation of TGA are studied. In all of them two brain blood flow HMPAO SPECT were performed, within the first 48 hours from the onset and three months after as an evolutive control. The first patient showed a left temporal perfusion defect and temporoparietal hypoperfusion. The second showed frontotemporal hypoperfusion, temporal mesial defect and hypoperfusion in basal ganglia, all in the left side. The third patient showed thalamic hyperperfusion and cerebellum hypoperfusion, both in the left. In all of them, control SPECT normalized. Conclusion. Three etiopatogenic theories about TGA have been reported: epilepsy, migraine and blood flow impairment. In TGA neuroanatomic image and neurophisiologic studies usually do not show significative alterations. Conversely, functional studies as brain blood flow HMPAO SPECT, do show changes being the most common bilateral temporobasal hypoperfusion, although this is not the only pattern described. Causes of this variable behaviour remain unclear but can be related to different clinic expressions and, over all, to time of evolution from onset. The three cases in this study show three different perfusion patterns reported in TGA and all of them withhold the vascular etiopathogenic theory (AU)

Assessment of the diagnostic capacity of planar scintigraphy and SPECT with 99mTc-HMPAO-labelled leukocytes in superficial and deep sternal infections after median sternotomy.

Sternal infection is a rare complication of median sternotomy but is associated with considerable morbidity and mortality, particularly in the case of deep sternal infection (mediastinitis). Successful treatment depends on early diagnosis and on the location (deep or superficial) of the infection. Radiological techniques have many limitations, and although 67Ga scintigraphy is effective, it delays diagnosis by 48 h. We assessed the diagnostic capacity of planar scintigraphy and single photon emission computed tomography (SPECT) with 99mTc-hexamethylpropylene amine oxime (HMPAO)-labelled leukocytes in deep sternal infections after median sternotomy. We prospectively studied 41 patients with clinical suspicion of deep sternal infection 4 and 20 h after administration of the tracer. The final diagnosis was deep sternal infection in nine patients and superficial sternal infection in 10, with infection being ruled out in 22 patients. Planar scintigraphy did not detect any of the deep sternal infections at either 4 h or 20 h. SPECT correctly identified eight of the nine deep sternal infections at 4 h and all seven at 20 h, with no false positive results. Planar scintigraphy identified 16 of the 18 superficial sternal infections at 4 h and all of them at 20 h. SPECT identified 17 of these 18 infections at 4 h and all of them at 20 h. Other infections unrelated to the sternotomy were identified in seven patients. Leukocytes labelled with 99mTc-HMPAO are a highly reliable method for the early diagnosis of sternal infections after median sternotomy. Use of SPECT allows determination of the depth of the infection and differentiation of superficial from deep sternal infections. It is also possible to detect other sites of infection, thus providing alternative diagnoses.

[Follow-up in lung transplant by the study of the pulmonary epithelial permeability and the pulmonary scintigraphies of ventilation and perfusion: preliminary results]. / Seguimiento del trasplante pulmonar mediante el estudio de la permeabilidad epitelial pulmonar y las gammagrafías pulmonares de ventilación y de perfusión: resultados preliminares.

INTRODUCTION: Acute rejection is the most common complication in lung transplantation. OBJECTIVE: This work aimed to assess the contribution of pulmonary clearance of radioaerosols and relative pulmonary perfusion to diagnose acute rejection in lung transplantation. MATERIAL AND METHOD: We have designed a prospective study and present the results obtained for the preliminary phase. This work includes 5 patients who have received a lung transplantation and in whom 28 studies of pulmonary clearance of 99mTc-DTPA and relative pulmonary perfusion with 99mTc microspheres were performed. The pulmonary biopsy diagnosed 9 rejection episodes, 2 associated to CMV infection. RESULTS: The mean radioaerosol clearance time increased when the follow-up was favorable and decreased in 6 of the 9 rejection episodes, including 2 associated to CMV infection. There was only one case with decreased mean clearance time that was not associated to rejection. CONCLUSIONS: Calculating relative pulmonary perfusion can be useful in the follow-up of single lung transplantation but not in bipulmonary ones. Our results suggest that measuring 99mTc-DTPA clearance is useful to suspect a rejection episode.

Planar scintigraphy and SPET with 99Tcm-HMPAO-labelled leukocytes in patients with median sternotomy: normal patterns.

The aim of this study was to determine the normal planar and SPET patterns of the thoracic distribution of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) in 20 patients who had undergone a previous median sternotomy and without infectious complications at follow-up. The study included anterior and oblique anterior planar views at 4 and 20 h. SPET of the chest was also carried out at 4 and 20 h. At 4 h, the planar views showed low background vascular activity in the lungs and cardiac region in addition to the sternal uptake, which showed two patterns: homogeneous in five patients and heterogeneous in 15. A long and narrow defect of uptake along the sternal midline was the most characteristic finding. At 4 h, in addition to the background vascular activity in the lungs and cardiac region, the greatest uptake on SPET was in the sternum anteriorly and the marrow spine posteriorly without any focal uptake, allowing visualization of the mediastinum free of focal activity. At 20 h, both the planar and SPET images showed a higher organ-to-background ratio. Knowledge of these post-surgical patterns will make it easier to interpret planar and SPET images when 99Tcm-HMPAO-labelled leukocytes are used in the diagnosis of mediastinitis and sternal infections in patients who had previously undergone median sternotomy. Planar views were better for the assessment of sternal uptake, but SPET views were better for the direct visualization of the mediastinum by eliminating overlapping sternal uptake.

[Postoperative uptake of Ga-67 in planar scintigraphy and SPECT after median sternotomy]. / Patrones de captación postquirúrgica del Ga67 tras esternotomía media en gammagrafía planar y SPECT

Surgical alterations after median sternotomy can difficult the interpretation of scintigraphic images with Ga67. To analize the use of Ga67 scintigraphy in this patology, we wanted to know the Ga67 distribution in patients who had suffered median sternotomy. We studied 8 patients in the first month after median sternotomy without infection complication and performed planar images and SPECT. Ga67 showed uptake in liver, spleen and bone. Sternal uptake was greater or lesser than liver uptake but always showed an homogeneous distribution. No mediastinum uptake was observed. Surgical wound showed Ga67 uptake during the first week after sternotomy. To know the <> distribution of Ga67 in patients after median sternotomy allows the scan interpretation when we suspect infectous complications.

Optimization of X-ray mammography and technetium-99m methoxyisobutylisonitrile scintimammography in the diagnosis of non-palpable breast lesions.

The purpose of this study was to evaluate the contribution of technetium-99m methoxyisobutylisonitrile (MIBI) scintimammography to the early diagnosis of breast cancer in 78 patients with non-palpable breast lesions detected by mammography. In all cases biopsy was indicated and they were classified into three groups according to the mammographic findings: high (28), intermediate (30) and low (20) mammographic probability of malignancy. Histological diagnosis confirmed 37 benign and 41 malignant lesions. In the high-probability group 99mTc-MIBI scintimammography changed the four false-positives into true negatives at the expense of two false-negatives; in the intermediate group it changed nine of the 17 false-positives into true-negatives at the expense of one false-negative, and in the low-probability group it changed five of the 16 false-positives into true-negatives without false-negatives. Applying scintimammography to patients included in the intermediate and low-probability groups together, 14 of the 33 mammographic false-positives were changed into true-negatives with 1 false-negative; thus, 41% of the unnecessary biopsies would have been avoided. When MIBI scintimammography was applied to the low-probability group, the negative predictive value was 100% and the unnecessary biopsies would have been reduced by 31%.

Hepatobiliary scintigraphy for the diagnosis of bile leaks produced after T-tube removal in orthotopic liver transplantation.

Choledochocholedochostomy (CC) over a T-tube is a well-recognized technique for biliary reconstruction in orthotopic liver transplantation (OLT). Bile leaks after T-tube removal are common, having a significant morbidity. The aim of this study was to evaluate the utility of hepatobiliary scintigraphy (HBS) for diagnosing bile leaks in liver transplant patients who develop abdominal pain after T-tube removal. Twenty consecutive patients (14 males, 6 females; mean age 44 years) were studied. The interval between T-tube removal and HBS ranged from 8 to 120 h. Hepatobiliary scintigraphy was carried out after the intravenous injection of 185 MBq 99Tc(m)-mebrofenin. A final diagnosis of bile leak was based on surgical, endoscopic retrograde cholangiopancreatography (ERCP) and ultrasound data, and clinical outcome. There were 13 patients with and 7 without bile leaks. On the scintigraphic images, bile leaks were defined as activity outside the biliary tract which moved along the right paracolic gutter, or the progressive accumulation of activity related to fluid collections as seen on ultrasound. Nine of 12 patients needed surgical repair; the other 3 were treated with endoscopic sphincterotomy. One patient with a negative HBS developed an abdominal abscess after aspirative puncture of a biloma. In the seven patients without bile leaks, all scintigrams showed normal biliary transit of activity. A diagnosis of no bile leaks was based on clinical follow-up in five patients and by ERCP in two patients. Based on these results, we conclude that HBS is an effective method for the diagnosis of bile leaks after T-tube removal in liver transplant patients.

Semi-quantitative assessment of cerebral blood flow with 99mTc-HMPAO SPET in type I diabetic patients with no clinical history of cerebrovascular disease.

In 65 type I diabetic patients we prospectively evaluated brain perfusion by means of single-photon emission tomography after the injection of 740- 1110 MBq of technetium-99m hexamethylpropylene amine oxime. Thirty-five of the patients presented complications secondary to their diabetes. None showed CNS symptoms. A semiquantitative analysis was performed drawing 50 symmetrical regions of interest (ROIs) per patient. The relative contribution of each ROI to the total blood flow in each slice was compared with the relative contribution of the same ROI in a control group of ten healthy volunteers. Relative values of any ROI in the study group higher or lower than the mean +/-2 SD in respect of the same ROI in the control group were considered abnormal. The results revealed hypoperfusion in 207 ROIs in the 65 patients with diabetes mellitus: of these ROIs, 113 were frontal, 10 frontotemporal, 20 temporal, 18 parietal, 11 occipital and 35 cerebellar. A total of 137 ROIs showed hyperperfusion: 17 frontal, 3 frontotemporal, 19 temporal, 18 parietal, 19 parieto-occipital, 29 occipital and 32 cerebellar. Out of 65 type I diabetic patients, 61 showed at least one hypoperfused ROI (P = 0.0064 vs. controls) and 25 showed more than three hypoperfused ROIs. None of the control subjects showed more than three hypoperfused regions (P<0.001). The results obtained demonstrate the existence of subclinical abnormalities of brain blood perfusion in patients with type I diabetes mellitus and no history of cerebrovascular disease, thereby allowing the initiation of intensive preventive measures.

Assessment of cerebral blood flow in diabetic patients with no clinical history of neurological disease.

We assessed cerebral blood flow in 78 diabetic patients (40 Type 1 and 38 Type 2) with no previous history of central nervous system disease using 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) single photon emission tomography (SPET) and found areas of severe hypoperfusion in 36% of them. All cerebral anatomical regions showed abnormalities related to hypoperfusion, but they were most frequently seen in the fronto-temporal region, followed by the occipital and parietal regions. 99Tcm-HMPAO SPET has been shown to be able to detect subclinical alterations in blood flow in diabetes, a finding that may account for the high prevalence of cerebrovascular disease seen in these patients. This technique could, therefore, play an important role in future preventative strategies.