Pharyngeal clearance and pharyngeal transit time determined by a biomagnetic method in normal humans.

Clearance and transit time are parameters of great value in studies of digestive transit. Such parameters are nowadays obtained by means of scintigraphy and videofluoroscopy, with each technique having advantages and disadvantages. In this study we present a new, noninvasive method to study swallowing pharyngeal clearance (PC) and pharyngeal transit time (PTT). This new method is based on variations of magnetic flux produced by a magnetic bolus passing through the pharynx and detected by an AC biosusceptometer (ACB). These measurements may be performed in a simple way, cause no discomfort, and do not use radiation. We measured PC in 8 volunteers (7 males and 1 female, 23-33 years old) and PTT in 8 other volunteers (7 males and 1 female, 21-29 years old). PC was 0.82 +/- 0.10 s (mean +/- SD) and PTT was 0.75 +/- 0.03 s. The results were similar for PC but longer for PTT than those determined by means of other techniques. We conclude that the biomagnetic method can be used to evaluate PC and PTT.

A physiological manoeuvre to improve the positivity of the gastro-oesophageal reflux scintigraphic test.

One of the best examinations used routinely to detect gastro-oesophageal reflux (GOR) is scintigraphy and attempts are continuously being made to improve the performance of the test. We have tested a new manoeuvre to improve the results. Three hundred and twenty eight patients (190 males and 138 females, aged 1 month to 84 years, average 4.47 years) were studied after a 12 h fast period with 100 MBq of 99Tcm-phytate, 50 ml volume, directly delivered into the stomach in a mixture of orange juice. All patients were strongly suspected of having GOR. Conventional acquisition was done for 20 min, at a rate of one frame every 20 s. In the middle of the examination, small children were put in the upright position and held there for a few seconds or released in a way that allowed movement; adults were asked to stand up and walk a few metres. The test was then continued for the remaining 10 min. The global index of positivity was 64.6% (76 positive cases in the first half of the examination and 134 positive cases only after the manoeuvre). The mean of GOR episodes observed in the positive cases without the manoeuvre was 0.5 per patient, significantly different from the mean of 1.59 noted after the manoeuvre (P<0.01). In 28 cases the manoeuvre increased either the intensity or the frequency of reflux previously detected without it. We believe that this manoeuvre should be performed in all scintigraphic tests aiming to detect GOR. In the present series, the manoeuvre increased the frequency of GOR episodes.

Obtenção de matriz mineral de osso bovino e a comprovação de sua biocompatibilidade / Obtaintion of mineral matrix of bovine bone and its proof of its biocompatibility

A estrutura óssea bonina, tanto na condição de tecido cortical como medular, viabiliza através de processo termo-químico a obtenção de material mineral rico em cálcio e fósforo com características funcionais plenemente adequadas para sua aplicação como enxerto reabsorvível e condutor para reparações de defeitos ósseos. A implantação de cilindros deste material em tíbia de coelho com posterior análise histológica por microscopia de luz, eletrônica e fluorescência, comprovam a integração biocompatível com a matriz óssea original e o estímulo condutor na neoformação tecidual rico em atividade celular para a reparação óssea do leito receptor

ESR dosimetry of 89Sr and 153Sm in bone.

The radiation absorbed dose in the rabbit bone delivered by 153Sm-EDTMP (samarium ethylenediaminetetra methylene diphosphonic acid) and 89SRCl2 (strontium chloride) was measured by means of electron spin resonance (ESR). These radioisotopes are used in systemic radiotherapy for palliation of painful bone metastases. The knowledge of the dose is important in order to avoid side effects to the bone marrow. The ESR radiation dose signal was calibrated by the additive dose method using cobalt-60 gamma rays. For 153Sm-EDTMP, the bone doses in three rabbits were (4 +/- 2), (5 +/- 1) and (5 +/- 2) cGy kg/MBq. For 89SrCl2, a dose of (2 +/- 1) cGy kg/MBq was found in one rabbit.

Bone scintigraphy in testicular tumors.

PURPOSE: Testicular tumors do not occur frequently. Primary treatment is surgical, and radiotherapy and chemotherapy can play important roles in cases of metastatic disease. Bone scintigraphy is used largely for early detection of skeletal metastases from several tumors, and conventional radiographic studies are less sensitive than the nuclear technique for such a purpose. The aim of this study was to identify the role of bone scintigraphy in cases of testicular tumors, regardless of the grade. MATERIALS AND METHODS: The authors examined 28 patients (8 to 52 years old) with proved testicular tumors using Tc-99m MDP (750 MBq; 20 mCi) injected intravenously. Whole-body images were obtained 2 hours later, at 500,000 counts per image. Radiographic studies were obtained to investigate abnormal areas noted on scintigraphy. RESULTS: The results of bone scintigraphy were abnormal in seven cases, consisting of variable but diffuse uptake in the iliac bone on the same side as the affected testicle. MDP uptake was substantial in five of these patients (four seminomas, one nonseminoma; only two radiographic studies were abnormal), and the two other patients had moderate uptake of the radiopharmaceutical (two seminomas; radiographic studies were normal). Metastases were confirmed by biopsy in three cases. DISCUSSION: Early metastases from seminomas can occur through the lymphatic drainage toward the iliac lymph node chain. This could explain these findings. The scintigraphic aspects of the affected iliac bones seem characteristic. CONCLUSIONS: Early detection of metastases is very important to ensure the efficacy of radiotherapy and chemotherapy. Bone scintigraphy may play an important role in such cases and seems to be more sensitive than conventional radiography. Testicular tumor metastases should be considered when iliac involvement is observed. Paget's disease should be included in a differential diagnosis.

A scintigraphic study of oropharyngeal swallowing dynamics in Chagas' disease.

We studied oropharyngeal function in patients with Chagas' disease and oesophageal disease. Twenty-four patients with Chagas' disease, 17 of them with oesophageal disease, were submitted to scintigraphic oropharyngeal transit. A single swallow of a 10-mL bolus of water labelled with 40 MBq 99m Tc-phytate, followed by image acquisition at 20 images s-1 yielded time-activity curves in which oropharyngeal dynamics was evaluated. Thirteen normal volunteers were used as controls. Oral transit was longer for chagasics with oesophageal disease than for controls (P=0.004) or for chagasics with a normal oesophagus (P=0.028). Oesophageal filling rate, measured by the slope of the ascending aspect of the oesophageal radioactivity curve, was lower for chagasics with oesophageal disease than for controls (P=0.037). Also, maximum oesophageal filling rate was lower (P=0. 021) and occurred later (P=0.003) for chagasics with oesophageal disease than for controls. Pharyngeal clearance was positively correlated with oral transit (r=0.603, P=0.002). We conclude that chagasic oesophageal disease is associated with oral transit delay and a slower oesophageal filling rate.

The use of bone scintigraphy to detect active Hansen's disease in mutilated patients.

Mutilation of extremities was very frequent in patients affected by leprosy in the past; although it is now much less common, it is still seen, mainly in patients with long-term disease. In general, mutilation of the nose and ears is caused by the bacillus and mutilation of the hands and feet a consequence of chronic trauma. Leprosy must be chronically treated and any decision to interrupt therapy is based on laboratory tests and biopsy. Scintigraphy is a non-invasive procedure which could be of great value in to determining disease activity. We studied eight patients (five males and three females, aged 64-73 years) who presented with mutilation of the nose (2), ear (1), feet (3) or foot and hand (2). Conventional three-phase bone scintigraphy (750 MBq) and X-ray examinations of the affected areas were performed in all patients. Bone scintigraphy was abnormal in four patients (the presence of bacilli was confirmed by biopsy in two of them), and normal in the other four. In all patients except for the one with ear mutilation, radiography only showed the absence of bone. We conclude that bone scintigraphy is very useful to determine disease activity in cases of mutilation caused by leprosy. It seems to be superior to conventional radiography and may enable bone biopsies to be avoided.

Aging, esophageal motility, and gastroesophageal reflux.

OBJECTIVES: To compare esophageal motility and gastroesophageal reflux characteristics in young, middle-aged, and older healthy volunteers. DESIGN: Comparison of conventional esophageal manometry and scintigraphic study of gastroesophageal reflux in volunteers aged 20 to 30 years, 50 to 60 years, and 70 to 80 years. SETTING: Gastroenterology and nuclear medicine laboratories of a tertiary care university hospital. PARTICIPANTS: Forty healthy adult volunteers recruited from the community, 20 aged 20 to 30 years, 10 aged 50 to 60 years, and 10 aged from 70 to 80 years. MEASUREMENTS: Each volunteer underwent conventional esophageal manometry and scintigraphic study of gastroesophageal reflux. Contractile wave amplitude, duration, velocity, and lower esophageal sphincter relaxation duration, as well as the presence of abnormal peristalsis, were correlated with the proportion of volunteers with gastroesophageal reflux and the number and duration of gastroesophageal reflux episodes. RESULTS: Quantitative manometric parameters showed no correlation with gastroesophageal reflux patterns. Abnormal peristalsis was found more frequently in the older volunteers. The number of gastroesophageal reflux episodes per volunteer was similar in the three age groups, but the duration of gastroesophageal reflux episodes was longer in the older volunteers. CONCLUSION: Healthy older persons have impaired clearance of refluxed materials associated with a high incidence of defective esophageal peristalsis. This may explain the higher severity of reflux esophagitis in older people.

An improved mouth-piece to prevent environmental contamination during radioaerosol inhalation procedures.

The literature suggests that environmental contamination is common during labeled aerosol inhalation procedures in nuclear medicine. We have tested an adherent mask to prevent environmental contamination in 70 procedures. Two groups of patients were evaluated. Group 1 (60 inhalation cases in which the mask was used) presented no environmental contamination in 95% of the procedures (means of 553 dpm and 596 dpm before and after inhalation, p > 0.05, mean of the differences before/after inhalation 6.95, SD = 21.2 dpm) and the only 3 cases in which contamination did occur concerned bearded men; Group 2 (10 inhalation cases in which the mask was not used) showed large increases of environmental radioactive levels in 70% of the procedures (means of 601 dpm and 2,756 dpm before and after inhalation, p < 0.05, mean of the differences 3,066, SD = 2,98 dpm). We conclude that such a mask is very helpful in avoiding environmental contamination during radioaerosol inhalation procedures.

Oesophageal transit time evaluated by a biomagnetic method.

The aim of this work was to determine the oesophageal transit time (OTT) of a bolus using the biomagnetic technique and compare the results to those obtained by means of scintigraphy. For the biomagnetic evaluation, a test meal (yoghurt) uniformly labelled with 5 g of powder ferrite was swallowed in a single gulp by 19 normal volunteers in the upright position. One sensor (first order gradiometer) was placed at the furcula and a second one at the xiphoid process to detect the passage of the test meal and the magnetic signal output was recorded in a computer. The OTT was determined by plotting the voltage signal against time. The scintigraphic technique was used in the same volunteers: the test meal was labelled with less than 350 MBq of 99mTc-phytate and swallowed in the same way. The bolus transit was recorded at 4 frames s(-1) (100-120 frames acquisition) and the OTT was determined by drawing two regions of interest in the same areas as the sensors. The results were determined by plotting counts against time. The averages for OTTs were 3.8 +/- 0.8 s for the scintigraphic technique and 4.6 +/- 0.9 s for the biomagnetic technique. Although scintigraphic OTT was significantly shorter than magnetic OTT, there was a significant correlation between them. We conclude that the biomagnetic study may be used to evaluate OTT.

A novel biomagnetic method to study gastric antral contractions.

A novel non-invasive method to study the motion associated with gastric antral contractions is discussed. The method is based on magnetic flux changes detected by an a.c. biosusceptometer, produced by a magnetic test meal within the stomach. Measurements are made at the surface of the torso and are easy to perform. Simultaneous measurements were made with electrogastrography and scintigraphy showing remarkable coincidence. The effect of a drug on the amplitude of antral contractions was also assayed with the new method.

Rapid distal small bowel transit associated with sympathetic denervation in type I diabetes mellitus.

BACKGROUND: The pattern of progression of a meal from the stomach to the caecum in diabetes mellitus is controversial and the differential roles of transit through the jejunum and the ileum have not been investigated in diabetes. AIMS: To determine gastric emptying and transit rates through proximal and distal regions of the small bowel in type I diabetic patients. SUBJECTS: The study included six diabetic patients with evidence of autonomic neuropathy (DM-AN group), 11 diabetics without autonomic dysfunction (DM group), and 15 control volunteers. METHODS: Gastric emptying and small bowel transit of a liquid meal were evaluated scintigraphically in these subjects. Transit through regions of interest corresponding to the proximal and distal small intestine up to the caecum was determined and correlated with gastric emptying rates, cardiovascular measurements of autonomic function, and the occurrence of diarrhoea. RESULTS: Gastric emptying and transit through the proximal small bowel were similar in the three groups. The meal arrived to the caecum significantly earlier in DM-AN patients (median; range: 55 min; 22-->180 min) than in the DM group (100 min; 44-->180 min, p < 0.05) or in controls (120 min; 80-->180 min, p < 0.02). Accumulation of chyme in the distal small bowel was decreased in DM-AN patients, who showed values for peak activity (30%; 10-55%) significantly lower than in the DM group (49%; 25-77%, p = 0.02) and controls (50%; 30-81%, p = 0.02). In DM patients (n = 17), the time of meal arrival to the caecum was significantly correlated with both orthostatic hypotension (coefficient of contingency, C = 0.53, p < 0.01) and diarrhoea (C = 0.47, p < 0.05), but not with gastric emptying rates. CONCLUSIONS: Patients with type I diabetes mellitus and sympathetic denervation have abnormally rapid transit of a liquid meal through the distal small bowel, which may play a part in diarrhoea production.

Age-related reduction in 99Tcm-DTPA alveolar-capillary clearance in normal humans.

Age is known to reduce the efficacy of body organs and systems, even in the absence of disease. The alveolar-capillary clearance (ACC) rate is representative of the alveolar-capillary barrier's functional state. We studied 29 healthy non-smokers, who were selected after clinical and radiographic evaluation. The patients were divided into three groups based on age: Group I, < or = 30 years (n = 10); Group II, 31-55 years (n = 9); Group III, > or = 56 years (n = 10). Each patient inhaled 750 MBq 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA) aerosol generated by a Venticis nebulizer (particles with a mean diameter of 1.1 microns) for 5 min. Forty frames of 30 s duration each were acquired and the ACC rates for the right and left lungs determined using a computer program. The mean ACC rates for the three groups were as follows: Group I, 1.31% min-1; Group II, 1.08% min-1; Group III, 0.76% min-1. The differences between Groups I and III (P < 0.001) and Groups II and III (P = 0.03) were shown to be significant. There was no significant difference between Groups I and II. Possible explanations for an age-related reduction in ACC rates include a reduction in the internal alveolar surface, the closure of the small airways, a reduction in the lung blood capillaries and a reduction in cardiac output. We conclude that there appears to be an age-related reduction in ACC rates in healthy non-smokers, even in the absence of clinically and radiographically detectable lung disease. However, larger studies are required.

The influence of ageing on oesophageal motility after ingestion of liquids with different viscosities.

OBJECTIVES: To verify the influence of ageing on oesophageal motility elicited by the swallowing of liquids with different viscosities. DESIGN: In order to study the effect of ageing on oesophageal function, healthy volunteers of three age groups were studied by manometric and scintigraphic methods during the swallowing of water and a high viscosity liquid. METHODS: Forty healthy volunteers (20 aged 20 to 30 years, 10 aged 50 to 60 years and 10 aged 70 to 80 years) were submitted to oesophageal manometry during 10 swallows of water, 10 swallows of sugar cane syrup and 10 "dry' swallows. Basal pressure of the upper oesophageal sphincter and the lower oesophageal sphincter, amplitude, duration and velocity of contraction and the duration of the lower oesophageal sphincter relaxation were measured. Morphology and peristalsis of contractile waves were studied. The same volunteers underwent scintigraphic oesophageal transit studies with the same boluses. Oesophageal clearance time and patterns of transit were studied. RESULTS: Water and sugar cane syrup did not differ as to quantitative contraction parameters, but sugar cane syrup led to a higher incidence of synchronous contractions. The three age groups had similar amplitude and velocity of contractile waves. The youngest group had shorter duration of contractile waves 10 and 5 cm above the lower oesophageal sphincter. The oldest group had markedly more frequent synchronous contractions and failures of contraction after both water and sugar cane syrup swallows. This was associated with a high incidence of scintigraphic transit abnormalities in this group. CONCLUSION: Abnormal oesophageal peristalsis and incomplete oesophageal emptying of both low and high viscosity liquids are significantly more frequent in healthy elderly persons than in younger persons.

Uma nova proposta para o estudo do trânito esofagiano através das técnicas biomagnéticas e cintilográficas / New proposal for esophageal transit study by biomagnetic and scintigraphic techniques

Apresentamos neste trabalho os resultados iniciais de uma nova proposta de aparato para o estudo do tempo de trânsito esofagiano em voluntários assintomáticos de um bolus de alimento-teste AT (10 ml de iogurte) marcado com 5g de pó de ferrita (estudo biomagnético, B) e com 350 MBq de (99m)Tc (estudo cintilográfico, C). Para B este novo aparato consiste de uma configuração de espiras em oposição de fase excitada por um sinal senoidal de 10 kHz. O sinal de resposta é obtido quando o AT passa entre os arranjos de bobinas posicionadas sobre as regiões de interesse (ROIs) do esôfago (fúrcula, F, e apêndice xifóide, X) produzindo um sinal de tensão medido por um amplificador lock-in Stanford SR530. Para C marcamos as ROIs com reparos posicionados sobre F e X. Usamos uma câmara de circulação Orbiter Siemens para as aquisições dinâmicas de deglutição. A análise dos dados foi feita em um microcomputador PC 386. Os resultados foram (4.1+0.7)s para B e (3.7+0.9) s para C (R=0.6, P<0.07)

Abstract - This work shows the initial results for a new apparatus to study the esophageal transit time in assymptomatic persons for a yogurt bolus ( 1 O mi) uniformely labeled with 5g of ferrite powder (biomagnetic study. B) or 350MBq of 99mTc (scintigraphic study, C). For the B study the detection is made by means two pair of coils in opposite phase excited by a 1 O kHz sinusoidal voltage. We obtainted the signal response when the bolus traverses the coils placed on the regions-of-interest (RO!s) of the esophagus (furcula, F, and xiphoid process, X) and produces a signal voltage that is measured by a lock-in amplifier Stanford SR530. For C studies an Orbiter Siemens scintilation camera is used linked to a computer. The data analysis shows a (4.1±0.7)s in B studies and (3.7±0.9) s in C studies ( R=0.6, P<0.07 )

Tempo de trânsito faringeano medido através dos métodos cintilográfico e biomagnético / Pharyngeal transit time measured by of scintilographic and biomagnetic methods

Apesar do método Cintilográfico se mostrar o melhor estabelecido para o estudo do trânsito digestivo, recentemente o método Biomagnético vem sendo utilizado, possuindo algumas vantagens em relação ao Cintilográfico. O objetivo deste estudo é comparar ambos os métodos para a medida de tempo de trânsito faringeano. Foram estudados 3 voluntários, obtendo-se valores consideravelmente diferentes do método Cintilográfico, possivelmente devido a resolução do detetor biomagnético.

Abstract - The Scintigrafic method is well established to study the digestive tract motility. Nevertheless, the Biomagetic method has recently been employed and it does have some advantages over the Scintigraphic one. The aim of this study is to compare pharyngeal transit time measured by both methods. Our preliminary results indicate that there is a difference between the values obtained with each method, probabily due to the Biomagnetic detector resolution