Measurement of blood perfusion in tissue using Doppler ultrasound

A diagnostic tool for noninvasive evaluation of microcirculatory blood flow using continuous-wave CW Doppler ultrasound is presented. In this study, the properties of this method are investigated both theoretically and experimentally. The method utilizes a nondirectional CW Doppler flowmeter. Blood perfusion in tissue is shown to be proportional to the integral integral of fS (f)df where S(f) is the Doppler power spectrum and f is the Doppler frequency. The instrumentation needed to implement the method is described. Using an experimental flow model it is demonstrated that the above integral is proportional to the product between the number of scatterers in the sample volume of the Doppler probe and the mean speed of these scatterers. This is true even for low flow velocities (down to 1 mm/s). The results from in-vivo measurements on tissues in the finger, and the calf demonstrate that the method can monitor changes in the blood perfusion. It also shows the present limitations of the method due to movement artefacts.     

The incidence of recurrence and hypothyroidism following treatment with antithyroid drugs,surgery or radioiodine in all patients with thyrotoxicosis in Malmö during the period 1970–1974

The incidence of recurrence and of hypothyroidism was determined in all new patients treated for thyrotoxicosis during the period 1970-1974 in an unselected, well-defined urban population. A total of 309 patients were followed up for a median time period of 108 (1-192) months. There was a cumulative incidence of 51% recurrence in patients who were treated with antithyroid drugs for Graves' thyrotoxicosis, whereas after surgery or radioiodine treatment there were few recurrences, but 32% and 78% cumulative incidences of hypothyroidism. There were no recurrences after surgery or radioiodine treatment in patients with toxic multinodular goitre or solitary toxic adenoma, but 29% and 40% cumulative incidences of hypothyroidism following radioiodine treatment. Late hypothyroidism occurred after surgery for Graves' thyrotoxicosis, and in all groups treated with radioiodine. Thus it is advisable that all patients with Graves' thyrotoxicosis, regardless of treatment, and all patients with toxic multinodular goitre or solitary toxic adenoma treated with radioiodine, should be followed up for many years, and probably for life.     

Unilateral renal artery stenosis and hypertension. II. Angiographic findings correlated with blood pressure response after surgery

The findings at preoperative nephroangiography of 42 hypertensive patients with unilateral renal artery stenosis or occlusion were correlated with the blood pressure response following surgery and also with the preoperative renal vein renin activity ratio. A stenosis reducing luminal area by at least 90 per cent (or occlusion) and the presence of collateral circulation are considered to be highly suggestive of renovascular hypertension.     

A new ultrasonic method for fluid property measurements

A new ultrasonic method for fluid property measurements is described. The method uses ultrasound to generate acoustic streaming in a fluid. The resulting flow velocity will vary due to several viscous parameters of the fluid. If there are acoustic scatterers in the fluid, it will be possible to monitor the resulting flow velocity with an ultrasound Doppler device. The same acoustic energy is then utilized both to generate the acoustic streaming in the medium and to measure the resulting flow. The method seems to be very well suited for monitoring biological processes. Of special interest, for measurements on contaminated blood or on fluids in a fermentation process, is the method's ability to investigate liquids in a completely closed vessel.     

Unsuccessful DTIC treatment of a patient with glucagonoma syndrome

Various chemotherapeutic modalities have been tried in the treatment of patients with malignant glucagonomas. Promising results have been reported after drug treatment with dimethyltriazenoimidazole carboxamide (DTIC). We present a patient with a metastasizing pancreatic glucagonoma, in whom treatment with neither DTIC nor with the combination of streptozotocin and 5-fluorouracil resulted in any noticeable improvement.     

Evaluation of Doppler ultrasound for blood perfusion measurements.

The need to develop clinical methods for the noninvasive monitoring of regional blood perfusion, i.e., the blood flow through the very fine capillaries in body tissue, has long been felt. Hitherto existing methods exhibit limitations, such as insufficient measurement depth and poor time- or space-resolution, which restrict the measurements that can be performed. Dymling (1982) introduced a new CW Doppler ultrasound method for noninvasive blood perfusion measurement which might be one possible solution to this problem. Preliminary experiments indicated a correlation between blood flow and measured perfusion value. Unexpectedly large variations in the recorded perfusion values lead to further investigation of the method, both in vitro using a specially designed flow phantom and in vivo. This study indicates that at least some of the large variations recorded are the result of measurement errors caused by movement artifacts or ultrasonic signal interferences. Methods to diminish the effects of these artifacts are discussed.     

Unilateral versus bilateral adrenalectomy in multiple endocrine neoplasia IIA

Factors influencing the result of various forms of surgical treatment for pheochromocytoma were studied in patients with multiple endocrine neoplasia IIA (MEN IIA) syndrome. The material consisted of 18 patients belonging to 4 non-related families operated on during 1966–1981 with a mean follow-up time of 7.4 years. Twenty-seven adrenals were removed at 22 operations. In all adrenals, multiple pheochromocytomas and/or medullary hyperplasia were present. In 13 patients the first operation was a unilateral adrenalectomy. Four of these had to be reoperated on because of recurring or persisting symptoms. Five patients were operated on bilaterally at the first instance. In 4 of these, the reason was bilateral macroscopic tumor involvement. Various pre- and intraoperative findings were evaluated with respect to the surgical result. The maximum diameter of the largest tumor was the only factor relating positively to surgical success with unilateral operation. Of 9 patients who remained asymptomatic following unilateral adrenalectomy, 8 had tumors less than 5 cm in diameter. The 4 patients who had to be reoperated on with a contralateral adrenalectomy all had a maximum tumor diameter exceeding 5 cm. A pragmatic approach to the problem of timing and extent of adrenal surgery in MEN IIA is advocated. Clinical, biochemical, histopathological, genetic, and social dimensions of the disease should be taken into consideration when choosing the surgical procedure.

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Los diferentes factores que influyen sobre el resultado de las varias formas de tratamiento del feocromocitoma fueron estudiados en pacientes con el síndrome de neoplasias endocrinas múltiples 2A. El material consistió de 18 pacientes pertenecientes a 4 familias no relacionadas, durante el período 1966–1981, con un promedio de seguimiento de 7.4 años. Se removieron veintisiete suprarrenales en 22 operaciones. Se encontró que en todas las suprarrenales había feocromocitomas múltiples y/o hiperplasia medular. En 13 pacientes la operación inicial fué una adrenalectomía unilateral. Cuatro de éstos tuvieron que ser reoperados debido a síntomas recurrentes o persistentes. Cinco pacientes fueron operados bilateralmente en la primera instancia. En cuatro de éstos la razón fue la presencia de tumor macroscópico bilateral. Varios hallazgos pre e intraoperatorios fueron evaluados respecto al tratamiento quirúrgico. El diámetro máximo del tumor de mayor tamaño fue el único factor que apareció positivamente relacionado con el éxito quirúrgico de la operación unilateral. De 9 pacientes que permanecieron asintomáticos después de la adrenalectomía unilateral 8 tenían tumores de menos de 5 cm. Todos los 4 pacientes que tuvieron que ser reoperados para adrenalectomía contralateral exhibieron un diámetro máximo de tumor en exceso de 5 cm. Se aboga por un enfoque pragmático del problema de cuándo realizar la operación, así como de la extensión de la cirugía suprarrenal en casos del síndrome de NEM 2A. Deben tomarse en consideración las dimensiones clínicas, bioquímicas, histopatológicas, genéticas y sociales de la enfermedad cuando se vaya a escoger el procedimiento quirúrgico.

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Résumé Les facteurs qui exercent une influence sur les différentes formes de traitement chirurgical du phéochromocytome ont été étudiés chez des malades qui présentaient des néoplasmes endocriniens multiples de type 2A (MEN 2A syndrome). 18 sujets appartenant à 4 familles ont été opérés de 1966 à 1981, l'évolution ayant été suivie en moyenne pendant 7.4 années, 27 exérèses surrénaliennes ont été pratiquées au cours de 22 opérations. Tous les spécimens contenaient des phéochromocytomes multiples ou/et une hyperplasie médullaire. Chez 13 patients fut pratiquée une surrénalectomie unilatérale; 4 durent être réopérés pour subir l'ablation de la surrénale du côté opposé en raison de la persistance ou de la récidive des symptômes de l'affection. 5 malades subirent une double surrénalectomie d'emblée; chez 4 d'entre eux fut constaté une atteinte bilatérale des surrénales.Les découvertes pré et per-opératoires ont été étudiées en fonction du résultat du traitement chirurgical. Seul le diamètre maximum de la tumeur la plus importante a été trouvé en corrélation directe avec le succès obtenu par la surrénalectomie unilatérale. En effet des 9 opérés qui restèrent asymptomatiques après cette opération 8 présentaient des tumeurs dont le diamètre était inférieur à 5 cm. En revanche 4 des sujets qui durent etre reopérés et subir l'exérèse de l'autre surrénale présentaient des tumeurs d'un diamètre supérieur à 5 cm.Une approche pragmatique du problème du moment et de l'importance de la chirurgie surrénalienne dans le cas tumeurs multi-endocriennes est préconisée. Les facteurs cliniques, biochimiques, histo-pathologiques génétiques et sociaux doivent être pris en considération dans le choix de la thérapeutique chirurgicale.