[Pseudo-stenosis of the renal artery: a possible defect of color Doppler sonography]. / Pseudostenose der Nierenarterien: Mögliche Fehler der Farbdopplersonographie.

The diagnostic value of pulsed Doppler sonography for the detection of renal artery stenosis was questioned by recent studies. Until now, the diagnostic value of colour-coded Doppler sonography of the renal arteries is not clearly defined in relation to pulsed Doppler. This study deals with specific problems of colour-coded Doppler sonography in the examination of the renal arteries. Because of basic technical principles of colour-coded Doppler sonography a stenosis can be imitated especially at the origin of the right renal artery by using a ventral approach to the vessel. This pseudo-stenosis is due to a change of colour similar to an aliasing-phenomenon in a curved vessel. In order to avoid false positive results, a laterodorsal approach to the vessel should be applied additionally. A spectral waveform should be also registered routinely.

[Noninvasive follow-up by color-coded Doppler sonography after surgical interventions on the extracranial cerebral arteries]. / Nicht-invasive Verlaufskontrolle mittels farbkodierter Doppler-Sonographie nach operativen Eingriffen an den extrakraniellen hirnversorgenden Arterien.

By means of colour-coded Doppler sonography we studied retrospectively the incidence of postoperative changes in 54 patients following 58 carotid endarterectomies. The interval between operation and ultrasound varied from one to 41 months. The overall incidence of recurrent carotid disease was 50% with a 31% (18 of 58) of hemodynamically insignificant restenoses, a 13.8% (8 of 58) incidence of haemodynamically significant restenoses, and a 5.2% (3 of 58) of occlusions. The segment that had been endarterectomized showed a bulbous dilatation in 24.1% (14 of 58). In all of these cases extensive flow reversal zones could be demonstrated, the possible importance of which is discussed. Examinations in 9 patients with reimplantation of subclavian artery to the common carotid artery and grafting technique between these arteries and in 11 patients with reimplantation of vertebral artery to the common carotid artery demonstrated one occlusion of the ipsilateral vertebral artery.

[Changes in the thoracic roentgen image in patients with acquired immune deficiency syndrome]. / Veränderungen am Thoraxröntgen bei Patienten mit dem erworbenen Immunmangelsyndrom.

Since the earliest reports of what was later termed the acquired immune deficiency syndrome (AIDS) appeared in 1980/81, with the recognition of opportunistic infections and Kaposi's sarcoma in homosexual men and i.v. drug abusers, more than 60% of AIDS patients develop pulmonary manifestations at some time in the course of their disease. Radiographic evaluation of the chest plays an important role in diagnosis. In fact, radiological changes are unspecific and either bacteriological proof or histological verification needs to be confirmed.

Intestinal phosphate and calcium absorption: joint regulation by thyroid hormones and 1,25-dihydroxyvitamin D3.

Thyroxine (T4) and triiodothyronine (T3) activate Na+-dependent inorganic phosphate (Pi) transport in organ-cultured embryonic chick small intestine. Induction of transport activity requires intact protein synthesis and can be expressed in enterocytes with varying degrees of differentiation. T3 and T4 exert their effect independent of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), which is shown to stimulate Pi uptake only in the final stage of embryonic differentiation. At this time point, a potentiating effect of 1,25(OH)2D3 and T4 on Pi transport in cultured jejunum can be demonstrated. Thyroid hormones appear to stimulate Na+ gradient-driven Pi transport without concomitantly raising (Na+-K+)-ATPase activity. T4 has no influence whatsoever on calcium uptake by cultured embryonic small intestine while 1,25(OH)2D3 is effective at all stages of embryonic development investigated (day 15-20). However, when both hormones were present in the culture medium, the effect of 1,25(OH)2D3 on calcium transport is doubled. Our results suggest that the hyperphosphataemia associated with hyperthyroidism is likely to result, at least in part, from the independent effect of thyroid hormones as well as from their potentiation of the 1,25(OH)2D3 action on Na+-dependent intestinal Pi transport. In addition, their permissive effect on 1,25(OH)2D3-induced calcium absorption provides an explanation for unaltered calcium absorption in a number of hyperthyroid patients, although reduced plasma levels of 1,25(OH)2D3 are generally observed in this condition.

Color-coded Doppler imaging of normal vertebral arteries.

Using color-coded Doppler sonography, we studied the vertebral arteries of 42 persons without history or physical signs of vertebrobasilar disease. The intertransverse portion of the vertebral artery was visualized in all persons on both sides. Its origin was visualized in 37 persons (88.1%) on the right side and in 28 (66.7%) on the left; the atlas loop was visualized in 32 persons (76.2%) on the right side and in 36 (85.7%) on the left. Four vertebral arteries were hypoplastic. Peak systolic blood velocity ranged from 19 to 98 (mean 56) cm/sec and peak diastolic blood velocity ranged from 6 to 30 (mean 17) cm/sec. Resistive indices ranged from 0.62 to 0.75 (mean 0.69). Thus, color-coded Doppler sonography seems to be a promising noninvasive method for the evaluation of hemodynamics in the extracranial portion of the vertebral arteries.

[Sonographic localization of the kidneys for the purpose of radiation treatment of the abdomen: how accurate is this method?]. / Sonographische Nierenlokalisation im Rahmen der abdominellen Strahlenbehandlung: Wie genau ist diese Methode?

In 31 patients, the kidneys were located with ultrasonography before urography was carried out. The projection of the medial, lateral, cranial and caudal margins of the kidney were marked on the patient's back with a pellet. On X-ray film, the mean distance between the pellet and margin of the kidney varied from 0.12 to 1.13 cm; nevertheless the standard deviations were high (up to 2.63 cm). In 11 patients, more than one-third of the kidney was located outside the sonographically determined borders; on the left side this happened in 10 patients. We conclude that sonographical localization of the kidneys for protection during irradiation of the abdomen should only be used when other localization procedures cannot be carried out.

[Sonographic structural analysis of the Achilles tendon and biomechanical implications]. / Sonographische Strukturanalyse der Achillessehne und biomechanische Implikationen.

Ruptures of the Achilles tendon mainly occur on the ground of predisposing destruction of tendon structure. The aim of this retrospective US study was to evaluate the location and extent of tendon abnormalities. 62 patients (49 male, 13 female; 19 to 57 years, mean 38) with achillodynia of short duration and/or clinically suspected tendon abnormalities were evaluated sonographically. Together with a review of the literature, US findings (location, extent, and echo pattern) were compared with clinical findings. With US, abnormalities could be detected with a sensitivity of 0,76 and a specificity of 0.9. Pathologic lesions could be grouped as follows: (1) pain without any clinical signs or US findings (tenalgia); (2) nodular tendinitis which in 52% appeared in the form of a tiny hypoechoic lesion in the ventromedial part of the tendon 2-3 cm proximal to the os calcis; (3) peritendinal oedema; (4) circumscribed tendon swelling, (5) extensive inhomogeneities of tendon structure. With US, abnormalities of the Achilles tendon may be detected at an early stage of the disease and hence the risk of tendon rupture may be predicted to better advantage.

Healing of Bone Affections and Gangrene with Low-Intensity Laser Irradiation in Diabetic Patients Suffering from Foot Infections.

OBJECTIVE: Evalution of low-intensity laser irradiation on the healing of bone affections and gangrene in patients suffering from diabetic microangiopathy. DESIGN: Case-report study. PATIENTS: Two consecutive diabetic male patients with gangrene, osteomyelitis, and bone fractures. INTERVENTION: Helium-neon laser irradiation (36 J/cm2 ) 50 min/day. MAIN OUTCOME PARAMETER: Healing of gangrene and corticalis lesion as well as remineralisation of bone affections. RESULTS: Within a mean period of 14 weeks not only a complete healing of the diabetic gangrenes but also a radiographically determined reestablishment of corticalis and remineralisation of preexisting bone affections could be achieved. CONCLUSION: We therefore conclude that low-intensity laser irradiation should be further tested as an additional beneficial therapeutic modality for the healing of gangrene and bone affections in diabetic patients.

Interstitial lung disease in progressive systemic sclerosis: high-resolution CT versus radiography.

High-resolution computed tomographic (HRCT) scans and chest radiographs were obtained in 23 patients with progressive systemic sclerosis (PSS) to assess the diagnostic merits of HRCT compared with chest radiography in detecting interstitial lung involvement in these patients. HRCT scans showed interstitial disease in 21 patients (91%). The most frequent finding was the so-called subpleural lines, which were demonstrated in 17 patients (74%). Honeycombing was seen in seven patients (30%), while parenchymal bands were seen in six patients (26%). Chest radiographs, on the other hand, showed definite interstitial opacification patterns in only nine patients (39%); six patients (26%) had equivocal reticular areas of attenuation, while eight patients (35%) had normal chest radiographs. Thus, HRCT is much more sensitive than chest radiography when assessing minimal interstitial lung involvement in patients with PSS.

Color Doppler imaging of inferior vena cava: identification of tumor thrombus.

Color-coded Doppler sonography (CCDS) was used for the examination of tumor thrombus (n = 7) and benign thrombosis (n = 6) of the inferior vena cava. Tumor thrombus was due to hepatocellular carcinoma in two cases and to renal cell carcinoma in five cases. Whereas no specific information about the nature of thrombus formation could be gained by gray scale sonography, a typical patchy vascularization pattern was noted within tumor thrombi in six of seven cases using CCDS. This ws due to marked neovascularization within the tumor thrombi, confirmed by histologic examination in all cases. In one patient no vascularization within the tumor thrombus could be observed by CCDS because the thrombus was relatively small. In patients with bland thrombosis, either no vascularization of the thrombus was seen (n = 5) or linear recanalization of the thrombus occurred (n = 1). Therefore, it might be possible to differentiate tumor from nontumor thrombus in the inferior vena cava by using CCDS. Further studies are needed to confirm this preliminary hypothesis.