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P Hendrickx

Publications and source records attributed to P Hendrickx.

At least 19 recordsLinked to original sources
PubMed2000

Grids and high kilo-volt-peak-setting in bedside chest radiographic examinations.

Bedside chest radiographic examinations in intensive care units with grids are impaired by artefacts caused by angulation of the grid (grid cut-off). Two different grids--a grid with a high strip density of 70 lines per cm and the "InSight portable imaging system"--were examined in an intensive care unit with respect to their susceptibility to angulation, image quality and handling of the grid. Five radiologists compared 50 radiographs of each grid considering ten image quality criteria. Using the "InSight portable imaging system" major artefacts were undetectable even at an angulation of 10%; no adjustment of the grid was required, which reduced the amount of time needed to take the radiograph by 26%. The increase in dosage demanded by the employment of the grids at low kilovolt peak setting could be partially compensated by the use of high kilovolt peak setting. The image quality of the "InSight portable imaging system" together with a high kilovolt peak setting is satisfactory, and due to its simplified handling, the portable imaging system has proved to be suitable for bedside chest radiography in intensive care.

Artifacts↗
PubMed1997

[Value of Doppler color ultrasonography in diagnosis of arterial occlusive disease of the lower extremity. A direct comparison with percutaneous angiography].

UNLABELLED: A Direct Comparison with Percutaneous Angiography: AIM: To compare colour-coded Doppler sonography (CCDS) with conventional angiography in severe occlusive vascular disease of the lower limb. METHODS: In 55 patients 1141 vessel segments were evaluated, 700 of them with atheromatous plaques, 270 with stenoses, 208 with occlusions and 6 with aneurysms. RESULTS: Deeper-seated vessels such as the abdominal aorta, the pelvic arteries, the superficial femoral artery at the level of the adductor canal and parts of the lower leg arteries are less accessible for direct CCDS. Many pathological changes however can be diagnosed indirectly by changes in the spectral wave form distal to the lesion. In superficial vascular segments (the common femoral artery, the profunda femoris artery, the superficial femoral artery above the adductor canal and the popliteal artery) image quality was excellent, more pathological changes were found, and the degree of stenosis was better estimated in comparison to angiography. CONCLUSION: The value of CCDS in patients with intermittent claudication is limited to those who have been examined with angiography e.g. before angioplasty, to follow-up examinations after vascular dilatation or surgery and to supplementary visualisation after angiography especially in readily accessible (superficial) vascular segments.

Adult↗
PubMed1997

Single i.v. bolus dose of ondansetron in the prevention of postoperative nausea and emesis.

In this placebo controlled, double blind multicentre study, the efficacy and safety of a single i.v. bolus dose of ondansetron 4 mg were evaluated in the prevention of postoperative nausea and vomiting (PONV), which remains one of the most unpleasant side effects experienced by patients postoperatively. The study population included patients having general anesthesia and undergoing major gynecological or elective abdominal surgery by laparoscopy. Thirty three percent of placebo-treated patients had at least one emetic episode over 24 hrs compared with 21% in the ondansetron group (p = 0.03). Forty two percent of placebo-treated patients experienced nausea in the 24 hours post-recovery period, compared to 27% of patients treated with ondansetron 4 mg (p = 0.01). Several factors appeared to be associated with an increased risk of developing PONV, namely gender (female), type of surgery (gynecological), experience of previous PONV and duration of anesthesia; the use of propofol was not a significant factor. Ondansetron was well tolerated, with no side effect being reported as a significant problem.

Adolescent↗
PubMed1995

[The value of color Doppler ultrasound in follow-up of percutaneous transluminal angioplasty of the thigh area].

The value of colour-coded Doppler sonography to evaluate results of percutaneous transluminal angioplasty of the superficial femoral artery was tested in 26 patients. Because of good accessibility, morphology may be demonstrated similar to intravenous DSA. However, accurate evaluation of dilatation success also requires haemodynamic measurements. Numerous parameters were determined one day before, one day after and one month after angioplasty at various points of the extremity (dilated segment, popliteal artery, lower leg arteries). Results were compared with those of normal individuals. Because of the large range of scatter and overlapping between normal and pathological values, only a few parameters can be used as valuable indicators for successful PTA. Spectral wave form becomes bi- or triphasic pattern and due to this the Pulsatility Index rises distal to the dilated area. An increasing systolic acceleration rate, peak systolic velocity and prestenotic Pulsatility Index have excellent predictive value. Using a Damping Factor, the later walking range may be predicted.

Adult↗
PubMed1995

Long-term survival after embolization of potentially lethal bleeding malignant pelvic tumours.

Transcatheter embolization was performed in 45 patients suffering from potentially lethal bleeding originating from malignant tumours in the pelvic region. In 21 cases, the basic disease was rectosigmoidal and in 20, gynaecological in origin. Uncommon bleeding sites were embolized in four other cases. The median survival time (Kaplan-Meier) was 6 months. Most patients died from tumour cachexia. In 10 cases (22%), recurrent bleeding occurred, in three of these with lethal consequences. Successful reembolization was performed on seven patients. The different embolization materials used showed a minor impact on the therapeutic result. Embolization therapy proved to be an effective measure in potentially lethal malignant pelvic bleeding. Gianturco, Anderson and Wallace (GAW) coils should be given preference where there is urgency, as they are accurate, easily and quickly insertable, and cause few complications.

Adult↗
PubMed1995

[Use of multi-grid screens in intensive care units].

Bedside chest radiographic examinations in intensive care units with grids and high kilovoltage-peak settings are impaired by artifacts caused by the angulation of the grid (grid cutoff). We have tried to optimize the use of grids in bedside chest radiographic examinations. The sensitivity to the effect of grid cutoff was examined in two grids with the same grid ratio (12:1) but different numbers of lamelle per cm (40 versus 70) using a water-phantom. The alignment of the grid in a bedside setting was optimised. 100 chest examinations in the intensive care unit were compared by five radiologists according to ten criteria. Grids with a high number of lamelle per cm (70) proved to be less sensitive to the effects of grid cutoff. By positioning the grid with the lamelle vertical to patient's body-axis, asymmetric exposure of the lungs could be avoided. In addition, this setting allows an easy alignment of the grid by adjusting the grid together with the moveable part of the patient's bed. In examinations with grids, the advantages of high kilovoltage-peak setting were apparent. Bedside radiographic examinations in intensive care units with grids with a high number of lamelle and high-kilovoltage-peak setting can be performed without any major additional effort. By this method the image quality can be improved, especially in lungs with increased scatter-radiation.

Artifacts↗
PubMed1995

Embolisation of bleeding pelvic lesions from benign origin--long-term results.

Long-term outcome and survival after emergency embolisation of life-threatening bleeding caused by non-malignant small pelvic lesions were analysed and related to the techniques and embolisation materials used. Emergency transcatheter embolisation was performed in 11 patients, heavily bleeding from uterine arteriovenous malformations (4 patients), pelvic fractures (4 patients), Endoxan induced cystitis (1 patient), haemorrhoids (1 patient) and polyposis recti (1 patient) using GAW-coils. Ethibloc and Gelfoam strips as embolisation materials, alone or in combination. Follow-up was obtained up to 7.5 years with analysis of survival. Only in one patient, with terminal hepatic insufficiency and severe disturbance of coagulation, recurrent bleeding occurred 1 month after embolisation. Two other patients died during follow-up for other reasons (cardiac insufficiency at 17 months, ileus at 52 months). Complications in relation to the embolisation therapy did not occur. In conclusion, percutaneous transcatheter embolisation is a safe and effective procedure in severe hemorrhage resulting from non-malignant lesions of the pelvis.

Adult↗
PubMed1994

[Principles of quantitative color Doppler ultrasound of pelvic and leg arteries. Normal sample].

Statistical analysis of a group of 25 healthy individuals, examined via angiodynography, shows a large range of scatter for all measured parameters in pelvic and lower extremity arteries. Blood flow and velocity values, systolic acceleration and vessel diameter decrease whereas the pulsatility index rises from the centre towards the periphery. Problem areas for morphological and quantitative evaluation are the abdominal aorta, pelvic vessels, superficial femoral artery in the distal adductor canal and the fibular artery. Nearly all vessels showed tri- or multiphasic spectral patterns. Biphasic waveform, however, may be normal in lower extremity arteries. The data yielded by colour-coded Doppler sonography were comparable to results obtained with other procedures.

Adolescent↗
PubMed1992

[Arthritic changes in small and large joints in digital and conventional x-ray images].

In order to evaluate the suitability of digital radiography for the diagnosis of skeletal abnormalities, inflammatory joint changes were used to test this technique. Early erosive changes, fine irregularities and marginal lamellar abnormalities demand a high degree of resolution from the imaging method. 6 observers studied images of the hand of 67 and of the foot of 19 patients. Joint changes were staged according to the scheme proposed by Larsen; in this study the early stages predominated. With similar techniques there were no significant differences between the digital and conventional techniques. Images of 39 large joints (knee, shoulder, elbow, ankle) were compared only subjectively since even minor differences in projection were able to obscure some erosions. However, in this case also both techniques appear to be of similar value.

Adult↗
PubMed1992

[The diagnosis of lymphatic vascular dysplasia and lymphatic fistula formation].

The importance of lymphangiography for diagnosing the formation of lymphatic fistulas and vascular dysplasias of the lymphatic vessels is on the increase within the scope of therapeutic invasiveness. Its importance and ranking in diagnosing lymphatic circular disorders is demonstrated and exemplified by case reports on three patients suffering from chylothorax of various origin, on one patient with chyluria, and one patient with lymphoedema in the soft parts of the neck. In two chylothorax patients, lymphangiography resulted in successful surgery. It is the decisive method in diagnosis and therapy planning in fistulas and dysplasias of the lymphatic vessel system.

Adult↗
PubMed1992

[The mammographic and sonographic clinical picture of cystosarcoma phyllodes].

Cystosarcoma phylloides is characterized by frequent local recurrences, by questionable tumour status and by the often large size or extension. This very rare tumour is mentioned in the literature mostly as a case report. During 1974-1989 a group of 15 cases could be collected. Starting with the different pathological and anatomical features, the typical mammographic and sonographic criteria are described. The outline of the tumour is smooth and often lobulated. The solid component has echo levels lower than the surrounding breast tissue and is mostly homogeneous. Some parts may be cystic. Endotumoral calcifications are very rare. In all cases a zone of dorsal acoustic enhancement was seen. Differential diagnosis is discussed. In large breast tumours with slow and episodic growth, the tentative diagnosis cystosarcoma phylloides should be considered more often.

Adult↗
PubMed1991

[The value of angiodynography in follow-up of surgical vascular prostheses].

Apart from the proximal anastomosis, aortoiliac/-femoral bypass is accessible to angiodynography. The spectral waves can mostly be derived and analyzed very well. Femoropopliteal grafts can be demonstrated over the whole length, including the anastomoses if they are not located in the adductor (Hunter's) canal. Pathological findings such as stenosis or aneurysms can be easily detected. Because of a large range of scatter, blood velocity or flow are no suitable parameter to determine functioning and prognosis of the bypass. A triphasic spectral waveform in the graft, the failing of aneurysms, stenosis or turbulent blood flow in the anastomosis, a high "Pulsatility Index" and a short systolic blood flow acceleration distal to the bypass, proved to be more important parameters, that can be easily determined via colour coded Doppler sonography.

Adult↗
PubMed1991

[Phantom studies using echo contrast media to improve the Doppler color sonographic imaging of the superficial femoral artery in the adductor canal].

The adductor canal was simulated using 2.6 cm muscular tissue and 2 fasciae to analyse the limits of colour-coded Doppler sonography (angiodynography) in this region. Defects in the spectral signal cause a significant underestimation of mean, peak systolic and peak diastolic (backflow) velocities and of calculated blood flow. Furthermore the pulsatility index is overestimated and the colour-coded visualisation of the arteries is almost lost. For the most part, these changes can be compensated by administration of a sonographic contrast agent (SH U 454). A minimum of 9 mg microbubbles/ml blood is required. Nevertheless, the adjustment of system controls (e.g. transducer power) becomes more difficult and an ideal setting impossible.

Contrast Media↗
PubMed1991

[Postoperative conventional tomography of the temporal bone in the assessment of inadequate perception in patients with cochlear implants].

Between August 1984 and August 1990, 166 patients received a 22-channel cochlear implant (Nucleus) in the ENT clinic in Hannover. Some of these patients who were able to understand speech nevertheless complained of inadequate perception. To study this further a phantom skull with a cochlear implant was examined by CT and by conventional tomography of the petrous bone in various image planes. The method of choice for evaluating the position and appearance of the cochlear implant proved to be conventional tomography of the petrous bone in the frontal transorbital plane. In 7/23 patients examined it was possible to demonstrate dislocation of the electrodes; this is evidently responsible for the faulty perception.

Adolescent↗
PubMed1990

[Duplex sonography: accuracy, reproducibility and possibilities for error. Checking quantitative flow measurements against an in vitro model].

Using a pulsatile model of tubes, duplex-sonographic measurements of flow were compared with actual flow. The correlation coefficient between actual and duplex-sonographically obtained flow was 0.975, mean percentage deviation being -18.1% (P less than 0.0001). The obvious scatter (margin of error -69.2 to +50%) is to be explained by the simulation closely imitating a real situation: the transducer was hand-held and tubes were placed in muscle or fat tissue. Accuracy was increased by multiple measurements, especially when taking into account only the maximal value of any series of measurements. Vessel diameter was easy to measure accurately (mean error less than 0.01% [-18.7 to +9.4%]). Repeated measurements of flow velocity had only a small scatter (coefficient of variance 0.064). In muscle or fat the Doppler signal was attenuated and the error the greater the deeper the level at which measurements were made. Low flow (common in patients with obstructive vascular disease) can also cause faulty results.

Analysis of Variance↗
PubMed1990

[A realistic cardiovascular model for evaluating clinical applicability of duplex and color-Doppler equipment].

To evaluate the accuracy and reliability of colour-coded Doppler devices (CCDD) for practical use, a circulatory phantom with in vivo characteristics was developed. The experimental design consists of a piston-diaphragm metering pump with an adjustable piston volume and frequency of stroke as well as silicone tubings with different elasticity and diameters comparable with cadaver arteries. Depending on physiological conditions, blood as a circulating fluid and the surrounding soft tissues of the artery near the Doppler probe should be employed. The transducer should be manually guided. Thus, comparable to physiological frequency spectral displays, different types of wave forms (e.g. monophasic, triphasic) were initiated to analyze the reliability of CCDDs for practical use.

Blood Flow Velocity↗