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Biomedical subjects

G Helweg

Publications and source records attributed to G Helweg.

At least 19 recordsLinked to original sources
PubMed2002

[Diagnosis of climbing related overuse injuries].

Sport climbing shows an enormous increase in participation, evolving to more popularity, including even school sport activity on high standards. Therefore the number of climbing related injuries is increasing and becomes a more frequently encountered medical problem. Typical climbing associated injuries involve predominantly the upper limb. Overuse injuries are the most common climbing related injuries. The clinical examination is the first line investigation, which is often limited especially in the acute phase. However, an exact diagnosis is desirable for therapeutic management. Imaging modalities have shown to be capable for detection of climbing related injuries. An overview about the current use of x-ray, ultrasound and magnetic resonance imaging in different climbing related overuse injuries is presented.

Arm Injuries↗
PubMed2001

US findings in the scrotum of extreme mountain bikers.

PURPOSE: To sonographically investigate whether mountain bikers have a higher prevalence of scrotal abnormalities compared with that in nonbikers. MATERIALS AND METHODS: Eighty-five male mountain bikers (mean age, 25 years; age range, 17-45 years) and 31 healthy nonbikers (mean age, 24 years; age range, 15-37 years) were examined for scrotal findings at ultrasonography (US). Only male subjects with a history of extensive off-road biking (> or =2 h/d 6 d/wk; covered distance, >5,000 km/y) were assigned to the group of mountain bikers, whereas the control group did not engage in bicycling. In addition to clinical evaluation, US examination of the scrotum was performed by using a linear-array transducer operating at a frequency of 8.0 MHZ: RESULTS: Eighty (94%) mountain bikers had abnormal findings at scrotal US. Thirty-nine (46%) had a history of intermittent scrotal tenderness or discomfort but no severe scrotal trauma. Abnormal findings at US included scrotal calculi in 69 (81%), epididymal cysts in 39 (46%), epididymal calcifications in 34 (40%), testicular calcifications in 27 (32%), hydroceles in 24 (28%), varicoceles in nine (11%), and testicular microlithiasis in one (1%). In the control group, abnormal findings were noted in five (16%), all of whom had epididymal cysts. The overall difference in the number of scrotal abnormalities in bikers compared with the number in nonbikers was significant (P <.0001, chi2 test). CONCLUSION: US shows a significantly higher prevalence of extratesticular and testicular disorders in these mountain bikers compared with nonbikers.

Adolescent↗
PubMed2000

[Value of high-resolution ultrasound in the evaluation of finger injuries in extreme sport climbers].

AIM: To determine the value of high-resolution ultrasound in the evaluation of finger injuries and changes due to strain in the fingers of extreme rock climbers. METHODS: High-frequency ultrasound was performed on 208 fingers of 52 extreme rock climbers (mean age: 29.7 yrs) and on 80 fingers of 20 healthy volunteers (mean age: 28.5 yrs). The following parameters were sonographically assessed: thickness of the pulley-system A2, distance between phalanx and tendon (PS distance), gliding ability of the flexor tendons, and the periarticular and peri-tendinous space. The examination was performed on the handling in a supinated position with extended fingers, followed by active and passive flexion of about 40 degrees. All climbers also underwent clinical examination. RESULTS: The pulley-system of climbers showed a significantly increased thickness of 0.17 (+/- 0.09) cm compared with the healthy volunteers (p < 0.001). PS-distances of up to 0.51 (+/- 0.15) cm were found only in symptomatic climbers and proved to be a sign of tendon bow-stringing. No impairment of gliding ability was seen in both groups. Tendon sheath cysts were detected in 76% (62) of symptomatic fingers of the climbers. CONCLUSIONS: Non-invasive high-resolution ultrasound examination of fingers proved to be a very helpful method for diagnosing changes due to strain as well as finger injuries in rock climbers, especially in cases where the clinical examination was difficult to perform.

Adult↗
PubMed1999

[Assessment of renal resistance index in children with vesico-ureteral reflux].

AIM: To assess the value of the renal resistive index (RI) in evaluating renal perfusion in children with vesicoureteral reflux (VUR). METHOD: We investigated 92 kidneys in 46 children with VUR with a mean age of 6 +/- 4 years. The RI was measured at the level of the interlobar-/arcuate-arteries using a color Doppler unit Acuson 128 XP/10 (Mountain View, Cal.). The results of the RI-measurement were correlated to the findings in renal scintigraphy. RESULTS: Children with VUR grade I-III showed RI-values less than the normal physiological upper limit of 0.7. Patients with VUR grade IV-V demonstrated a significant increased RI-value of 0.77 +/- 0.07 (p < 0.0001). The correlation of the RI-measurements with the scintigraphic findings revealed a correlation-coefficient of r2 = 0.61. CONCLUSION: Changes of renal perfusion were only found in high-grade VUR, demonstrating a good correlation with the scintigraphic findings. Therefore color Doppler ultrasound seems to be helpful in the follow-up of patients with high-grade reflux.

Child↗
PubMed1999

Crossing vessels at the ureteropelvic junction: detection with contrast-enhanced color Doppler imaging.

PURPOSE: To investigate the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) preoperatively by means of contrast agent-enhanced color Doppler imaging (CDI). MATERIALS AND METHODS: Twenty-nine patients (13 female patients, 16 male patients; age range, 17-76 years; mean age, 45 years) with symptomatic UPJ obstruction were examined with CDI before and after intravenous infusion of the contrast agent. The type (i.e., arterial or venous) and position of the vessel relative to the UPJ (i.e., anterior or posterior) were assessed. The CDI findings were correlated with the surgical findings at laparoscopic pyeloplasty. RESULTS: Among the 29 patients, crossing vessels were detected with nonenhanced CDI in 15 patients, with enhanced CDI in 22 patients, and with laparoscopy in 23 patients. Enhanced CDI depicted crossing vessels in 22 (96%) of the 23 laparoscopically confirmed cases compared with nonenhanced CDI, which depicted 15 (65%) of the 23 cases. The rate of detecting crossing vessels increased significantly with use of the contrast agent (P < .016, McNemar test). CONCLUSION: Compared with nonenhanced CDI, contrast-enhanced CDI significantly improves the detection of crossing vessels at the UPJ and is useful in the presurgical evaluation of UPJ obstruction.

Adolescent↗
PubMed1998

Intraurethral ultrasound: diagnostic evaluation of the striated urethral sphincter in incontinent females.

The aim of our study was to evaluate the striated urethral sphincter (rhabdosphincter) in incontinent females by means of intraurethral ultrasound (IUUS). Thirty-four incontinent and 11 continent female patients were examined by means of 12.5-MHz endoluminal ultrasound (US). The distance between the inner contour of the sphincter muscle and the US catheter was measured in the contracted and the non-contracted condition. The US findings were correlated with those obtained by urodynamic studies. Partial or complete loss of sphincter function was detected in patients with stress urinary incontinence (SUI). Reduced sphincter function was not observed in patients with urge incontinence and continent volunteers. The findings on US were found to correlate well with the grade of SUI. The IUUS technique offers the benefit of direct visualization of the sphincter mechanism. Therefore, endoluminal US may become an important adjunct in the diagnostic evaluation of SUI and will possibly provide new insights for a better therapeutic strategy.

Adult↗
PubMed1998

Transurethral ultrasound: evaluation of anatomy and function of the rhabdosphincter of the male urethra.

PURPOSE: A combined anatomic-sonographic study was undertaken to investigate whether the anatomical arrangement and the contractions of the rhabdosphincter of the male urethra could be visualized by transurethral ultrasound. Furthermore, this new technique was compared with standard urodynamic tests. MATERIALS AND METHODS: In 7 cadavers transurethral ultrasound was performed to define sono-morphological criteria of the rhabdosphincter, and the sonographic pictures were then compared to histological sections. In 48 patients the rhabdosphincter of the male urethra was investigated by transurethral ultrasound and urodynamic techniques. Of these patients 40 were completely continent after radical prostatectomy and 8 presented with urinary stress incontinence after transurethral resection of the prostate or radical prostatectomy. The decrease of the distance between the rhabdosphincter and the transducer during contraction served as quantitative parameter for the contractility of the muscle. RESULTS: The anatomical arrangement and contractions of the rhabdosphincter loop could be clearly visualized on transurethral ultrasound (during contraction the rhabdosphincter retracts the urethra, pulling it towards the rectum). Ultrasound showed scars in 3 patients with postoperative urinary stress incontinence, thinning of the muscle in 3 complete atrophy of the rhabdosphincter in 2 and minimal contractions of the rhabdosphincter in 1. Urethral closure pressures were decreased and decrease in rhabdosphincter-transducer distance was statistically significantly decreased in the incontinent patients. CONCLUSIONS: Our sono-morphological data and anatomical histological results strongly suggest that the rhabdosphincter constitutes the main component of the continence mechanism in post-prostatectomy patients. Unlike urethral pressure profiles, which can only reveal zones of higher intraluminal pressure between the bladder and the penile urethra, transurethral ultrasound is highly specific for measurement of the function of the rhabdosphincter.

Humans↗
PubMed1996

Blood pressure changes after extracorporeal shock wave nephrolithotripsy: prediction by intrarenal resistive index.

In order to identify a high-risk group for the development of arterial hypertension after extracorporeal shock wave nephrolithotripsy (ESWL), we correlated the increase in renovascular resistance induced by ESWL in 79 normotensive patients with changes in arterial blood pressure occurring 20 (+/- 3) months after therapy. Renal vascular resistance was measured as resistive index (RI) by duplex Doppler sonography in both kidneys. Mean RI before treatment was 0.620 +/- 0.035 (SD). After treatment, we observed a significant and age-dependent increase in the RI in the treated kidney to 0.673 +/- 0.06. Of the patients with a post-ESWL RI > 0.690, 39% developed hypertension. Posttherapy RI values surpassing 0.690 showed a 0.8 sensitivity and a 0.7 specificity in predicting arterial hypertension. Intrarenal Doppler ultrasound (US) is useful to find the high-risk group for arterial hypertension after ESWL.

Adolescent↗
PubMed1996

[Ultrasound diagnosis of the shoulder].

Sonography of the shoulder joint is a well-established technique in the hands of the experienced examiner, when using a standardized protocol. It has proved invaluable in assessing pathological soft tissue changes, especially after trauma. The static evaluation of anatomy and dynamic assessment of function are especially helpful in both preoperative staging and postoperative follow-up. The normal anatomy, examination techniques, including our own variations, and pathological conditions are discussed. The findings and various classifications of impingement syndrome, rotator cuff injuries, biceps tendon lesions and inflammatory changes are examined. Review of the major articles in the literature shows excellent correlation with our results, the overall sensitivity in the case of rotator cuff lesions being over 90%. A well-performed ultrasound examination in most cases obviates the need for the more invasive arthroscopy and the more cumbersome and expensive MRI examinations.

Adolescent↗
PubMed1996

Anatomy of the eustachian tube as demonstrated by endoluminal ultrasonography.

Using a new application of the endoluminal approach, we were able to demonstrate the sonographic anatomy of the eustachian tube in vitro and in vivo and correlate it with the plastic-embedded specimen. Five adult normocephalic cadavers, two patients, and one specimen especially prepared for embedding in plastic were examined. A specifically developed device was used to insert the ultrasound transducer employing an endo-oral approach. The investigation was performed using an intravascular ultrasound unit. In all cases the tube could be visualized in its entirety and relevant anatomic structures identified and compared with the specimen at the corresponding levels. The deeper layers, including the paratubal structures and the mucosa, could be distinguished for the first time by means of endoluminal ultrasonography. Now that endoluminal ultrasonography has revealed this anatomic information, further studies will be able to gauge the clinical efficacy of our method in cases of ventilatory, drainage, and clearance problems. The images showed no difference between the structures in vitro and in vivo, and the vivo examination was even easier than the in vitro one owing to better tissue turgor.

Adult↗
PubMed1995

Variability of Doppler parameters in the healthy kidney: an anatomic-physiologic correlation.

Contradictory results have been obtained in classifying various renal diseases when trying to use the resistive index measured by duplex Doppler technique in renoparenchymal arteries. These measurements may have been influenced by the lack of standardization of the anatomic site at which the renoparenchymal artery is sampled. To elucidate this influence, we measured the resistive index, peak systolic velocity, end diastolic velocity, and pulsatility index in 120 healthy kidneys at three different positions of the renal vasculature. The resistive index at the level of the interlobar-arcuate arteries proved to be the parameter with the most consistent results and should be preferred in clinical applications.

Adult↗
PubMed1995

Age-related changes in resistive index following extracorporeal shock wave lithotripsy.

PURPOSE: Changes in intrarenal vascular resistance after extracorporeal shock wave lithotripsy (ESWL*) were studied with Doppler ultrasound techniques. MATERIALS AND METHODS: In 76 patients the resistive index was measured at an interlobar artery before and after ESWL in the treated and contralateral kidneys. The resistive index levels were compared to N-acetyl-beta-D-glucosaminidase levels in 40 patients. RESULTS: We found an age-related positive linear correlation between post-therapeutic resistive index increases and patient age. N-acetyl-beta-D-glucosaminidase levels were also elevated after ESWL but these elevations were not age-related. CONCLUSIONS: Elderly patients have a higher risk of post-ESWL renal tissue damage.

Acetylglucosaminidase↗
PubMed1994

[Eosinophilic cellulitis (Wells syndrome) with involvement of para-articular muscles and fascia].

A 62-year-old woman developed eosinophilic cellulitis of her right arm, accompanied by systemic signs (fever, leucocytosis) and massive restriction of the motility of her right shoulder joint. Sonography and computed tomography revealed massive cutaneous and subcutaneous oedema, and accumulations of fluid around the deep muscular fasciae, interstices and (less severe) within the joint. High-dose systemic corticosteroid treatment led to rapid clearing of the skin lesions, and joint motility was restored several weeks later. This is the first case of eosinophilic cellulitis in which involvement of deep structures adjacent to joints has been demonstrated by modern imaging techniques.

Administration, Oral↗
PubMed1992

[Magnetic resonance tomography in follow-up of hydatidiform mole].

The value of magnetic resonance imaging (MRI) was studied in a case of a gestational trophoblastic tumour. In addition to the tumour size, MRI made it possible to measure necrotic areas, which are assumed to be a sign of response to chemotherapy. Moreover, uterine zonal anatomy and subserosal uterine veins yielded important information on tumour biology. Complete remission was induced in high-risk patients by etoposide, methotrexate, and actinomycin D treatment.

Adult↗
PubMed1992

[The value of nuclear magnetic resonance tomography in diagnosing invasive trophoblast disease].

13 patients between 19 and 35 years, 12 of them with histologically verified trophoblastic disease, were examined by MRI, to prove the diagnostic value of this method. In line with the excellent results of MRI described in the literature with respect to the differentiation of tissue characterisation, vascularisation and localisation of tumours, the response to chemotherapy was evaluated comparatively to HCG-titres (5 patients). The results showed, that a decrease of HCG-titres correlated with significant tumour reduction. MRI was performed with 1.5 Tesla machines. Axial, sagittal and coronal images of pelvis and abdomen in T1, proton density and T1 sequences, one after administration of Gd-DTPA, were carried out. Except for one case with decreasing titres, GTP was proven by MRI. The tumour showed a remarkable lack of homogeneity and signal increase in 7 cases in T2-weighted images. In one case, the tumour showed a marked signal enhancement after applying Gd-DTPA, compared with the normal myometrium. In 5 cases, destruction of the zonal anatomy of the uterus and dilatation of subserosal uterine and pelvis veins were found. The uterus was larger in size than expected for the duration of gravidity. In correlation with the clinical examination and HCG titres, MRI has the potential of multiplanar imaging and signal characterisation of tissue, and is therefore useful to evaluate the tumour extent and to detect residuals. Gradient echo-technique and the use of contrast media will reduce the duration of examination, but more experience is required.

Adult↗
PubMed1992

Peyronie's disease: MR findings in 28 patients.

Induratio penis plastica (Peyronie's disease) is a chronic fibrotic process involving the penis. Proper treatment of the disease requires assessment of the degree of inflammation preceding or accompanying the fibrous Peyronie's plaques. Owing to its high tissue contrast and its multiplanar capability, MR imaging offers excellent visualization of penile anatomy. To determine the usefulness of MR imaging in the diagnosis and staging of Peyronie's disease, we used MR imaging with a surface coil to examine 28 consecutive patients with clinical evidence of the disease. Eighteen patients had contrast-enhanced MR imaging with gadopentetate dimeglumine. In seven patients who subsequently had surgery or biopsy, MR findings were correlated with histopathologic findings. On unenhanced images, fibrous plaques were shown in 20 patients. Enhanced MR images showed focal contrast enhancement around or within the plaques in seven patients. Images in three patients with plaques showed no enhancement. Images in five patients showed focal areas of contrast enhancement without evidence of plaques. Histologic studies demonstrated that the degree of contrast enhancement correlated with the extent of inflammatory cell infiltration. In two patients with unenhancing plaques on MR, histology confirmed the absence of inflammation. Our results suggest that MR imaging not only depicts the localization and extent of fibrous plaques in patients with Peyronie's disease but also reveals the presence of inflammation. This makes MR imaging the technique of choice for planning therapy and for evaluating the response to conservative treatment.

Adult↗
PubMed1992

[The value of imaging procedures in the diagnosis and therapy follow-up of induratio penis plastica (Peyronie's disease)].

The diagnosis of penile induration (Peyronie's disease; IPP) requires an appropriate history, clinical examination, autophotography and plain films in cases of calcified plaques, but ultrasound is the modality of choice. Besides the benefit of an exact staging (Kelâmi method) high-frequency ultrasound probes offer the possibility of detecting nonpalpable plaques early detection of changes in the tunica albuginea. Evaluation of inflammatory changes and disappearance of hyperechoic signs around the plaques or an increasing density of the corresponding corpus cavernosum can be detected by ultrasound, but sometimes to a restricted extent. In selected cases MRI offers the additional benefit of early detection of inflammatory changes of the dependent corpus cavernosum. Our own experience in the diagnosis of Peyronie's disease by ultrasound and MRI in cases of inflammatory changes are presented, especially after administration of Gd-DTPA. For hemodynamic disorders causing erectile dysfunction, in 50% of cases with IPP combined, pharmacocavernosometry and pharmaco-cavernosography are of considerable value. The use of modern diagnostic imaging modalities, e.g. ultrasound and especially MRI, increases the diagnostic impact in cases of IPP.

Adolescent↗