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Biomedical subjects

R Forstner

Publications and source records attributed to R Forstner.

At least 19 recordsLinked to original sources
PubMed2004

Preoperative high-frequency duplex scanning of potential pedal target vessels.

OBJECTIVE: The aim of this prospective study conducted at a tertiary referral center was to evaluate the efficacy of high-frequency duplex scanning in the preoperative evaluation of potential pedal target vessels. Material and methods The study population consisted of thirty-three consecutive diabetics suffering critical limb ischemia, with indications of infra-popliteal occlusive disease. Duplex ultrasound was performed by an angiologist unaware of any prior imaging procedures. The pedal vessels were divided into four segments. The inner diameter-, the grade of calcification (on a scale from 1-to-3), the maximal systolic velocity, and the resistance index ([V.max syst-V min syst]/V max syst), were assessed by using a 13-MHz probe, and the pedal target vessel best suited for surgery was identified. Results of duplex scanning were compared to (1) the results of selective digital subtraction angiography (DSA) and contrast-enhanced magnetic resonance angiography (CE-MRA) studies interpreted by two radiologists, (2) the site of distal anastomosis predicted by a vascular surgeon according to DSA and CE-MRA studies, (3) the definitive site of distal anastomosis, and (4) early postoperative results (patency at three months). RESULTS: Duplex scanning depicted significantly more pedal vascular segments than selective DSA- (P =.004, McNemar test). Agreement in predicting the site of distal anastomosis expressed as kappa value as follows: duplex versus DSA/CE-MRA, kappa 0.71;-DSA/CE-MRA versus definitive anastomosis, kappa 0.67; -and duplex versus definitive anastomosis kappa 0.82. Two patients were excluded from surgery as all three imaging modalities failed to demonstrate a pedal target vessel. Two patients had exploratory dissection of a pedal vessel (according to CE-MRA findings) that turned out to be occluded (as predicted by duplex scanning). In one patient the operation had to be terminated due to lack of autologous bypass material. In 31 patients who underwent pedal artery bypass, the resistance index could not be correlated to the run-off as assessed by intra-operative angiography. CONCLUSIONS: High-frequency duplex focusing on the vacular-morphology is a worthwhile diagnostic tool to evaluate-potential pedal target vessels and extremely helpful when contrast-related methods (selective DSA, CE-MRA) do not sufficiently depict the pedal vasculature.

Aged↗
PubMed2002

Pedal artery imaging--a comparison of selective digital subtraction angiography, contrast enhanced magnetic resonance angiography and duplex ultrasound.

OBJECTIVE: to evaluate selective digital subtraction angiography (DSA), contrast-enhanced magnetic resonance angiography (CE-MRA) and duplex ultrasound (duplex) in preoperative pedal artery imaging. MATERIAL AND METHODS: DSA, CE-MRA and duplex were studied prospectively in 37 patients suffering from critical leg ischaemia. Two radiologists independently reviewed both the CE-MRA and DSA images. The pedal vessels were scored on a scale from 0 to III (0=vessel not visualised, I=vessel faintly visualised, II=stenosis >50%, III=vessel without relevant stenosis). Duplex ultrasound was performed by an angiologist blind to both the DSA and MRA findings and the pedal arteries were scored 0-III according to their diameter. Each examiner named the pedal artery best suitable for bypass surgery. Agreement in artery assessment was expressed as kappa values. Patency of the bypass at 30 days was used as validation of the artery's suitability as the run-off vessel. RESULTS: interobserver agreement for DSA (weighted Kappa 0.63, CI 0.53-0.73 and CE-MRA (weighted kappa 0.60, CI 0.5-0.7) was moderate to substantial. CE-MRA depicted significantly more vascular segments than DSA (p congruent with 0.0001).In the prediction of the distal outflow vessel duplex and CE-MRA proved to be superior to DSA. CONCLUSION: because of the moderate inter-observer agreement it may be questionable to regard selective DSA as gold standard imaging procedure in preoperative pedal artery imaging. CE-MRA and duplex are very helpful in assessing the pedal artery morphology and should be used if selective DSA does not sufficiently depict the pedal vasculature.

Aged↗
PubMed2002

Pedal artery imaging using DSA, CE-MRA and duplex.

Diabetic macroangiopathy is associated with a typical disease pattern, mostly affecting the tibial but sparing the pedal arteries. Bypass grafts to these patent pedal vessels have evolved into a feasible technique. Restoring a palpable pulse in the ischemic foot they create the prerequisite to heal an ulcer or gangrene. Preoperative evaluation of pedal arteries demands a detailed depiction of the entire pedal vascular system. At present, the main options for preoperative pedal artery imaging are selective DSA contrast enhanced MRA and Duplex ultrasound. The aim of this review article is to give a survey of these three techniques and to determine their potential to depict pedal run off vessels. Selective DSA is still the standard diagnostic tool in preoperative pedal artery imaging. CE MRA offers high contrast related resolution but in-plane resolution is inferior to the concurrent imaging techniques. Duplex is the preferable method to evaluate a pedal artery's diameter and morphology. Both, CE MRA and Duplex are worthwhile additional imaging techniques in case DSA did not sufficiently depict the pedal vasculature.

Angiography, Digital Subtraction↗
PubMed2001

Prognostic factors in surgically treated stage ib-iib cervical carcinomas with special emphasis on the importance of tumor volume.

OBJECTIVE: The aim of the study was to analyze the importance of tumor volume as a prognostic factor for overall survival (OS) in surgically treated stage Ib-IIb cervical carcinoma. METHODS: One hundred thirteen of one hundred sixty-five patients with histopathological stage Ib-IIb cervical carcinoma (44 Ib1, 24 Ib2, 10 IIa, 35 IIb) treated by radical abdominal hysterectomy between 1989 and 1999, for whom tumor volume could be assessed, were included in this study. Of the 113 patients, 90 (79.6%) received postoperative radiotherapy. Measurement of tumor volume was performed on giant histological sections using a semiautomatic image analyzer. The prognostic significance of tumor volume was analyzed and compared with that of various clinicopathological parameters using uni- and multivariate statistics. RESULTS: The 5-year disease-free survival was 71.4%. Increasing tumor volume was associated with more frequent lymph node metastases and a significant decrease in OS (P = 0.0112). The Median tumor volume was smaller in stage IIa tumors than in stage Ib2 tumors, and histopathological stage did not correlate linearly with lymph node metastases as well as OS. Stage Ib2 tumors were associated with worse overall survival than stage IIa tumors. In univariate analysis, lymph node metastases, histopathological stage, lymph vascular space involvement, tumor volume, parametrial spread, and tumor involvement of resection margins were significant parameters for OS. In multivariate statistical analysis, only lymph node metastases and histopathological staging remained independent prognostic factors for OS. CONCLUSIONS: Tumor volume does not seem to confer additional prognostic information if histopathological stage and lymph node status are known. However, it may provide important prognostic information if lymph node status is not known or histopathological stage cannot be assessed.

Adenocarcinoma↗
PubMed2001

Unbiased evaluation of the arthroscopic extra-articular technique for Bankart repair: a clinical and radiographic study with a 2- to 5-year follow-up.

This study performed an unbiased reexamination of patients who at least 2 years previously had undergone an arthroscopic extra-articular Bankart repair and prospectively evaluated the development of degenerative changes in the shoulder. Two unbiased observers who had never seen the patients before and had in no way been involved in the treatment of the patients were given unlimited access to the patients' files, surgical reports, and radiographs. Of the 80 patients 72 (90%) attended the follow-up 42.5 months (24-66) after the index procedure. Failures in terms of stability (redislocations and subluxations) were recorded in 14% of the patients. The Rowe score was 97 points (51-100), the Constant score was 94 (56-100) in injured shoulders and 97 points (80-100) in noninjured shoulders (P = 0.002). A return to the preinjury level of activity was recorded in 73% of the patients. There was a significant increase in degenerative changes between the pre- and postoperative radiographic assessments (P < 0.0001). At 2- to 5-year follow-up therefore the extra-articular arthroscopic Bankart repair resulted in stable and well-functioning shoulders in a high percentage of patients. However, the signs of radiographic degenerative changes increased between the preoperative assessments and the 2- to 5-year follow-up.

Arthroscopy↗
PubMed2000

[Pseudoaneurysm of the pediatric popliteal artery after arthroscopic meniscus resection].

Arterial injuries following arthroscopic procedures are extremely rare, but may have dramatic consequences without early diagnosis and appropriate treatment. We report a case of popliteal artery pseudo-aneurysm a following arthroscopic meniscectomy in a child. Non-invasive diagnostic workup included Doppler flow color imaging and computed tomography with contrast and 3D workup. The arterial lesion was repaired surgically by an posterior approach using a vein patch plasty. The popliteal artery is in close relationship to the posterior capsule of the knee joint. During knee flexion the vessel is positioned forward and placed even closer to the horn of the lateral meniscus. For this reason arthroscopic surgical manipulation in the posterior aspects of the knee joint must be performed under direct visualization. Indistinct swelling in the popliteal fossa and calf following arthroscopic surgery should arouse suspicion of an arterial injury.

Adolescent↗
PubMed2000

Three-dimensional targeting: a new three-dimensional ultrasound technique to evaluate needle position during breast biopsy.

OBJECTIVE: To evaluate the role of three-dimensional (3D) ultrasound (US) following needle breast biopsy under two-dimensional (2D) needle guidance. METHODS: A total of 188 core-needle biopsies and 24 fine-needle aspiration biopsies were 3D US correlated after typical 'freehand' US needle guidance. All cases were examined with a linear 3D US volume scanner (5-13 MHz, Voluson 530D, Medison-Kretztechnik, Zipf, Austria). After core-needle stroke or localization of fine needle, a 3D US data volume set was acquired and a multiplanar analysis performed. This needle position check in all three planes is called '3D targeting'. 66 women with a mean age of 51 years (range, 27-80 years) showed 77 breast lesions (55 solid lesions, 22 cysts) with a mean diameter of 1.5 (range, 0.3-5.0) cm. RESULTS: In 49 women with 55 solid breast lesions, 16 lesions were malignant and 39 lesions benign. In 53 solid breast lesions 188 core-needle biopsies were performed (mean 3.6 biopsies/lesion). After core-needle biopsy 23 lesions (16 malignant, seven benign) were surgically removed. In 22 cases final histology confirmed results of the core-needle specimen. In one case a core-needle specimen of a 5 mm lesion showed atypical lobular hyperplasia. The definitive histology after surgery was invasive lobular carcinoma. Twenty-two cysts and two benign solid lesions were punctured with a fine needle followed by aspiration biopsy. The overall sensitivity of core-needle results in this study was 94% (specificity 100%, accuracy 0.98, positive predictive value 1, negative predictive value 0.97). In 117 core-needle strokes of benign (21) and malignant (12) lesions 3D targeting prospectively revealed 95 lesion hits, Twelve marginal lesion hits and nine out-of-lesion hits. In one case after the initial large core-needle path a 5-mm lesion was disguised by air bubbles, therefore 3D targeting failed during the second biopsy procedure. CONCLUSION: 3D US combined with 3D targeting technique is a reliable and objective tool demonstrating exact spatial positioning of core and fine needle during biopsy procedure.

Adult↗
PubMed2000

Whole-body scintigraphy in melanoma patients: comparison of 99Tcm-tetrofosmin and 201Tl.

The aim of this study was to determine the diagnostic value of 99Tcm-tetrofosmin whole-body imaging in comparison to 201Tl scintigraphy in patients with metastatic melanoma. In 27 patients with known or suspected melanoma metastases we performed 201Tl scintigraphy and 99Tcm-tetrofosmin scintigraphy using a 1-day protocol. In five patients with known locoregional metastasis the in vivo uptake kinetics of both radiotracers were compared. The final diagnosis was confirmed by surgical histology in 39 lesions (group I) and computed tomography (CT) and clinical course in 14 lesions (group II). In group I, containing mainly locoregional metastases, 201Tl scintigraphy correctly identified 36 of 39 metastases and 99Tcm-tetrofosmin 35 of 39 resulting in a sensitivity of 92% and 90% respectively. The T/B ratios of 201Tl (1.4-4.0, mean 2.15) were statistically significantly higher in comparison to tetrofosmin (1.3-3.0, mean 1.88). However, both radiotracers showed similar uptake and washout kinetics with a maximum of tracer uptake between 1 and 5 min p.i. In group II, containing mainly cerebral and pulmonary metastases, both methods correctly identified six of 14 metastases resulting in a sensitivity of only 43%. We conclude that the uptake of 99Tcm-tetrofosmin and 201Tl in melanoma metastases is very similar. The T/B ratios with 99Tcm-tetrofosmin are significantly lower than with 201Tl. In locoregional melanoma metastases the sensitivity of tetrofosmin scintigraphy is identical with 201Tl imaging and amounts to 90%. In cerebral and lung metastases the sensitivity of both methods is limited when using whole-body scintigraphy.

Adult↗
PubMed1999

[Diagnostic imaging in staging of gynecologic carcinomas].

The prognosis in patients with gynecologic cancers depends not only on the stage but also on a wide spectrum of other findings. Cross-sectional imaging modalities, including sonography, CT and MRI, have increasingly been used for optimal treatment planning in gynecologic cancers. Their staging criteria are based on the well-established FIGO staging system. CT and MRI compete with sonography, which plays a pivotal role in the evaluation of the female pelvis. This paper reviews the role of sonography, CT and MRI in the staging of gynecologic malignancies. It puts the emphasis on MRI, which has been established as imaging modality of choice in the preoperative evaluation of cervical and endometrial cancer, and which seems slightly superior to CT in the staging of ovarian cancer.

Diagnostic Imaging↗
PubMed1999

Glutaric aciduria type I: ultrasonographic demonstration of early signs.

BACKGROUND: Glutaric aciduria type I (GA-I) is a rare inherited metabolic disease with increased excretion of glutaric acid and its metabolites. Diagnosis is often delayed until the onset of irreversible neurological deficits. MATERIAL AND METHODS: We reviewed the clinical and imaging (US, CT and MRI) findings in six patients with proven GA-I and with emphasis on the early US findings. Coronal and sagittal US images of the brain were obtained through the anterior fontanelle in all patients. CT was obtained in three patients and MRI was obtained in two. RESULTS: Macrocephaly was found in all patients, being present in three children at birth or developing rapidly within the first weeks of life. US showed, in all patients, bilateral symmetrical cyst-like dilatation of the sylvian fissures. Progressive fronto-temporal atrophy developed within the first months. CT and MRI demonstrated fronto-temporal atrophy with lack of opercularisation in all cases and basal ganglia or periventricular hypodensities in three patients. CONCLUSIONS: In patients with macrocephaly at birth or rapidly developing within the first weeks of life, US should be performed as the primary imaging modality. Cyst-like bilateral widening of the sylvian fissures is the first sign of GA-I, followed by progressive fronto-temporal and ventricular enlargement. These patients should be screened for GA-I in order to initiate treatment in the asymptomatic stage.

Abnormalities, Multiple↗
PubMed1999

Conservative treatment of acute Ormond's disease.

Ormond's disease is a chronic inflammatory process of the retroperitoneum, which sometimes takes a very acute course. We report the case of a man with acute bilateral hydronephrosis. Diagnosis was based on typical criteria seen by magnetic resonance imaging, which made biopsy unnecessary.

Acute Disease↗
PubMed1998

Sclerotic variant of lymphangiomatosis of bone: imaging findings at diagnosis and long-term follow-up.

Lymphangiomatosis is an extremely rare congenital disorder affecting visceral organs and/or the skeletal system. In bone is is usually characterized by multiple lytic lesions with a lacelike pattern and sclerotic margins of various thickness. In this case report we demonstrate the rare sclerotic variant of lymphangiomatosis. We report the development of predominantly sclerotic lesions at different sites by serial radiographs with a long-term follow-up, and show the MRI findings of lymphangiomatosis of the spine.

Adult↗
PubMed1998

[Ultrasound diagnosis of iliopectineal bursitis--contribution to differential diagnosis of leg swelling].

PURPOSE: To describe the pathognomic sonographic morphology of iliopectineal bursitis as a contribution to the differential diagnosis of leg swelling. METHODS: Characterization of the enlarged iliopectineal bursa by sonography (including CCDS) (n = 6) and comparison with CT (n = 4) and MRI findings (n = 1). RESULTS: There were 6 enlarged iliopectineal bursas in 5 female patients which exhibited an elongated oval form and were typically located in the groin region lateral and dorsal of the vessels and in the pelvis lateral to the iliac vessels. On sonography, cystic structures with echo-free contents (n = 1) in arthrosis, homogeneous echoic contents (n = 3) in abrasive reactions after hip TEP, and with inhomogeneous, pseudo-tumorous contents (n = 2) in PCP. CONCLUSIONS: Sonography enables the reliable diagnosis of an iliopectineal bursitis by means of its elongated oval from and extension from the groin region in continuity to the pelvis with medial displacement of the femoral and iliac vessels. It can thus help to avoid unnecessary operations or biopsies. In cases of doubt, use of CT or MRT enables a certain anatomical assignment.

Aged↗
PubMed1997

Primary amenorrhea: evaluation with MR imaging.

PURPOSE: To determine the accuracy of magnetic resonance (MR) imaging in the evaluation of patients with a history of primary amenorrhea. MATERIALS AND METHODS: Twenty-nine patients with primary amenorrhea underwent T2-weighted MR imaging in the axial and sagittal planes. Contrast material-enhanced and unenhanced T1-weighted MR imaging was performed in selected cases. MR imaging findings were correlated with surgical findings in 23 patients and with clinical findings in six patients. RESULTS: Surgical correlation was available in 14 of 17 patients with female anatomic anomalies (Mayer-Rokitansky-Küster-Hauser syndrome [n = 9], transverse vaginal septum [n = 3], imperforate hymen [n = 1], cervical agenesis [n = 1]), which confirmed MR imaging findings. In nine of 12 patients with congenital disorders of sexual differentiation (testicular feminization [n = 5], true hermaphrodite [n = 2], gonadal dysgenesis [n = 2]) who underwent surgical correlation, 13 of 16 (81%) gonads were correctly localized with MR imaging. Overall, there was excellent correlation between the classification of patients with MR imaging versus classification with the combination of surgical and laboratory findings (K = 0.88). CONCLUSION: MR imaging is useful in the work-up of patients who present with primary amenorrhea both for accurate diagnosis of pathologic conditions and for surgical planning.

Adolescent↗
PubMed1996

Abdominopelvic MR imaging in the nonobstetric evaluation of pregnant patients.

Managing a pregnant patient with a suspected nonobstetric abdominopelvic disorder is challenging. Information from imaging affects the treatment options, which range from operating emergently and risking miscarriage to terminating the pregnancy or delaying treatment until after delivery. The most common indications for MR imaging during pregnancy are disorders of the central nervous and cardiovascular systems. In the evaluation of the abdomen and pelvis, sonography plays the pivotal role; however, sonography may be inconclusive because of its limited specificity in tissue characterization and technical difficulties caused by the enlarged uterus. For these reasons MR imaging has emerged as a valuable adjunct to sonography. In this pictorial essay we describe a variety of nonobstetric abdominopelvic disorders during pregnancy in which MR imaging contributed to patient management.

Abdomen↗
PubMed1995

Magnetic resonance imaging of vascular lesions of the scrotum and penis.

We report 2 rare cases of vascular lesions in the scrotum and penis: an arteriovenous malformation in a young man and a lymphohemangioma in a boy. Both patients had undergone previous treatment and had recurrent lesions. Magnetic resonance imaging was performed preoperatively for detailed information regarding lesion extent and involvement of adjacent structures.

Adolescent↗