Biomedical subjects

R P Spielmann

Publications and source records attributed to R P Spielmann.

At least 19 recordsLinked to original sources

PubMed2001

[New knowledge regarding tumor cell inactivation and histological evaluation after radiofrequency therapy. Single case observation and in vitro proof of a new hypothesis].

In a study, a radiofrequency (RF) treatment was performed on a patient with a small breast cancer after vacuum biopsy. As usual in cases with a malignant diagnosis, surgical excision and axillary dissection followed. Histopathology revealed some residual tumor in the margin of the cavity. It could not be distinguished from vital tumor on the hematotoxylin eosin (HE) stain. Based on the correlation of MRI and histopathology after subsequent surgical excision, we did, however, presume that the residual was contained within the zone of inactivation. Thus the hypothesis arose that, if too high temperatures can be avoided, it might be possible to inactivate tumor cells without significantly impairing histopathologic assessment. This hypothesis was supported by the following in vitro experiment performed on a fresh specimen: An RF treatment was performed using temperatures up to 70 degrees C only. Half of the specimen underwent HE-staining, the other half vitality testing. The results indicate that if a given temperature range is strictly observed it appears possible to inactivate tissue before tissue sampling, since histopathologic diagnosis will not be impaired. Further technologic improvements may eventually allow to develop a pre-treatment method which might permit to avoid potential hematogenous tumor spread during subsequent biopsy.

Biopsy↗

PubMed2001

CT-guided obturator nerve block for diagnosis and treatment of painful conditions of the hip.

Obturator nerve blocks (ONB) have been performed by anaesthesiologists mainly to eliminate the obturator reflex during transurethral resections. An effect on hip pain has also been described. However, being a time-consuming and operator-dependent procedure if performed manually, it has not been widely used for chronic hip pain. The purpose of this pilot study was to check whether CT guidance could improve reproducibility of the block (= immediate effect) and to test its potential value for treatment of chronic hip pain. Fifteen chronically ill patients with osteoarthritis underwent a single ONB. Sixteen millilitres of Lidocaine 1% mixed with 2 ml Iopramide was injected into the obturator canal. The patients were followed up to 9 months after the intervention. With a single injection pain relief was achieved for 1-8 weeks in 7 of 15 patients. Excellent pain relief for 3-11 months was achieved in another 4 patients. Reasons for a mid-term or even long-term effect based on a single injection of local anaesthetic are not exactly known. The CT-guided ONB is a fast, easy and safe procedure that may be useful for mid-term (weeks) and sometimes even long-term (months) treatment of hip pain.

Arthroplasty, Replacement, Hip↗

PubMed2001

[MR angiography in diagnosis of vasculitis and benign angiopathies of the central nervous system].

PURPOSE: To evaluate TOF 3D magnetic resonance angiography (MRA) of the intracranial arteries in patients with vasculitis or vasculitis-like benign angiopathy of the central nervous system (CNS). METHOD: The results of MRA in 20 patients with clinically and radiographically proven vasculitis (17/20) or vasculitis-like benign angiopathy (3/20) of the CNS were retrospectively analysed. Patients with hyperintense lesions of more than 3 mm on T2-weighted MRI images were included in this trial. An inflammatory, embolic, neurodegenerative or metastatic origin of these lesions was excluded by extensive clinical studies. For the MR-examination a TOF 3D FISP sequence was used on a 1.5 T imager. RESULTS: MRA showed characteristic changes for vasculitis or angiopathy in 15 of 20 patients (75%). CONCLUSIONS: In patients suspected of having a vasculitis or vasculitis-like angiopathy, MRA is recommended as a non-invasive modality. If the results of MRI and extensive clinical studies are carefully correlated, MRA may substitute conventional angiography in cases with typical vascular changes.

Adolescent↗

PubMed2000

Reliability of cranial CT versus intracerebral pressure measurement for the evaluation of generalised cerebral oedema in children.

OBJECTIVE: To examine the extent to which intracranial pressure (ICP) in children after severe brain trauma can be determined by cranial CT. MATERIALS AND METHODS: Two experienced paediatric radiologists, without any knowledge of the clinical symptoms, evaluated 124 CT scans from 65 children (average age 5.4 years) who underwent intracranial measurement of their cerebral pressure. RESULTS: CT had high sensitivity (99.1%) for 'high cerebral pressure' but a much lower specificity (78.1%). The examiners tended to estimate ICP as 'high' even when actual ICP was low. Since therapy for lowering cerebral pressure involves potential risks, actual cerebral pressure measurement, particularly in children, should be considered before intervention (e.g. hyperventilation or trepanation). We report the change in different intracerebral fluid compartments with varying cerebral pressure and modifications of the density of the brain tissue in an inter- and intraobserver comparison. CONCLUSION: The radiologist cannot differentiate, for methodological reasons, between a change in the intracranial fluid compartments not associated with a change in ICP and one in which it is critically elevated. Before any interventional treatments such as decompression-trepanation or hyperventilation are instituted, measurement of ICP should be considered, especially in children.

Brain Edema↗

PubMed2000

Interventional MRI of the breast: lesion localisation and biopsy.

With the growing use of breast MRI an increasing need exists for reliable MR-guided preoperative localisation or even MR-guided needle biopsy. In this article an overview is given of the different approaches and the present state of the art. With closed magnets the following approaches have been made: freehand localisation (similar to CT-guided freehand localisation), and freehand localisation combined with a frameless stereotaxic system operating with support by ultrasound. One localisation device for supine localisation and a thermoplastic mesh for breast stabilisation have been reported. Most investigators have used compression devices to immobilize the breast and prevent shift during needle insertion. Thus far, one immobilisation and aiming device has been designed for open magnets. A small number of experiences exist with interventions on open MR units using a navigation system. Wire localisations are presently a well-established procedure. Magnetic-resonance-guided needle biopsy has been accomplished in closed systems as well as by the use of breast immobilisation devices. However, problems still exist due to severe needle artefacts, tissue shift during the intervention and fast equalization of contrast enhancement in lesions with surrounding tissue. Therefore, needle biopsy is not recommended for lesions < 10 mm. Magnetic-resonance-guided vacuum biopsy is somewhat more invasive but promises to solve most of these problems.

Biopsy↗

PubMed2000

Role of radiology in the diagnosis of neurosarcoidosis.

Clinical studies report a rate of 5% and autopsy results a rate of 25% of brain involvement in sarcoidosis. The aim of this study was to evaluate the role of radiology in the diagnosis of patients with neurosarcoidosis. The chest radiographs and MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the information that was provided in the request form and clinical charts. All patients had neurological signs and symptoms; 21 patients were examined with contrast enhancement. Facial nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: periventricular high-signal lesions on T2-weighted images (46%); multiple supratentorial and infratentorial brain lesions (36%); solitary intra-axial mass (9%); solitary extra-axial mass (5%); and leptomeningeal enhancement (36%). Neurological signs and symptoms can be significant manifestations of sarcoidosis. Magnetic resonance imaging shows a wide spectrum of brain abnormalities associated with neurosarcoidosis. The patient's history and chest X-ray are helpful in arriving at the correct diagnosis, but in selected cases with isolated brain involvement biopsy may still be required.

Adolescent↗

PubMed2000

Spiral computed tomography before and after cricothyroid approximation.

Cricothyroid approximation raises the vocal pitch by simulating the contraction of the cricothyroid muscle with sutures. The aim of this study was to determine the role of spiral computed tomography (CT) in patients scheduled for cricothyroid approximation. Twenty-nine transsexual patients were examined with spiral CT before and after laryngoplastic surgery. Computed tomography findings were correlated with phoniatric findings in all patients. The average reduction of the cricothyroid distance was 6 mm (range 2-10 mm). The vocal pitch elevation was more remarkable in the patient group with greater reduction of the cricothyroid distance. Computed tomography accurately determines the cricothyroid distance before and after surgery and is an ideal method for follow-up purposes, especially when there is a postoperative reversion towards a lower pitch. In addition, CT provides important data as to the most appropriate extent and site of intracordal intervention to be done for a desired pitch elevation.

Adult↗

PubMed2000

Suspected acute appendicitis: is ultrasonography or computed tomography the preferred imaging technique?

OBJECTIVE: To compare the sensitivity and specificity of unenhanced spiral computed tomography (CT) and ultrasonography (US) in patients with suspected acute appendicitis. DESIGN: Prospective study. SETTING: University hospital, Germany. SUBJECTS: 120 consecutive patients with acute appendicitis as a differential diagnosis, whose clinical findings were not enough to make operation essential, but were too severe to send home. INTERVENTIONS: CT and US of the appendix. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive value. RESULTS: The results were correlated with surgical and histopathological findings at appendicectomy or clinical follow-up. 93 patients had acute appendicitis, 27 patients did not. The sensitivity of CT was 95% and of US 87%. The corresponding specificities were 89% and 74%, positive predictive values 97% and 92%, negative predictive values 83% and 63%. In the 27 patients who did not have acute appendicitis, the correct diagnosis was established with CT in 14 patients and with US in eight. CONCLUSION: CT is more sensitive and specific than US in patients suspected of having acute appendicitis, but in whom the presentation is equivocal. The use of unenhanced spiral CT led to a significant improvement in the accuracy of preoperative diagnosis and a lower negative appendicectomy rate.

Acute Disease↗

PubMed2000

Direct measurement of sound velocity in various specimens of breast tissue.

RATIONALE AND OBJECTIVES: Previous studies using ultrasound CT or clinical amplitude/velocity reconstruction imaging ultrasound may indicate that cancers differ from normal breast tissue by increased sound velocity. However, only limited experience with direct measurements of sound velocity exists. This study aimed to investigate sound velocity measured directly in a variety of breast specimens. METHODS: Sound velocity was measured directly by forceps in fresh breast specimens chosen to contain one type of tissue only. Eighty specimens (31 cancers, 18 benign changes of glandular/fibrous tissue, 22 fatty tissues, 5 fibroadenomas, 2 compound tissues, 1 phylloides tumor, and 1 inflammation) were analyzed. RESULTS: Ultrasound velocities in carcinoma, benign changes, fibroadenoma, inflammation, and the phylloides tumor were very similar, with almost complete overlap. In contrary, the ultrasound velocity of fatty tissue was significantly lower. Compound tissues containing fat had an intermediate sound velocity. CONCLUSIONS: Sound velocity may add complementary information to echogenicity (B-scan). Because fat lobules exhibit low ultrasound velocity and carcinomas do not, a locally exact combination of ultrasound velocity information and reflexivity information should allow improved breast cancer detection by ultrasound.

Breast Diseases↗

PubMed2000

Value of spiral CT in patients with cricothyroid approximation.

Cricothyroid approximation raises the vocal pitch by simulating contraction of the cricothyroid muscle with sutures. The aim of this study was to determine the role of spiral CT in patients scheduled for cricothyroid approximation. 29 transsexual patients were examined with spiral CT prior to and after laryngoplastic surgery. CT findings were correlated with phonographic findings in all patients. The average reduction of the cricothyroid distance was 6 mm (range 2-10 mm). Vocal pitch elevation was greatest in patients with the largest reduction of the cricothyroid distance. CT accurately determines the cricothyroid distance prior to and after surgery and is an ideal method for follow-up, especially in post-operative reversion towards a lower pitch. In addition, CT provides important data in determining the most appropriate extent and site of intracordal intervention to achieve a desired pitch elevation.

Adult↗

PubMed2000

Vertigo after stapes surgery: the role of high resolution CT.

CT findings in patients with vertigo after stapes surgery include a prosthesis shaft entering the vestibule and compressing the saccule, a complete dislocation of the stapes prosthesis, air bubbles and fluid collections within the vestibule and outside the oval window indicating a perilymphatic fistula, and bony fragments leading to compression of the basal saccule. Although immediate post-operative vertigo is often transient, patients with persistent or recurrent vertigo should be imaged as high resolution CT will determine the underlying cause in the majority of cases.

Fistula↗

PubMed1999

[Routine skull CT in psychiatric diagnosis].

PURPOSE: To prospectively assess the spectrum of brain CT findings in psychiatric patients and to determine the number of patients that had an underlying cause for the symptoms. PATIENTS AND METHODS: Over a period of six months, 142 patients (78 males, 64 females; median age 61 [18-91] years) were referred for CT brain scans. Their scans were reviewed, along with the clinical information that was provided in the request form. All the hard copies were reviewed to assess areas of ischaemia, infarction, atrophy, tumours, and haematomas. The majority of requests were to exclude vascular event or space-occupying lesions. Clinical indications included mood disorders (depression, mania), schizophrenic disorders, dementia, personality and behavioural disorders. RESULTS: 31 (22%) were normal. 111 (78%) had varying degrees of ischaemia, infarction and cerebral/cerebellar atrophy. 7 (4.9%) had space-occupying lesions which included two gliomas and five meningiomas. There were two chronic subdural haematomas and one arteriovenous malformation. CONCLUSION: 1. In our series, pathologic findings in "routine" brain CT's were encountered in 78%. 2. The incidence of brain tumours was 4.9%, compared with 0.00005% of the general population. 3. CT scanning in psychiatric patients is cost-effective and especially indicated when there is an atypical presentation, or inadequate response to standard treatment.

Adolescent↗

PubMed1999

[Role of magnetic resonance imaging in the diagnosis of neurosarcoidosis].

Neurological involvement is a significant cause of morbidity and mortality in patients with sarcoidosis. The aim of this study was to evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of patients with neurosarcoidosis. The MRI brain scans of 22 patients with sarcoidosis were retrospectively reviewed, along with the clinical information provided in the request form. All patients had signs and symptoms referable to the head and were examined with gadolinium enhancement. Cranial (facial) nerve paralysis was the most common clinical manifestation identified in 10 patients. A wide spectrum of MR findings was noted: periventricular and white matter lesions on T2 W spin echo images, mimicking multiple sclerosis (46%); multiple supratentorial and infratentorial brain lesions, mimicking metastases (36%); solitary intraaxial mass, mimicking high-grade astrocytoma (9%); solitary extraaxial mass, mimicking meningioma (5%); leptomeningeal enhancement (36%). The diagnosis of neurosarcoidosis is often difficult, particularly so in patients who lack either pulmonary or systemic manifestations of sarcoidosis. MRI shows a wide spectrum of brain abnormalities associated with neurosarcoidosis. These findings, however, are not specific for sarcoidosis and one must consider appropriate clinical circumstances in arriving at the correct diagnosis. In selected cases with isolated brain involvement, meningeal or cerebral biopsy may be required.

Adolescent↗

PubMed1999

Computed tomography and magnetic resonance imaging features of olfactory neuroblastoma: an analysis of 22 cases.

The computed tomography (CT) and magnetic resonance imaging (MRI) studies of 22 patients with a histologically proven olfactory neuroblastoma were retrospectively reviewed. The tumours displayed a variety of imaging characteristics and aggressiveness. The expansile tendency of olfactory neuroblastoma is characterised by bowing of the sinus walls. The destructive aspect is manifested as tumour replacing the turbinates, septum, and sinus walls with extension into contiguous areas. The density/signal and enhancement characteristics are non-specific. Olfactory neuroblastoma should be suspected in all ages following identification of a mass in the superior nasal cavity demonstrating both expansile and destructive growth patterns. The otorhinolaryngologist and the radiologist should be aware of this tumour entity, as early diagnosis appropriately guides therapy and predicts survival.

Adult↗

PubMed1999

[Radiological evaluation of complications of implantable venous access port systems].

OBJECTIVE: Clinical signs and symptoms sometimes throw suspicion on functional complications and venous thrombosis due to implantable venous access ports. Objective was to determine frequency of these problems using radiologic imaging. METHODS: 61 patients were examined by means of fluoroscopy. If indication was given we injected radiopaque (contrast) medium. In the case of suspected vascular thrombosis the radiological finding was verified by sonography, phlebography or by venous magnetic resonance imaging angiography. RESULTS: Altogether 46 complications were documented in 37 out of 61 examined patients (61%). Occlusions of port-catheter were proved in 24 cases. It was the radiologically most frequently recorded complication (52%;) and found coincident with other problems in 9 patients (37%;). Pain frequently indicates break of catheters. Implantation of catheters into jugular and axillary veins predisposes to break of catheters just as port-catheters lateral implanted into subclavian veins ("pinch-off-sign"). CONCLUSIONS: Functional tests of venous access systems using fluoroscopy and phlebography give information that helps to decide if clinically problematic port-systems should be used furthermore. Directions of catheter which are predestined to complications should be avoided.

Catheters, Indwelling↗

PubMed1999

[Direct in-vitro measurement of ultrasound velocity in carcinomas, mastopathic tissue, fatty tissue and fibroadenomas of the female breast].

PURPOSE: The study aimed to investigate ultrasound velocity (SV) in carcinomas, fibrocystic changes, fibroadenomas and fatty tissue of the female breast by means of direct in-vitro measurements. We intended to test whether or not differences in SV exist between the various types of tissue and whether the SV is a useful criterion to differentiate the different tissues. METHOD: SV was measured by comparing transmission time of the ultrasound beam through the specimen and through water. Altogether 40 specimens (12 cancer, 14 fibrocystic changes = FCD, 10 fatty tissues, 3 fibroadenomas, and 1 mixed tissue) were analysed. RESULTS: Velocity differed significantly between fat (1478.5 +/- 6.5 m/s) and tumor (1523.1 +/- 5.9 m/s) (p approximately 10(-11)) and between fat and FCD (1526.0 +/- 9.0 m/s) (p approximately 10(-12)). No significant differences and much overlap were seen between the ultrasound velocities of tumors and FCD. Ultrasound velocity in fibroadenomas (1533.2 +/- 3.8 m/s) was comparable with that in carcinomas and FCD. CONCLUSIONS: We conclude that ultrasound velocity may add complementary information to echogenicity (B-scan). Thus, a locally exact correlation of echogenicity and sound velocity might allow for an improved tissue characterization.

Adipose Tissue↗

PubMed1998

[Possibilities of follow-up imaging after implantation of a carbon fiber-reinforced hip prosthesis].

INTRODUCTION: There are many problems in the radiological diagnosis of aseptic loosening in total hip arthroplasty. Computed tomography (CT) and magnetic resonance tomography (MRT) are not usable for metallic implants (stainless steel, cobalt alloy, titanium alloy). MATERIAL AND METHODS: From April 1993 to December 1993 15 CFRP non-cemented hip prostheses have been implanted. In a prospective clinical study plane radiographs, CT and MRT have been analysed. RESULTS: Three stems were revised (1 femoral fracture, 1 severe thigh pain, 1 aseptic loosening). CFRP are not visible in plane radiographs. There was a complete (two-third of the cases) or nearly complete (one-third of the cases) small sclerotic interface between the prosthesis and the bone, these were apparent in CT and MRT in stable implant cases and did not have any clinical correlations. DISCUSSION: The small sclerotic interface is quite different in comparison to so called "Reactive Lines". In one case of aseptic loosening there was an interposition of soft tissue between prosthesis and bone in MRT and CT. CFRP inaugurates new diagnostic possibilities in aseptic loosening of hip prosthesis and in tumour surgery too.

Aged↗

PubMed1997

[Value of contrast medium magnetic resonance tomography of the breast in breast reconstruction with implant].

Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanced MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar tissue in all cases with indeterminate findings. However, due to false-positive calls caused by enhancing granulomas specificity could not be improved. Contrast-enhanced MRI allowed decisive additional information in our study group and improved the sensitivity significantly (concerning all diagnoses). Contrast-enhanced MRI is recommended in patients with diagnostic problems or high risk of recurrence after silicone implants.

Breast Implants↗