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Biomedical subjects

J M Friedrich

Publications and source records attributed to J M Friedrich.

At least 55 records · Page 3Linked to original sources
PubMed1993

[MR-myelography of the lumbar spine using a PSIF sequence: first experiences].

A rapid gradient-echo acquisition (PSIF) was used to delineate the lumber spine. Because this sequence is heavily T2 weighted the cerebrospinal fluid shows a bright signal, the myelon has a poor signal. 5 healthy volunteers and 5 patients with suspected lumbar disc herniation were examined by this technique. All MR myelograms were compared with spin-echo sequences (sagittal and transversal slices). All lumbar disc herniations which were recognized by MRI were also delineated by MR myelography.

Adult↗
PubMed1993

[Long-term results of percutaneous transluminal angioplasty and stent implantation in venous stenoses following transfemoral thrombectomy].

Thirty consecutive patients were operated on for iliofemoral venous thromboses. In each case, a transfemoral thrombectomy was performed and an arterio-venous fistula was created. Three to six months later, a cross-over arterio-venography revealed 10 severely stenosed venous segments in 8 patients (common iliac vein 4, external iliac vein 3, common femoral vein 3). All stenoses were treated by percutaneous transvenous angioplasty (PTA). Six times a flexible, self-expanding Wallstent was placed within the stenosis after dilation (PTA+S). Complications did not occur. Median follow up was 17 months (3-23 months). PTA+S proved superior (4/6 excellent results) when compared to PTA alone (1/4 excellent result), because of frequent restenosis after the latter. Minor results following PTA+S were caused by intimal hyperplasia within the stent, when the av-fistula was kept patent for more than a year after stent placement.

Adolescent↗
PubMed1992

[Abdominal sonography in primary diagnosis of blunt abdominal trauma].

200 patients with blunt abdominal trauma were scanned by ultrasound primarily. 152 showed a normal sonographic examination. In 24 patients an organic injury was visualised. These 20 splenic injuries, 2 lesions of the kidney, 1 splenic and renal lesion and 1 hepatic and splenic rupture were confirmed by CT in 9 cases, by laparotomy in 9 cases, by sonographic follow-up in 2 cases. 23 patients showed an intraabdominal fluid collection, in 16 patients a decrease was seen by ultrasound. 7 patients were directly operated on because of a visible increase of intraabdominal fluid. The lesions consisted of 3 hepatic ruptures, 2 retroperitoneal bleedings. Ultrasound is a reliable tool in the diagnosis of blunt abdominal trauma on the day of admittance and in the evaluation of injuries in respect of operative or conservative management.

Abdominal Injuries↗
PubMed1992

[MR angiography of occlusive changes in the superior thoracic inlet veins].

We used MR angiography to assess the thoracic inlet veins in 5 normal volunteers and 14 patients with thrombosis of these veins. The results were compared with conventional venography and contrast-enhanced computed tomography (CT). The normal anatomy was readily depicted by MR angiography in all normal volunteers. Pathology was assessed correctly by MR angiography in all patients. Thrombosis of the internal jugular vein was seen on MR angiography in all cases whereas conventional venography failed to demonstrate this region adequately in 3 cases. The best overview of the thoracic inlet veins was achieved in the coronal plane; however, for detailed demonstration of pathology, imaging in additional planes was necessary. We conclude that MR angiography is a promising method for non-invasive assessment of thoracic veins.

Evaluation Studies as Topic↗
PubMed1992

[Magnetic resonance tomography of the liver with TurboFLASH and segmented acquisition. Fast imaging with flexible image contrast].

The value of a fast imaging sequence in diagnosing focal liver lesions was assessed in 43 patients. The sequence (TurboFLASH with segmented acquisition) allows the acquisition of T1- and T2-weighted images within a breath-hold interval. Lesion-liver contrast was compared with T2-weighted spin-echo, T1-weighted gradient-echo, and single shot TurboFLASH sequences. All lesions that were seen with the latter sequences were also visible on the segmented TurboFLASH images. Contrast on the segmented TurboFLASH images was similar to that of T2-weighted spin-echo sequences and superior to T1-weighted gradient-echo sequences. Signal of fat could be nulled at an inversion time of 10 ms, signal from liver tissue could be nulled at an inversion time of 300 ms. By minimising the liver signal, the lesions could be "highlighted". This was not possible with the other imaging sequences. The segmented TurboFLASH technique allows breath-hold imaging of the liver with arbitrary image contrast. The lesion-liver contrast is comparable to time-consuming T2-weighted spin-echo sequences.

Biopsy, Needle↗
PubMed1992

[The value of tumor volumetry as opposed to bidimensional determination of tumor size during follow-up of hepatic metastases from colorectal carcinoma].

36 patients with liver metastases due to colorectal carcinoma under treatment with arterial perfusion chemotherapy of the liver with 5-fluoro-2-desoxyuridine (FUDR) via a subcutaneous pump were investigated by axial liver CT at 6-monthly intervals. In all examinations a dynamic CT scan with intravenous bolus injection of contrast medium was carried out following a native scan. Changes in tumour size were documented by means of 1. volumetry and 2. bidimensional measurement according to WHO criteria. Since we were not able to assess small newly developing lesions within the liver using the volumetric classification, the WHO-classification showed much higher sensitivity in cases of progressive disease. In addition, volumetric determination of tumour size by means of region-of-interest technique proved to be rather impracticable in clinical routine compared to bidimensional measurement.

Aged↗
PubMed1992

[The place of portangiography in the follow-up control of locoregional chemotherapy].

101 portangiographies in patients with liver metastases from colorectal primaries who underwent hepatic intraarterial or intraperitoneal chemotherapy were performed and studied between January 1991 and February 1992. 81% of the examinations did not involve complications. In 19% of the angiographies abnormalities of the arterial perfusion of the liver, like occlusion, dissection or narrowing of hepatic arteries, were found. We conclude that portangiography is a very important investigation before regional chemotherapy.

Angiography↗
PubMed1992

[Magnetic resonance tomographic imaging of pulsatile CSF movement in communicating hydrocephalus before and after shunt placement].

16 patients with hydrocephalus communicans and 5 healthy volunteers were examined to demonstrate the pattern of the pulsatile CSF flow. After implantation of a CSF shunt system the same patients were examined again to show the influence of the shunt on the CSF pulsations. We used a flow-sensitised, cardiac-gated 2D FLASH sequence and analysed the phase and magnitude images. It could be shown that most patients (n = 12) had a hyperdynamic pulsatile flow preoperatively. After shunt implantation the pulsatile CSF motion and the clinical symptoms were improved in 8 of these patients. MRI of pulsatile CSF flow movement seems to be a helpful noninvasive tool to estimate the prognosis of a shunt implantation in patients with hydrocephalus communicans.

Adult↗
PubMed1992

[Sonographic findings in lateral ligament lesions of the upper ankle joint following conservative and operative therapy].

72 patients with injury of the ankle joint were examined with ultrasound after therapy. Sonographic findings were assessed by plain x-ray films and stress views. In 39 patients an injury of the lateral ligament was treated by surgery and in 33 patients without surgery. 40 patients showed a scar of the lateral ligaments. Patients treated without surgery and showing a scar in ultrasound demonstrated a smaller tilt of the talus in stress views than patients without scars. Measurement of stability was not possible. In conclusion, sonography is a valuable tool in examining the ankle joint after therapy. With regard to stability, stress films cannot be replaced by sonography.

Adolescent↗
PubMed1992

[Clinical potentialities and limitations of two- and three-dimensional time-of-flight MR angiography in the diagnosis of carotid stenosis].

For diagnosing a carotid artery stenosis, 26 patients underwent MR angiography. A spin echo (SE) sequence with presaturation on which the flowing blood appears with low signal intensity was applied, as well as a two- and three-dimensional gradient echo (GRE) sequence with flow compensation, showing blood flow with high signal intensity. Subsequently, projection angiograms were made from the MR images with a maximum intensity projection algorithm. Degree, length and localisation of a carotid artery stenosis were reviewed. To find out the clinical usability, the results of the MR angiograms were compared subsequently with the findings of intravenous digital subtraction angiography (i.v. DSA). In comparison with DSA a correlation in the degree of stenosis was noticed in 42 out of 48 SE-, in 39 out of 52 2-D GRE and in 41 out of 48 3-D GRE sequence angiograms. The length of 34 moderate and severe stenoses, demonstrated by DSA, was overestimated 5 times with the SE-sequence, 9 times with the 3-D and 23 times with the 2-D GRE sequence. MR angiography with a 3-D GRE sequence is suitable for screening for carotid artery stenosis. In cases of severe stenosis an SE sequence should be performed for more precise delineation of the stenotic lesion.

Aged↗
PubMed1992

[Angiographic diagnosis in giant cell arteritis of the arm arteries].

Three women of 66, 68 and 69 years of age presented with chronic arm claudication caused by giant cell arteritic stenoses and occlusions of their arm arteries. In the early stage of the disease, arteriography revealed smooth or undulatory long-segment narrowings. Subsequently, spindle-shaped filiform stenoses developed. They were unilateral in one patient, bilateral-symmetric in another and like a string of beads in the third. In the end, untreated arteritis resulted in smoothly tapered occlusions of the diseased vessels. In patients with symptoms and signs suggestive of giant cell arteritis, typical arteriographic findings may confirm the diagnosis even if histopathological proof is lacking.

Aged↗
PubMed1992

[Stent-supported percutaneous therapy of iliac vein stenosis following operative thrombectomy and placement of a shunt].

Among 15 patients with acute thrombotic disease of pelvic veins who had been submitted to operative thrombectomy and creation of arteriovenous fistula in the groin, 12 presented with stenotic lesions 3 months later. These stenoses were submitted to percutaneous angioplasty. If angioplasty failed, percutaneous placement of a vascular stent (wall stent) was performed immediately (n = 7). Stenting in cross-over-technique proved practicable in all cases. Secondary stenotic disease in the exclusively dilated area was observed in 3/5 cases and was also treated with a wall stent. In one patient with recurrent stenoses who refused stenting, extended thrombosis occurred after occlusion of the AV-fistula. At mid-term PTA was successful in only two cases. Intimal hyperplasia was observed in only one wall stent treated patient. Percutaneous treatment of iliacal stenoses in patients with postthrombotic syndrome may be performed safely under the protective effect of the fistula. With the presented technique, patency of pelvic veins could be restored in 11/12 patients with postoperative significant venous stenoses.

Adult↗
PubMed1992

[Malignant fibrous histiocytoma: productive use of imaging procedures].

Malignant fibrous histiocytoma (MFH) of soft tissue is a rare tumor. We present a case of MFH in the bicipital muscle. Local muscle hypertrophy or lesions of the long tendon of the bicipital muscle may be a difficult differential diagnosis. This case is used for outlining advantages of ultrasound, computed tomography and magnetic resonance imaging. In conventional radiography MFH is seen as a soft-tissue tumor sometimes involving the bone. CT is the best way to test bone involvement. Tumor extension will be assessed with great accuracy by means of ultrasonics and magnetic resonance imaging (MRI).

Arm↗
PubMed1992

Indication for surgery of asymptomatic carotid lesions.

The incidence of cerebrovascular diseases with transient or persistent neurologic dysfunction has increased significantly. Although patients with symptomatic carotid artery stenosis clearly benefit from operative therapy, the indication to prophylactic surgery of asymptomatic carotid lesions however is still controversial. Based on data from a recently completed prospective randomized study and on analysis of the literature the indication and results of surgical treatment of asymptomatic stenoses of the carotid arteries are discussed. From 1970 to 1990 a total of 744 uni-or bilateral reconstructions of the internal carotid artery were performed in 631 patients. The perioperative morbidity (permanent neurologic deficiency) and mortality was 1.1% (n = 8) resp. 0.8% (n = 6). During the follow up period up to 18 years another 9 patients suffered from stroke (1.2%). The annual stroke incidence amounted to 0.2%. An important prerequisite for surgery is the so called critical internal carotid artery stenosis, implying reduced cerebral vasomotor reactivity or high embolic risk of an ulcerative plaque. Proper selection of patients (exclusion of multiple concomitant diseases) and an experienced team of vascular surgeons with operative morbidity and mortality below 1-2% validates surgical treatment of asymptomatic carotid artery stenoses.

Carotid Artery Diseases↗