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J Lissner

Publications and source records attributed to J Lissner.

At least 19 recordsLinked to original sources
PubMed1996

Sjoegren's syndrome: MR imaging of the parotid gland.

To date, myoepithelial sialoadenitis (Sjoegren's syndrome) has been diagnosed with sialography and other techniques. First results of MR imaging offer new possibilities in the diagnostic imaging of this disease. Thirty-six patients with immunohistologically and serologically confirmed Sjoegren's syndrome and 25 patients suffering from other diseases, included as a control group, were examined by MR in transverse and coronal orientation. T-2-weighted sequences (TR/TE 1600/25/90) and T1-weighted sequences (TR/TE 500/25 ms) plain and after Gd-DTPA administration were obtained. In all patients the parotid gland showed characteristic internal patterns and abnormalities in gland size. There was a nonhomogeneous internal pattern with a characteristic speckled, honeycomb-like appearance visible especially on T2-weighted sequences. Enhancement with Gd-DTPA yielded no additional information. A staging system with four stages of Sjoegren's syndrome (no characteristic changes to a nodular and swollen gland) was developed. Magnetic resonance has become an important new tool in assessing parotid gland changes in patients suffering from Sjoegren's syndrome, and could well replace the more invasive and unpleasant diagnostic methods in the near future.

Acute Disease↗
PubMed1995

Topography of the cortical motor hand area: prospective study with functional MR imaging and direct motor mapping at surgery.

PURPOSE: To localize the cortical motor hand area with functional magnetic resonance (MR) imaging and electrical stimulation at surgery and to detect changes due to central lesions. MATERIALS AND METHODS: Fast-gradient-echo and functional MR images of the brain were acquired in four healthy volunteers and six patients with tumors in the central region before, during, and after repetitive opening and closing of the hand. Open brain surgery was performed, and the exposed cortex was stimulated. RESULTS: At functional MR imaging, circumscribed changes in signal intensity that correlated in time with the task were seen in the central region of the contralateral brain. In the healthy volunteers, the area of change was spotlike and projected into the posterior bank of the precentral gyrus. In four of the six patients, this area was diffuse and projected into the precentral gyrus. The locations of the cortical hand area as determined with intrasurgical mapping and functional MR imaging were identical. CONCLUSION: Identification of the cortical area responsible for motor hand function was similar with functional MR imaging and with direct stimulation at surgery. A space-occupying lesion can change the cortical representation of motor hand function.

Adult↗
PubMed1995

[Diagnosis of fractures of the occipital condyles].

The imaging diagnosis of occipital condyle fractures by CT and MRT is reported for cases of 4 patients. Following the conventional X-ray diagnosis of the skull and upper cervical spine, CT proved to be the primary diagnostic method after a skull and brain injury: for all 4 cases we succeeded in detecting the occipital condyle fracture and in determining its size and location by reconstructions (coronal, sagittal, 3-D). In the case of complex accompanying injuries like soft tissue hematomas (cerebral, in the spinal cord, and the soft tissue of the neck) or for the detection of brain stem contusion, MRT had significant advantages. MRT can offer a higher image quality in soft tissue, especially in the spinal cord and the brain.

Adolescent↗
PubMed1994

[The value of the liver-specific superparamagnetic contrast medium AMI-25 for the detection and differential diagnosis of primary liver tumors versus metastases].

The value of the superparamagnetic contrast medium AMI-25 and its clinical acceptability was investigated in a phase-III-multicenter study. 18 patients with primary and secondary hepatic tumours were studied using T2- and T1-weighted spin-echo sequences, FATSAT sequences and FLASH-2-D-breathold sequences, both before and after intravenous application of AMI-25 (0.2 mmol GE/ml 15 mmol/kg KG in 100 ml 5% glucose infusion), using a 1.5 Tesla MRT (Magnetom 63 SP, Siemens). In 6 patients the MRT findings could be correlated with in vitro results within 30 minutes following surgical resection. In 8 patients a diagnosis of metastases was made. Amongst patients with primary liver tumours (FNH 6 cases, HCC 3 cases, adenomatosis 1 case) 3 of the 10 patients showed more lesions following the injection of contrast; similarly, in 4 patients of the 8 with secondary tumours contrast increased the number of visible lesions. The absence of contrast enhancement separated primary from secondary lesions. Amongst the patients with secondary liver tumours, in vitro correlation always showed more tumours than had been visualised whereas there was exact in vivo/in vitro correlation amongst patients with primary liver tumours.

Contrast Media↗
PubMed1994

Glomus tumors of the skull base: combined use of MR angiography and spin-echo imaging.

PURPOSE: To evaluate the use of magnetic resonance (MR) angiography in the diagnosis of glomus tumors of the skull base. MATERIALS AND METHODS: In 40 patients with pulsatile tinnitus, spin-echo (SE) images, single sections, and maximum intensity projections from gradient-echo sequences, including arterial MR angiography and MR venography, were evaluated for tumor detection. Interpretations by two independent observers were correlated with findings from histologic examination, digital subtraction angiography, computed tomography, and clinical follow-up. RESULTS: Glomus tumors were detected near the tympanic plexus (n = 8) and close to the superior (n = 8) and inferior (n = 1) ganglia of the vagus nerve. Sixteen of 18 proved tumors were detected with SE images alone. Although four high-lying jugular bulbs were misinterpreted as tumor due to similar signal intensity, combined evaluation allowed differentiation between tumor and sinusal blood flow in all cases. CONCLUSION: The authors recommend combined SE imaging and MR angiography for ruling out tumor in patients with pulsatile tinnitus.

Adult↗
PubMed1994

Dural sinus thrombosis: value of venous MR angiography for diagnosis and follow-up.

OBJECTIVE: The purpose of this study was to determine the value of venous MR angiography as the sole procedure for the diagnosis and follow-up of dural sinus thrombosis. MATERIALS AND METHODS: Forty-two patients with clinical findings suggestive of dural sinus thrombosis were examined with venous MR angiography and spin-echo MR imaging. Maximum-intensity-projection reconstructions and individual sections of the MR angiograms were examined for direct and indirect signs of dural sinus thrombosis by assessing flow signal from the major sinuses, the jugular bulb, upper jugular veins, ascending cortical veins (occlusion or increased flow due to formation of collaterals), diploe (emissary) veins and extracranial veins, and the deep subcortical veins (Galen's and internal cerebral veins). Direct signs of dural sinus thrombosis on MR angiograms included lack of typical high flow signal from a sinus that did not appear aplastic or hypoplastic on single sections from MR angiography and the frayed appearance of the flow signal from a sinus after recanalization. Indirect signs of dural sinus thrombosis included evidence of formation of collaterals, unusually prominent flow signal from deeper medullary veins, cerebral hemorrhage, visualization of emissary veins, and signs of increased intracranial pressure. When available, conventional angiograms were evaluated by analogous criteria as appropriate. Digital subtraction or cut-film angiograms were available for correlation in nine patients. In nine patients, MR angiography was repeated up to eight times during the course of follow-up. The results of MR angiography for all patients were compared with results in 10 control subjects. Confirmation of the diagnosis of dural sinus thrombosis was based either on conventional angiographic findings or on the changes seen in follow-up examinations. RESULTS: Dural sinus thrombosis could be ruled out in 25 of the 42 patients on the basis of clinical and MR angiographic findings. In 17 patients with MR angiographic findings that indicated dural sinus thrombosis, conventional angiography confirmed the diagnosis in nine patients, and changes seen on repeat MR angiograms during follow-up confirmed the diagnosis in nine patients as well (one patient's diagnosis was confirmed by both techniques). Individual frames from two-dimensional fast low-angle shot sequences allowed direct visualization of thrombus. Limited spin-echo sequences as performed here provided inconsistent findings and were insufficient for diagnosis. In the 10 control subjects, attenuation of flow signal was seen in the torcular Herophili in all studies; one subject had a nonpathologic variant of the sinojugular system. CONCLUSION: MR angiography is the technique of choice for diagnostic evaluation and follow-up of dural sinus thrombosis, and it is reliable as the sole examination for this condition. When MR angiographic findings are unremarkable and other abnormalities must be ruled out, routine spin-echo MR imaging should be performed.

Adult↗
PubMed1993

[The 31-phosphorus spectroscopy of space-occupying lesions of the salivary glands. The clinical results and differential diagnosis].

In a prospective study, 15 normals and 20 patients with space-occupying lesions of the salivary glands were examined by MRT images and by in vivo 31-phosphorus spectroscopy. The spectra of malignant tumours showed a significant increase in concentration of phosphomonoesters, phosphodiesters and inorganic phosphates when compared with normals. In addition there was an enormous reduction in creatine phosphates. Increased pH values and marked increase in concentration of inorganic phosphates correlated with poorly vascularised necrotic tumour segments. Concentrations of ATP and PCr were similar to normal muscle tissue. High concentrations of PME and PDE correlated directly with the proliferation of tumour cells and were an important marker for the bioenergy and phospholipid metabolism of the growing tumour. Standardised in vivo 31-phosphorus spectroscopy of space-occupying lesions of the salivary glands provides noninvasive prognostic information on the type and behaviour of the lesion and is complementary to clinical and histological findings.

Adult↗
PubMed1993

Skull base tumors: gadodiamide injection--enhanced MR imaging--drop-out effect in the early enhancement pattern of paragangliomas versus different tumors.

A phase III trial was conducted in 40 patients with known or suspected skull base tumors to evaluate the safety and efficacy of high-dose gadodiamide injection for use as a paramagnetic contrast medium in conventional and dynamic magnetic resonance (MR) imaging. Contrast material enhancement was assessed dynamically with use of a gradient-recalled sequence. The time-intensity curve of selected regions of interest showed a reproducible dropout effect in the form of a dip in the curve during the early enhancement of the sigmoid sinus and jugular bulb; the same phenomenon was observed in all glomus tumors of the skull base, regardless of size or location. In contrast, schwannomas, meningiomas, and a variety of other lesions showed a continuous increase in the time-intensity curve. The drop-out sign, which is probably a result of a paramagnetic phenomenon during the early phase of enhancement, seems to be specific for glomus tumors. High-dose gadodiamide injection may show a specific dynamic pattern for glomus tumors, allowing differentiation from other tumors of the middle and posterior skull base.

Drug Combinations↗
PubMed1993

MR imaging with Gd-DTPA in lesions of the head and neck.

The diagnostic value of MR in the head and neck with special emphasis on the contrast medium Gd-DTPA will be demonstrated. A total of 1,260 patients underwent MR with different pulse sequences plain and with Gd-DTPA. The sequences were analyzed and compared with CT. Due to the different pattern of enhancement the contrast medium helped in differentiating malignant and benign tumors from other processes like cysts and inflammatory changes. Except lesions with small bony erosion and inflammatory changes of the salivary glands MR with Gd-DTPA proved to be diagnostically advantageous in all cases. Gd-DTPA improved the delineation of tumor margins. MR in combination with Gd-DTPA offers a lot of new advantages for diagnosing lesions of the head and neck. However, due to the prolonged examination time and the lack of noninvasiveness the use of Gd-DTPA has to be considered critical for every single area of the head and neck.

Blood Vessels↗
PubMed1992

[MR angiography in neuropediatric problems: the technic and the clinical results].

31 children aged between 6 months and 14 years with various neurovascular abnormalities were examined by MR angiography in a prospective study. In order to test the sensitivity and specificity of the MR results, these were compared in 8 cases with the findings of digital subtraction angiography or conventional angiography. In 24 patients arterial MR angiography was performed; in 17 these showed anomalies or abnormalities of the intracranial vascular system. In 7 patients venous MR angiography was performed and demonstrated the presence of sinus thrombosis in 6 of these. Comparison between MR angiography and DSA showed agreement in 7 cases; in one patient the degree of a stenosis was exaggerated by MR. The results of this study indicate that arterial and venous MR is of great value as an additional study in paediatric neurovascular problems.

Angiography, Digital Subtraction↗
PubMed1992

[MR angiography for tumor diagnosis in the head-neck region: the study technic and clinical results].

40 normal individuals and 153 patients with lesions in the head and neck were examined by conventional imaging methods and by means of MR angiography (1.5-tesla Magnetom). The problems to be solved concerned the relationship between tumors and vessels and vascular anomalies and abnormalities at the skull base (56 cases), the facial skeleton (62 cases) and the neck (35 cases). Digital subtraction angiography was performed in 54 patients and the findings correlated with MR angiography. Optimal results were obtained by using a FISP 3D sequence; in this way arterial structures could be rendered reproducibly down to a diameter of 2 mm. The venous system in the head and neck was best shown by a FLASH 2D sequence. Correlation with arterial DSA showed high accuracy of MR angiography (91%) concerning displacement of vessels, the topography and the recognition of vascular occlusions. Our results indicate that MR angiography is a rapid and reliable procedure for evaluating the arterial and venous changes due to tumors in the head and neck region.

Angiography, Digital Subtraction↗
PubMed1992

[Pre- and postoperative NMR tomographic studies in avascular femur head necrosis].

46 patients with avascular necrosis of the femoral head were examined by T2- and T1-weighted MR before and after infusion of Gd-DTPA. Both sides were involved in 12 cases. The classification was done according to Ficat. In early stages and in postoperative studies a correlation of signal intensity after infusion of Gd-DTPA and clinical symptoms was found. Hyperintensity of the avascular area or of the implanted material was assumed to be vascularised or vital components in 4 cases of Ficat I and in 15 postoperative studies. Contrariwise, we found in 5 patients with severe postoperative symptoms, low signal intensity areas due to avascular regions.

Contrast Media↗
PubMed1992

[NMR tomography of the liver with the new contrast agent Gd-BOPTA. The results of an in-vivo phase-I test].

A phase 1 study on 8 normals has been carried out to determine the effectiveness and safety during MRI of a new hepatobiliary contrast medium Gd-BOPTA for causing enhancement of the upper abdominal organs. Gradient echo sequences (flash), T1 and T2-weighted spin echo sequences and turbo-flash sequences were used. The contrast medium was given as a single infusion in various concentrations (0.005, 0.05, 0.1, and 0.2 mmol/kg body weight). Optimal contrast of liver parenchyma was obtained with a dose of 0.05-0.1 mmol/kg body weight, resulting in contrast increase of 149.1% during gradient echo sequences and 107.8% during T1 spin echo sequences. In general, the increased contrast lasted for about two hours. Because of the biliary and renal excretion there was an enormous increase in signal intensity of the bile ducts and a significant increase in the kidneys and ureters. The results of the first in-vivo trial of Gd-BOPTA encourages the performance of further clinical studies of this new hepatobiliary contrast medium.

Acetates↗
PubMed1992

[The proton MR spectroscopy of intracranial tumors. The differential diagnostic aspects for gliomas, metastases and meningiomas].

Twenty-two patients with intracranial tumours were examined by MR images and in vivo proton-MR-spectroscopy. The changes of relative concentrations of NAA, PCr/Cr, Cho, and Ins were measured spectroscopically and the amount of these metabolites were related to different tumour groups. Analysis of the results has shown that the spectra from all the tumours differed from normal spectra. All cerebral tumours showed marked reduction of the Pcr/Cho quotient and the NAA/Cho quotient was also reduced. The Ins/Cho quotient for meningiomas and metastases was also lower than in normals; in gliomas of low malignancy the quotient was slightly raised and in gliomas of greater malignancy it was significantly higher than normal. The spectra of cerebral metastases showed unusual high lipid signals of 0.9 ppm and 1.25 ppm. The only common feature for meningiomas was marked reduction of NAA concentration. In summary, localised in vivo proton-MR-spectroscopy can be used clinically to obtain valuable information for the differential diagnosis of gliomas and intracerebral metastases.

Brain Neoplasms↗
PubMed1992

[The clinical value of magnetic resonance tomography in cystic space-occupying lesions of the mouth floor].

11 patients with cystic lesions of the floor of the mouth were examined by MR imaging. Coronal slices provided an optimal visualisation of the lesions, but axial and sagittal slices added important information with regard to the exact topographic relationship between tumour and muscles. In particular, the mylohyoid muscle could be defined as a key structure. T1-weighted sequences enabled best visualisation of anatomic details, whereas T2-weighted sequences facilitated the primary diagnosis of cystic lesions. The contrast agent Gd-DTPA did not add information of significant diagnostic value. Our results indicate that MRI allows an exact visualisation of location and extent of cystic lesions and their relationship to surrounding muscles. We conclude that MRI is of high value in planning the operative strategy.

Cysts↗
PubMed1992

[Magnetic resonance tomography and magnetic resonance angiography in lymphangiomatosis].

Generalised lymphangiomatosis is a rare benign congenital abnormality of the lymphatic vessels with a complex pattern. 3 patients with different types of lymphangiomatosis were studied by MRT and MRA and histopathologically. All patients had multiple organ involvement in the abdomen, the skeleton and the skull. The basis in each case was lymphangiomatosis of capillary-cavernous, cystic or cavernous type. The results of MRT and MRA in diagnosing splenic, vascular and skeletal changes correlated accurately with operative findings and with the histopathological classification. In summary, MRT combined with MRA and using paramagnetic contrast media are the diagnostic methods of choice for the investigation of generalised lymphangiomatosis with multiple organ involvement.

Abdomen↗
PubMed1992

Focal liver lesions: MR imaging with Mn-DPDP--initial clinical results in 40 patients.

Manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis(phosphate) (DPDP) was evaluated as a contrast agent for magnetic resonance (MR) imaging (1.5 T) of focal liver lesions in 40 patients. Doses of 5 and 10 mumol/kg were administered intravenously. Mn-DPDP-enhanced T1-weighted images were compared quantitatively and subjectively with standard T1- and T2-weighted nonenhanced images. Use of Mn-DPDP resulted in a statistically significant increase in signal intensity of liver parenchyma in T1-weighted images at both doses. No enhancement was seen in metastases, cholangiocarcinomas, or lymphomas, while all hepatocellular carcinomas were enhanced. Enhancement was seen in focal nodular hyperplasia and in regenerative nodules. The lesion-to-liver contrast in Mn-DPDP-enhanced gradient-recalled-echo images was superior to that of all precontrast images (P less than .01). The number of nonenhancing malignant liver lesions detected in spin-echo (SE) images was increased (272 in T2-weighted SE images vs 390 in T1-weighted Mn-DPDP-enhanced SE images). Image interpretation (eg, visualization and demarcation of the lesions) was markedly better in Mn-DPDP-enhanced images than in all precontrast images (P less than .001).

Adult↗