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Biomedical subjects

J Lissner

Publications and source records attributed to J Lissner.

At least 55 records · Page 3Linked to original sources
PubMed1989

[In vivo 31P magnetic resonance spectroscopy and MRI in patients with superficial tumors].

Simultaneous 31P-MR spectroscopy (MRS) and MR imaging (MRI) of 10 patients suffering from superficial tumours like carcinoma, lymphoma and adenoma, revealed significantly enhanced concentrations of phosphomonoester, phosphodiester and inorganic phosphorus in the tumour, whereas the concentration of phosphocreatine was lower in comparison to muscle tissue. In all tumours the pH showed a slight alkaline shift. The existing of necrotic regions detected by MRI was accompanied by an increase of inorganic phosphorus in the spectra. A follow-up study of a patient with a lymphoma during chemotherapy showed a tumour regression, whereas the spectra indicated a continuous approach of tumour values to the muscle values.

Contrast Media↗
PubMed1989

[MRI of the nasopharynx with Gd-DTPA: its value and differential diagnostic criteria].

81 patients with masses in the nasopharynx were examined by MRI and CT. In cases of primary lesions of the nasopharynx (such as carcinomas and fibromas), MRI with Gd-DTPA was superior to CT. Secondary tumors involving the nasopharynx were visualized equally well with MRI with Gd-DTPA and CT. The results show that MRI should be the primary method of examination in lesions of the nasopharynx. CT is a secondary procedure useful for showing small areas of bone erosion. MRI with the paramagnetic contrast medium Gd-DTPA permits differentiation between inflammatory, cystic and neoplastic masses.

Angiography↗
PubMed1989

[Gd-DTPA-supported magnetic resonance tomographic perfusion follow-up of shockwave-treated tumors].

The signal characteristics of 14 shockwave-treated and 14 solid control tumors were studied before and after injection of Gd-DTPA in an animal model. T1-weighted images of shockwave-treated tumors documented no significant signal intensity increase after contrast media injection in comparison with the untreated control tumors. The reduction of perfusion in shockwave-treated tumors can be documented in vivo by the signal intensity changes of the tumors after contrast media injection.

Animals↗
PubMed1989

[The value of MRT of the thorax in congenital tracheal stenoses].

MRI of the thorax was performed in 24 children aged between six weeks and five years, in whom a tracheal stenosis had been demonstrated by bronchoscopy. Since bronchoscopy can only demonstrate the interior of the trachea, various imaging methods, such as CT and angiography, were used to demonstrate the topography and cause of the tracheal stenosis. MRI has shown that the most common cause of a stenosis in the central section of the trachea is focal compression by an aberrant brachiocephalic trunk (10 cases). Stenosis of the distal trachea could be due to anomalies of the aortic arch (5 cases), a dilated pulmonary artery (4 cases) or a soft tissue mass (3 cases). In all these patients, MRI was greatly superior to the conventional methods. By using a special technique, MRI made it possible to clarify the cause and localisation of a tracheal stenosis by a non-invasive examination.

Aorta, Thoracic↗
PubMed1989

Detection and quantification of chronic cerebrovascular disease: comparison of MR imaging, SPECT, and CT.

Twenty patients with angiographically proved occlusion of the internal carotid artery (ICA) (19 unilateral, one bilateral) were studied with magnetic resonance (MR) imaging, iodine-123 iodoamphetamine (IMP) single photon emission computed tomography (SPECT), xenon-133 SPECT, and computed tomography (CT). All patients had a history of stroke or prolonged reversible ischemic neurologic deficit for more than 4 weeks. By regions of interest, T1, T2, regional cerebral blood flow (rCBF), and the number and size of the lesions were determined. The data were expressed as interhemispheric ratios (diseased/nondiseased). The highest ratios obtained were for MR imaging (T1, 2.60 +/- 0.42; T2, 1.61 +/- 0.22 [mean +/- standard deviation]) followed by Xe-133 SPECT (0.58 +/- 0.13) and IMP SPECT (0.56 +/- 0.13). Correlation coefficients for MR imaging (1/T1, 1/T2) and IMP SPECT were below .21. The lesion size was greatest on IMP SPECT images, intermediate on MR images, and least on CT scans. However, MR imaging was superior in detection of pathologic areas (detection rates: MR, 100%; IMP SPECT, 91%; CT, 79%). Relaxation times do not correlate with rCBF.

Brain↗
PubMed1989

Cisplatin, fluorouracil with leucovorin calcium enhancement, and synchronous accelerated radiotherapy in the management of locally advanced head and neck cancer: a phase II study.

In a phase II study, patients with locally advanced squamous cell carcinoma of the head and neck were treated with simultaneous chemoradiotherapy. Treatment was divided into three courses. Chemotherapy consisted of cis-diamminedichloroplatinum (II) (cisplatin [cis-DDP]) 60 mg/m2 intravenously (IV), fluorouracil (5-FUra) 350 mg/m2 IV, and folinic acid (leucovorin calcium [FA]) 50 mg/m2 IV on day 2 as bolus, and 5-FUra 350 mg/m2 over 24 hours and FA 100 mg/m2 over 24 hours on days 2 through 5. Radiotherapy consisted of 23.4 Gy over nine days divided into 13 fractions of 1.8 Gy each delivered twice a day from day 3 through day 11. This regimen was repeated on days 22 and 44. Total radiation dose amounted to 70.2 Gy over 51 days. Between August 1984 and October 1986, 62 (modified AJCC stage III, four; IV A, eight; IV B, 50) consecutive patients were entered in the study. Three patients died during treatment due to tumor hemorrhage. Of 59 patients, 48 (81%) achieved a clinically complete response (cCR); 11 (19%) achieved a partial response (cPR). Mean follow-up of the surviving patients was 29+ (24 to 44) months. Actuarial 2-year survival probability is 52%, including three early deaths from tumor bleeding. Tumor and neck nodes control rates at 2 years were 92% for stage III and IV A patients and 65% for stage IV B patients. Patients with cCR had a significantly better 2-year tumor and neck nodes control probability compared with patients who achieved cPR after therapy (P less than .001). Six patients developed distant metastases. Overall toxicity was tolerable, mucositis particularly was not a limiting factor.

Adult↗
PubMed1989

Paragangliomas of the jugular bulb and carotid body: MR imaging with short sequences and Gd-DTPA enhancement.

Twenty-six patients with glomus jugulare (16), glomus tympanicum (three), or carotid glomus (seven) tumors were examined with contrast-enhanced CT scans and MR scans without and with Gd-DTPA. MR and CT scans had similar sensitivities, but the enhanced MR scans were diagnostically more specific than either CT or nonenhanced MR. Dynamic MR scanning permitted measurement of the degree of Gd-DTPA enhancement over time. We recommend contrast-enhanced MR with short sequences and a dynamic approach in patients with suspected carotid, tympanic, and jugular paragangliomas.

Carotid Body Tumor↗
PubMed1989

[Magnetic resonance tomography of the parotid gland: plain diagnosis and Gd-DTPA].

Pathological lesions of the parotid gland were examined comparatively with different examination sequences both plain and with the contrast medium Gd-DTPA. There were 36 benign lesions (parotitis, Sjögren's syndrome, adenoma, etc.) and 24 malignant tumours (squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma etc.) Examinations were carried out at 1.0 T with long and short spin echo sequences in transverse and frontal layer orientation before and after application of Gd-DTPA as contrast medium. In the patients suffering from parotitis the best results were obtained with plain T1 and T2 sequences; the contrast medium Gd-DTPA remained without superior diagnostic relevance. However, in Sjögren's syndrome (myoepithelial sialadenitis) administration of the contrast medium always yielded a characteristic honeycomblike pattern. In benign and malignant space-occupying growths MRI supplied additional diagnostic information with Gd-DTPA in respect of defining the tumour borderlines and paths of infiltration. MRI is now a significant diagnostic tool in inflammatory and tumorous lesions of the parotid gland.

Adenocarcinoma↗
PubMed1988

[Magnetic resonance tomographic studies of paragangliomas of the glomus caroticum and glomus jugulare using Gd-DTPA].

The value of magnetic resonance tomography in the diagnosis of paragangliomas in the head and neck has been studied and compared with CT and angiography. Magnetic resonance tomography on its own equals the accuracy of CT, but the use of Gd-DTPA improves diagnostic accuracy. In 19 patients with a glomus jugulare tumour, MR tomography with Gd-DTPA accurately diagnosed all tumours larger than 5 mm. In seven patients with a carotid body tumour, it was possible to arrive at an exact differential diagnosis. Sensitivity was better than that of CT or of sonography. Where there is clinical suspicion of a glomus tumour, magnetic resonance tomography with Gd-DTPA should be the first investigation; if there is a positive finding, angiography should be carried out to demonstrate the circle of Willis.

Carotid Body Tumor↗
PubMed1988

[Gd-DTPA contrast enhancement in the nuclear magnetic resonance tomographic diagnosis of thoracic space-occupying lesions].

The optimal technique for examining mediastinal masses is the use of T1 weighted spin-echo sequences (TR 500 msec/TE 17 msec) in transverse and coronal slice orientation pre and post contrast application. This setup provides an excellent morphological depiction of anatomy and pathology as well as T2 comparable information about tumor structure without the disadvantage of a reduction of the signal-to-noise ratio.

Adenocarcinoma↗
PubMed1988

[Results of magnetic resonance tomography of the temporomandibular joint using optimized surface coils].

One hundred temporo-mandibular joints were examined with a super-conducting nuclear resonance tomograph (1.0 Tesla) using various high resolution surface coils. The optimal method proved to be a spin echo sequence with a repetition time of 1,000 msec and an echo period of 28 msec with a 4 mm slice width. There were significant advantages from the non-invasive MRT diagnosis of the temporo-mandibular joints when compared with CT and with arthrography in recognising abnormal discs, changes in the tissues and for post-operative control.

Adult↗
PubMed1988

Indications for the use of Gd-DTPA in MRI of the central nervous system. Experiences in patients with cerebral and spinal diseases.

A total of 209 intracranial and spinal diseases were evaluated before and after administration of the paramagnetic contrast agent Gd-DTPA. The results justify the use of Gd-DTPA in intracranial and spinal tumors for better visualization of location and extent of a lesion and for better tissue differentiation. In inflammatory diseases Gd-DTPA allows the differentiation between active and chronic lesions.

Brain Neoplasms↗
PubMed1988

The induction of chromosome aberrations during the course of radiation therapy for morbus Hodgkin.

In a patient with Morbus Hodgkin, structural aberrations of the chromosome type in peripheral lymphocytes were analyzed during radiation therapy (accumulated target dose 44.6 Gy: 22 fractions of 1.8 Gy each and 2 fractions of 2.5 Gy each at the end of the therapy). The blood was sampled about 5 min after a fraction and/or 24, 48, or 72 h thereafter. The frequency of dicentric chromosomes:acentric fragments:centric ring chromosomes is 37:14:1 throughout the therapy. Independent of the time of blood sampling after a fraction, the distributions of dicentrics and acentrics are overdisperse and represent negative binomial distributions. The yields from these aberrations, as determined during the course of radiotherapy, are best fitted to a linear-quadratic function with a negative quadratic term. The two dose-effect curves (blood sampling about 5 min and 24 to 72 h after a fraction) of dicentrics and acentrics do not differ significantly. Up to an accumulated target dose of about 20 Gy the percentages of cells with chromosome aberrations increase to about 48 to 65% and, at this level, remain constant until the end of therapy.

Adult↗
PubMed1988

[Diseases of the lymphatic system of the head and neck region. A comparative study of MRI and CT].

The diagnostic possibilities of magnetic resonance imaging compared with computed tomography in lymphomas and pathological enlargement of the lymph nodes in the head and neck region are presented. Whereas plain MRI examinations showed the same diagnostic sensitivity as CT, application of the paramagnetic contrast medium Gd-DTPA in 50 of 87 patients clearly increased diagnostic accuracy. Signal intensities of T1- or T2-weighted images before therapy (operation, chemotherapy, radiotherapy) and after administration of Gd-DTPA were enhanced, compared with posttherapeutic and plain examinations. An increase after therapy in two patients signalled a relapse or residual tumour tissue; a decrease in three cases was evaluated as response to therapy. Other differential diagnostic processes such as lipomas, neurinomas, glomus tumours etc. were differentiated with the help of signal intensity curves after administration of contrast media and the use of a gradient echo sequence TR/TE = 30/12 msec with a flip angle of 30 degrees. Differentiation of tissue based on morphological criteria such as homogeneity of tumour tissue or the delineation against surrounding tissue structures showed in the case of Hodgkin's disease and inflammatory diseases mainly homogeneous elements without ring-shaped structure. Non-Hodgkin lymphomas had a predominantly homogeneous structure. In squamous cell carcinomas MR revealed in two cases a ring-shaped enhancement.

Adult↗
PubMed1988

[Dynamic contrast medium studies with flash sequences in nuclear magnetic resonance tomography of the breast].

In this study the dynamic contrast behavior after Gd-DTPA of different breast tissues and tumors has been investigated with a series of T1-weighted FLASH-sequences during the first 5 minutes after the application of Gd-DTPA. The results of these dynamic FLASH-measurements have been compared to the results of the SE-sequences 6-10 and 11-15 minutes after Gd-DTPA in 40 patients with 54 different breast tissues. It could be shown that in a number of cases a better differentiation (e.g. DD between carcinomas and proliferative dysplasia) was possible on FLASH-scans early after contrast medium than on the late SE-scans. Only the distinction between non-proliferative and proliferative dysplasia was better on the late SE-scans. Evaluation of the enhancement dynamics may be helpful in some cases as an additional information. Further investigations are necessary to confirm these findings and to assess their value.

Breast↗
PubMed1987

[Value of high-resolution CT and nuclear magnetic resonance tomography compared to the standard procedures in the diagnosis of meniscal lesions].

The knees of 20 patients with evidence of meniscal tears were examined via high-resolution computed tomography (HRCT); 10 of these were studied by MRI. The HRCT study was performed directly after double-contrast arthrography (AG). For comparison with HRCT, slice orientation for MRI examination was in transverse view; gradient echo sequences using the FISP technique were applied instead of spin echo sequences. All results were correlated to the arthroscopy (AS) findings. In 95% of the cases AG and AS results agreed, HRCT/AS in 85% and MRI/AS in 70%. In certain cases HRCT provided additional information which influenced appropriate surgical treatment. MRI is a noninvasive nonionising method but gives a less exact documentation of the lesion than AG and HRCT. The gradient echo mode is superior to the SE mode in respect of outlining meniscal structures, at least in transverse view.

Adult↗