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U Keske

Publications and source records attributed to U Keske.

32 records · Page 2Linked to original sources
PubMed1995

[Estimating patient dose in radiologic examinations using conversion factors].

The principles for estimation of the patient's radiation dose from conventional radiographic and computed tomography examinations are presented on the basis of published exposure simulation data. The relationship between absorbed dose in air, or axis dose, organ doses, and effective dose is explained. It is shown how organ doses can be calculated from the absorbed dose free in air or axis dose using published computed conversion factors. Calculation of the effective dose from organ doses using tissue weighting factors is described. Finally, examples of dose calculation are given for a conventional radiographic and a CT examination.

Body Burden↗
PubMed1994

[[111In]-DTPA-D-phenylalanine octreotide SPECT for the scintigraphic imaging of enhanced somatostatin-receptor density in endocrine ophthalmopathy].

Recently, [111In]-DTPA-D-phenylalanine-octreotide was introduced for clinical use. This radioligand binds specifically to somatostatin receptors and is suitable for SPECT examinations. The aim of this study was to clarify whether an increased somatostatin receptor density can be imaged and quantified in patients with endocrine ophthalmopathy (e.o.). 7 patients between 34 and 55 years with e.o. at stages III to VI and 4 controls between 38 and 63 years were examined. All patients and controls received approximately 200 MBq [111In]-DTPA-D-phenylalanine-octreotide by IV injection. A SPECT examination was performed 4 hours after injection and a normalised tracer uptake (A(n)) was calculated for both orbitae. In patients with e.o. the values of A(n) were significantly higher compared with controls (P = 0.002). There was a correlation between A(n) and exophthalmus stages according to Hertel with r = 0.844 (P = 0.001). These results indicate that [111In]-DTPA-D-phenylalanine-octreotide SPECT might be useful for the in vivo assessment of an increased somatostatin receptor density in e.o. These findings could have an impact on the treatment with somatostatin analogous in e.o.

Adult↗
PubMed1994

[The spiral CT of cervical lymph node enlargements. The initial clinical results].

Spiral CT was performed before treatment in 35 patients with suspected cervical lymph node enlargement. By coronary and sagittal reconstruction it is possible to utilise the M/Q quotient which has become accepted as the result of sonographic and MRI examinations. It is now possible to obtain high diagnostic accuracy (97%) for distinguishing between reactive change from metastatic infiltration of lymph nodes (> 8 mm) by using CT. Using spiral CT with 5 mm table movement, three patients diagnosed as stage N1 by axial CT were shown to be N2b. This represents a highly sensitive and highly specific method of lymph node diagnosis. Further diagnostic improvement derives from the ability to relate the lymph nodes to surrounding tissues. Spiral CT is also suitable for defining other space occupying lesions, e.g., the exact extent of retropharyngeal abscesses, abnormalities of the salivary glands or laryngoceles.

Abscess↗
PubMed1994

Dopamine D2 receptor imaging with iodine-123-iodobenzamide SPECT in idiopathic rotational torticollis.

UNLABELLED: The cause of idiopathic rotational torticollis (IRT) is not completely understood to date. However, basal ganglia are believed to be involved in the pathophysiology of IRT. To elucidate this disorder further, the value of iodobenzamide (IBZM) SPECT was studied for the evaluation of striatal dopamine D2 receptors in these patients. METHODS: Striatal dopamine D2 receptor density was assessed in 10 patients with IRT using 123I-IBZM SPECT. The images were interpreted by a nuclear medicine physician initially to determine IBZM binding within the striatum and the cerebellum and, secondly, interstriatal IBZM binding. The results were correlated with the clinical parameters of the patients and compared with the results obtained from normal controls. RESULTS: No difference was found in average, specific striatal IBZM binding (basal ganglia/cerebellum ratio) between patients and controls. However, interstriatal analysis of IBZM binding revealed a significantly higher binding in the striatum contralateral to the direction of the torticollis (p = 0.026, by chi-square test). CONCLUSION: It was concluded that the striatal dopamine D2 receptor status is altered in patients with IRT.

Adult↗
PubMed1994

[123I-iomazenil- and 99mTc-HMPAO in the diagnosis of focal epilepsies: a comparison of untreated and treated patients].

The purpose of this study was to compare HMPAO- and IMZ-SPECT findings in treated and untreated patients with focal epilepsies. We examined 20 patients (untreated 13; treated 7). All patients had a normal CT and/or MRI scan. In all patients both whole-brain activity and regional count density (rcd) were evaluated by SPECT. Furthermore, the specific and non-specific binding of IMZ were calculated for each ROI and the results of both, treated and untreated patients were compared. Our data indicate that the normalized cerebral total binding of IMZ was significantly increased in all regions in the group of treated patients (p < 0.001). In contrast, no difference in the tracer binding was found with HMPAO-SPECT. We conclude that the difference in the IMZ-binding might be due either to exogenous or endogenous factors. In our study IMZ-SPECT had a higher sensitivity and a lower specificity in the detection of decreased rcd in areas with EEG findings that indicate an epileptogenic focus compared with HMPAO-SPECT.

Adolescent↗
PubMed1993

[Bolus administration in spiral CT of the upper abdomen].

In 60 patients the density increases in the abdominal aorta and pancreas were examined quantitatively the visualisation of the arterial liver blood flow qualitatively in a test volume by means of spiral CT and a feed or speed differentiation of 10 mm/s for three different contrast medium boli. It was shown that during the entire study over 24 seconds the boli with 100 ml contrast medium at injection speeds of 3 ml/s and 50 ml contrast medium at 1.5 ml/s resulted in a continual density increase of the abdominal aorta from 221 to 265 Hounsfield Units (HU) or 161-167 HU, respectively. For measuring the abdominal aorta the bolus of 50 ml contrast medium at 3 ml/s was less suitable than the boli of 100 ml contrast medium with 3 ml/s and 50 ml with 3 ml/s because of the rapid in density from 250 to 118 HE. The bolus of 50 ml contrast medium and 3 ml/s, on the other hand, with 54 HU enhancement of the pancreas was approximately equal to the larger amount of contrast medium of 100 ml contrast medium and 3 ml/s with 56 HU, whereas 50 ml contrast medium and 1.5 ml/s with 46 HU was inferior. While all boli could sufficiently enhance the extrahepatic section of the hepatic artery, the larger amount of contrast of 100 ml proved to be superior to the other boli in the visualization of central intrahepatic vascular branches.

Adult↗
PubMed1992

[The determination of cerebral dopamine (D2) receptor density by using 123I-IBZM-SPECT in Parkinson disease patients].

An alteration of the dopaminergic nigrostriatal system is believed to be the main pathogenetic factor of Parkinson's disease (PD). We report on our initial results on the determination of the post-synaptic dopamine-D2-receptor binding of 123I-IBZM in patients with PD. Drug-native patients showed a significantly higher IBZM binding in the basal ganglia as compared to patients on specific dopaminergic medication. Age, duration of the disease and the severity of the disease do not seem to influence the IBZM-receptor binding. We conclude that 123I-IBZM-SPECT is an extremely useful tool for the evaluation of the functional state of cerebral dopamine-D2-receptors.

Aged↗
PubMed1990

[Improved inner ear diagnosis by controlled use of computerized tomography].

Problems in the examination of the inner ear using conventional CT are described. Intraoperative findings often differ from CT findings. A new development HR-CT is introduced. Findings of middle and inner ear malformations and otosclerosis are demonstrated. It is shown that HR-CT imaging using a new 1024 matrix, enables better spatial resolution. This new CT technique improves inner ear examination, especially in the preparation for cochlear implantation.

Child, Preschool↗
PubMed1990

[High-resolution computerized tomography of the petrous bone with two-dimensional and three-dimensional reconstruction].

Fifty patients with various diseases of the petrous bone were examined by HR-CT with a 1024 x 1024 matrix. It is demonstrated that the improved spacial resolution results in a better discrimination of subtle anatomical structures and therefore leads to an expansion of the diagnostic possibilities in diseases of the auditory and vestibular organs. Evaluation of the two-dimensional reconstructed images shows that best quality is obtained with contiguous 1 mm, sections in the primary scans. In most cases these reconstructed images are diagnostically sufficient. In addition they help to reduce patient strain (no problem with patient positioning, no further x-ray exposure, time-saving). Three-dimensional reconstructions from the base of the skull allow a good visualization of complex and extensive osseous destructions of the temporal bone. The disadvantage of this method is on the one hand the lacking representation of soft tissue and the poor spacial resolution (no 3-D imaging of the ossicular chain), and on the other hand the smoothing of contours because of arithmetical filters. Thus tumor expansion and finer osseous erosions may not be distinguishable. Consequently, 2D primary or reconstructed images must continue to be the basis of diagnosis.

Adult↗
PubMed1990

[99mTc-MAG3 and 131I-OIH in patients with kidney insufficiency and with normal kidneys].

Renal clearance of 99mTc-mercaptoacetyltriglycine (MAG3) and 131J-orthoidohippurate (OIH) were compared by simultaneous measurement in 50 patients. Renal time-activity-curves of both radiopharmaceuticals were compared in 50 patients. With regard to the clearance, good correlation (r = 0.95) with a mean ratio MAG3-/OIH-clearance of 0.62 was found. No significant difference between patients with normal (n = 30) and impaired (n = 20) renal function could be demonstrated. Renal time activity curves and relative renal function showed good correspondence in patients with normal (n = 13) and impaired (n = 7) renal function. It is concluded that MAG3 may be used as substitute for OIH in patients with normal and impaired renal function.

Humans↗
PubMed1990

[A comparison of different methods of calculating clearances using 99mTc-mercaptoacetyltriglycine and 123I- or 131I-ortho-iodohippuric acid].

Using labelled MAG3 (n = 172) or OIH (n = 102) the results of three different techniques of calculating renal clearance were compared. The following techniques were used: Tauxe (single plasma concentration determination), Oberhausen (modified, combined partial body and plasma disappearance clearance) and Winkler (partial body clearance). For OIH, linear regression analysis revealed a positive correlation of Tauxe and Oberhausen clearances with a correlation coefficient (r) of 0.90 and a mean ratio (mean) Oberhausen/Tauxe clearances of 1.03. For MAG3, the Oberhausen values were found to be significantly lower than the Tauxe values with an equally good correlation. For this radiopharmaceutical the Winkler values were significantly higher than the Tauxe and Oberhausen values. For OIH, no such difference was noted. However, the correlation coefficient was significantly lower. Whereas with the Tauxe method, a mean ratio MAG3-/OIH clearances of 0.62 was observed in an earlier investigation, from the present data a ratio of 0.53 is calculated for the Oberhausen clearance. The difference between the Tauxe and Oberhausen clearances with MAG3 is of importance when comparing clearance values obtained with clearance calculation techniques and for establishing normal values for the MAG3 clearance.

Adult↗
PubMedDate not supplied

Drug smuggling by ingested cocaine-filled packages: conventional x-ray and ultrasound.

PURPOSE: To evaluate the imaging characteristics and the diagnostic value of both abdominal ultrasound and conventional abdominal x-ray in identifying ingested drug packages in "body packers." MATERIALS AND METHODS: Twelve individuals were studied prospectively by abdominal ultrasound and by abdominal x-ray to rule out incorporated drug containers. RESULTS: Both abdominal ultrasound and abdominal x-ray correctly identified the 7 of 12 individuals who had ingested multiple drug packages. In 5 of the 12 individuals, ultrasound as well as abdominal x-ray were correctly unremarkable with regard to abdominal foreign bodies. CONCLUSIONS: Abdominal ultrasound and abdominal x-ray both represent valuable diagnostic tools in the assessment of ingested drug packages. Abdominal x-ray is superior to ultrasound in differentiating ingested drug-filled condoms from "pseudocondoms."

Adult↗