[Malignant perirenal mesenchymoma with renal infiltration. Imaging in CT and MRI].
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Diagnosis, Differential↗
Biomedical subjects
K Preidler
Publications and source records attributed to K Preidler.
[Acute abdominal pain: CT diagnosis of omental volvulus].
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Abdomen, Acute↗
Multislice CT-image-guided endoscopic sinus surgery using an electromagnetic tracking system.
Our objective was to assess the practicability and accuracy of a computer-assisted multislice CT-guided frameless electromagnetic tracking for endoscopic sinus surgery. Eighty-two patients with various paranasal sinus diseases were evaluated. Prior to surgery, axial multislice spiral-CT scans with 2.5-mm collimation, 0.8-mm reconstruction increment, and a pitch of 3 were acquired. After Ethernet transfer of the CT data set to the guidance system, coronal and sagittal images were reconstructed. For intraoperative navigation the Insta Trak System (Visualization Technology, Boston, Mass.) was used. Navigational procedures are described in detail in the paper. Accuracy was assessed by means of visual landmarks which could be clearly identified endoscopically as well as on CT images. A second parameter for accuracy was calculated by the system itself as the root mean square (RMS). The system was able to display the position of the aspirating tip relative to anatomical structures with an average accuracy of 0.70 +/- 0.40 mm. Root mean square values showed a mean value of 0.40 +/- 0.20 mm. During surgical procedures the Insta Trak System provides the surgeon with additional image-based information to the endoscopic view. The device accuracy is high and the system proves to be practicable and efficient in ENT surgery.
Adolescent↗
[Differential diagnosis of space-occupying adrenal masses].
Computed tomography (CT) and magnetic resonance (MR) imaging are first line modalities in the evaluation of patients with adrenal gland masses, and have the potential to be very accurate for the localization of adrenal gland masses in patients with diseases associated with hyperfunctioning conditions of the adrenal gland. Both CT and MR imaging allow a specific diagnosis of acute adrenal hemorrhage, adrenal myelolipoma, and adrenal cysts. CT is also helpful in the assessment of patients with Addison's disease, particularly the subacute form secondary to granulomatous diseases. Quantitative evaluation of adrenal masses on unenhanced CT scans and/or qualitative analysis on chemical-shift MR imaging have been shown to be accurate in distinguishing adrenal adenomas from non-adenomas. Attenuation of 11 HE or less on unenhanced CT scans and/or signal loss on opposed phase MR images indicate adenoma with a high specificity and acceptable sensitivity. More recently, delayed-enhanced CT has yielded higher sensitivity and specificity values in distinguishing between adrenal adenomas and non-adenomas than both unenhanced CT and chemical-shift MR imaging do. On delayed-enhanced CT scans, adrenal adenomas exhibit a greater washout of contrast material than do adrenal non-adenomas. Therefore, adrenal non-adenomas have significantly higher attenuation than adenomas on delayed-enhanced CT scans obtained at several arbitrarily chosen time points (3-60 min) after the initiation of contrast material administration.
Adenoma↗
Primary biliary cystadenocarcinoma perforating the duodenum and left intrahepatic biliary tree--mimicking a hydatid cyst.
We report the case of a 76-year-old woman with biliary cystadenocarcinoma perforating the left biliary tree and exhibiting intra-tumoral gas bubbles resulting from invasion of the duodenum. The clinical history included subfebrile temperatures of 3 months duration, and pains associated with an abdominal mass in the right upper quadrant. Blood tests showed leucocytosis, and radiological studies revealed the features of a partially calcified septated tumor with nodular components combined with multiple gas-fluid levels, mimicking an infected hydatid cyst. Intraoperative ultrasonography, cholangiography and frozen section histology were necessary to prove the malignant nature of this cystic tumor. Provided that complete resection with strict adherence to oncological precepts is possible, the prognosis of cystadenocarcinoma is better than in hepatocellular or cholangiocellular carcinoma.
Aged↗
Renal masses--evaluation by amplitude coded colour Doppler sonography and multiphasic contrast-enhanced CT.
OBJECTIVE: To assess the efficacy of amplitude coded colour Doppler US (aCDS) in the evaluation of renal masses as shown by multiphasic contrast-enhanced CT. MATERIAL AND METHODS: Eighty patients (155 kidneys) with suspicion of renal masses underwent aCDS and spiral CT. The findings were classified into normal kidneys, kidneys with tumours, kidneys with cysts, and those with "other findings" (i.e. bleeding, calcifications, inflammation, parenchymal hypertrophy). The aCDS findings were compared to CT results and to histological findings or clinical, laboratory and follow-up data. RESULTS: Eighteen renal cell carcinomas and 8 other tumours were found; 78 kidneys had cysts, 12 polycystic kidneys and 10 fibrotic kidneys were detected, 20 kidneys showed other findings. Diagnostic aCDS data were obtained in 129 kidneys (83.2%) showing pathology with an accuracy of 94%. CT adequately showed pathology in all patients with some diagnostic uncertainty in the evaluation of complicated cysts. CONCLUSION: Though contrast-enhanced multiphasic spiral CT is the method of choice for evaluating renal masses, US including aCDS can provide valuable information, particularly in differentiating vascularized from non-vascularized lesions and in the evaluation of complicated renal cysts.
Adult↗
Functional magnetic resonance imaging of human renal allografts during the post-transplant period: preliminary observations.
Graft dysfunction is a common occurrence during the first weeks following renal transplantation. The current study was designed to evaluate the potential of renal magnetic resonance (MR) perfusion imaging to differentiate acute allograft rejection (AAR) from acute tubular necrosis (ATN) during the post-transplant period. Twenty-three consecutive patients with clinically suspected ATN and/or AAR and eight consecutive control patients (asymptomatic, serum creatinine concentration < 1.5 mg/dL) underwent MR perfusion imaging of the renal allograft within 64 days after transplantation. Histopathology was obtained in all cases with clinical suspicion of ATN or AAR. Sixty sequential fast gradient-recalled-echo MR images were acquired in each patient after intravenous administration of gadolinium-DTPA (0.1 mmol/kg). Histopathology revealed 6 patients with pure AAR, 4 patients with a combination of AAR and ATN, 12 patients with ATN and 1 patient with normal findings. Kidney graft recipients with normal renal function showed a moderate increase in signal intensity (SI) of the renal cortex and medulla after administration of contrast agent followed by an immediate and short decrease in SI of the medulla (biphasic medullary enhancement pattern). The increase in cortical SI of patients with AAR was significantly smaller (61 +/- 4% increase above baseline) than that measured in normal allografts (136 +/- 9% increase above baseline) (p < 0.05) and patients with ATN (129 +/- 3% increase above baseline) (p < .05). Patients with ATN had a slightly delayed and diminished cortical enhancement and an uniphasic and lesser medullary enhancement pattern compared to that observed in normal allografts (p < 0.05). A close correlation (r = 0.72) was found between serum creatinine concentration levels and changes in SI. Thus, MR imaging results and histopathology were in agreement in 22 of 23 patients (96%). MR perfusion imaging of renal allografts can be used to noninvasively differentiate ATN from AAR during the post-transplant period, and may also be helpful in cases were covert AAR is superimposing ATN during a phase of anuria. Patients with ATN can be separated from normals in the majority of cases as reflected by an uniphasic medullary enhancement pattern.
Adult↗
[Evaluation of renal vascularization using amplitude-coded Doppler ultrasound].
PURPOSE: To evaluate the benefit of "Colour Doppler Energy" (CDE) or "Power Doppler" applications in healthy kidneys and in renal disease including paediatric assessment. PATIENTS AND METHOD: Ten healthy volunteers (range: neonate to adults) were studied using conventional colour Doppler sonography (CDS) and CDE in order to evaluate the visibility of intrarenal vasculature. In addition, ten children and ten adults with known renal disease were evaluated. The findings were compared to clinical, scintigraphic and biopsy results. RESULTS: CDE showed far better visualisation of intrarenal vasculature than CDS. CDE demonstrated focal and diffuse reduced cortical perfusion with an overall accuracy of 95% and a sensitivity of 88%. In 7 healthy volunteers cortical vasculature was visualised throughout the kidney. In 3 infants incomplete visualisation was obtained because of motion artifacts. In the diseased kidneys, CDE findings correlated well with clinical findings, scintigraphy results and biopsy findings. CONCLUSION: CDE can be successfully applied to adults and infants demonstrating renal vasculature in healthy kidneys and in kidneys with focally or diffusely altered perfusion.
Adolescent↗
Retro- and para-pharyngeal ganglioneuroma.
A patient with slight dysphagia and dyspnoea on exertion was referred to us. We diagnosed a large retro- and para-pharyngeal ganglioneuroma. The mass was surgically removed in toto. The case is presented and the features are discussed.
Ganglioneuroma↗
Ultrafast computed tomography and three-dimensional image processing of CT sialography in patients with parotid masses poorly defined by magnetic resonance imaging.
The purpose of this study was to determine the efficacy of ultrafast computed tomography (UF CT) in patients with parotid masses poorly defined by magnetic resonance imaging (MRI) and to evaluate the diagnostic potential of three-dimensional (3-D) UF CT sialography when compared with conventional CT sialograms. Thirteen patients with clinical suspicion of a parotid mass, in whom MRI was degraded by motion, underwent UF CT of the parotid region. Two radiologists independently assessed the CT and MR with respect to tumor localization, intraglandular tumor location, tumor margin characteristics, and infiltration of surrounding tissue. In 9 patients, CT sialography was performed using 3-D image processing. Anatomical details and pathologic findings were assessed by three readers using a numerical grad and compared with the findings derived from conventional CT sialography. Histopathologic specimens were obtained in all cases and correlated with the radiographic findings in a consensus manner following the blinded interpretations. UF CT and (suboptimal) MRI provided the same diagnostic information for the evaluation of tumor localization, and intraglandular location. UF CT was superior to MRI in the detection of tumor infiltration, and definition of tumor margins in 2 cases (15%), resulting in a substantial difference in treatment. Three-dimensional CT sialography offered significant improvement in demonstration of anatomic detail (2.5 +/- 0.2 vs 1.5 +/- 0.1, respectively) and pathologic findings (2.6 +/- 0.1 vs 1.3 +/- 0.2, respectively) when compared with conventional CT sialography. UF CT is a viable alternative in uncooperative patients with parotid masses. UF CT 3-D sialography has the potential to allow more precise pre-surgical planning and contributes to the diagnosis and therapy planning of parotid masses.
Adult↗
Effects of iopromide on vasoactive peptides and allergy-mediated substances in healthy volunteers.
RATIONALE AND OBJECTIVES: Little information is available about the direct action of angiographic contrast media on vasoactive peptides and allergy-mediated substances in humans. This study defined the acute effects of iopromide, a nonionic contrast medium (370 mg/mL iodine), on vasoactive peptides, allergy-mediated substances, and hemodynamic parameters in healthy volunteers. METHODS: Pulmonary digital subtraction angiography was performed in seven healthy volunteers with no cardiovascular or pulmonary disease. Iopromide was administered as a total volume of 100 mL through a 7-Fr catheter inserted in the right femoral vein. The injected volumes and duration of injection (15-20 mL/second) were kept constant. The following hemodynamic parameters were monitored continuously: results of electrocardiogram, heart rate, and phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and 3 to 5 minutes after injection of contrast media to determine the concentrations of the following vasoactive peptides: renin, angiotensin I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic guanosine monophosphate, and myoglobin; and to allergy-mediated substances such as tryptase, eosinophil protein X, and eosinophil cationic protein, using radioimmunoassay techniques. RESULTS: Iopromide substantially increased atrial natriuretic peptide (48.8 +/- 8.9 to 85.8 +/- 13.0) and antidiuretic hormone (3.4 +/- 0.3 to 4.6 +/- 0.5) levels, whereas renin decreased (0.9 +/- 0.1 to 0.8 +/- 0.2) slightly but not significantly. Iopromide did not induce substantial changes in the other vasoactive peptides or in allergy-mediated substances after the contrast medium was injected. Similarly, cardiovascular parameters (heart rate, pulmonary and systemic blood pressures, and results of electrocardiogram) also remained unchanged after contrast injection. CONCLUSION: Iopromide caused no appreciable hemodynamic alterations associated with the changes in atrial natriuretic peptide and antidiuretic hormone and no evidence of allergy-mediated reactions in all volunteers.
Adult↗
[Mammography of the reconstructed breast--a comparison of different methods of reconstruction].
The choice of a breast reconstruction technique is considerably influenced by the possibility of detecting recurrence. Mammography is the most important diagnostic aid in detecting a tumor. We have compared the mammographic evaluation of different reconstruction methods. 41 patients were investigated and divided into three subgroups: Group I (n = 10): Reconstruction with autologous tissue (TRAM-flap); group II (n = 22): Reconstruction with silicone gel-filled implants, muscle and soft tissue replacement (latissimus flap or submuscular expander technique and silicone gel prostheses); group III (n = 9): Reconstruction with silicone gel-filled implants. Evaluation was performed employing a scoring system. The mammographic appearance of autologous breast reconstructions consisting of skin, subcutaneous fat and muscle is comparable to involuted breasts. One mammography in this group was of poor, one of acceptable, and eight of good quality. Autologous reconstruction is associated with the highest chance of recurrence detection. Within group II and III, parts of the reconstructed breast are covered by the X-ray absorbing silicone gel prosthesis. In group II, seven mammographies were considered poor, 14 acceptable, and one good; in group III it was two, four und three respectively. The interpretation depended on the implant soft tissue ratio. If thin soft tissue layers cover the prosthesis, inspection and palpation become increasingly important, nevertheless it is not possible to achieve comparable data as with mammography.
Adult↗
Pulmonary hypertension. Response of vasoactive peptides to a nonionic contrast medium in patients undergoing pulmonary angiography.
RATIONALE AND OBJECTIVES: The degree to which pulmonary angiography may contribute to serious complications in patients with pulmonary hypertension has not been clarified and remains a matter of debate. Accordingly, this study was designed (1) to detect the potential release of vasoactive peptides and (2) to investigate the hemodynamic response after administration of a nonionic contrast medium in patients with pulmonary hypertension undergoing pulmonary angiography. Allergy-mediating substances also were measured to monitor for possible anaphylactoid reactions. METHODS: Pulmonary digital subtraction angiography was performed in 20 patients with pulmonary hypertension (mean pulmonary arterial pressure more than 20 mm Hg). Iopromide was administered as a total of 100 mL via a 7F catheter inserted from the right femoral vein. The injected volume and duration of injection (15 to 20 mL/sec) were kept constant. Hemodynamic parameters were continuously monitored, including electrocardiogram, heart rate, phasic and mean pulmonary arterial and peripheral arterial pressures. Blood samples were obtained before and after administration of contrast media to assay for the concentration of the following vasoactive peptides using radioimmunoassay techniques: renin, angiotensin-I-converting enzyme, angiotensin II, aldosterone, atrial natriuretic peptide, antidiuretic hormone, cyclic-guanosine monophosphate, and myoglobin, as well as allergy-mediating substances such as tryptase, eosinophil protein X, and eosinophil cationic protein. RESULTS: Administration of iopromide caused significant increases in atrial natriuretic peptide (from 61.3 +/- 11.8 to 94.0 +/- 16.7) and antidiuretic hormone (from 6.6 +/- 1.9 to 12.3 +/- 3.1), whereas renin significantly decreased (from 3.0 +/- 0.6 to 1.3 +/- 0.5). After administration of contrast media, there were no significant changes in the other measured vasoactive peptides, allergy-mediating substances, and monitored cardiovascular parameters. CONCLUSION: Administration of iopromide for pulmonary angiography in patients with pulmonary hypertension resulted in no appreciable hemodynamic alterations associated with the observed changes in atrial natriuretic peptide, antidiuretic hormone, and renin. No allergy-mediated reactions were observed in these patients.
Adult↗
Three-dimensional processing of ultrafast CT sialography for parotid masses.
PURPOSE: To evaluate the diagnostic potential of three-dimensional image processing of ultrafast CT sialography in comparison with conventional CT sialography in patients with parotid masses. METHODS: In nine patients, CT sialography was done with three-dimensional image processing. The visibility of anatomic details and pathologic findings, derived from three-dimensional images, were graded numerically by three observers and compared with the findings obtained from conventional CT sialograms. Histopathologic specimens were obtained in all cases. RESULTS: Ultrafast CT images showed no motion artifact. Three-dimensional CT sialography offered significant improvement in demonstration of ductal anatomy (2.5 +/- 0.2 versus 1.5 +/- 0.1, respectively) and ductal pathology (2.6 +/- 0.1 versus 1.1 +/- 0.2, respectively) over conventional CT sialography. In two cases, the therapeutic regimen was altered substantially. CONCLUSION: Ultrafast CT three-dimensional sialography has the potential to allow more precise presurgical planning and contributes to the diagnosis and therapy planning of parotid masses, especially in patients in whom MR image quality is degraded by motion artifact.
Adult↗
The sphenoid sinus during childhood: establishment of normal developmental standards by MRI.
To obtain baseline standards of normal age-related development of the sphenoid sinus during childhood magnetic resonance images of the sphenoid sinus in 401 patients less than 15 years old were reviewed. T1-weighted sagittal and T2-weighted axial scans were evaluated for bone marrow conversion, development of pneumatization, spatial enlargement and septation of the sphenoid sinus. The sphenoid sinus had a uniformly low signal intensity (red bone marrow) on T1-weighted images in all children less than 4 months old. Signal intensity changes from hypo- to hyperintense (bone marrow conversion) started at age of 4 months. Onset of pneumatization was observed in 12% of the patients at age 13-15 months. By age 43-48 months, 85% of the patients showed pneumatization of the anterior part of the sphenoid bone. Pneumatization was complete in all patients older than 10 years. Enlargement of the sinus showed a characteristic profile in each dimension. Median septation was observed irregularly with age, with a maximum of 77%. Septum variants were noticed between 4.5% and 20%. The recognition of this phenomenon may serve as a reference for evaluating normal and abnormal development of the sphenoid sinus and may be of great value for diagnostic and therapeutic management of pathologic conditions of the child's sphenoid sinus and its surrounds.
Adolescent↗
MRI appearance of gestational choriocarcinoma within the myometrium.
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Choriocarcinoma↗
Relationship between heart rate threshold, lactate turn point and myocardial function.
We examined the relationship between heart rate threshold (HRT), lactate turn point (LTP) and myocardial function expressed as left ventricular ejection fraction (LVEF) determined by radionuclide ventriculography. Two groups of subjects (G I: N = 8; G II: N = 7) with and without a deflection of heart rate performance curve (HRPC) underwent sitting cycle ergometry. HRT (G I), aerobic threshold (AeT; G I, G II), and LTP (G I, G II) were determined by means of linear regression break point analysis. Also, a break point in LVEF performance curve (LVEFBP) was obtained. Power output at HRT and at LTP was not significantly different between G I and G II (272.5 +/- 38.7 W; 294.3 +/- 20.6 W). Power output at LVEFBP (G I: 182.6 +/- 31.7 W; G II: 211.8 +/- 21.5 W) was not significantly different to power output at LTP (G I: 194.2 +/- 32.7 W; G II: 215.2 +/- 24.4 W) and HRT (G I: 193.0 +/- 38.2 W). Significant differences (p < 0.05) could only be found between G I and G II for heart rate (HR) at LTP (G I: 163.5 +/- 5.8 b.min-1; G II: 154.4 +/- 6.7 b.min-1) and LVEF at the end of the load (LVEFend) (G I: 77.9 +/- 2.9%; G II: 71.3 +/- 7.0%). The drop of LVEF at LVEFBP was significantly related to LTP in all cases. The present data suggest that the noninvasive determination of anaerobic threshold by means of heart rate curve analysis is not always possible due to different response of myocardial function and heart rate to graded cycle ergometer exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Malignant peritoneal mesothelioma. Different appearance forms in CT and ultrasound].
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Contrast Media↗