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Biomedical subjects

E Sorantin

Publications and source records attributed to E Sorantin.

At least 19 recordsLinked to original sources
PubMed2003

[3D cross section of the laryngotracheal tract. A new method for visualization and quantification of tracheal stenoses].

PURPOSE: Demonstration of a technique for 3D assessment of tracheal stenoses, regarding site, length and degree, based on spiral computed tomography (S-CT). PATIENTS AND METHODS: S-CT scanning and automated segmentation of the laryngo-tracheal tract (LTT) was followed by the extraction of the LTT medial axis using a skeletonisation algorithm. Orthogonal to the medial axis the LTT 3D cross sectional profile was computed and presented as line charts, where degree and length were obtained. Values for both parameters were compared between 36 patients and 18 normal controls separately. Accuracy and precision was derived from 17 phantom studies. RESULTS: Average degree and length of tracheal stenoses were found to be 60.5% and 4.32 cm in patients compared to minor caliber changes of 8.8% and 2.31 cm in normal controls (p <0.005). For the phantoms an excellent correlation between the true and computed 3D cross sectional profile was found (p <0.005) and an accuracy for length and degree measurements of 2.14 mm and 2.53% respectively could be determined. The corresponding figures for the precision were found to be 0.92 mm and 2.56%. CONCLUSION: LTT 3D cross sectional profiles permit objective, accurate and precise assessment of LTT caliber changes. Minor LTT caliber changes can be observed even in normals and, in case of an otherwise normal S-CT study, can be regarded as artefacts.

Adolescent↗
PubMed2003

18F-FDG PET: early postoperative period of oro-maxillo-facial flaps.

AIM: We addressed the feasibility of FDG-PET to differentiate between viability and non-viability in the immediate postoperative assessment of flaps (autologous microvascular anastomosed pedicled flaps) in oro-maxillo-facial surgery. METHODS: 3-7 days after surgery, FDG-PET was done in 38 patients who had received flaps for re-construction of the mandible after partial resection. The studies were done on a dedicated full ring PET-scanner (ECAT EXACT HR+, Siemens/CTI). Acquisition started between 60 and 80 min post injection. The findings of the soft tissue component of the flaps were grouped using a three point scale: (I) no defect, (II) small defects, (III) one large defect. The results of PET were compared with the clinical course for at least 3 months. RESULTS: "No defect" on the FDG-PET study identified vi-ability of the flap and predicted normal clinical follow-up (22/38 patients). "Small defects" visualized areas of decreased perfusion and decreased glucose metabolism indicating risk of non-viability (13/38 patients); adapt-ing the postsurgical management led to delayed but uncomplicated healing of the flaps in these patients. "One large defect" demonstrated early necrosis of the flap (3/38 patients). After removal and replacement of this necrotic portion of the flap the second FDG-PET scan of these 3 patients demonstrated the uncomplicated post-operative healing. CONCLUSION: FDG-PET facilitated the assessment of viability and non viability of flaps in the immediate postsurgical period, and demonstrated the usefulness of FDG-PET for postoperative care and prognosis.

Adult↗
PubMed2002

[Nontraumatic injury (battered child)].

The recognition of a battered child represents a challenge for all groups of adults dealing with children. Radiology plays a special role in this setting. By detection typical injuries, imaging is able to confirm the suspicion of a battered child. Recognition of those injuries on films, taken for other reasons, gives the caretaker an important hint, thus maybe preventing a fatal outcome for the child. One of the most important injury types is represented by the so called "shaken baby syndrome". The infant is held by the thorax and shaken. Thus causing a repetitive acceleration-deceleration trauma, which leads to the typical paravertebral rib fractures, intracranial bleeding and eye injuries. After shaking the child is thrown away, with subsequent injuries. The aim of this article is the presentation of an overview regarding the radiology of the battered child. Typical examples will be shown.

Battered Child Syndrome↗
PubMed2002

Imaging guided interventional procedures in paediatric uroradiology--a case based overview.

OBJECTIVE: To describe the potential and application of interventional image guided procedures in the paediatric urinary tract. PATIENTS AND METHODS: The different techniques are illustrated using case reports. The examples comprise established indications such as percutaneous nephrostomy for compromised kidneys in obstructive uropathy and infection, sonographic guided renal biopsy including monitoring or treatment of complications after biopsy, and evaluation and balloon dilatation of childhood renal artery stenosis. There are new applications such as treatment of stenosis in cutaneous ureterostomy or sonographically guided catheterism for deployment of therapeutic agents. RESULTS: Generally, the procedures are safe and successful. However, complications may occur, and peri-/post-interventional monitoring is mandatory to insure early detection and adequate management. Sometimes additional treatment such as percutaneous embolisation of a symptomatic post biopsy arterio-venous fistula, or a second biopsy for recurrent disease may become necessary. CONCLUSION: Imaging guided interventional procedures are performed successfully in a variety of diseases of the paediatric urinary tract. They can be considered a valuable additional modality throughout infancy and childhood.

Abscess↗
PubMed2000

Gastroesophageal reflux and diaphragmatic motility after repair of congenital diaphragmatic hernia.

At the Department of Pediatric Surgery in Graz, 31 boys and 23 girls were operated on for congenital diaphragmatic hernia (CDH) from 1978 to 1994. In 49 patients the defect was on the left, in five on the right side. In 46 cases, the hernia was diagnosed within the first week of life; in eight children at a later date. 19 children (35%) died. 25 of the 35 survivors (71%) came to a follow-up examination on average 9.4 (1-17) years after the operation. 24 h pH-monitoring or manometry and Upper G.I. series revealed pathological gastroesophageal reflux (GER) in 16 patients. Nine children were treated conservatively; in seven patients an antireflux procedure was performed. A thoracic position of the stomach or left liver lobe, presence of a hernial sac, gestational age, prenatal diagnosis, use of a patch or severity of lung hypoplasia did not significantly influence the incidence of GER. In three patients, a hiatal hernia was found. The motility of the diaphragm was documented with M-mode sonography (n = 18); a restricted motility could be demonstrated in five patients. GER is very common in patients after repair of CDH. We recommend long-term follow-up with special interest in respect of GER.

Child↗
PubMed2000

CT findings in post-operative subphrenic abscess with teratomatous inclusions.

A 39-year-old woman presented with abdominal pain after tubal sterilization. CT showed a subphrenic abscess with fatty inclusions owing to laceration or rupture of a mature ovarian teratoma. Although subphrenic abscess is a well recognized post-operative complication, and ovarian teratomas are frequent, a teratomatous inclusion within a subphrenic abscess is a unique finding.

Adult↗
PubMed2000

Helical CT angiography with maximum intensity projection in the assessment of aortic coarctation after surgery.

OBJECTIVE: The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography. SUBJECTS AND METHODS: Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients. RESULTS: The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found. CONCLUSION: CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.

Adolescent↗
PubMed2000

3-D image analysis of abdominal aortic aneurysm.

In this paper we propose a technique for 3-D segmentation of abdominal aortic aneurysm (AAA) from computed tomography (CT) angiography images. Output data form the proposed method can be used for measurement of aortic shape and dimensions. Knowledge of aortic shape and size is very important for selection of appropriate stent graft device for treatment of AAA. The technique is based on a 3-D deformable model and utilizes the level-set algorithm for implementation of the method. The method performs 3-D segmentation of CT images and extracts a 3-D model of aortic wall. Once the 3-D model of aortic wall is available it is easy to perform all required measurements for appropriate stent graft selection. The method proposed in this paper uses the level-set algorithm instead of the classical active contour algorithm developed by Kass et al. The main advantage of the level set algorithm is that it enables easy segmentation surpassing most of the drawbacks of the classical approach. In the level-set approach for shape modeling, a 3-D surface is represented by a real 3-D function or equivalent 4-D surface. The 4-D surface is then evolved through an iterative process of solving the differential equation of surface motion. Surface motion is defined by velocity at each point. The velocity is a sum of constant velocity and curvature-dependent velocity. The stopping criterion is calculated based on image gradient. The algorithm has been implemented in MATLAB and C languages. Experiments have been performed using real patient CT angiography images and have shown good results.

Algorithms↗
PubMed1999

An automatic method for the identification and interpretation of clustered microcalcifications in mammograms.

We investigated a method for a fully automatic identification and interpretation process for clustered microcalcifications in mammograms. Mammographic films of 100 patients containing microcalcifications with known histology were digitized and preprocessed using standard techniques. Microcalcifications detected by an artificial neural network (ANN) were clustered and some cluster features served as the input of another ANN trained to differentiate between typical and atypical clusters, while others were fed into an ANN trained on typical clusters to evaluate these lesions. The measured sensitivity for the detection of grouped microcalcifications was 0.98. For the task of differentiation between typical and atypical clusters an Az value of 0.87 was computed, while for the diagnosis an Az value of 0.87 with a sensitivity of 0.97 and a specificity of 0.47 was obtained. The results show that a fully automatic computer system was developed for the identification and interpretation of clustered microcalcitications in mammograms with the ability to differentiate most benign lesions from malignant ones in an automatically selected subset of cases.

Breast Diseases↗
PubMed1998

Application of M-mode sonography to functional evaluation in pediatric patients.

To assess the feasibility and advantages of functional motion-mode (M-mode) sonography in pediatric patients with various non-cardiac M-mode applications, 50 patients aged 6 days to 14.5 years with megaureter, diaphragmatic palsy and spinal cord malformation were studied. In addition to initial conventional brightness-mode gray-scale ultrasound. M-mode sonography was performed for evaluation of motion and possible impairment. The findings were compared with other imaging results. The impact of the sonographic results on clinical management was evaluated retrospectively. Impaired motion was demonstrated by conventional sonography in all cases. Only M-mode sonography enabled adequate documentation for comparison with follow-up examinations, but allowed only semiquantitative assessment. Thus even gradual improvement or deterioration can be followed in an unbiased way by using a better-documented investigation for comparison, though an objective 'ranking', especially of diaphragmatic movement, could not be achieved. M-mode sonography enables a non-invasive and non-ionizing evaluation and documentation of motion impairment in pediatric patients. It improves documentation of motion and enables a better comparison with previous findings. It is especially useful for follow-up in evolving disease.

Adolescent↗
PubMed1998

Renography before heart transplantation in patients with cardiomyopathy.

UNLABELLED: In patients with ischemic cardiomyopathy (CM), abnormal renograms may result not only from circulatory failure (which should reverse after transplantation) but also from intrinsic renal disease (which contraindicates heart transplantation). Here, the outcome of heart transplantation was related to preoperative renograms, and the differentiating and prognostic value of renography was analyzed. METHODS: The study population consisted of 50 patients with ischemic CM expecting heart transplantation. Anatomical renal pathology was excluded in all patients. Dynamic renal scintigraphy was performed with 99mTc-mercaptoacetyltriglycine. Background-subtracted renograms were inspected visually and characterized numerically. Mean parenchymal transit time (mPTT), renal tracer content at 15 min (RTC15) and retention index (RI) were determined. The parametric renogram values were related to a normal reference group of 64 patients. The preoperative renograms were matched with the postoperative outcome. RESULTS: Three characteristic types of symmetrical findings in the kidneys were found: no pathological findings, mildly delayed peak and excretion phase and severely delayed peak and excretion phase. Pathological renograms were observed in 36 of 50 (72%) patients. The mean parametric renogram values in ischemic CM were as follows: Group A (normal kidney function), mPTT = 142+/-26.6 sec, RTC15 = 22.3%+/-4.6% and RI = 24.7+/-11.9; Group B (mild dysfunction), mPTT = 210+/-44.0 sec, RTC15 = 42.6%+/-10.3% and RI = 101.4+/-50.5; Group C (severe dysfunction), mPTT = 320+/-94.2 sec, RTC15 = 79.6%+/-15.9% and RI = 347.7+/-194.7; and reference patients (normal kidney function), mPTT = 137+/-31.1 sec, RTC15 = 22.8%+/-3.8% and RI = 24.6+/-7.9. Postoperative serum creatinine levels were <1.5 mg/dl in all Group A patients, between 1.5 and 2.5 mg/dl in 78% of Group B patients and >2.5 mg/dl in 75% of Group C patients. CONCLUSION: Renography revealed abnormal kidney function when structural pathology was excluded. The renographic abnormalities in ischemic CM did not reflect simply the circulatory failure. The numerical grading of renograms allowed patient stratification, suggestive of possible renal insufficiency after cardiac transplantation and immunosuppressive therapy. With further experience, renography may become a useful tool for predicting postoperative outcome in ischemic CM.

Adult↗
PubMed1997

Comparison of hepaticoantrostomy and hepaticojejunostomy for biliary reconstruction after resection of a choledochal cyst.

Twelve infants operated upon for choledochal cyst (CC) are reviewed with emphasis on the operative technique of biliary tract reconstruction, incidence of cholangitis, postoperative hypergastrinemia, biliary excretion, and upper gastrointestinal (GI) motility in a follow-up of 24 to 35 months. In 7 patients biliary reconstruction was performed with a Roux-en-Y hepaticojejunostomy (HJ), and in 5 with a hepaticoantrostomy (HAST). In the HJ group 4 patients had recurrent episodes of cholangitis and intermittent diarrhea and serum gastrin levels were significantly elevated in 5. Hepatobiliary scintigraphy showed unobstructed excretion of labelled bile through bile ducts into the Roux-en-Y loop, but with significantly delayed emptying of bile into the distal jejunum in all patients. Gastric emptying and upper intestinal passage were normal. In the HAST group no episode of cholangitis occurred and serum gastrin levels were within the normal range. Scintigraphically, hepatobiliary excretion, and duodenojejunal passage of labelled bile was normal, except in 1 patient who developed a postoperative stenosis of the left hepatic duct. Upper GI contrast studies demonstrated normal gastric emptying without reflux into the biliary system. These results suggest that biliary reconstruction with HAST can be performed safely with a low incidence of complications HAST offers a more physiologic method of biliary reconstruction after resection of a CC that allows bile to drain directly into the duodenum.

Anastomosis, Roux-en-Y↗
PubMed1997

The sonographically thickened wall of the upper urinary tract system: correlation with other imaging methods.

BACKGROUND: Sonographically detected, upper urinary tract wall thickening (UUTWT) was reported to occur in urinary tract infection, urinary tract stone disease, rejection after renal transplantation and vesico-ureteral reflux (VUR). A possible association with obstruction can be hypothesized. OBJECTIVE: The assessment of a potential relationship of UUTWT with VUR or obstruction in patients without one of the above-mentioned conditions. MATERIALS AND METHODS: We analyzed 38 patients (74 upper urinary tracts) with at least unilateral UUTWT and concomitant imaging studies such as voiding cystourethrography (VCU), intravenous urography (IVU) and diuretic renography (DR). RESULTS: At sonography 49 urinary tracts showed UUTWT. In 33, ipsilateral VUR could be demonstrated at VCU, 11 revealed obstruction at IVU and/or DR, and 4 showed non-obstructive pelvicalyceal dilatation at IVU and DR. In one patient, all imaging studies were normal. The positive predictive value of UUTWT for the presence of VUR was 67.4 % and for obstruction it was 22.5 %. Altogether, UUTWT indicated pathology in 98 % of urinary tracts. CONCLUSION: After exclusion of urinary tract infection, urinary stone disease and prior renal transplantation, the most common associated findings in UUTWT are VUR and obstruction. Therefore, VCU seems to be justified in all cases of UUTWT. Nonrefluxing systems should be further evaluated with DR and/or IVU for exclusion of obstruction.

Child↗
PubMed1997

[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↗
PubMed1996

[Detection of perfusion of kidney transplants. Comparison between color-coded and amplitude-coded Doppler ultrasound].

OBJECTIVE: To evaluate the efficiency of colour Doppler energy (CDE) in comparison to conventional colour Doppler sonography (CDI) in the detection of renal blood flow signals in asymptomatic patients after renal transplantation. SUBJECTS AND METHODS: Fifteen asymptomatic volunteer patients after renal transplantation were examined with CDI and CDE. The examination parameters were kept constant; only the Doppler-receiver gain was varied. Assessment and comparison of blood flow signals were obtained with a self defined score system. RESULTS: CDI showed Doppler signals in the main stem vessels, segmental and interlobar vessels in all patients; in the arcuate arteries blood flow signals were detected in only 11 of 15 patients. There was no Doppler signal in peripherally located medullary and cortical vessels. CDE showed blood flow signals in the main stem, segmental and interlobar vessels and additionally in the arcuate, interlobular and medullary as well as in the cortical vessels in all patients. CONCLUSION: CDE is more sensitive than CDI and improves the detection of blood flow signals in peripheral medullary and cortical vessels of renal transplants.

Adult↗
PubMed1995

SPET quality control: a comprehensive test procedure for evaluating the rotation system parameters COR-offset, y-shift and detector tilt.

This paper describes a method for SPET quality control that facilitates the determination of COR-offset, parallel y-shift and detector tilt by means of a single, comprehensive test using a special phantom consisting of three point sources. The evaluation of the method was performed by a series of measurements utilizing manually adjusted detector tilts and a simulation of y-shift by moving the phantom. The results show that y-shift and detector tilt are measured with reasonable accuracy, and that y-shift caused by variations in detector tilt can be differentiated from y-shift caused by other factors.

Evaluation Studies as Topic↗