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Biomedical subjects

Erich Sorantin

Publications and source records attributed to Erich Sorantin.

10 recordsLinked to original sources

Laryngo-tracheal profile: a new method for assessing laryngo-tracheal stenoses.

We present the clinical application of a new method for objective assessment of both grade and length of laryngo-tracheal stenoses (LTS) on a CT-based skeletonization algorithm, called laryngo-tracheal profile (LTP). Extraction of the laryngo-tracheal tract (LTT)-medial axis was performed after S-CT scanning. Orthogonal to the medial axis, the LTT cross-profile was computed, and the length and degree of LTS were presented as line charts. Clinical application of this newly developed method is demonstrated on three patients who had to undergo preoperative assessment before surgical treatment of tracheal stenoses. LTP provides an objective method of assessment of both the length and degree of tracheal stenoses in precise correlation to defined anatomical landmarks. This method provides important additive information for preoperative evaluation as well as for monitoring of therapeutical success. Current methods used so far are able to evaluate the severity of LTS, but do not provide exact quantitative assessment of complex LTS. Especially in CT-scans of strong curved passages, where an overestimation of the cross-sectional area results by an oblique cut of the tubular structure, LTP may overcome this problem by a simple post processing skeletonization algorithm.

Adult↗

Neonatal trauma.

A variety of traumatic lesions can occur during the neonatal period. Some of those lesions are clearly birth injuries due to delivery and others are caused by necessary procedures during intensive care in critically ill neonates. As usual patient history must be known and knowledge about the typical complications is necessary in order to select the appropriate imaging modality and thus enabling correct interpretation of those investigations by the radiologist. The purpose of this article is to present typical neonatal injuries, describe the underlying pathomechanisms and aetiology as well as the imaging findings.

Abdominal Injuries↗

Fractures and dislocations of the foot in children.

The challenge of managing pediatric foot injuries is the identification of the rare injuries that require operative treatment and the management of complications such as compartment syndrome, post-traumatic foot deformities, and avascular necrosis. With these complications in mind, the authors discuss fractures of the talus, calcaneus, lesser tarsal bones, Lisfranc's joint, metarsals, and phalanges. Dislocation of metatarsophalangeal or interphalangeal joints is also discussed.

Child↗

Model-based quantitative AAA image analysis using a priori knowledge.

Abdominal aortic aneurysm (AAA) is a serious vascular disease which may have a fatal outcome. AAA shape and size is important for diagnostics and intervention planning. In this paper, we present a new method for segmentation of AAA from computed tomography (CT) angiography images. The method works by segmenting the inner and the outer aortic border. Segmentation of AAA is a challenging problem because of low contrast of the outer aortic border. In our method, the inner aortic border is segmented using a geometric deformable model (GDM) and morphological postprocessing. The GDM is implemented using the level-set algorithm. The outer aortic border is segmented by a preprocessing method utilizing a priori knowledge about the aorta shape, followed by the GDM-based method, and morphological postprocessing. The preprocessing algorithm operates on a slice-by-slice basis with some information flow among neighboring slices. The GDM performs three-dimensional (3D) segmentation, reducing possible errors in the previous step. The proposed method is automatic and requires minimal user assistance. The method was statistically validated on 12 patient scans having a total number of 497 image slices. Statistical analysis has confirmed high correlation between the results obtained by the proposed method and the gold standard obtained by manual segmentation by an expert radiologist.

Algorithms↗

Management of intussusception.

Intussusception represents the most common abdominal emergency in infancy. The classical clinical triad, consisting of abdominal colics, red jelly stools and a palpable mass, is only present in approximately 50% of cases, 20% of patients are symptom free at clinical presentation. Primary imaging modality of choice is ultrasound scanning, which enables the diagnosis or exclusion of an intussusception at a sensitivity of 98-100%, specificity of 88% and a negative predictive value of 100%. In emergency cases, additional plain films are necessary to detect potential intestinal perforation, to identify intestinal obstruction or other diseases mimicking the clinical presentation. Once the diagnosis of an intussusception is established, non-surgical reduction (NSR) is used. A surgical approach is chosen in patients with signs of perforation, shock or peritonitis. Depending on the choice of guiding imaging technique, different contrast media are used for NSR. Barium suspension or air with fluoroscopic guidance, or saline only or mixed with water-soluble contrast under sonographic guidance, has to be used. Regardless of the used contrast medium, NSR is an effective technique, being successfully employed in more than 90% of cases.

Abdomen, Acute↗

Frequency and significance of lumbar and inferior mesenteric artery perfusion after endovascular repair of abdominal aortic aneurysms.

PURPOSE: To evaluate the frequency and influence of perfused side branches (lumbar arteries [LA] and inferior mesenteric artery trunks) on development of type II endoleaks (EL-II) and on volume changes of abdominal aortic aneurysms (AAA) after endovascular repair. METHODS: Of 114 patients undergoing EVR of AAA, 89 patients (83 men; mean age 72+/-7.5 years, range 51-88) with >6 months' follow-up and no type I endoleaks were retrospectively analyzed to determine any relationships between retrograde perfusion, endoleaks, and sac volume. Data were derived from computed tomographic angiographic (CTA) scans taken before and after intervention, at discharge, and at 1, 3, 6, and semi-annually thereafter in follow-up. Two groups were identified and compared based on their status at 6 months post EVR: without perfused side branches (group 1) and with perfused collaterals (group 2); group 2 was further divided according to the absence (2a) or presence (2b) of endoleak. RESULTS: Median follow-up was 24 months (range 6-36). Based on a total of 582 CTAs analyzed, 17 (19%) patients developed type II endoleaks (EL-II) during follow-up. There was a significant difference in the number of perfused LAs prior to EVR between groups 1 (n=44) and the 45 patients with postprocedural patent collateral arteries in group 2 (p<0.05); there was no significant difference between groups 2a and 2b (p=0.88) relative to the number of pre-existing patent collaterals. The number of pLAs preoperatively and the rate of type II endoleak were significantly correlated (p<0.05). No type II endoleak was seen in patients without perfused side branches (p=0.01). No significant differences in mean volumes were found between groups 1 and 2a (no EL-II), but significant differences between groups 1 and 2b were seen in later follow-up. CONCLUSIONS: A larger number of patent LAs before EVR was associated with a significantly higher rate of type II endoleak. Patent collateral vessels were common after aneurysm repair, but the frequency decreased during follow-up. Persistent side branch perfusion was associated with increased type II endoleak after endovascular AAA repair. Significant differences in volume changes in later follow-up were seen between patients with or without type II endoleak.

Aged↗

Diagnostic and prognostic value of 99mTc-tetrofosmin scintigraphy in maxillofacial flaps.

In oro-maxillofacial malignancies, new therapeutic approaches are placing changing demands on the diverse diagnostic modalities. In contradistinction to mandibular reconstruction of former years, the transplants (microvascular anastomosed pedicled flaps, "flaps") now consist of one or more arteries feeding a soft tissue component attached to a piece of bone suitably fitted to fill the defect. We addressed the diagnostic value of technetium-99m tetrofosmin scintigraphy in differentiating between viability and non-viability of the soft tissue portion of flaps in the immediate postoperative assessment. A total of 60 patients who had received flaps for reconstruction of the mandible after partial resection were investigated with (99m)Tc-tetrofosmin 3-5 days after surgery. Scintigraphy consisted of (a) radionuclide angiography, (b) static planar imaging in four projections starting at 10 min post injection, and (c) single-photon emission tomography (SPET) performed immediately after the planar imaging. Normal perfusion associated with no defects throughout the soft tissue portion of the transplant was observed in 46/60 patients. This scintigraphic pattern was identical to viability and normal postoperative follow-up. Hypoperfusion and small defects on planar and SPET images indicated viability and uncomplicated postoperative healing in 6/60 patients, but non-viability/inadequate healing of the flap in 4/60 patients. Absence of perfusion combined with a large defect on static planar and SPET images definitively showed the non-viability of the flap (4/60 patients). It is concluded that (99m)Tc-tetrofosmin scintigraphy is a sensitive diagnostic tool for the immediate postoperative assessment of the viability and the adequacy of implantation of the soft tissue portion of flaps. Therefore tetrofosmin scintigraphy is an important modality in order (a) to define the optimal therapeutic regimen in the immediate postoperative period and (b) to provide better prognosis.

Adult↗

Spiral-CT-based assessment of tracheal stenoses using 3-D-skeletonization.

PURPOSE: Demonstration of a technique for three-dimensional (3-D) 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 skeletonization algorithm. Orthogonal to the medial axis the LTT 3-D cross-sectional profile was computed and presented as line charts, where degree and length was 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 was found to be 60.5% and 4.32 cm in patients compared with minor caliber changes of 8.8% and 2.31 cm in normal controls (p << 0.0001). For the phantoms an excellent correlation between the true and computed 3-D 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 3-D 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 artifacts.

Adolescent↗

CT-based virtual tracheobronchoscopy in children--comparison with axial CT and multiplanar reconstruction: preliminary results.

BACKGROUND: 3D post-processing of spiral-CT (S-CT) data using perspective projection allows the generation of virtual views similar to endoscopy. OBJECTIVE: To evaluate whether simultaneous reading of axial S-CT, multiplanar reconstruction (MPR) and virtual tracheobronchoscopy (VTB) is more precise and accurate than reading of axial S-CT and MPR alone in paediatric patients. MATERIALS AND METHODS: S-CT studies of 15 symptomatic and 4 normal patients were investigated. Two radiologists independently read two sets of images for airway abnormalities: first axial CT and MPR, followed by axial CT, MPR and VTB. A final decision was later made by consensus. All results were compared to fibre-optic bronchoscopy (FTB). Interobserver agreement was used as an indicator of precision for the display technique used. RESULTS: At reading of axial S-CT and MPR an interobserver agreement of 89.5% (kappa=0.776, P<0.00103) was found. Based on the consensus decision, a diagnostic accuracy of 89.5% at a sensitivity 86.6% and specificity of 100% (kappa=0.776, 95% CI 0.491-1.062, P<0.00103) was achieved. At reporting on axial S-CT, MPR and VTB, all cases were classified correctly by both readers, indicating 100% accuracy, interobserver agreement, sensitivity and specificity (kappa=1.00, 95% CI 1.0-1.0, P<0.000258). CONCLUSIONS: The simultaneous display of axial S-CT, MPR and VTB raises the precision, accuracy and sensitivity of radiological reports.

Adolescent↗