Soft Tissue Attenuation Research Articles

Time-domain analysis of power law attenuation in space-fractional wave equations.

Ultrasound attenuation in soft tissue follows a power law as a function of the ultrasound frequency, and in medical ultrasound, power law attenuation is often described by fractional calculus models that contain one or more time- or space-fractional derivatives. For certain time-fractional models, exact and approximate time-domain Green's functions are known, but similar expressions are not available for the space-fractional models that describe power law attenuation. To address this deficiency, a numerical approach for calculating time-domain Green's functions for the Chen-Holm space-fractional wave equation and Treeby-Cox space-fractional wave equation is introduced, where challenges associated with the numerical evaluation of a highly oscillatory improper integral are addressed with the Filon integration formula combined with the Pantis method. Numerical results are computed for both of these space-fractional wave equations at different distances in breast and liver with power law exponents of 1.5 and 1.139, respectively. The results show that these two space-fractional wave equations are causal and that away from the origin, the time-domain Green's function for the Treeby-Cox space-fractional wave equation is very similar to the time-domain Green's function for the time-fractional power law wave equation.

Outcomes of spring ligament reconstruction for idiopathic flexible flatfoot deformity

Category: Hindfoot Introduction/Purpose: Idiopathic flatfeet are usually caused by attenuation of the medial soft tissues rather than a lateral osseous deficiency. Our prospective study aimed to quantify the functional and radiological outcome of a new technique for spring ligament reconstruction using a hamstring graft for idiopathic flat feet Methods: Our prospective study included 17 feet in 14 patients, from 05/14 to 05/17, on which a spring ligament reconstruction was performed. This pre-tensioned allograft reconstruction was performed using a blind talar tunnel, with the graft being passed deep to the navicular tuberosity, through a tunnel in the medial cuneiform and then sutured back onto its proximal limb to control abduction. Additional procedures included medial head of gastrocnemius recession (17), calcaneal osteotomy (16), FDL transfer (3), tibialis posterior synovectomy (2), peroneus longus to brevis transfer (2). There was a minimum of 6 months follow-up. Radiographic analysis was performed for standardised parameters. Paired t-test was used for analysis Results: The average age was 41 (range 23 -65). The mean BMI was 31.1 (range 24.6 – 37.3). Mearys line improved from a mean of 24.1 (9 – 36.4) to a mean of 13.8 (-3.1 – 26.7). This was statistically significant (p<0.001). Talar uncoverage angle improved from a mean of 39.5 (27.7 – 55.8) to 23.9 (3.5 – 39.7). First metatarsal talar angle improved from a mean of 18.9 (8.4 – 33.9) to 10.3 (-6.1 – 21.5). There were no wound infections. There was one revision (5.9%) to a triple arthrodesis; at revision it was found that the allograft had attenuated to incompetency. Of the patients that improved the least, 80% (4/5) were over the age of 49. Our numbers are insufficient to statistically analyse this Conclusion: This new method of spring ligament reconstruction provides a predictable solution for more anatomical reconstruction of idiopathic flatfoot deformity, with statistically significant improvements in all radiographic parameters. Further numbers will be needed but we would exercise caution in using this technique in older patients.

Anterior mediastinal Hodgkin lymphoma presenting as an extremely hypervascular tumor on computed tomography

Rationale:In the thorax, Hodgkin lymphoma (HL) most frequently involves the anterior mediastinal and paratracheal regions and tends to spread to contiguous nodal groups. Enlarged lymph nodes typically have homogeneous soft tissue attenuation similar to that of muscle tissue on computed tomography (CT).Patient concerns:A contrast-enhanced CT examination of a 19-year-old man with right-sided chest pain showed an intense, heterogeneously enhancing mass with organization of serpentine and dilated blood vessels in the right anterior mediastinum that had invaded the upper lobe of the right lung.Diagnoses:Following a wedge resection, histopathological examination showed Reed-Sternberg cells that were positive for CD-15 and CD-30, which is typical of HL.Interventions:The patient was started treatment with 6 cycles of doxorubicin, bleomycin, vincristine, and dacarbazine (ABVD) regimen.Outcomes:After chemotherapy, the patient had shown a partial response to the treatment.Lessons:This presentation of HL as an extremely hypervascular anterior mediastinal mass on CT imaging has not been previously reported in the literature. This case suggests that HL should be included in the differential diagnosis of a hypervascular anterior mediastinal mass, especially if the patient is a young adult.

Is HRCT Temporal Bone Necessary in All Cases of Active Squamous Chronic Otitis Media?

To assess the usefulness of high resolution computed tomography (HRCT) temporal bones in cases of active squamous chronic otitis media (COM). Comparison of HRCT findings with operative findings. A prospective study of 104 clinically diagnosed patients with COM were included. Each patient was subjected to full clinical evaluation and HRCT temporal bone was done. Preoperative HRCT finding were correlated with surgical findings. The sensitivity of HRCT temporal bone in detecting cholesteatoma was 91.81%. However it could not differentiate cholesteatoma from other soft tissue density like granulation or hypertrophic mucosa or discharge, but soft tissue attenuation content with bone erosion was considered as hallmark of cholesteatoma. The sensitivity and specificity of HRCT for detecting malleus, incus and stapes erosion was 71.5 and 88.5%, 86.3 and 95% and 53.1 and 64.7% respectively. The sensitivity and specificity for detecting erosion of lateral semicircular canal (LSCC) was 77.78 and 98.2%. The sensitivity and specificity for facial canal was 80 and 100%. HRCT gives excellent details about the extent of cholesteatoma with reasonable accuracy in expert hands. It helps to warn the surgeon about anatomical variations preoperatively and detects complications if any. It effectively depicts integrity or erosion of dural plate, sinus plate, LSCC, facial nerve. Malleus and incus are seen reasonably well but status of stapes are not recorded effectively.

Computed tomography of solitary fibrous tumor of the pleura abutting the mediastinum: A diagnostic challenge

Background:Solitary fibrous tumor of the pleura (SFTP) arising from the mediastinal pleura may be confused with primary mediastinal tumors. We studied the computerized tomographic (CT) findings of patients with SFTP that could suggest a diagnosis of SFTP.Materials and Methods:At our hospital from January 1995 to June 2012, 39 patients with histologically confirmed SFTP were surgically treated; seven of them abutting the mediastinal pleura. The study group included seven patients aged between 53 and 81 years. Baseline CT scans were retrospectively reviewed to identify radiological findings suggestive of SFTP including: (1) smooth and sharply delineated contours; (2) obtuse, acute, or tapering angles between the lesion and the mediastinum depending on the size; (3) homogeneous soft-tissue attenuation; (4) “geographic pattern” due to the contemporary presence of large vessels, necrosis, and calcifications; (5) displacement of the lung parenchyma; (6) presence of a cleavage plane; and (7) absence of lymphadenopathy or pleural methastasis.Results:All tumors formed acute angles with the pleura. Six out of the seven presented smoothly tapering margins, three had a “geographic pattern” of attenuation and displaced the anterior junction line; one showed an outside junction line development. Four cases had a clear pleural origin.Conclusions:The possibility of SFTP should be taken into account when a mass abuts the mediastinum projecting inside the thoracic cavity in the presence of an intense and “geographical pattern” of enhancement without lymphoadenopathy or pleural metastasis. These findings assume greater significance in the presence of discrepancy between the size of the lesion and the clinical presentation.

Infectious and Non-Infectious Diseases Causing the Air Crescent Sign: A State-of-the-Art Review.

Aspergilloma, also known as mycetoma or fungus ball, is characterized by a round or oval mass with soft-tissue attenuation within a preexisting lung cavity. The typical computed tomography (CT) aspect of an aspergilloma is a mass separated from the wall of the cavity by an airspace of variable size and shape, resulting in the air crescent sign, also known as the meniscus sign. This CT feature is non-specific and can be simulated by several other entities that result in intracavitary masses. This review describes the main clinical and imaging aspects of the infectious and non-infectious diseases that may present with fungus-ball appearance, including pulmonary hydatid cyst, Rasmussen aneurysm, pulmonary gangrene, intracavitary clot, textiloma, lung cancer, metastasis, and teratoma, focusing on the differential diagnosis.

Finite element simulation on posterior tibial tendinopathy: Load transfer alteration and implications to the onset of pes planus

BackgroundPosterior tibial tendinopathy is a challenging foot condition resulting in pes planus, which is difficult to diagnose in the early stage. Prior to the deformity, abnormal internal load transfer and soft tissue attenuation are anticipated. The objective of this study was to investigate the internal load transfer and strain of the ligaments with posterior tibial tendinopathy, and the implications to pes planus and other deformities. MethodsA three-dimensional finite element model of the foot and ankle was reconstructed from magnetic resonance images of a 28-year-old normal female. Thirty bones, plantar fascia, ligaments and tendons were reconstructed. With the gait analysis data of the model subject, walking stance was simulated. The onset of posterior tibial tendinopathy was resembled by unloading the tibialis posterior and compared to the normal condition. FindingsThe load transfer of the joints at the proximal medial column was weaken by posterior tibial tendinopathy, which was compromised by the increase along the lateral column and the intercuneiforms during late stance. Besides, the plantar tarsometatarsal and cuboideonavicular ligaments were consistently over-stretched during stance. Particularly, the maximum tensile strain of the plantar tarsometatarsal ligament was about 3-fold higher than normal at initial push-off. InterpretationPosterior tibial tendinopathy altered load transfer of the medial column and unbalanced the load between the proximal and distal side of the medial longitudinal arch. Posterior tibial tendinopathy also stretched the midfoot plantar ligaments that jeopardized midfoot stability, and attenuated the transverse arch. All these factors potentially contributed to the progress of pes planus and other foot deformities.

Feline injection site sarcoma: computed-tomographic density and assessment of tumor dimensions by different methods

ABSTRACT: Feline injection site sarcoma is a malignant neoplasm with digitiform projections into muscular planes that are ill recognized during physical examination and may compromise tumor margin demarcation. This study compared tumoral size of 32 cats measured by different methods, and evaluated the CT density of 10 tumoral tissues (Hounsfield unit) based on histograms. Tumor axes were measured by physical examination and CT images. Larger craniocaudal axis measurements were obtained following multiplanar reconstruction of pre- and post-contrast CT images (p=0.049 and p=0.041 respectively); dorsoventral axis measurements taken from post-contrast CT images were also larger (p=0.010). Tumor volume estimates increased following contrast-enhancement. Histograms tended to produce two peaks: one in the fat and another in the soft tissue attenuation range. Multiplanar reconstructed post-contrast CT images provided clearer definition of tumor margins and more judicious determination of tumor size. A tendency of common FISS attenuation profile could be described.

Post Mortem Ultrasound and Computed Tomography Findings of an Extraluminal Urinary Bladder Leiomyoma in a Dog

Background: Neoplasia of the urinary bladder is common in dogs, accounting approximately 0.5 to 1.0 percent of all neoplasms. Most of the neoplasia of the urinary bladder is epithelial in origin and only 10% of urinary bladder neoplasms in dogs are from mesenchymal origin, of which the most frequent types are leiomyoma / leiomyosarcoma, and hemangioma / hemangiosarcoma. Virtual autopsy refers to the postmortem use of radiology, ultrasound and cross-sectional imaging prior to conventional necropsy. This paper reports the detection of a rare extra-luminal urinary bladder mass diagnosed as leiomyoma with a virtual autopsy techniques.Case: A 16-year-old male Schnauzer had previous history of seizure and no complains related to the urinary system. The animal was treated symptomatically to the neurological signs and responded to medical treatment. Nine weeks later from the first visit to the hospital the dog was found dead at home. Then postmortem ultrasound and computed tomography of the abdomen were performed. Postmortem ultrasound revealed a homogenously hypoechoic, rounded and slightly irregularly marginated mass located externally but adjacent to the left cranial wall of the urinary bladder and appears to extend from its serosal margins. Postmortem computed tomography was performed after postmortem ultrasound. A pedunculated homogenous soft tissue attenuating mass was located at the left lateral aspect of the urinary bladder and extended cranially. It had a stalk that connected to the left lateral wall of the urinary bladder. A partial necropsy of the abdomen was done just to examine the mass. A round extraluminal, pedunculated mass was observed at the left lateral aspect of the urinary bladder wall. It was pale pink on the outside and white inside, with a soft to firm consistency. The lumen and mucosal surface of the urinary bladder was smooth and regular. The histology of the mass revealed a densely cellular neoplastic proliferation, expansive, composed of spindle-shaped cells with moderate to large eosinophilic cytoplasm, sometimes wavy and with indistinct edges. The nuclei were large, oval to flattened, with dense chromatin and inconspicuous nucleoli. Anisocytosis and anisokariosis were discrete and no mitotic figures were observed. The arrangement consisted of dense, irregular and multidirectional bundles and the stroma was scarce. The mass was histologically confirmed as leiomyoma.Discussion: In this case, we performed postmortem ultrasound and computed tomography as part of a virtual necropsy study and in both modalities the urinary bladder mass was able to be identified, followed by a partial necropsy to further investigate the nature of the mass and to collect a sample to obtain the histological diagnosis. A few of the disadvantages of the postmortem ultrasound and computed tomography specially in this case were the lack of color Doppler investigation on ultrasound and the lack of evaluation of the patter of contrast enhancement on computed tomography. These techniques could have added important information related to the vascularity characteristics of the mass in a live patient. This is the first case report in veterinary medicine that describes an extra-luminal pedunculated urinary bladder leiomyoma in a canine patient, and it is emphasized the approach by postmortem ultrasound, postmortem computed tomography and conventional necropsy findings to reach the definitive diagnosis.

Applications of Dual-Energy Computed Tomography for Artifact Reduction in the Head, Neck, and Spine.

Conventional computed tomography (CT) uses a polychromatic energy beam to offer superb anatomic detail of the head and spine. However, technical challenges remain that can degrade the diagnostic image quality of these examinations. Dual-energy CT analyzes the changes in attenuation of soft tissues at different energy levels, from which different reconstructions can be made to yield the optimal contrast-to-noise ratio, reduce beam-hardening artifact, or evaluate tissue composition. In this article, selective applications of the dual energy CT technique are discussed, highlighting a powerful tool in the diagnostic CT evaluation of the head, neck, and spine.

Calibration of the 125I-induced x-ray fluorescence spectrometry-based system of in vivo bone strontium determinations using hydroxyapatite as a phantom material: a simulation study

Objective. The calibration of in vivo x-ray fluorescence systems of bone strontium quantification, based on 125I excitation, is dependent on a coherent normalization procedure. Application of this procedure with the use of plaster of Paris (poP) as a phantom material requires the application of a coherent conversion factor (CCF) to make the calibration functions transferable between the phantom material and human bone. In this work we evaluate, with the use of Monte Carlo simulation, the potential benefit of employing a newly developed hydroxyapatite phantom material into the calibration protocol. Approach. Simulations being performed on bare bone phantoms, as the emission spectrum in this case is equivalent to an emission spectrum of an adequately corrected measurement for soft tissue attenuation of emitted strontium signal. We report that the application of hydroxyapatite phantoms does in fact remove the need for a coherent correction factor (CCF). Main results. The newly developed phantoms can thus be used for the calibration of in vivo bone strontium systems removing one step of the calibration protocol. Calibration is, however, limited to cases in which the concentration is relative to the amount of calcium in the specimen, which is, the most useful quantity in a clinical sense. Determining concentrations on a per-mass-of-material basis, that is, a concentration not normalized to the calcium content of the phantom/bone, results in large biases in estimated bone strontium content. Significance. The use of an HAp phantom material was found to remove the need for a CCF. It was also found that in the case of an incomplete conversion ratio when preparing the phantom material that there would be little effect on the differential coherent cross-section and thereby the coherent normalization-based calibration protocol.

Imaging Properties of 3D Printed Materials: Multi-Energy CT of Filament Polymers

Clinical applications of 3D printing are increasingly commonplace, likewise the frequency of inclusion of 3D printed objects on imaging studies. Although there is a general familiarity with the imaging appearance of traditional materials comprising common surgical hardware and medical devices, comparatively less is known regarding the appearance of available 3D printing materials in the consumer market. This work detailing the CT appearance of a selected number of common filament polymer classes is an initial effort to catalog these data, to provide for accurate interpretation of imaging studies incidentally or intentionally including fabricated objects. Furthermore, this information can inform the design of image-realistic tissue-mimicking phantoms for a variety of applications, with clear candidate material analogs for bone, soft tissue, water, and fat attenuation.

Primary and secondary omental infarction: A 5-year experience in a tertiary care hospital

Objective: The aim of this study is to describe the computed tomography (CT) features of primary and secondary omental infarction. Materials and Methods: Five cases of primary and seven cases of secondary omental infarction are described with emphasis on CT features. The etiology and clinical features are described with the ultimate clinical outcome. Results: In this case series of 12 patients, five omental infarcts (42%) were classified as primary. Seven cases (58%) were postoperative with four infarcts following cesarean section, one following a total abdominal hysterectomy, one occurring after a laparoscopic ovarian cystectomy, and one occurring after laparoscopic hemicolectomy. Of the seven secondary omental infarctions, one was associated with secondary thickening of the transverse colon and one patient developed an abscess. Three patients from the secondary group and one patient from the primary group underwent omentectomy. Primary infarcts showed an ill-defined fat attenuation lesion with thin stranding located in the right upper quadrant in three and left lower quadrant in two patients. The postoperative omental infarcts showed more pronounced inflammatory change and soft tissue attenuation foci interspersed with fat density foci. They were located in the right lower quadrant in four patients, in the right upper quadrant in two patients, and in the left lower quadrant in one patient. The patients were followed to clinical resolution. Conclusion: It is possible to distinguish primary and secondary omental infarcts on the basis of CT features. Even though, a nonsurgical cause of acute abdomen, surgical management may become necessary in patients with secondary omental infarction and secondary infection who fail to respond to antibiotics and percutaneous drainage. The majority of the secondary cases followed cesarean section in our series.

Computed tomography for the management ofexit-site and tunnel infections in peritoneal dialysis patients .

To evaluate the effectiveness of computed tomography (CT) for detection of exit-site and tunnel infections with a Tenckhoff catheter. The study enrolled patients with exit-site or tunnel infections who underwent ultrasonography (US), CT scans, and subsequent catheter removal or partial catheter reimplantation from 2010 to 2014. Control cases on peritoneal dialysis who underwent abdominal CT scans for other reasons were randomly selected. Attenuation of the soft tissue around the Tenckhoff catheter was measured in Hounsfield units (HU). 9 infected cases and 15 control cases were identified. CT showed increased attenuation around the catheter in all cases, while ultrasonography detected a hypoechoic area only in one case with abscess formation. Maximal attenuation of the inflamed soft tissue was high (median, 36 HU) compared with normal fatty tissue (median, -75 HU). In all cases, one or two sites with increased fat density were observed focally along the catheter, and these areas did not always extend directly from the exit site. In this retrospective study comprising a small number of cases, increased attenuation of fatty tissue around the Tenckhoff catheter correlated with exit-site or tunnel infections. CT might be an auxiliary tool for diagnosis, although CT costs much more than US and is not always available in general practice. Further prospective studies are needed. .

A Frequency-Shift Method to Measure Shear-Wave Attenuation in Soft Tissues.

In vivo quantification of shear-wave attenuation in soft tissues may help to better understand human tissue rheology and lead to new diagnostic strategies. Attenuation is difficult to measure in acoustic radiation force elastography because the shear-wave amplitude decreases due to a combination of diffraction and viscous attenuation. Diffraction correction requires assuming a cylindrical wavefront and an isotropic propagation medium, which may not be the case in some applications. In this paper, the frequency-shift method, used in ultrasound imaging and seismology, was adapted for shear-wave attenuation measurement in elastography. This method is not sensitive to diffraction effects. For a linear frequency dependence of the attenuation, a closed-form relation was obtained between the decrease in the peak frequency of the gamma-distributed wave amplitude spectrum and the attenuation coefficient of the propagation medium. The proposed method was tested against a plane-wave reference method in homogeneous agar-gelatin phantoms with 0%, 10%, and 20% oil concentrations, and hence different attenuations of 0.117, 0.202, and 0.292 [Formula: see text]/Hz, respectively. Applicability to biological tissues was demonstrated with two ex vivo porcine liver samples (0.79 and 1.35 [Formula: see text]/Hz) and an in vivo human muscle, measured along (0.43 [Formula: see text]/Hz) and across (1.77 [Formula: see text]/Hz) the tissue fibers. In all cases, the data supported the assumptions of a gamma-distributed spectrum for the source and linear frequency attenuation for the tissue. This method provides tissue attenuation, which is relevant diagnostic information to model viscosity, in addition to shear-wave velocity used to assess elasticity. Data processing is simple and could be performed automatically in real time for clinical applications.

COMPARISONS AMONG COMPUTED TOMOGRAPHIC FEATURES OF ADIPOSE MASSES IN DOGS AND CATS.

A better understanding of the CT features of different forms of canine and feline adipose tumors would be valuable for improving patient management and treatment. The purpose of this retrospective, cross-sectional study was to describe and compare the CT features of pathologically confirmed lipomas, infiltrative lipomas, and liposarcomas in a sample of canine and feline patients. A total of 50 animals (46 dogs, four cats) and a total of 60 lesions (23 lipomas, 20 infiltrative lipomas, and 17 liposarcomas) were included in the study. Lipomas appeared as round to oval-shaped (n = 21), well-marginated (n = 20) fat-attenuating lesions. Infiltrative lipomas appeared as homogeneous, fat-attenuating masses but, unlike lipomas, they were most commonly characterized by an irregular shape (75%; P < 0.001), and linear components, hyperattenuating relative to the surrounding fat (100%; P < 0.05). Liposarcomas were represented exclusively by heterogeneous lesions with soft tissue attenuating components with a multinodular appearance (76.5%; P < 0.05). Regional lymphadenopathy (n = 10) and amorphous mineralization (n = 4) were also observed in association with liposarcomas. Computed tomography can provide useful information regarding disease location, extent, and involvement of the adjacent structures. Tumor definition and shape were the most useful parameters to differentiate between lipomas and infiltrative lipomas. The presence of a heterogeneous mass, with a multinodular soft tissue component and associated regional lymphadenopathy and mineralization, were features favoring a diagnosis of liposarcoma.

Numerical evaluation of time-domain Green's functions for space-fractional wave equations

Ultrasound attenuation in soft tissue follows a power law as a function of the ultrasound frequency. Several different models for the power law attenuation of medical ultrasound have been developed using fractional calculus, where each contains one or more time- or space-fractional derivatives. For certain time-fractional models, exact and approximate time-domain Green's functions have been derived and evaluated numerically, but a similar analysis has not yet been performed on the space-fractional models. To address this deficiency, time-domain Green's functions are numerically calculated here for two space-fractional models, namely the Chen-Holm and Treeby-Cox space-fractional wave equations. Numerical results are computed for both of these in breast and liver with power law exponents of 1.5 and 1.139, respectively. The results show that these two space-fractional wave equations are causal everywhere. Away from the origin, the time-domain Green's function for the dispersive Treeby-Cox space-fractional wave equation is very similar to the time-domain Green's functions calculated for the corresponding time-fractional wave equations, but the time-domain Green's function for the nondispersive Chen-Holm space-fractional wave equation is quite different. To highlight the similarities and differences between these, time-domain Green's functions are compared and evaluated at different distances for both breast and liver.

Evaluation of rapid maxillary expansion through acoustic emission technique and relative soft tissue attenuation

ObjectivesAcoustic emission (AE) is a non-destructive test to detect energy release. This technique was applied during rapid maxillary expansion (RME) to evaluate the reaction of the craniofacial skeleton. Materials and methodsA swine model was analysed. Soft tissues were removed from two heads, while other two were preserved intact. A palatal expander (PE) was positioned and AE sensors were placed on the intermaxillary, fronto-nasal, and maxillo-lacrimal sutures. The PE was activated and AE recorded during RME. Differences between parameters were analysed with Mann-Whitney U test and Kruskal-Wallis test, and correlations with Spearman-Rho test (significance p<0.05). ResultsPE activations were accompanied by clusters of AE hits. In the presence of soft tissues, amplitudes were generally lower (p<0.001) and durations were higher (p<0.001). No differences were found in the respective energy values. Differences were found in the AE (p<0.05) among the four channels, with AE characterised by higher values in proximity of the maxillo-lacrimal sutures. High-energy hits were represented by burst-type waves, and low-energy ones by continuous-type. ConclusionsAlthough soft tissues create possible attenuation of the signal, AE can be detected during RME with sensors on the skin. AE provided further information of energy release, on top of the mechanical parameters. Source location was one of the main limitations.

Comparison of stress cardiovascular magnetic resonance imaging (CMR) with stress nuclear perfusion for the diagnosis of coronary artery disease

ObjectivesTo assess the diagnostic performance of stress cardiac magnetic resonance (stress CMR) vs stress single-photon emission computed tomography (SPECT) in patients presenting to the emergency department (ED) with chest pain. BackgroundSPECT imaging is the most utilized outpatient procedure in the United States. The diagnostic accuracy of SPECT can be limited by soft tissue attenuation and low spatial resolution. Stress CMR has much higher spatial resolution and without the susceptibility to soft tissue attenuation. MethodsEighty-seven patients without a history of CAD presenting to the ED with chest pain were prospectively enrolled. Patients underwent both stress CMR and stress SPECT imaging within 12 hours of presentation. Both the stress imaging tests were interpreted immediately for clinical purposes and coronary angiography was performed if either was abnormal. Patients were considered to have significant CAD if identified by angiography (≥50%) or if a cardiac event (cardiac death, myocardial infarction or revascularization) occurred during follow-up (mean 2.6 ± 1.1 years). ResultsThirty-seven patients were referred for coronary angiography; 29 due to a positive stress test and eight patients for persistent chest pain despite two negative stress tests. There were 22 patients who had significant CAD (≥50%). The remaining patients were followed for 2.6 ± 1.1 years. At the conclusion of the follow-up period, there were four clinical events. The sensitivity, specificity, and diagnostic accuracy of CMR are 85%, 93%, and 89%, respectively. The sensitivity, specificity, and diagnostic accuracy of stress SPECT are 84%, 91%, and 88%, respectively. ConclusionStress CMR has similar diagnostic accuracy as stress SPECT in diagnosis of CAD.

MP19-06 PREOPERATIVE RADIOLOGIC ASSESSMENT FOR PERINEPHRIC FAT INVASION (T3A): COMPARISON WITH PATHOLOGICAL STAGING

You have accessJournal of UrologyImaging/Radiology: Uroradiology III1 Apr 2016MP19-06 PREOPERATIVE RADIOLOGIC ASSESSMENT FOR PERINEPHRIC FAT INVASION (T3A): COMPARISON WITH PATHOLOGICAL STAGING Zhamshid Okhunov, Jae Young Park, Chenhui Zhao, Molly Baker, Mohammad Helmy, Chandana Lall, Mari Bozoghlanian, and Jaime Landman Zhamshid OkhunovZhamshid Okhunov More articles by this author , Jae Young ParkJae Young Park More articles by this author , Chenhui ZhaoChenhui Zhao More articles by this author , Molly BakerMolly Baker More articles by this author , Mohammad HelmyMohammad Helmy More articles by this author , Chandana LallChandana Lall More articles by this author , Mari BozoghlanianMari Bozoghlanian More articles by this author , and Jaime LandmanJaime Landman More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2754AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We assessed the accuracy of computed tomography (CT) in diagnosing perinephric fat invasion (PNFI) in patients with renal cell carcinoma (RCC). METHODS We retrospectively reviewed preoperative CTs of patients who underwent extirpative surgery for pT1 - pT3a RCC. CT criteria used to assess PNFI were PN soft-tissue stranding (PNSTS), peritumoral vascularity (PTV), increased density of the PNF, tumor margins (TM), and presence of contrast-enhancing soft-tissue nodules in the PN space. PNSTS was defined as linear areas of soft tissue attenuation, corresponding to the bridging septa of the PN space. PTV was defined as asymmetrically enlarged, irregular vessels adjacent to the neoplasm, within the PN space. The CT density of the PNF was measured by placing a circular region of interest, as large as possible within the perirenal space, juxtaposed to the RCC. The CT density of the PNF of the normal contralateral kidney, measured at the area of the lower pole, was used as the standard of reference. A sharply demarcated tumor was characterized as confined within the kidney while ill-defined TM was suggestive of neoplastic invasion of the PNF. The final histopathology was used as the standard of reference. We analyzed the sensitivity and specificity stratified by tumor size (≤4cm, >4 - ≤7cm, >7 - ≤10cm, and >10cm). RESULTS A total of 161 patients were included. Table 1 demonstrates sensitivity and specificity of all assessed variables in predicting PNFI on CT. In logistic regression analysis, PNSTS, increased PTV, ill-defined TM and an enhancing nodule in the perinephric fat were significant predictors of PNFI. In multivariate analysis, PNSTS was the only significant factor for PNFI (table 2). CONCLUSIONS CT imaging does not reliably predict PNFI. However, for tumors >7cm, the absence of PNSTS excludes PNFI. Furthermore, absence of PTV reliably excludes PNFI among tumors from 4 to 10 cm. For tumors < 4cm, a well-defined tumor margin also excludes PNFI. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e205-e206 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Zhamshid Okhunov More articles by this author Jae Young Park More articles by this author Chenhui Zhao More articles by this author Molly Baker More articles by this author Mohammad Helmy More articles by this author Chandana Lall More articles by this author Mari Bozoghlanian More articles by this author Jaime Landman More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...