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1.
Cancer Imaging ; 24(1): 81, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38956721

RESUMEN

BACKGROUND: Numerous studies have shown that magnetic resonance imaging (MRI)-targeted biopsy approaches are superior to traditional systematic transrectal ultrasound guided biopsy (TRUS-Bx). The optimal number of biopsy cores to be obtained per lesion identified on multiparametric MRI (mpMRI) images, however, remains a matter of debate. The aim of this study was to evaluate the incremental value of additional biopsy cores in an MRI-targeted "in-bore"-biopsy (MRI-Bx) setting. PATIENTS AND METHODS: Two hundred and forty-five patients, who underwent MRI-Bx between June 2014 and September 2021, were included in this retrospective single-center analysis. All lesions were biopsied with at least five biopsy cores and cumulative detection rates for any cancer (PCa) as well as detection rates of clinically significant cancers (csPCa) were calculated for each sequentially labeled biopsy core. The cumulative per-core detection rates are presented as whole numbers and as proportion of the maximum detection rate reached, when all biopsy cores were considered. CsPCa was defined as Gleason Score (GS) ≥ 7 (3 + 4). RESULTS: One hundred and thirty-two of 245 Patients (53.9%) were diagnosed with prostate cancer and csPCa was found in 64 (26.1%) patients. The first biopsy core revealed csPCa/ PCa in 76.6% (49/64)/ 81.8% (108/132) of cases. The second, third and fourth core found csPCa/ PCa not detected by previous cores in 10.9% (7/64)/ 8.3% (11/132), 7.8% (5/64)/ 5.3% (7/132) and 3.1% (2/64)/ 3% (4/132) of cases, respectively. Obtaining one or more cores beyond the fourth biopsy core resulted in an increase in detection rate of 1.6% (1/64)/ 1.5% (2/132). CONCLUSION: We found that obtaining five cores per lesion maximized detection rates. If, however, future research should establish a clear link between the incidence of serious complications and the number of biopsy cores obtained, a three-core biopsy might suffice as our results suggest that about 95% of all csPCa are detected by the first three cores.


Asunto(s)
Biopsia Guiada por Imagen , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/diagnóstico por imagen , Estudios Retrospectivos , Anciano , Biopsia Guiada por Imagen/métodos , Persona de Mediana Edad , Próstata/patología , Próstata/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Biopsia con Aguja Gruesa/métodos , Clasificación del Tumor , Imagen por Resonancia Magnética Intervencional/métodos , Imágenes de Resonancia Magnética Multiparamétrica/métodos
2.
Rofo ; 195(6): 486-494, 2023 06.
Artículo en Inglés, Alemán | MEDLINE | ID: mdl-36724803

RESUMEN

PURPOSE: The Liver Imaging Reporting and Data System (LI-RADS v2018) standardizes the interpretation and reporting of MDCT and MRI examinations in patients at risk for hepatocellular carcinoma (HCC). MATERIALS AND METHODS: For focal liver lesions (called "observations") it assigns categories (LR-1 to 5, LR-M, LR-TIV, LR-TR), which reflect the probability of benignity or malignancy (HCC or other non-HCC malignancies) of the respective observation. The categories assigned are based on major and ancillary image features, which have been developed by the American College of Radiology (ACR), revised several times (now v2018), and validated in many studies. The value of ancillary features to modify LI-RADS categories assigned to observations based on major features is shown. RESULTS: This review summarizes the relevant CT and MRI features and presents a step-by-step approach for readers not familiar with LI-RADS on how to use the system. Relevant imaging features and the value of different modalities (contrast-enhanced CT, MRI with extracellular gadolinium chelates or liver-specific contrast agents) is explained. CONCLUSION: The widespread adoption of LI-RADS for CT/MRI reporting in high-risk patients would help to reduce inter-reader variability. It could improve communication between radiologists, oncologists, hepatologists, pathologists, and liver surgeons, and lead to better patient management. KEY POINTS: · LI-RADS has been developed and revised to address the need for improved diagnosis and standardized categorization of findings in chronic liver disease.. · CT/MRI LI-RADS consists of major criteria and ancillary features to classify observations.. · LI-RADS terminology helps to clarify the communication of liver observations between radiologists and referring physicians.. CITATION FORMAT: · Schima W, Kopf H, Eisenhuber E. LI-RADS made Easy. Fortschr Röntgenstr 2023; 195: 486 - 494.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico por imagen , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Medios de Contraste , Sensibilidad y Especificidad
3.
Insights Imaging ; 10(1): 86, 2019 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-31463643

RESUMEN

Central venous port devices are indicated for patients, who need long-term intravenous therapy. Oncologic patients may require intermittent administration of chemotherapy, parenteral nutrition, infusions, or blood transfusions. A venous port system is composed of a port chamber attached to a central catheter, which is implanted into the central venous system. The subcutaneous location of the catheter chamber improves the patients' quality of life and the infection rate is lower than in non-totally implantable central venous devices. However, proper implantation, use, and care of a port system are important to prevent short- and long-term complications. Most common early complications (< 30 days) include venous malpositioning of catheter and perforation with arterial injury, pneumothorax, hemothorax, thoracic duct injury, or even cardiac tamponade. Delayed complications include infection, catheter thrombosis, vessel thrombosis and stenosis, catheter fracture with extravasation, or fracture with migration or embolization of catheter material. Radiologic imaging has become highly relevant in intra-procedural assessment and postoperative follow-up, for detection of possible complications and to plan intervention, e.g., in case of catheter migration. This pictorial review presents the normal imaging appearance of central venous port systems and demonstrates imaging features of short- and long-term complications.

4.
Wien Klin Wochenschr ; 125(11-12): 339-45, 2013 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-23674050

RESUMEN

The National Lung Screening Trial (NLST) could demonstrate, for the first time, in a prospective randomized trial, that low-dose CT screening (LD-CT) may decrease lung cancer mortality. At the moment, it is unclear how these results will be applicable to Austria. Specifically, the definition of the population at an increased risk for lung cancer and management of the high rate of false-positive results are problematic. As a consequence, lung cancer screening in Austria is recommended following the guidelines of the Austrian Society of Radiology and the Austrian Society of Pneumology. The recommendations suggest that only individuals with a significantly increased risk for lung cancer should be screened (age > 55 years, 30 pack-years, active or former smokers since < 15 years). The screened individuals must be informed about the high probability of false-positive screening results and the necessity for additional follow-up examinations or invasive examinations. The screened individuals must be informed that a CT screening may not prevent them from developing an inoperable lung cancer. In addition, CT screening examinations should be performed with a low-dose CT technique for at least three years at yearly intervals. In view of the high probability of false-positive findings, the evaluation of detected pulmonary nodules should be performed according to an already established standardized protocol.


Asunto(s)
Detección Precoz del Cáncer/normas , Neoplasias Pulmonares/diagnóstico por imagen , Guías de Práctica Clínica como Asunto , Neumología/normas , Protección Radiológica/normas , Radiología/normas , Tomografía Computarizada por Rayos X/normas , Austria , Humanos
5.
Eur Radiol ; 23(6): 1553-63, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23239063

RESUMEN

PURPOSE: The aim of this study was to survey the current CT protocols used by members of the European Society of Thoracic Imaging (ESTI) to evaluate patients with interstitial lung diseases (ILD). METHODS: A questionnaire was e-mailed to 173 ESTI members. The survey focussed on CT acquisition and reconstruction techniques. In particular, questions referred to the use of discontinuous HRCT or volume CT protocols, the acquisition of additional acquisitions in expiration or in the prone position, and methods of radiation dose reduction and on reconstruction algorithms. RESULTS: The overall response rate was 37 %. Eighty-five percent of the respondents used either volume CT alone or in combination with discontinuous HRCT. Forty-five percent of the respondents adapt their CT protocols to the patient's weight and/or age. Expiratory CT or CT in the prone position was performed by 58 % and 59 % of the respondents, respectively. The number of reconstructed series ranged from two to eight. CONCLUSION: Our survey showed that radiologists with a special interest and experience in chest radiology use a variety of CT protocols for the evaluation of ILD. There is a clear preference for volumetric scans and a strong tendency to use the 3D information. KEY POINTS: • Experienced thoracic radiologists use various CT protocols for evaluating interstitial lung diseases. • Most workers prefer volumetric CT acquisitions, making use of the 3D information • More attention to reducing the radiation dose appears to be needed.


Asunto(s)
Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Radiografía Torácica/métodos , Tomografía Computarizada por Rayos X/métodos , Algoritmos , Europa (Continente) , Humanos , Internacionalidad , Enfermedades Pulmonares Intersticiales/patología , Pautas de la Práctica en Medicina , Dosis de Radiación , Interpretación de Imagen Radiográfica Asistida por Computador , Radiología/métodos , Radiología/normas , Sociedades Médicas , Encuestas y Cuestionarios
6.
Respir Care ; 57(3): 427-43, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22391269

RESUMEN

The bedside chest x-ray (CXR) is an indispensible diagnostic tool for monitoring seriously ill patients in the intensive care unit. The CXR often reveals abnormalities that may not be detected clinically. In addition, bedside CXRs are an irreplaceable tool with which to detect the malposition of tubes and lines and to identify associated complications. Although the image quality is often limited, bedside CXRs still provide valuable diagnostic information. The interpretation of the bedside CXRs is often challenging, and requires extensive radiologic experience to avoid misinterpretation of the wide spectrum of pleural and pulmonary disease. The clinical information is of substantial value for the interpretation of the frequently nonspecific findings.


Asunto(s)
Sistemas de Atención de Punto , Radiografía Torácica/métodos , Enfermedades Respiratorias/diagnóstico por imagen , Cateterismo Venoso Central , Tubos Torácicos , Cuidados Críticos , Humanos , Contrapulsador Intraaórtico , Intubación Intratraqueal , Pulmón/diagnóstico por imagen , Neumonía/diagnóstico por imagen , Neumotórax/diagnóstico por imagen , Atelectasia Pulmonar/diagnóstico , Atelectasia Pulmonar/diagnóstico por imagen , Edema Pulmonar/diagnóstico por imagen , Radiografía Torácica/instrumentación , Síndrome de Dificultad Respiratoria/diagnóstico por imagen
7.
Eur J Radiol ; 81(5): 1029-33, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21752567

RESUMEN

BACKGROUND: The aim of this retrospective study was to compare the diagnostic accuracy, the frequency of complications, the duration of the interventions and the radiation doses of CT fluoroscopy (CTF) guided biopsies of lung lesions with those of multislice CT (MS-CT) biopsy mode-guided biopsies. METHODS: Data and images from 124 consecutive patients undergoing CTF-guided lung biopsy (group A) and 132 MS-CT-biopsy mode-guided lung biopsy (group B) were reviewed. CTF-guided biopsies were performed on a Siemens Emotion 6 CT scanner with intermittent or continuous CT-fluoroscopy, MS-CT biopsy mode-guided biopsies were performed on a Siemens Emotion 16 CT scanner. All biopsies were performed with a coaxial needle technique. RESULTS: The two groups (A vs. B) did not differ significantly regarding sensitivity (95.5% vs. 95.9%), specificity (96.7% vs. 95.5%), negative predictive value (87.9% vs. 84%) or positive predictive value (98.8% vs. 98.9%). Pneumothorax was observed in 30.0% and 32.5% of the patients, respectively. Chest tube placement was necessary in 4% (group A) and 13% (group B) of the patients. The duration of the intervention was significantly longer in group A (median 37 min vs. 32 min, p=0.04). The mean CT dose index (CTDI) was 422 in group A and 36.3 in group B (p<0.001). CONCLUSION: Compared to CTF-guided biopsies, chest biopsies using the MS-CT biopsy mode show dramatically lower CTDI levels. Although the diagnostic yield of the procedures do not differ significantly, biopsies using the MS-CT-biopsy mode have a three-fold higher rate of chest tube placement.


Asunto(s)
Biopsia/estadística & datos numéricos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiología , Dosis de Radiación , Radiografía Intervencional/estadística & datos numéricos , Cirugía Asistida por Computador/estadística & datos numéricos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Austria/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Prevalencia , Radiometría , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
8.
Eur J Radiol ; 77(1): 164-6, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19709835

RESUMEN

PURPOSE: Small subpleural pulmonary lesions are difficult to biopsy. While the direct, short needle path has been reported to have a lower rate of pneumothorax, the indirect path provides a higher diagnostic yield. Therefore, we tried to optimize the needle pathway and minimize the iatrogenic pneumothorax risk by evaluating a CT fluoroscopy guided direct approach to biopsy subpleural lesions. MATERIAL AND METHODS: Between 01/2005 and 01/2007, CT fluoroscopy guided core biopsies were performed in 24 patients. Using our technique, the tip of the guide needle remains outside the visceral pleura (17 G coaxial guide needle, 18 G Biopsy-gun, 15 or 22 mm needle path). The position of the lesion relative to the needle tip can be optimized using CT fluoroscopy by adjusting the breathing position of the patient. The Biopty gun is fired with the needle tip still outside the pleural space. Cytological smears are analyzed by a cytopathologist on-site, and biopsies are repeated as indicated with the coaxial needle still outside the pleura. RESULTS: Median nodule size was 1.6 cm (0.7-2.3 cm). A definitive diagnosis was obtained in 22 patients by histology and/or cytology. In one patient, only necrotic material could be obtained. In another patient, the intervention had to be aborted as the dyspnoic patient could not follow breathing instructions. An asymptomatic pneumothorax was present in seven patients; chest tube placement was not required. CONCLUSION: The presented biopsy approach has a high diagnostic yield and is especially advantageous for biopsies of small subpleural lesions in the lower lobes.


Asunto(s)
Biopsia con Aguja/métodos , Nódulos Pulmonares Múltiples/diagnóstico por imagen , Nódulos Pulmonares Múltiples/patología , Pleura/diagnóstico por imagen , Cirugía Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Anciano , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
Int J Biomed Imaging ; 2007: 23624, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17710253

RESUMEN

PURPOSE: beyond the pure morphological visual representation, MR imaging offers the possibility to quantify parameters in the healthy, as well as, in pathologic lung parenchyma. Gas exchange is the primary function of the lung and the transport of oxygen plays a key role in pulmonary physiology and pathophysiology. The purpose of this review is to present a short overview of the relaxation mechanisms of the lung and the current technical concepts of T1 mapping and methods of oxygen enhanced MR imaging. MATERIAL AND METHODS: molecular oxygen has weak paramagnetic properties so that an increase in oxygen concentration results in shortening of the T1 relaxation time and thus to an increase of the signal intensity in T1 weighted images. A possible way to gain deeper insights into the relaxation mechanisms of the lung is the calculation of parameter Maps. T1 Maps based on a snapshot FLASH sequence obtained during the inhalation of various oxygen concentrations provide data for the creation of the so-called oxygen transfer function (OTF), assigning a measurement for local oxygen transfer. T1 weighted single shot TSE sequences also permit expression of the signal changing effects associated with the inhalation of pure oxygen. RESULTS: the average of the mean T1 values over the entire lung in inspiration amounts to 1199 +/- 117 milliseconds, the average of the mean T1 values in expiration was 1333 +/- 167 milliseconds. T1 Maps of patients with emphysema and lung fibrosis show fundamentally different behavior patterns. Oxygen enhanced MRT is able to demonstrate reduced diffusion capacity and diminished oxygen transport in patients with emphysema and cystic fibrosis. DISCUSSION: results published in literature indicate that T1 mapping and oxygen enhanced MR imaging are promising new methods in functional imaging of the lung and when evaluated in conjunction with the pure morphological images can provide additional valuable information.

10.
Eur Radiol ; 17(5): 1242-55, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17149625

RESUMEN

A wide variety of artifacts can be seen in clinical MR imaging. This review describes the most important and most prevalent of them, including magnetic susceptibility artifacts and motion artifacts, aliasing, chemical-shift, zipper, zebra, central point, and truncation artifacts. Although the elimination of some artifacts may require a service engineer, the radiologist and MR technologist have the responsibility to recognize MR imaging problems. This review shows the typical MR appearance of the described artifacts, explains their physical basis, and shows the way to solve them in daily practice.


Asunto(s)
Artefactos , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Medios de Contraste , Diagnóstico Diferencial , Errores Diagnósticos , Humanos
11.
Invest Radiol ; 40(5): 249-56, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15829821

RESUMEN

PURPOSE: We sought to evaluate the performance of dual-readout and single-readout computed radiography compared with direct radiography for detecting subtle lung abnormalities with a standard and a low-dose technique. MATERIALS AND METHODS: Posteroanterior radiographs of an anthropomorphic chest phantom were obtained with a single-readout storage phosphor radiography system (CRS, pixel size 200 microm), a dual-readout storage phosphor radiography system (CRD, pixel size 100 microm), and a direct detector (DR, pixel size 143 microm) at dose levels of 400 and 800 speed. Ten templates were superimposed to project 4 types of lesions over low- and high-attenuation areas, simulating nodules, micronodules, lines, and patchy opacities. Six radiologists evaluated 60 hard-copy images for the presence or absence of lesions. Statistical significance of differences was evaluated using receiver operating characteristic analysis and analysis of variance. RESULTS: For both low- and high-attenuation areas, CRD (Az = 0.85 and 0.66) was superior to CRS (Az = 0.75 and 0.58) for overall performance and all lesion subtypes (P < 0.05). DR (Az = 0.87 and 0.67) performed slightly better than CRD, being significant only for the detection of micronodules. Acquisition dose significantly affected only the detection of lines and micronodules, whereas the detection of nodules and patchy opacities was not significantly different with reduced exposure, regardless of the system used. CONCLUSION: The dual-readout CR system significantly outperformed the single-readout CR and almost equaled the performance of DR. Dose reduction was more critical for small-sized lesions (micronodules, lines) than for nodular or patchy opacifications and affected mainly the lesions in high attenuation areas.


Asunto(s)
Enfermedades Pulmonares/diagnóstico por imagen , Dosis de Radiación , Intensificación de Imagen Radiográfica/métodos , Tomografía Computarizada por Rayos X/métodos , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Variaciones Dependientes del Observador , Fantasmas de Imagen , Curva ROC , Intensificación de Imagen Radiográfica/instrumentación , Tomografía Computarizada por Rayos X/instrumentación , Pantallas Intensificadoras de Rayos X
12.
Eur J Radiol ; 53(1): 120-4, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15607862

RESUMEN

AIM: The aim of our study was to assess the availability of videofluoroscopy to examine patients with swallowing disorders in Austria. MATERIALS AND METHODS: A questionnaire was sent to the department heads of the radiology departments of all hospitals (n=143) and to all non-hospital-based radiologic practices (n=226) throughout Austria. The survey focused on the availability of videofluoroscopic swallowing studies and on the studies performed in patients with deglutition disorders. RESULTS: The questionnaire was completed and returned by 134 of 143 radiology departments (94%) and 65 of 226 non-hospital-based radiologists (29%). Videofluoroscopic swallowing studies were performed in 38 of 134 radiology departments (28%) and in 21 of 65 practices (32%). The method is available in all nine Austrian states (100%) and 27 of 99 districts (27%). The number of examinations performed in different states ranged from 0.7 to 19 studies/10,000 population per year. The number of videofluoroscopic examinations per department or practice in the year 2001 ranged between 5 and 690 (median, 100 examinations). To 85% of videofluoroscopy units patients were referred from otorhinolaryngology/phoniatrics-logopedics, to 69% of videofluoroscopy units referrals were also from internal medicine, from neurology in 54%, and from pediatrics in 20%. CONCLUSION: Despite the widespread availability of videofluoroscopy throughout Austria, its use still varies largely between different states. The data show that in general there is a wide-spread demand for videofluoroscopic swallowing studies.


Asunto(s)
Cinerradiografía/estadística & datos numéricos , Trastornos de Deglución/diagnóstico por imagen , Fluoroscopía/estadística & datos numéricos , Austria , Humanos , Medicina Interna/estadística & datos numéricos , Neurología/estadística & datos numéricos , Otolaringología/estadística & datos numéricos , Pediatría/estadística & datos numéricos , Radiología/estadística & datos numéricos , Servicio de Radiología en Hospital/estadística & datos numéricos , Derivación y Consulta/estadística & datos numéricos , Logopedia/estadística & datos numéricos
13.
AJNR Am J Neuroradiol ; 25(8): 1310-7, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15466324

RESUMEN

BACKGROUND AND PURPOSE: Surgically or conservatively treated brain abscesses may resolve, or pus may re-accumulate, requiring further intervention or treatment change. We hypothesized that diffusion-weighted (DW) imaging is useful in depicting features of abscesses related to therapeutic success or failure. METHODS: Conventional contrast-enhanced T1- and T2-weighted imaging and DW imaging were performed in seven patients (aged 30-69 years) with proved pyogenic brain abscesses. The center of the abscess was qualitatively and quantitatively analyzed at initial and follow-up imaging in all patients. We correlated the signal intensity on trace DW images and the apparent diffusion coefficients (ADCs) with the clinical and laboratory data, particularly with respect to treatment failure and repeat therapy. RESULTS: Surgical drainage was performed in six patients; one patient was treated with only antibiotics. All abscess cavities initially had high signal intensity (restricted diffusion) on DW images, with a mean ADC value of 0.52 x 10 (-3)mm (2)/s. Low signal intensity at DW imaging with high ADC were seen on follow-up images in the patient receiving medication and in four patients in whom the abscesses were drained; this correlated with a good therapeutic response. Two patients underwent drainage; their second follow-up DW images showed areas of high signal intensity and low ADC values suggesting re-accumulation of pus. Increased C-reactive protein level and WBC count correlated well with DW image findings. CONCLUSION: DW imaging was superior to conventional MR imaging in evaluating the success or failure of abscess therapy. Restricted diffusion in a drained abscess corresponded to pus.


Asunto(s)
Absceso Encefálico/diagnóstico , Absceso Encefálico/terapia , Imagen de Difusión por Resonancia Magnética , Adulto , Anciano , Antibacterianos/uso terapéutico , Absceso Encefálico/metabolismo , Absceso Encefálico/patología , Proteína C-Reactiva/metabolismo , Imagen de Difusión por Resonancia Magnética/normas , Drenaje , Femenino , Estudios de Seguimiento , Humanos , Recuento de Leucocitos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia
14.
AJR Am J Roentgenol ; 182(3): 671-5, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14975968

RESUMEN

OBJECTIVE: Many studies have suggested that Hounsfield measurements on unenhanced CT can reliably differentiate adrenal adenomas from nonadenomas using a scanner-independent threshold level. The purpose of this study was to determine whether establishment of a scanner-independent threshold for differentiation of adenomas from nonadenomas is technically feasible. MATERIALS AND METHODS: Surgically resected adrenal tumor specimens (total, seven; adenomas, three; nonadenomas, four; size range, 17-76 mm), were placed in an anthropomorphic phantom. Lesion specimens were scanned with one MDCT and two single-detector scanners. Scanning protocols for all three scanners included variations in kilovoltage (140, 120, and 80 [Somatom Plus 4, Somatom VolumeZoom] or 100 [Tomoscan AV] kVp) and slice thickness. Hounsfield measurements were performed on exactly matched slices using regions of interest of a constant size. RESULTS: The difference in lesion Hounsfield measurements among scanning protocols with 140, 120, and 100/80 kVp was up to 6.2 H for the adenoma group and up to 3.8 H for the nonadenoma group. The comparison of the Tomoscan AV and the Somatom Plus 4 scanners showed a mean difference of 2.6 H at 120 kVp and of 4.6 H at 140 kVp. The differences between the Tomoscan AV and Somatom VolumeZoom scanners were 1.7 and 3.6 H for 120 and 140 kVp, respectively. Between the two Somatom scanners, the divergence was 2.9 and 3.3 H for the two kilovoltage settings. Differentiation between adenomas and nonadenomas was better at lower kilovoltage. Slice thickness did not affect the CT density measurements significantly. CONCLUSION: Significant differences in CT density measurements of adrenal tumors may occur when different CT scanners or imaging protocols are used. The dependence of measurements on scanner type and scanning technique makes the recommendation of a universal, scanner- and protocol-independent threshold problematic.


Asunto(s)
Adenoma/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adenoma/patología , Neoplasias de las Glándulas Suprarrenales/patología , Femenino , Humanos , Técnicas In Vitro , Masculino , Fantasmas de Imagen , Reproducibilidad de los Resultados
15.
AJR Am J Roentgenol ; 181(5): 1415-21, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14573447

RESUMEN

OBJECTIVE: The aim of this study was to evaluate how ambient light and interactive adjustment of density and contrast affect the detection of catheter fragments when interpreting bedside chest radiographs on soft-copy displays. MATERIALS AND METHODS: A total of 131 catheter fragments were superimposed over 10 bedside chest radiographs obtained with storage phosphor technology. Images were displayed on a clinical intensive care unit viewing station (color cathode-ray tube monitor, 21 inch [53 cm], 1280 x 1024 matrix) and were independently evaluated by five radiologists. The number of catheter fragments per image varied between 12 and 14, with an approximately equal distribution in high- and low-absorption areas. Detectability of catheter fragments was assessed under subdued and bright ambient light conditions with and without interactive adjustment of window width and level. RESULTS: Under subdued light, the detection rate of catheter fragments was significantly higher than under bright light (51.8% vs 56.6%, p < 0.05). Interactive window setting adjustment significantly increased the detection rate from 52.5% to 60.8% (p < 0.05) under subdued light and from 47.9% to 55.6% (p < 0.05) under bright light. With adjustment of window settings, the difference between the detection rates under subdued light (60.8%) and under bright light (55.6%) did not reach statistical significance. CONCLUSION: Detection of catheters on soft-copy display is significantly decreased by bright ambient light, an effect that can be largely compensated for by means of interactive adjustment of window settings.


Asunto(s)
Cateterismo , Luz , Sistemas de Atención de Punto , Intensificación de Imagen Radiográfica , Radiografía Torácica/normas , Análisis de Varianza , Humanos , Radiografía Torácica/métodos
16.
Eur J Radiol ; 48(1): 61-70, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14511861

RESUMEN

In patients after chest trauma, imaging plays a key role for both, the primary diagnostic work-up, and the secondary assessment of potential treatment. Despite its well-known limitations, the anteroposterior chest radiograph remains the starting point of the imaging work-up. Adjunctive imaging with computed tomography, that recently is increasingly often performed on multidetector computed tomography units, adds essential information not readily available on the conventional radiograph. This allows better definition of trauma-associated thoracic injuries not only in acute traumatic aortic injury, but also in pulmonary, tracheobronchial, cardiac, diaphragmal, and thoracic skeletal injuries. This article reviews common radiographic findings in patients after chest trauma, shows typical imaging features resulting from thoracic injury, presents imaging algorithms, and recalls to the reader less common but clinically relevant entities encountered in patients after thoracic trauma.


Asunto(s)
Algoritmos , Traumatismos Torácicos/diagnóstico por imagen , Humanos , Tomografía Computarizada por Rayos X
17.
J Thorac Imaging ; 18(3): 124-37, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12867810

RESUMEN

Substantial advances in detector technology characterize digital chest radiography. This article compares the various systems from a radiologist's point of view. Computed radiography (CR) is a well-established system that is robust, has good reproducibility, and is relatively inexpensive. Image quality has been continuously improved in recent years while the physical size of the readout units has been reduced and the throughput increased. CR is the only digital system that can be used for bedside chest radiographs. Improved detector properties and dual reading have made it a dose-efficient system. Although now widely available, a 4K image matrix does not appear to offer a general diagnostic improvement for imaging the chest. New developments with respect to detector composition and readout process can be expected in the future. Direct radiography (DR) is the common name for different technologies that are characterized by a direct readout matrix that covers the whole exposure area. Conversion of x-ray intensity into electric signals can either be direct (selenium-based systems) or indirect (scintillator/photodiode systems). Advantages of DR systems are a high image quality and the potential for dose reduction. The role of selenium radiography (Thoravision) has decreased after the advent of DR systems although this dedicated chest unit offers high image quality at 400 speed acquisition dose. Especially in a PACS environment, CR and DR systems will increasingly substitute for conventional radiography with advantages for CR for bedside chest radiographs and for DR for high-end chest stands.


Asunto(s)
Intensificación de Imagen Radiográfica/métodos , Radiografía Torácica/métodos , Humanos , Dosis de Radiación , Intensificación de Imagen Radiográfica/instrumentación , Radiografía Torácica/instrumentación
18.
Radiology ; 227(1): 216-21, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12668747

RESUMEN

PURPOSE: To evaluate the performance of the most recent generation of storage phosphor plates for the detection of low-contrast catheter material on bedside chest radiographs. MATERIALS AND METHODS: In 10 patients in the intensive care unit, bedside chest radiographs were obtained with a 400-speed conventional screen-film system and with storage phosphor plates with exposure levels comparable to a 200-, 400-, or 800-speed conventional system. The chest radiograph was divided into 20 regions, 60% of which were superimposed with low-contrast catheter fragments. Six observers independently assessed the presence of catheter fragments by using a receiver operating characteristic (ROC) methodology. RESULTS: Detection performance (mean area under the ROC curve [Az]) with the storage phosphor plates was significantly superior to that with the screen-film system (Az = 0.76) at all three dose levels (Az = 0.88, 0.87, and 0.83 for 200-, 400-, and 800-speed doses, respectively; P <.05). Increasing the dose to a 200-speed system did not significantly increase detection performance compared with that with the 400-speed digital radiographs (Az = 0.88 vs 0.87). Dose reduction to 800 speed significantly deteriorated the detection performance (Az = 0.83) compared with that with the 400- and 200-speed digital radiographs, respectively. CONCLUSION: The most recent generation of storage phosphor plates is superior to a 400-speed screen-film system for the detection of catheter material, even at an exposure level of 800 speed.


Asunto(s)
Sistemas de Atención de Punto , Intensificación de Imagen Radiográfica , Radiografía Torácica/normas , Sistemas de Información Radiológica , Pantallas Intensificadoras de Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Relación Dosis-Respuesta en la Radiación , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía Torácica/métodos
19.
Eur Radiol ; 12(5): 1139-44, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11976859

RESUMEN

The aim of this study was to assess the role of videofluoroscopy in the detection of structural abnormalities of the pharynx and esophagus in patients with different symptoms of impaired deglutition. Dynamic radiographic recording of deglutition was performed in 3193 consecutive patients (1578 men, 1615 women; mean age 54 years) suffering from dysphagia, suspicion of aspiration, globus sensation, and non-cardiac chest pain. We assessed different structural lesions from the oral cavity to the esophagus and classified them into eight categories. Their frequency and association with the different clinical symptoms were evaluated. Videofluoroscopy revealed 1040 structural abnormalities in 833 patients (26%) including mass lesions from the oral cavity to hyoid/larynx ( n=66), pharyngeal diverticula ( n=181), pharyngeal masses ( n=78), other pharyngeal narrowings ( n=71), webs ( n=98), masses ( n=39), and other narrowings ( n=73) of the upper esophageal sphincter, esophageal diverticula ( n=80), esophageal webs, rings and strictures ( n=194), and intrinsic and extrinsic esophageal lesions ( n=160). There was a considerable variance of findings for different symptoms. In a large proportion of symptomatic patients videofluoroscopy detects morphological abnormalities along pharynx and esophagus often combined with functional disorders. This fact underlines the role of videofluoroscopy as a diagnostic test for function as well as morphology.


Asunto(s)
Trastornos de Deglución/diagnóstico por imagen , Trastornos de Deglución/fisiopatología , Deglución/fisiología , Esófago/diagnóstico por imagen , Faringe/diagnóstico por imagen , Grabación en Video , Enfermedades del Esófago/diagnóstico por imagen , Esófago/fisiopatología , Femenino , Fluoroscopía , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Faríngeas/diagnóstico por imagen , Faringe/fisiopatología
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