Optimización de los protocolos y del uso de contrastes en tomografía computarizada de los equipos de tomografía por emisión de positrones

The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients.     

Ablación mediante microondas de metástasis pulmonar de sarcoma en paciente portador de marcapasos

We present the case of a patient with a pacemaker and a sarcoma lung metastasis treated with microwave ablation. Although the treatment of tumours with microwave ablation is a successful and minimally invasive approach, there are concerns about the safety of this procedure for patients with implanted cardiac devices, such as a pacemaker. After careful planning between radiology and cardiology, microwave ablation was indicated in the patient since it is safer and shorter than the radiofrequency technique. The lesion was treated without complications. It is important to communicate the procedures performed, as well as any complications in order to formulate guidelines for the use of microwave ablation in patients with pacemakers.     

Energía dual y angioTC de carótidas: calidad,eliminación de hueso y dosis de radiación de 80/140 kV frente a 100/140 kV

Objective

To study the differences in vascular image quality, bone subtraction, and dose of radiation of dual energy CT angiography of the supraaortic trunks using different tube voltages.

Material and methods

We reviewed the CT angiograms of the supraaortic trunks in 46 patients acquired with a 128-slice dual source CT scanner using two voltage protocols (80/140 kV and 100/140 kV). The “head bone removal” tool was used for postprocessing. We divided the arteries into 15 segments. In each segment, we evaluated the image quality of the vessels and the effectiveness of bone removal in multiplanar reconstructions (MPR) and in maximum intensity projections (MIP) with each protocol, analyzing the trabecular and cortical bones separately. We also evaluated the dose of radiation received.

Results

Of the 46 patients, 13 were studied using 80/140 kV and 33 with 100/140 kV. There were no significant differences between the two groups in age or sex. Image quality in four segments was better in the group examined with 100/140 kV. Cortical bone removal in MPR and MIP and trabecular bone removal in MIP were also better in the group examined with 100/140 kV. The dose of radiation received was significantly higher in the group examined with 100/140 kV (1.16 mSv with 80/140 kV vs. 1.59 mSv with 100/140 kV).

Conclusion

Using 100/140 kV increases the dose of radiation but improves the quality of the study of arterial segments and bone subtraction.     

Los patrones de vascularización pulmonar en la radiografía simple de tórax

Plain chest films are a fundamental tool in the practice of medicine. The apparent simplicity of plain chest films sometimes leads us to forget that interpreting them correctly can provide very valuable information, especially if the interpretation is grounded in key clinical information.     

Clasificación y características del cáncer de intervalo en el programa de detección precoz de cáncer de mama en el Principado de Asturias

Objective

To review and classify the interval cancers found in the Principality of Asturias's Breast Cancer Screening Program (PDPCM). A secondary objective was to determine the histological characteristics, size, and stage of the interval cancers at the time of diagnosis.

Material and methods

We included the interval cancers in the PDPCM in the period 2003-2007. Interval cancers were classified according to the breast cancer screening program protocol, with double reading without consensus, without blinding, with arbitration. Mammograms were interpreted by 10 radiologists in the PDPCM.

Results

A total of 33.7% of the interval cancers could not be classified; of the interval cancers that could be classified, 40.67% were labeled true interval cancers, 31.4% were labeled false negatives on screening, 23.7% had minimal signs, and 4.23% were considered occult. A total of 70% of the interval cancers were diagnosed in the year of the period between screening examinations and 71.7% were diagnosed after subsequent screening. A total of 76.9% were invasive ductal carcinomas, 61.1% were stage II when detected, and 78.7% were larger than 10 mm when detected.

Conclusions

The rate of interval cancers and the rate of false negatives in the PDPCM are higher than those recommended in the European guidelines. Interval cancers are diagnosed later than the tumors detected at screening. Studying interval cancers provides significant training for the radiologists in the PDPCM.     

Secuencia de disparo único eco de gradiente en fase y fase opuesta con preparación de la magnetización: descripción y optimización de la técnica con equipo de 1,5 T

Purpose

To implement in-phase and out-of-phase (IP/OP) techniques with Magnetization-Prepared Gradient Recalled Echo (MP-GRE) and to evaluate the feasibility and diagnostic image quality among pre and post-optimized MP-GRE sequences, including patients unable to cooperate with breath-hold requirements.

Materials and methods

Institutional review board approval with waiver of informed consent was obtained for this HIPAA-compliant retrospective study. Two groups of patients were included in the study, before and after optimization of MP-GRE parameters, with seventy-three (24 noncooperative/49 cooperative) and sixty-four (22 noncooperative/42 cooperative) consecutive patients, respectively. The motion-insensitive sequence used in this study was a single-shot 2D MP-GRE. Two radiologists qualitatively evaluated the sequences to identify the presence of phase cancellation artifact in OP images and to determine image quality, extent of artifacts (respiratory ghosting, bounce-point artifact, spatial misregistration and pixel graininess) and lesion conspicuity on the various sequences. The ability to visually detect liver steatosis and fatty adrenal adenomas was evaluated. Qualitative analyses were compared using the Wilcoxon and Mann-Whitney tests.

Results

There were statistically significant differences between all MP-GRE sequences concerning phase cancellation artifact (P<.0001) which was present in MP-GRE OP sequences and negligible to absent in the pre (IP₁) and post-optimized (IP₂) MP-GRE IP sequences, respectively, in all patients.Bounce point artifacts were significantly more pronounced in MP-GRE IP₁ (P<.0001). Spatial misregistration was slightly more prominent in noncooperative patients with MP-GRE IP₂ (P=.0027). MP-GRE OP and MP-GRE IP₂ showed significantly higher overall image quality (P<.0001).MP-GRE sequences subjectively identified hepatic steatosis (n=20) and adrenal adenomas (n=5) based on signal loss from IP to OP sequence.

Conclusion

Single shot IP/OP MP-GRE is feasible and allows motion resistant imaging with adequate diagnostic image quality. This technique is able to provide IP and OP information in patients unable to suspend respiration.     

Coronariografía mediante tomografía computarizada con sincronización prospectiva. Comparación de la calidad de imagen y dosis de radiación con equipos de 128 detectores de fuente única y doble fuente

Objective

To compare the image quality and radiation dose in a group of patients undergoing coronary CT angiography using a 128-slice dual source helical CT scanner with high pitch alto and prospective acquisition with those in a group of patients with similar clinical characteristics undergoing coronary CT angiography using a 128-slice single-source CT scanner with prospective sequential acquisition.

Material and methods

We included 80 patients with heart rates ≤65 beats/min: 40 underwent sequential 128-slice single source CT with prospective synchronization and the other 40 underwent 128-slice dual source helical CT with high pitch and prospective synchronization. Two radiologists independently assessed the quality of the images of the coronary arteries on the 80 coronary CT angiograms: image quality was classified on a four-point scale in which 1 represented excellent and 4 deficient. The effective dose of radiation was also calculated.

Results

The clinical characteristics of the patients in the two groups were similar. The image quality obtained with dual source CT was significantly better than that obtained with single source CT (P=0.006). The mean effective dose of radiation in the group undergoing dual source CT was 36% lower than in the group undergoing single source CT (1.4±0.6 mSv vs. 2.2±0.9 mSv; P<0.01).

Conclusion

Although both sequential 128-slice single source CT with prospective acquisition and 128-slice dual source helical CT with high pitch and prospective acquisition provide good image quality and low effective doses of radiation, 128-slice dual source helical CT with prospective acquisition provides better image quality and results in a lower effective dose of radiation.     

Seudoaneurisma de la cola pancreática: tratamiento percutáneo mediante inyección de trombina

Visceral artery pseudoaneurysms secondary to acute and/or chronic pancreatitis are a relatively common and potentially serious complication. Endovascular techniques are the most currently accepted techniques, given the higher morbidity-mortality of surgery. The thrombosis of the pseudoaneurysm using an ultrasound-guided percutaneous thrombin injection is emerging as a useful option in those cases in which endovascular embolisation is not possible. We present the case of a patient with a pseudoaneurysm of the transverse pancreatic artery secondary to chronic pancreatitis, and successfully treated by administering percutaneous thrombin.     

Revisión de aneurisma de aorta abdominal: hallazgos en la tomografía computarizada multidetector pre y postratamiento

The increase in the frequency of abdominal aortic aneurysms (AAA) and the widely accepted use of endovascular aneurysm repair (EVAR) as a first-line treatment or as an alternative to conventional surgery make it necessary for radiologists to have thorough knowledge of the pre- and post-treatment findings. The high image quality provided by multidetector computed tomography (MDCT) enables CT angiography to play a fundamental role in the study of AAA and in planning treatment.     

CT对比剂血管外渗发生机制的讨论及防治措施

对比剂外渗是进行CT增强扫描的重要不良反应之一.由于CT增强扫描越来越广泛的应用于临床,外渗的发生率也有上升趋势.对比剂外渗常常导致组织坏死而影响肢体的形态及功能,大量的对比剂外渗甚至会引发骨筋膜室综合症,造成肢体的不可逆损伤.本文将通过分析对比剂外渗的发生机制及发生影响因素来探讨其防治措施,进一步引起临床对于对比剂外渗的重视及降低其发生率.     

Trastorno de Tourette y de la lectura en un niño con disrupción del tracto parietofrontal izquierdo

We present the case of a nine-year-old boy with Tourette syndrome and reading disorder with a history of a severe infectious process in the late neonatal period. Brain MRI showed a left parietal malacotic cavity and diffusion tensor imaging and tractography showed a striking disruption of the white matter bundle that joins the left parietal region with the ipsilateral frontal region with involvement of the left superior longitudinal fasciculus and of the left arcuate fasciculus. Although Tourette syndrome and reading disorder are fundamentally hereditary neuropsychiatric disorders, they can also occur secondary to cerebral alterations like those existing in this boy. The introduction of modern neuroimaging techniques in patients with neuropsychiatric disorders (or the risk of developing them) can be very useful in the diagnosis and prognosis in the future.     

Los elementos decorativos ambientales en el Área de Imagen Médica mejoran la percepción de agradabilidad del paciente

Objectives

To evaluate the sensation of pleasantness perceived by patients attended in the radiology department in response to decorative elements hung on the walls in the waiting rooms and in the hallways of the imaging area.

Material and methods

The material resources comprised works of art in the form of “magic windows” representing scenes from nature installed on the ceilings and walls of the waiting area and hallways of the imaging area. Patients were given a brief questionnaire with general data and questions (sadness-cheerfulness, coldness-warmth, darkness-light, and pessimism-optimism) about their perception of the decorative elements.

Results

Of the 150 questionnaires collected, 142 were filled out correctly. The overall health of these patients was good in 84 (56%), not bad in 58 (39%), and poor in 8 (5%). The idea seemed very good to 70 patients (47%), good to 58 (39%), not bad to 8 (5%), indifferent to 11 (7%), bad to 1 (1%), and very bad to 2 (1%). As far a patients’ mobility, 119 patients (79%) walked into the department, 18 (12%) were wheeled in on beds, and 13 (9%) needed wheelchairs.

Conclusions

We found a high level of satisfaction with the decorative elements.     

Cribado de cáncer de mama. Estado actual

The currently available scientific evidence attests that mammographic screening and quality treatment have been able to reduce mortality attributable to breast cancer. Although screening is not without risks, population-based screening has clear advantages over opportunistic detection. Following the Council of the European Union's “Recommendations on cancer screening”, all the regional Autonomous Communities in Spain have screening programs that, in general, follow the same guidelines. The “European guidelines for quality assurance in breast cancer screening and diagnosis” serve as a reference that provides an overview of all aspects of screening. To achieve the foreseen objectives for the reduction of the morbidity and mortality attributable to breast cancer, screening programs must fulfill the established quality criteria and guarantee that patients have access to the best treatment options.     

Recanalización espontánea tras la embolización de una arteria renal con un tapón vascular Amplatzer tipo 4

The Amplatzer vascular plug (AVP) is an occluding device used in vascular embolizations. Thanks to its excellent maneuverability and effectiveness, it is being used more and more often. The latest version, the AVP 4, enables access to smaller and more tortuous vessels. To date, the only cases of spontaneous recanalization published occurred with earlier versions of the AVP. We present a case of recanalization after renal artery embolization with an AVP 4.     

Enfermedad valvular cardíaca. Valoración con tomografía computarizada multidetector

Heart valve disease is a clinical problem that has been studied with classical imaging techniques like echocardiography and MRI. Technological advances in CT make it possible to obtain static and dynamic images that enable not only a morphological but also a functional analysis in many cases. Although it is currently indicated only in patients with inconclusive findings at echocardiography and MRI or those in whom these techniques are contraindicated, multidetector CT makes it possible to diagnose stenosis or regurgitation through planimetry, to evaluate and quantify valvular calcium, and to show the functional repercussions of these phenomena on the rest of the structures of the heart. Given that multidetector CT is being increasingly used in the diagnosis of ischemic heart disease, we think it is interesting for radiologists to know its potential for the study of valvular disease.     

Disección aislada y espontánea de arterias viscerales

We present the cases of two men with isolated spontaneous dissection of visceral arteries diagnosed by multidetector CT. In the first patient, dissection of the celiac trunk was associated with periarterial changes. In the second patient, dissection of the superior mesenteric artery was associated with stenosis at the root of the celiac trunk. Both patients presented with acute pain, which was more intense and longer lasting in the first patient. Aortic dissection was suspected clinically in both patients.     

El esquema de biopsia transrectal puede predecir la gradación histológica incorrecta del cáncer de próstata

Objective

To identify factors that might explain why a prostate with a Gleason score (GS) <7 in the biopsy specimen can turn out to have a GS ≥7 in the surgical specimen.

Material and methods

We compared the GS of biopsy specimens with the GS of surgical specimens in 185 patients who underwent surgery for prostate cancer. We calculated the sensitivity, specificity, and predictive values for the GS of the biopsy specimens. We used Cohen's kappa to determine the degree of concordance between a GS of <7 and ≥7 for the biopsy specimen and the surgical specimen. Age, a family history of prostate cancer, total prostate-specific antigen (tPSA), digital rectal examination, prostate structure and volume, and the number of biopsy cores (biopsy scheme) were analyzed using multivariable logistic regression.

Results

Histological study of biopsy specimens yielded high sensitivity (98%) but low specificity (49%) for GS ≤6 and low sensitivity (35, 26%) and high specificity (93, 99%) for GS=7 and GS ≥7, respectively. Cohen's kappa for the GS from the biopsy and surgical specimens was 0.43 (95% CI=30-56%). The biopsy scheme was the only predictor of discordance in the GS between the two techniques. Among the other variables included in the model, only tPSA showed a slightly significant association. Taking a scheme with less than 7 cores as a reference, we found no difference with 8 to 9 cores but we did find a difference with 10 to 11 cores and with 12 or more cores, with a prevalence ratio of 0.138 (95% CI=0.030-0.513) and 0.277 (95% CI=0.091-0.806), respectively.

Conclusion

The GS of the biopsy depends on the scheme. This factor must be taken into account when choosing a treatment option in patients with low tumor grade in biopsy specimens.     

Comparación de las técnicas de inyección ecográfica y radioscópica en artro-TC y artro-RM de cadera

ObjectiveTo evaluate the usefulness of ultrasound-guided versus fluoroscopy-guided injection in CT arthrography and MR arthrography.Material and methodsWe reviewed all CT arthrography and MR arthrography studies done at our center between October 1, 2014 and October 1, 2015. We analyzed 32 studies: 26 with fluoroscopic guidance and 6 with ultrasound guidance. We compared the two techniques on the following parameters: presence of sufficient contrast material in the joint, extravasation or injection of contrast material in the soft tissues (presence of contrast material in the psoas or other soft tissues), and intra-articular gas bubbles. We used SPSS V. 20 to compare the techniques with Pearson's chi-square tests.ResultsContrast material was observed in soft tissues in 56.3% of ultrasound-guided injections, making 6.3% of the procedures invalid for diagnostic purposes. Extravasation of contrast material was observed in 53.8% of fluoroscopy-guided procedures, making 3.8% invalid for diagnostic purposes. Intra-articular gas was observed in 21.9% of ultrasound-guided studies and in 38.5% of fluoroscopy-guided studies. None of the differences between techniques were statistically significant at p < 0.05.ConclusionsOur study shows that ultrasound is as useful as fluoroscopy for injecting contrast material for CT arthroscopy and MR arthroscopy; ultrasound has the advantage of not using ionizing radiation.     

Manifestaciones radiográficas de las atelectasias pulmonares lobares en la radiografía de tórax y su correlación con la tomografía computarizada

Atelectasis is an important indicator of potentially severe underlying disease that must be diagnosed as early as possible. One of the most common mechanisms is the reabsorption of air distal to respiratory tract obstruction. The chest X-ray is an excellent tool to diagnose atelectasis, and it is especially useful for ruling out central bronchial obstructions (e.g., from endobronchial tumors). If the signs of volume loss are not recognized correctly, the diagnosis and treatment can be delayed. This article describes the main findings of lobar atelectasis on chest X-rays and their correlations with CT findings, including the classic signs described in the literature and other, less known and sometimes subtle signs.     

Embolización selectiva como tratamiento de la hemorragia obstétrica

Objective

To describe cases of obstetric hemorrhage that have called for selective intra-arterial embolization and the different embolization techniques used. To assess the clinical outcomes and postprocedural fertility.

Material and methods

We studied 27 women with obstetric hemorrhage. In 24 patients, embolization was performed by catheterizing both uterine arteries and in 2 patients only one uterine artery was catheterized (pseudoaneurysm). The materials used for embolization consisted of Spongostan in 17/27, particles in 9/27, and coils in 1/27. Clinical follow-up included an analysis of early and late complications and of postprocedural fertility.

Results

Hemorrhage was classified as primary (25/27) or secondary (2/27).The cause of bleeding was vaginal delivery (20), cesarean sections (5), abortion (1), and cervical ectopic pregnancy (1).The initial technical success rate was 100% and the clinical success rate was 92.6% (25 of the 27 patients).Bleeding ceased and the outcome was satisfactory in 25 patients. During clinical follow-up ranging from one to seven years, 23 patients had normal menstruation and 6 patients completed 7 full-term pregnancies.

Conclusion

Intra-arterial embolization for obstetric hemorrhage leads to good outcomes and few complications and it preserves fertility.