A Novel Technique for Minimizing the Metal Artifacts on Anterior Teeth in Cone-Beam Computed Tomography.

In endodontics, metal artifacts are the major weak points of employing cone-beam computed tomography (CBCT) in teeth with metallic posts and restorations. The aim of this article is to introduce a novel technique for preparation of beneficial CBCT images of anterior teeth with metal posts and/or crowns. In this novel technique, the patient who was instructed to take CBCT images for reason of implant surgery, was asked to puff out his cheeks/lips during the rotation of x-ray tube. By comparing the image taken with this technique to normal image it was obvious that after applying the cheek puffing technique, the metal artifacts around restored anterior teeth significantly reduced. Then it seems that this novel technique removes the metal artifacts from the crowned teeth to distances far from the tooth structure and enables more accurate diagnosis.

Segmentación del hígado en imágenes de tomografía computarizada

RESUMEN Fundamento: la segmentación del hígado utilizando datos de tomografía computarizada es el primer paso para el diagnóstico de enfermedades hepáticas. Actualmente la segmentación de estructuras y órganos, basado en imágenes, que se realiza en los hospitales del país, dista de tener los niveles de precisión que se obtienen de los modernos sistemas 3D, por lo que se requiere buscar alternativas viables utilizando el PDI sobre ordenador. Objetivo: determinar una variante eficaz y eficiente desde el punto de vista computacional en condiciones de rutina hospitalaria, para la segmentación de imágenes hepáticas con fines clínicos. Métodos: se compararon dos métodos modernos de segmentación (Graph Cut y EM/MPM) aplicándolos sobre imágenes de tomografía de hígado. Se realizó un análisis evaluativo y estadístico de los resultados obtenidos en la segmentación de las imágenes a partir de los coeficientes de Dice, Vinet y Jaccard. Resultados: con el método Graph Cut, en todos los casos, se segmentó la región deseada, incluso cuando la calidad de las imágenes era baja, se observó gran similitud entre la imagen segmentada y la máscara de referencia. El nivel de detalles visuales es bueno y la reproducción de bordes permanece fiel a la máscara de referencia. La segmentación de las imágenes por el método de EM/MPM, no siempre fue satisfactoria. Conclusiones: el método de segmentación Graph Cut obtuvo mayor precisión para segmentar imágenes de hígado.

ABSTRACT Background: liver segmentation using computed tomography data is the first step for the diagnosis of liver diseases. Currently, the segmentation of structures and organs, based on images, which is carried out in the country's hospitals, is far from having the levels of precision obtained from modern 3D systems, it is necessary to search for viable alternatives using the PDI on a computer. Objective: to determine an effective and efficient variant from the computational point of view in routine hospital conditions, for the segmentation of liver images for clinical purposes. Methods: Two modern segmentation methods (Graph Cut and EM/MPM) were compared by applying them to liver tomography images. An evaluative and statistical analysis of the results obtained in the segmentation of the images from the Dice, Vinet and Jaccard coefficients was carried out. Results: with the Graph Cut method, in all cases, the desired region was segmented, even when the quality of the images was low, great similarity was observed between the segmented image and the reference mask. The level of visual detail is good, and edge reproduction remains true to the reference skin. Image segmentation by the EM/MPM method was not always satisfactory. Conclusions: the Graph Cut segmentation method obtained greater precision to segment liver images.

Trends in computed tomography aortography and acute aortic syndrome in an emergency department within Aotearoa New Zealand.

OBJECTIVE: Acute aortic syndrome (AAS) comprises a triad of life-threatening aortic conditions that are difficult to diagnose because of their non-specific clinical presentations. Contrast-enhanced computed tomography aortography (CTA) has a high sensitivity and specificity for these conditions. However, under- and over-investigation of patients with suspected AAS using CTA carries significant risk. The aim of the present study was to evaluate the diagnostic imaging practices of CTA use for patients presenting to an ED with suspected AAS. METHODS: All atraumatic thoracic CTAs performed on patients aged ≥15 years old with suspected AAS who presented to Auckland City Hospital between 2009 and 2019 were included. Outcomes of interest were the annual ED and population incidences of AAS, and the rate of CTAs performed. RESULTS: A total of 1646 CTAs were included. There were 135 (8.2%) cases of at least one AAS diagnosis and 220 (13.4%) cases where an alternative diagnosis was made. The population-adjusted number of AAS diagnoses remained relatively stable over the study period, with a mean annual AAS incidence of 19.6 (95% confidence interval 9.9-33.7) per 100 000 patients, and 3.2 (95% confidence interval 1.6-5.4) per 100 000 population. The number of ED presentations increased during the study period, along with the population-adjusted rate of CTAs performed, from approximately 150 per 100 000 patients (2009) to 350 per 100 000 patients (2019). CONCLUSIONS: Thoracic CTA use for investigating suspected AAS in our ED has recently increased. However, the annual incidence of AAS did not increase over the same period, but was higher than reported in overseas institutions.

Safely Shortening the Observation Time After CT-Guided Lung Procedures.

OBJECTIVE: To determine safety of shortened observation time without follow-up chest x-ray (CXR) after CT-guided transthoracic procedures (lung biopsy or fiducial placement) in patients without immediate postprocedural pneumothorax (PTX). METHODS: Consecutive patients that underwent CT-guided procedures between January 5, 2015, and June 19, 2017, were included in this retrospective institutional review board-approved HIPAA-compliant study. Data regarding postprocedural course, complications, and clinical follow-up of the patients were obtained through a review of electronic medical records. Descriptive statistics were used. RESULTS: There were 441 procedures for 409 patients performed; 82 procedures were excluded because of predefined criteria. In 312 of 336 asymptomatic procedures (92.9%), asymptomatic patients did not undergo CXR after procedure, with 7 of 312 of these patients (2.2%) diagnosed with delayed PTX 2 to 10 days after the procedure. In 24 of 336 procedures (7.1%), asymptomatic patients underwent CXR within 4 hours with no PTX detected, and despite that 1 of 24 of these patients (4.2%) presented with delayed PTX 7 days after procedure. When no immediate postprocedural PTX was present, rate of observation PTX and delayed PTX was 1 of 359 (0.3%) and 8 of 359 (2.2%), respectively. Average duration of monitoring for outpatients (n = 295) was 2.0 hours with median of 1.8 hours. In 23 of 359 (6.4%) procedures, the patient became symptomatic during postprocedural observation with 1 of 23 (4%) developing PTX. CONCLUSIONS: Obtaining routine postprocedural CXRs in asymptomatic patients without immediate postprocedural PTX after CT-guided transthoracic procedures is likely not necessary given the low likelihood of PTX.

Virtual reality and augmented reality applications and simulation in vascular access management with three-dimensional visualization.

Obtaining adequate and precise anatomical information is mandatory to prevent vascular access-related complications in dialysis patients. For this purpose, we underwent Doppler ultrasound, vascular access angiogram, and plain computer-assisted tomography scan of the arm with vascular access. With the use of computer graphics software, the anatomical structure of the vascular access can be visualized three dimensionally which is shared among the staffs for precise and better recognition. Furthermore, created object is applicable for virtual reality and/or augmented reality presentation that provides useful means for education and practical procedures in the management of vascular access.

Prognostic Value of Infarct size Measured by Gated sPECT scintigraphy / Valor pronóstico del tamaño del infarto de miocardio cuantificado mediante SPECT gatillada

Background: Despite the improved sensitivity and specificity of SPECT myocardial perfusion imagingto detect myocardial involve-ment after acute myocardial infarction (AMI), there is little information about the usefulness of early infarct size (IS) measurement by this method for risk stratification and prognosis. Objectives: The goal of this study was to evaluate the usefulness of quantifying IS by gated SPECT scintigraphy to predict cardio­vascular events in patients with a first AMI. Methods: Patients with a first ST-segment elevation AMI were included from 2009 to 2014. Infarct size was estimated using the Cedars QPS software. The incidence of events (heart failure, ventricular arrhythmias, mortality and a composite of the three events) was evaluated at one year. Results: One-hundred and forty nine patients were included in the study; mean age was 59±11 years and 81.9% were men. Diabetes was present in 16.1% of cases, 9.4% had a history of myocardial revascularization, 84.6% were admitted in Killip and Kimball class A, 43% of AMIs were located in the anterior wall and 69.8% of the patients underwent reperfusion. Left ventricular ejection fraction estimated by gated SPECT scintigraphy was 51%±14%. Follow-up was completed in 95.9% of cases. An IS cutoff point of 22% (ROC curve) was established to predict the composite endpoint at follow-up (sensitivity 92%, specificity 81%, AUC: 0.94%), dividing the sample into two groups: Group I (IS <22%) and Group II (IS ≥22%). The prevalence of the composite endpoint was greater in Group II (2.1% Group I vs. 50% Group II; p<0.001). Infarct size ≥ 22% was the only variable identified as predictor of events during follow-up (OR 1.978; 95% CI 1.887-1.996; p<0.001). Conclusion: Early quantification of IS by gated SPECT scintigraphy is an independent risk predictor at one year that allows risk stratification in patients with a first AMI.

Introducción: Si bien la SPECT de perfusión miocárdica ha mejorado la sensibilidad y la especificidad en la detección del compromiso miocárdico luego de un infarto agudo de miocardio (IAM), aún es escasa la información sobre la determinación precoz del tamaño del infarto (TI) con este método para la estratificación del riesgo y su valor pronóstico. Objetivos: Evaluar la utilidad de la cuantificación del TI estimado por SPECT gatillada en la predicción de complicaciones cardio­vasculares en pacientes con un primer IAM. Material y métodos: Se analizaron los pacientes con IAM con elevación del ST desde 2009 a 2014, excluyéndose aquellos con IAM previo. El cálculo del TI se realizó con el softwareCedars QPS. Se evaluaron eventos al año: insuficiencia cardíaca, arritmias ventri-culares, muerte y la combinación de los tres eventos. Resultados: Se incluyeron 149 pacientes, con edad media de 59±11 años,el 81,9% de sexo masculino. El 16,1% eran diabéticos y el 9,4% presentaban revascularización previa. El 84,6% ingresaron en Killip y Kimball A, el 43% de los IAM fueron de territorio anterior y el 69,8% de los pacientes fueron reperfundidos. La fracción de eyección del ventrículo izquierdo por SPECT gatillada fue del 51% ±14%. Se realizó seguimiento clínico en el 95,9% de los casos. El punto de corte del TI (curva ROC) para predecir eventos combinados al seguimiento se estableció en 22% (sensibilidad: 92%, especificidad: 81%, ABC: 0,94),con el cual la muestra se dividió en dos grupos: Grupo I (TI<22%) y Grupo II (TI≥22%). La prevalencia de eventos combinados fue mayor en el Grupo II (2,1% Grupo Ivs. 50% Grupo II; p<0,001). El TI ≥22% se identificó como la única variable predictora de eventos al seguimiento (OR 1,978; IC 95% 1,887-1,996; p<0,001). Conclusión: La cuantificación precoz del TI mediante SPECT es un predictor independiente de riesgo al año que permite establecer una estratificación del riesgo en pacientes con un primer IAM.

Spatial heterogeneity of soil water around single roots: use of CT-scanning to predict fungal growth in the rhizosphere.

Whole-body computed tomography X-ray scanning (X-ray CT) of wheat, cotton and radish growing in pots containing 350 g of a white sand: clay mixture produced images from which digital data of the volumetric water content were obtained. The volumetric water contents were spatially heterogeneous around the root and altered with the depth at which the image was taken. Data represent a 'snapshot in time' of the soil around single roots in a living soil-plant system. The volumetric water contents of soil around seedlings were assessed for the growth of two soil-borne fungi, Gaeumannomyces graminis var. tritici and Rhizoctonia solani. The heterogeneity of water content was biologically significant: water contents around the roots of wheat, radish and cotton were of a great enough range to suggest the existence of heterogeneous sites in the rhizosphere which might favour or restrict fungal growth. In soil surrounding wheat roots, the most favourable regions for the growth of G. graminis were nearest the root, suggesting that the inner rhizosphere might be more amenable to the growth of this pathogenic fungus than the outer region of the rhizosphere, and the bulk soil. The technique of X-ray CT enables spatial examination of the response of soil water to environmental treatments of the soil-root system, and the non-destructive observation of the effect of the spatial heterogeneity of volumetric water content upon fungal growth in the soil, over time and at a range of depths.

Implicancia pronóstica de los estudios gated-SPECT normales en pacientes mayores de 70 años / Pronostic implication of normal gated SPECT studies in patients over 70 years old

Introducción: un resultado normal en la centellografía de perfusión miocárdica gatillada (gated-SPECT) tiene un alto valor predictivo negativo para enfermedad coronaria grave; existe un período de tiempo variable en que los pacientes permanecen con una tasa de eventos baja (menor a 1%). Sin embargo, algunas evidencias sugieren que este período de garantía (PG) no es el mismo en todos los grupos etarios. Objetivo: establecer el período de tiempo en el cual los pacientes ancianos (mayores de 70 años) mantienen una tasa de eventos cardíacos por debajo de 1%. Material y método: se estudiaron 554 pacientes mediante gated-SPECT, divididos en dos grupos: Grupo 1: (n=354) con gated-SPECT normal, y Grupo 2: (n=200) con gated-SPECT anormal. Definimos un gated-SPECT normal como aquel con score de suma en estrés (SSS) < 4 y parámetros funcionales normales. El seguimiento medio fue de 30,6 meses (rango: 12-62 meses) para la pesquisa de los eventos cardiovasculares (EC): muerte cardíaca (MC) e infarto agudo de miocardio no fatal (IAMNF), y eventos combinados (ECB): EC+ angioplastia coronaria, cirugía de revascularización miocárdica e implante de cardiodesfibrilador. Se utilizó prueba no paramétrica de Pearson y se calculó el estadístico x2, con un valor de p ?0,05 para el rechazo de la hipótesis nula (IC: 95%). Resultados: la comparación entre ambos grupos muestra diferencias en los tres primeros años para la aparición de EC (p <0,0001), MC (p <0,0001) y ECB (p <0,0001). La tasa de EC en el Grupo 1 para cada año fue de 0,56%, 0,59% y 0,50%, respectivamente, con una tasa acumulada a tres años de 1,65%. La tasa en el Grupo 2 fue de 2,50%, 1,58% y 3,84%, respectivamente (tasa acumulada: 7,92%). El período de tiempo en el cual los pacientes del Grupo 1 mantuvieron un riesgo de EC por debajo de 1% fue de 18 meses. Conclusión: el pronóstico de los pacientes ancianos que presentan un resultado normal en el gated-SPECT es muy bueno, con una tasa de EC menor a 1% por un lapso de 18 meses.

Introduction: a normal result in myocardial perfusion scintigraphy (gated-SPECT) has a high negative predictive value for severe coronary artery disease; there is a period of time in which patients remain with a low event rate (less than 1%). However, some evidence suggests that this guarantee period (PG) is not the same in all age groups. Objectives: to establish the period of time in which elderly patients (older than 70 years) maintain a rate of cardiac events below 1%. Material and methods: 554 patients were studied through gated-SPECT, divided into two groups: Group 1: (n = 354) with normal gated-SPECT, and Group 2: (n = 200) with abnormal gated-SPECT. We define a normal gated-SPECT as that with a stress sum score (SSS) <4 and normal functional parameters. The mean follow-up was 30.6 months (range: 12-62 months), for the investigation of cardiovascular events (CE): cardiac death (CD) and nonfatal infarction (NFAMI), and combined events (CBE): CE + coronary angioplasty, myocardial revascularization surgery and implanted cardiodefibrillator (ICD). Pearson's nonparametric test was used and the Χ2 statistic was calculated, with a value of p <0.05 for the rejection of the null hypothesis (CI: 95%). Results: the comparison between both groups shows differences for the appearance of CE: (p <0.0001), CD: (p <0.0001) and CBE: (p <0.0001). The CE rate in Group 1 for each year was 0.56, 0.59 and 0.50%, respectively, with a cumulative 3-year rate of 1.65%. The rate in Group 2 was 2.5, 1.58 and 3.84%, respectively (cumulative rate: 7.92%). The period in which Group 1 patients maintained a risk of CD below 1% was 18 months. Conclusion: the prognosis of elderly patients presenting a normal gated-SPECT result is very good, with a cardiac event rate of less than 1% for a period of 18 months.

Artifacts in Quantitative analysis of myocardial perfusion SPECT, using Cedars-Sinai QPS Software.

Quantitative analysis of myocardial perfusion Single photon emission computerized tomography (SPECT) images is increasingly applied in modern nuclear cardiology practice, assisting in the interpretation of myocardial perfusion images (MPI). There are different extensively validated state-of-the-art software packages, including QPS (cedars-Sinai), Corridor 4DM (University of Michigan) and Emory cardiac toolbox (Emory university), providing highly accurate and reproducible data. However, these software packages may suffer from potential artifacts related to patient or technical factors. By recognizing the source of such artifacts, the interpreting physician can avoid misinterpretation of MPI study. In this review, we discuss some of technical pitfalls that may occur in Quantitative Perfusion SPECT software (QPS, cedars-Sinai Medical center).

Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure.

BACKGROUND: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. OBJECTIVES: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. PATIENTS AND METHODS: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. RESULTS: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001) and ECTb (r = 0.68, 0.79, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001). However, Bland-Altman plots indicated significantly different mean values for EF, 11.4 and 20.9 using QGS and ECTb, respectively, as compared with echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. CONCLUSIONS: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated SPECT MPI measured with different software packages should not be used interchangeably.

A Unique Case of Diffuse Metastatic Neuroendocrine Cancer with Subcutaneous Nodules on (18)F-Fluorodeoxyglucose Positron Emission Tomography/Computer Assisted Tomography.

Neuroendocrine tumors (NETs) account for 8-10% of cases of carcinomas of unknown primary. Most of these cases are poorly differentiated with metastatic disease at the time of diagnosis. However, cutaneous metastatic presentation is rare. We present an interesting case of a 74-year-old woman presenting with cutaneous metastatic involvement from high grade poorly differentiated NET of unknown origin. She was referred to us with a diagnosis of lymphoma. (18)F-fluorodeoxyglucose positron emission tomography/computer assisted tomography imaging at our institution offered a differential diagnosis, including neuroendocrine cancer. Repeat skin lesion biopsy demonstrated "non-Merkel cell" carcinoma, favoring metastatic high-grade neuroendocrine carcinoma.

Epicardial fat volume is correlated with coronary lesion and its severity.

OBJECTIVE: To evaluate the correlation of epicardial adipose tissue volume (EATV) with the coronary artery lesion and its severity. METHODS: Inpatients with suspicious stable angina of coronary heart lesion were recruited. For patients with coronary artery lesions in CTA, further coronary angiography (CAG) was performed to evaluate the coronary artery lesion. Gensini scoring system was employed to assess the severity of coronary artery lesions. RESULTS: Patients were classified as coronary heart disease (CHD) group (n = 160). Results showed the mean EATV was 192.57 ± 30.32 cm(3) in CHD group, which was significantly larger than that in control group (138.56 ± 23.18 cm(3); P < 0.01). The coronary artery stenosis was classified as mild, moderate and severe stenosis according to the extent of coronary artery lesions, and results showed marked difference in the EATV among patients with different severities of coronary artery stenosis (P < 0.005). The Gensini score was positively related to EATV (r = 0.285, P = 0.000). The EATV increased with the increase in the number of affected coronary arteries. Multivariate Logistic regression analysis showed EATV was an independent risk factor of CHD after adjusting other confounding factors (OR = 1.023, P = 0.013). CONCLUSION: EATV is closely related to the severity of coronary artery lesions: the larger the EATV, the more severe the coronary artery lesions. Moreover, EATV is an independent risk factor of CHD.

Ischemic burden by 3-dimensional myocardial perfusion cardiovascular magnetic resonance: comparison with myocardial perfusion scintigraphy.

BACKGROUND: The extent and severity of ischemia on myocardial perfusion scintigraphy (MPS) is commonly used to risk-stratify patients with coronary artery disease. Estimation of ischemic burden by cardiovascular magnetic resonance (CMR) with conventional 2-dimensional myocardial perfusion methods is limited by incomplete cardiac coverage. More recently developed 3-dimensional (3D) myocardial perfusion CMR, however, provides whole-heart coverage. The aim of this study was to compare ischemic burden on 3D myocardial perfusion CMR with (99m)Tc-tetrofosmin MPS. METHODS AND RESULTS: Forty-five patients who had undergone clinically indicated MPS underwent rest and adenosine stress 3D myocardial perfusion and late gadolinium enhancement CMR. Summed stress and rest scores were calculated for MPS and CMR using a 17-segment model and expressed as a percentage of the maximal possible score. Ischemic burden was defined as the difference between stress and rest scores. 3D myocardial perfusion CMR and MPS agreed in 38 of the 45 patients for the detection of any inducible ischemia. The mean ischemic burden for MPS and CMR was similar (7.5±8.9% versus 6.8±9.5%, respectively, P=0.82) with a strong correlation between techniques (rs=0.70, P<0.001). In a subset of 33 patients who underwent clinically indicated invasive coronary angiography, sensitivities and specificities of the 2 techniques to detect angiographic coronary artery disease were similar (McNemar P=0.45). CONCLUSIONS: 3D myocardial perfusion CMR is an alternative to MPS for detecting the presence and rating the severity of ischemia.

Efficacy of Canadian computed tomography head rule in predicting the need for a computed-axial tomography scans among patients with suspected head injuries.

CONTEXT: The use of imaging modalities is crucial in the diagnostic field of critical medicine. However, the ethical and economic use of these techniques has become a major concern especially in resource-poor settings. The Canadian computed tomography Head Rule (CCHR) is being increasingly used all over the world to evaluate the necessity of a Computer-assisted Tomography (CT) scan in patients with suspected head injury. AIM: The aim of the current study is to evaluate the efficacy of CCHR to predict the occurrence of head injury, as evidenced radiologically by a CT Head, at a government tertiary care clinical setting in south India. SETTING AND DESIGN: The design was that of a hospital-based cross-sectional survey conducted at the Medical College Hospital, Thiruvananthapuram (Kerala, India). MATERIALS AND METHODS: The study subjects were patients with suspected head injury evaluated at the Surgical Casualty Department of the study setting. Fifty consecutive patients with suspected head injury were enrolled in the study. STATISTICAL ANALYSIS: The Chi-square test was used to assess the statistical significance of association between the outcome variable and the exposure characteristics. The diagnostic ability of the Glasgow Coma Scale (GCS) and CCHR were expressed in terms of sensitivity and specificity by considering CT diagnosed Head injury as the gold standard diagnostic tool. RESULTS: Clinical manifestations as measured by a GCS score < 13 failed to significantly predict a head injury in the CT scan. However, the same became statistically significant when the CCHR was added to the GCS score as a predictor (P value < 0.001). The sensitivity of the tool in predicting a head injury rose from 23.3 to 96.7%. CONCLUSION: The current study suggested that the CCHR could act as an excellent decision rule to indicate the need of a CT scan. The need of a decision rule was warranted in the context of the growth of newer diagnostic imaging facilities in India.

Comparison of rectal cancer tumor volume parameters measured by MRI sequences and CT with those by pathological specimen / 中国肿瘤临床

Objective:This study aimed to compare rectal cancer tumor volume parameters measured by MRI sequences (T1WI, T2WI, and DWI) and/or CT with those by pathological specimen. Methods:Twenty-two patients with rectal cancer were prospectively enrolled. MRI sequences including T1WI, T2WI, and DWI, and/or CT of the pelvis were performed before operation. Volume parameters, such as tumor length along the rectal axis, maximum tumor width perpendicular to rectal axis, and tumor actual area in that perpendicular plane, were measured on T1WI, T2WI, DWI, and CT, respectively, for each patient. The respective pathological parameters were further measured in surgical specimen after total mesorectal excision. The two kinds of parameter values measured in imaging and pathology were statistically compared and accuracy appraisal was performed. Results:The mean Lpath-L was 4.06±1.14 cm. The mean LT1-L, LT2-L, LDWI-L, and LCT-L were 3.91± 1.51, 4.62±1.41, 3.39±1.05, and 3.94±1.23 cm, respectively. Correlation coefficients were 0.688, 0.635, 0.688, and 0.720 (P<0.05). An average 6 mm overestimation was found in T2WI, and 1 to 6 mm underestimation in T1WI, DWI, and CT in length values compared with those measured in surgical specimen. The mean Lpath-W was 2.56 ±0.94 cm. The mean LT1-W, LT2-W, LDWI-W, and LCT-W were 3.62±0.99, 3.66±0.76, 3.23±0.58, and 3.64±1.04 cm, respectively. The magnitude of mean overestimation ranged from 5.1 to 11.1 mm. The Apath was 4.30 ±2.83 cm2. AT1, AT2, ADWI, and ACT were 8.98±3.90, 8.99±3.43, 8.41±3.09, and 9.63±4.40 cm2, respectively, which double overestimated the tumor area in the perpendicular rectal plane. Conclusion:The difference in longitudinal length between MRI sequences/CT and pathological specimen was in the range of?6 mm to 6 mm. The mean maximum tumor width and areas in the maximum tumor perpendicular plane were overestimated. This study indicated that gross tumor volume delineation based on CT or MRI for rectal cancer irradiation should be conservative in the axial images of rectum, and meticulous consideration is required along the rectum.

Pancreatic Cystic Neoplasm: Radiologic Evaluation and Differential Diagnosis / 대한췌담도학회지

Pancreatic cystic neoplasm is a clinically challenging entity. Its incidence estimated up to 45% of the general population. The biological behavior ranges from benign to malignant disease. The strategy for pancreatic cystic neoplasm could be to prevent progression to pancreatic cancer while minimizing the costs. The first step for the correct management is correct diagnosis. In this paper, the radiological differential diagnosis of them will be described.

CT Appearances of Mesenteric Tumors and the Differential Diagnosis / 中国普外基础与临床杂志

Objective To review the CT appearances and important differential diagnoses of various primary and secondary mesenteric neoplasms.Methods By describing the mesenteric anatiomy and major routes for the dissemination of metastatic mesenteric tumors, the article presents both the common and rare types of various primary and secondary mesenteric neoplasms, and addresses the characteristic CT appearances and important aspects of the differential diagnosis.Results CT study, especially the multi-slice spiral CT (MSCT), along with the clinical history and other related information, can nicely depict various mesenteric tumors and well differentiate them from infectious, inflammatory or vascular processes affecting the mesentery.Conclusion CT is the imaging method of choice for the evaluation of tumors of small bowel mesentery.