Validation of 2d ultrasound and volume estimation formulae for volume assessment of kidneys and spleens: an in-vitro study / alidación de la fórmula de estimación de volumen y ultrasonido 2D para la evaluación del volumen de los riñones y el bazo: un estudio in vitro

The accuracy of internal organ volume estimation done with ultrasound (US) was found to be multifactorial. Hence, we aimed to describe and validate the volume assessment of ultrasound and standard volume estimation formulae for different shaped intra-abdominal organs using spleens and kidneys.Dissected cadaveric kidneys (n=25) and spleens (n=29) were scanned to obtain linear measurements and ultrasound auto-generated volumes (USV). Linear measurements were used to calculate the volumes manually with ellipsoid, prolate, and Lambert volume estimating formulae. The actual volumes (AV) of organs were obtained by the water displacement method. Volume assessment accuracy of USV and different formulae were compared by comparing bias, precision and Bland-Altman plot analysis. The US linear and volume measurement procedure was reliable with high inter and intra-observer agreements (linear: Chronbach's α=0.983 to 0.934; volumes: Chronbach's α=0.989). USV estimates were accurate with a high correlation to AV and low estimation bias (-5.9%). Also, prolate (bias=-0.75%) and ellipsoid formulae (bias=-3.75%) were reliable with a negligible bias in estimated volumes. Contrary, the Lambert formula was unreliable due to a high bias (41.6%). For all evaluated methods, the estimation error found to be related to the organ size (T=3.483; p=0.001), mainly when the assessed organ is larger than 50 ml. Also, the shape related estimation error found to be related to the volume estimation formula used.This study has validated the USV for kidney and splenic volume assessments while describing volume-calculating formula employed, organ size and shape as significant contributors for volume estimation accuracy.

Se encontró que la precisión de la estimación del volumen de órganos internos realizada con ultrasonido (US) es multifactorial. El objetivo fue describir y validar la evaluación de volumen mediante ecografía y las fórmulas estándar de estimación de volumen para órganos intraabdominales de diferentes formas utilizando bazos y riñones.Se evaluaron riñones cadavéricos disecados (n = 25) y bazos (n = 29) para obtener medidas lineales y volúmenes autogenerados por ultrasonido (USV). Se utilizaron medidas lineales para calcular los volúmenes manualmente con fórmulas de estimación de volumen elipsoide, prolate y Lambert. Los volúmenes reales (AV) de los órganos se obtuvieron mediante el método de desplazamiento de agua. Se comparó la precisión de la evaluación del volumen de USV y diferentes fórmulas comparando el sesgo, la precisión y el análisis de la gráfica de Bland-Altman. El procedimiento de medición lineal y de volumen mediante US fue confiable con alta concordancia inter e intraobservadores (lineal: α de Chronbach = 0,983 a 0,934; volúmenes: α de Chronbach = 0,989). Las estimaciones de USV fueron precisas con una alta correlación con AV y un bajo sesgo de estimación (-5,9%). Además, las fórmulas prolate (sesgo= -0,75%) y elipsoide (sesgo = -3,75%) fueron confiables con un sesgo insignificante en los volúmenes estimados. Por el contrario, la fórmula de Lambert no fue confiable debido a un alto sesgo (41,6%). Para todos los métodos evaluados, se encontró que el error de estimación estaba relacionado con el tamaño del órgano (T = 3.483; p = 0.001), principalmente cuando el órgano evaluado es mayor de 50 ml. Además, se encontró que el error de estimación de forma está relacionado con la fórmula de estimación de volumen utilizada.Este estudio ha validado el USV para evaluaciones de volumen renal y esplénico al mismo tiempo que describe la fórmula de cálculo de volumen empleada, el tamaño y la forma de los órganos como contribuyentes significativos de la precisión de la estimación de volumen.

Delayed presentation of postinfectious encephalitis associated with SARS-CoV-2 infection: a case report.

Neurological manifestations of SARS-CoV-2 are increasingly being recognised and can arise as a result of direct viral invasion, para-infectious or postinfectious immune mechanisms. We report a delayed presentation of COVID-19 postinfectious immune-mediated encephalitis and status epilepticus occurring in a 47-year-old woman 4 weeks after SARS-CoV-2 pulmonary disease. SARS-CoV-2-specific IgG and IgM antibodies were detected in her cerebrospinal fluid with features of encephalitis evident in both magnetic resonance imaging of the brain and electroencephalogram. She made a complete recovery following treatment with high-dose intravenous corticosteroids and intravenous immunoglobulins. Diagnosis of COVID-19 postinfectious encephalitis may prove challenging in patients presenting many weeks following the initial infection. A high index of clinical suspicion and testing intrathecal SARS-CoV-2-specific antibodies are key to its diagnosis. Early immunotherapy is likely to result in a good outcome.

A novel approach for pre-surgical evaluation of facial morphometry in children using magnetic resonance imaging scans of the brain: a feasibility analysis / Un enfoque novedoso para la evaluación prequirúrgica de la morfometría facial en niños mediante imágenes por resonancia magnética de cerebro: un análisis de viabilidad

Pre-surgical evaluation of facial morphometry is frequently warranted for children with facial dysmorphism. Though many methods utilized previously for such purposes, data is scarce on using magnetic resonance (MRI) brain images for such purposes. The purpose of this study was to appraise the feasibility of utilizing MRI brain scans done in epilepsy imaging protocol to assess facial morphometry. Measurements of the face; orbit, mouth, and nose of children aged 1 to 7 years were obtained using T1 sagittal, T2 axial and three dimensional (3D) MRI images of the brain (n=20). Ability to obtain facial measurements, inter and intra-observer variability calculated. The mean age of the studied children was 4±2 years, of which 40% (n=8) were boys, and 60% (n=12) were girls. Obtaining facial measurements were reliable with high intra-observer (α=0.757 to 0.999) and inter-observer agreements (α=0.823 to 0.997). The landmarks of the cranium, upper face, and upper nose could be identified (100%) in both two dimensional (2D) and 3D images when such landmarks were contained in the imaging field of view (FOV). Landmarks of lower nose, (subalar width = 0%) or mouth (0%) were not contained in the FOV of 2D images, but contained in 3D images (100%). Both 2D and 3D images did not allow assessment of lower face or the mandible as such landmarks were not contained in the FOV.We conclude thatBrain MRIs performed to evaluate cerebral pathology can be executed to assess facial measurements, provided the FOV of the scan is adjusted to include all significant landmarks.

La evaluación prequirúrgica de la morfometría facial con frecuencia se justifica para niños con dismorfismo facial. Aunque muchos métodos se utilizaron anteriormente para tales fines, los datos son escasos sobre el uso de imágenes cerebrales por resonancia magnética (MRI) para tales fines. El propósito de este estudio fue evaluar la viabilidad de utilizar resonancias magnéticas cerebrales realizadas en el protocolo de imágenes de epilepsia para evaluar la morfometría facial.Medidas de la cara, la órbita, la boca y la nariz de niños de 1 a 7 años se obtuvieron mediante imágenes de resonancia magnética cerebral T1 sagital, axial T2 y tridimensional (3D) del cerebro (n = 20). Se obtuvieron las medidas faciales, y fue calculada la variabilidad inter e intraobservador.La edad de los niños estudiados fue de 4 ± 2 años, de los cuales el 40% (n = 8) hombre y el 60% (n = 12) mujer. La obtención de medidas faciales fue confiable con altos acuerdos intraobservador (α = 0,757 a 0,999) e interobservador (α = 0,823 a 0,997). Los puntos de referencia del cráneo, la cara superior y la nariz superior se pudieron identificar (100%) tanto en imágenes bidimensionales (2D) como en 3D cuando dichos puntos de referencia estaban contenidos en el campo de visión de la imagen (FOV). Los puntos de referencia de la parte inferior de la nariz (ancho subalar = 0%) o la boca (0%) no estaban contenidos en el campo de visión de las imágenes 2D, sino que estaban contenidos en las imágenes 3D (100%). Tanto las imágenes 2D como las 3D no permitieron la evaluación de la parte inferior de la cara o la mandíbula, ya que tales puntos de referencia no estaban contenidos en el campo de visión.Concluimos que las resonancias magnéticas cerebrales realizadas para evaluar la patología cerebral se pueden usar para evaluar las medidas faciales, siempre que el campo de visión de la exploración se ajuste para incluir todos los puntos de referencia importantes.

Impact of volume calculation formulae on volume estimation accuracy of different shaped objects: an in vitro ultrasound and CT study.

BACKGROUND: In image-assisted volume estimation, the volume of the object is calculated with a formula, using linear measurements of the objects. Since the volume estimation accuracy is thought to be influenced by the shape of the object, the volume estimation error would be related to the calculation formula used. PURPOSE: To evaluate the volume estimation accuracy of selected volume calculation formulae, for different shaped objects. MATERIAL AND METHODS: Globular (n = 5), elongated (n = 5), and near-spherical shaped plastic objects (n = 5), filled with water were subjected to ultrasound (US) and computed tomography (CT) in February 2018, to obtain the length, width, depth, and estimated volumes (EV). The volume was calculated manually using prolate, ellipsoid, and Lambert formulae. The actual volume (AV), EV, and calculated volumes were compared. RESULTS: The AV was in the range of 10-445 mL. The reliability of measurements was high as assessed by the intra-class variability (Cronbach's alpha = 0.992). The EV has shown a high correlation to AV (US: ρ = 0.914, P < 0.001; CT: ρ = 0.943, P < 0.001; ellipsoid: ρ = 0.876, P < 0.001; prolate: ρ = 0.891, P < 0.001; Lambert: ρ = 0.876, P < 0.001). Regardless of the shape, the highest and lowest estimation accuracies were reported for prolate (bias = -0.7) and Lambert formulae (bias = +23.3), respectively. By any method, the globular objects were estimated with the highest accuracy: (US [bias = -0.31]; CT [bias = -0.14]; ellipsoid [bias = -1.5]; prolate [bias = -0.7]; Lambert [bias = 32.9]); and elongated objects were estimated with the lowest accuracy: (US [bias = -17.5]; CT [bias = -32.6]; ellipsoid [bias = -18.4]; prolate [bias = -0.3]; Lambert [bias = 11.4]). CONCLUSION: The shape of the object and the calculation formula used has an impact on the volume estimation accuracy.

Diagnostic performance of renal ultrasonography in detecting chronic kidney disease of various severity.

Background: Association between early diagnosis of chronic kidney disease (CKD) and low morbidity and mortality rate has been proven. Thus, tools for early CKD diagnosis are vital. Ultrasonography has been widely used to diagnose and monitor the progression of CKD. Objectives: To determine the performance of selected renal ultrasonographic parameters for the diagnosis of early CKD. Methods: In a cohort of patients diagnosed with CKD (n = 100), diagnostic performance of ultrasonographically measured renal length (RL), renal cortical thickness (RCT), and parenchymal thickness (PT) was determined using receiver operating curve analysis; correlation of each parameter with the associated comorbidities and serum creatinine (Scr) levels was also determined. Severity of CKD was graded with estimated glomerular filtration rates (eGFR). Results: Of all patient participants, 85 had severity grades 2 or 3. Mean (standard deviation) Scr was 1.88 (0.60) mg/dL; eGFR was 43.3 (11.85) mL/min/1.73 m2. RL was 9.01 (0.83) cm, PT was 1.32 (0.22) cm, and RCT was 6.0 (0.10) mm. PT and RCT were positively correlated with eGFR (P = 0.01 and 0.002, respectively). Early CKD was better predicted by PT (area under the curve (AUC) 0.735; 82% sensitivity; 30% specificity; 68% positive predictive value (PPV)) and RCT (AUC 0.741; 82% sensitivity; 48% specificity; 51% PPV); severe CKD was better predicted by RL (AUC 0.809; 67% sensitivity; 26% specificity, 45% PPV; 13% negative predictive value). Conclusion: Index ultrasonic parameters show a diagnostic role in different stages of CKD. The index ultrasound and biochemical parameters showed a complementary role in predicting renal dysfunction.