Underwent Computed Tomography Examination Research Articles

Accuracy of a CT density threshold enhancement to identify pancreatic parenchyma necrosis in acute pancreatitis during the first week

PurposeThe purpose of this study was to identify attenuation threshold value on computed tomography (CT) that allowed discriminating between interstitial edematous pancreatitis (IEP) and necrotizing pancreatitis (NP) in patients with acute pancreatitis during the first week of the disease and evaluate interobserver reproducibility for the diagnosis of acute pancreatitis category. Materials and methodsPatients with acute pancreatitis who underwent CT examination of the abdomen between March 2015 and December 2019 were retrospectively included. Actual diagnosis of IEP or NP was based on final clinical report, follow-up evaluation, and complications. Six regions of interest were manually placed in the pancreatic gland and peripancreatic fat, and differences in CT attenuation values before contrast injection and during the portal venous phase of enhancement were computed. Performance in the diagnosis of AP category was evaluated using receiver operating characteristic analysis. Interobserver agreement was estimated by the intraclass correlation coefficient (ICC) and Bland Altman analysis was used to estimate reproducibility between pairs of observers. ResultsSixty-six patients with NP (46 men, 20 women; mean age, 55 ± 17 [SD] years; age range: 20-89 years) and 70 patients with IEP (39 men, 31 women; mean age, 54 ± 18 [SD] years; age range: 21–87 years) were included. An enhancement value less than 30 Hounsfield units (HU) in the pancreatic gland during the portal phase compared to non-contrast phase, yielded 90.9% sensitivity (60/66; 95% CI: 81.3–96.6), 94.3% specificity (66/70; 95% CI: 86.0–98.4) and an area under curve of 0.958 (95% CI: 0.919–0.996) for the diagnosis of NP versus IEP. Interobserver reproducibility for pancreas enhancement was good using Bland Altman plot and ICC was excellent for pancreatic gland analysis (ICC 0.978; 95% CI: 0.961–0.988) but poor or moderate (ICC ≤0.634) regarding peripancreatic fat necrosis. ConclusionBy using a pancreas enhancement threshold value of 30 HU, CT is accurate and reproducible for the diagnosis of NP during the first week of the disease.

Prognosis Analysis and Perioperative Research of Elderly Patients with Non-Muscle-Invasive Bladder Cancer under Computed Tomography Image of Three-Dimensional Reconstruction Algorithm.

To analyze the application value of computed tomography (CT) based on a three-dimensional reconstruction algorithm in perioperative nursing research and prognosis analysis of non-muscle-invasive bladder cancer (NMIBC), a retrospective study was performed on 124 patients with NMIBC who underwent surgical treatment in the hospital. All patients underwent CT examination based on the three-dimensional reconstruction algorithm before surgery, and transurethral resection of the bladder tumor was performed. The patients receiving conventional care were classified as the control group, and those receiving comprehensive care were classified as the case group, and the recovery status and recurrence of the two groups were compared. The results showed that the accuracy, specificity, and sensitivity of CT imaging information based on the three-dimensional reconstruction algorithm for NMIBC patients were 89.38, 93.77, and 84.39, respectively. The incidence of bladder spasm (9.68%), bladder flushing time (1.56 d), and retention of drainage tube time (2.68 d) in the case group were obviously lower compared with the control group (30.65%, 2.32 d, and 5.19 d) (P < 0.05). Serum BLCA-1 (3.72 ng/mL) and CYFRA21-1 (5.68 μg/mL) in the case group were significantly lower than those in the control group, with a statistically considerable difference (P < 0.05). Compared with the control group, the scores of role function (89.82 points), emotional function (84.76 points), somatic function (79.23 points), and social function (73.93 points) in the case group were observably higher (P < 0.05). In addition, one year after the operation, CT examination showed that the recurrence rate in the case group (6.45%) was significantly lower than that in the control group (22.58%) (P < 0.05). Therefore, CT detection based on the three-dimensional reconstruction algorithm was particularly important for preoperative diagnosis, prognosis, and recurrence monitoring of NMIBC patients. It could provide great clinical value for the diagnosis and prognosis monitoring of NMIBC.

Application of Multimodal Magnetic Resonance Imaging in Green Channel of Acute and Hyperacute Ischemic Stroke.

The purpose of this study was to observe the effects of multimodal magnetic resonance imaging (MRI) in the green channel of acute and hyperacute ischemic strokes, in order to better guide clinical treatment. The clinical data of 126 patients with acute and hyperacute ischemic stroke who received interventional treatment in the emergency green channel was collected retrospectively. The patients who received multimodal computed tomography (CT) were included in the CT group. Patients who underwent multimodal MRI examinations were included in the MRI group, and the door-to-needle time (DNT), neurological function, and prognosis of the two groups were compared. The result turned out that among the 126 patients included, 40 patients underwent CT examination (CT group) and 86 patients underwent MRI examination (MRI group). A comparison of general data between the CT group and the MRI group showed P > 0.05. The MRI group's DNT time (61.23 ± 9.32) min was shorter than that of the CT group (87.22 ± 14.26) min, P < 0.05. Through comparison, the P values of mRS scores and NIHSS scores in both groups were greater than 0.05. After treatment, the mRS score and NIHSS score of the MRI group was lower, with P < 0.05. According to the results of this study, it can be concluded that emergency multimodal MRI could shorten the DNT time of patients with acute and hyperacute ischemic stroke, reduce the degree of neurological impairment, and improve the prognosis.

Bladder paraganglioma: CT and MR imaging characteristics in 16 patients.

BackgroundBladder paraganglioma (BPG) is a rare extra-adrenal pheochromocytoma with variable symptoms and easy to be misdiagnosed and mishandled. The aim of the study was to document the imaging features of BPG using computed tomography (CT) and magnetic resonance imaging (MRI).Patients and methodsWe retrospectively enrolled consecutive patients with pathology-proven BPG, who underwent CT or MRI examinations before surgery between October 2009 and October 2017. The clinical characteristics, CT, and MRI features of the patients were described and analysed.ResultsA total of 16 patients with 16 bladder tumours (median age 51 years, 9 females) were included. Among them, 13 patients underwent CT examinations and eight patients underwent MRI examinations preoperatively. Tumour diameters ranged from 1.6−5.4 cm. Most of the tumours grew into the bladder cavity (n = 11) with oval shapes (n = 10) and well-defined margins (n = 14). Intratumour cystic degeneration or necrosis (n = 2) was observed. Two lesions showed peripheral tissue invasion, suggesting malignant BPGs. All 13 lesions imaged with CT exhibited slight hypoattenuation and moderate to marked enhancement. Compared to the gluteus maximus, all lesions showed slight h yperintensity in T2-weighted images, hyperintensity on diffusion-weighted images (DWI), hypointensity on apparent diffusion coefficient maps, hyperintensity on T1-weighted images and a “fast in and slow out” enhanced pattern on contrast-enhanced MRI images.ConclusionsBPGs are mostly oval-shaped, broadly-based and hypervascular bladder tumours with hypoattenuation on non-contrast CT, T2 hyperintensity, slight T1 hyperintensity compared to the muscle, marked restricted diffusion on DWI. Peripheral tissue invasion can suggest malignancy of the BPGs. All of these features contribute to preoperative decision-making.

Measuring morphological parameters of the pelvic diaphragm muscles using computed tomography in healthy dogs.

Evaluation of pelvic diaphragm muscles in dogs merits clinical attention because of the anatomical importance and their involvement in perineal hernia. This study aimed to evaluate the normal pelvic diaphragm muscles (levator ani and coccygeus muscles) using the computed tomography (CT) scan. For this purpose, 10 male and 10 female clinically normal, adult intact mixed-breed dogs weighing 15.00 to 20.00 kg were selected randomly. All animals underwent CT examination under general anesthesia and positioned in sternal recumbency. All the CT images were taken and reconstructed with a same protocol. The measurements of the pelvic diaphragm muscles were performed based on the presented guideline to the observer. The results were presented descriptively. The mean lengths of the coccygeus muscle in CT images were evaluated 4.60 cm for males and 4.30 cm for females. The mean lengths of levator ani muscle in CT images were measured 4.90 cm in males and 4.50 cm in females. In conclusion, the results of the present study can be beneficial to clinicians and researchers for further evaluation of the supporting muscles in pelvic cavity and underlying anatomical changes in perineal hernia in dogs.

Computed Tomography in Limb Salvage and Deformity Correction-3D Assessment, Indications, Radiation Exposure, and Safety Considerations.

Computed tomography (CT) is an essential tool in orthopedic surgery but is known to be a method with that entails radiation exposure. CT increases the risk of developing fatal cancer, which should not be underestimated. However, patients with bone defects and/or deformities must frequently undergo numerous investigations during their treatment. CT is used for surgical planning, evaluating callus maturation, alignment measurement, length measurement, torsion measurement, and angiography. This study explores the indications in CT scans for limb lengthening and deformity correction and estimates the effective radiation dose. These results should help avoid unnecessary radiation exposure by narrowing the examination field and by providing explicit scanning indications. For this study, 19 posttraumatic patients were included after the bone reconstruction of 21 lower limbs. All patients underwent CT examinations during or after treatment with an external ring fixator. The mean effective dose was 3.27 mSv, with a mean cancer risk of 1:117,014. The effective dose depended on the location and indication of measurement, with a mean dose of 0.04 mSv at the ankle up to 6.8 mSv (or higher) for vascular depictions. CT evaluation, with or without 3D reconstruction, is a crucial tool in complex bone reconstruction and deformity treatments. Therefore, strict indications are necessary to reduce radiation exposure—especially in young patients—without compromising the management of their patients.

Simplified size adjusted dose reference levels for adult CT examinations: A regional study

PurposeTo investigate retrospective classification of adult patients into small, average, and large based on effective diameter (EDia) from localizer image of computed tomography (CT) scans and to develop regional diagnostic reference levels (DRLs) and achievable doses (AD). MethodThe patients falling within the mean ± standard deviation (SD) of EDia were classified as average; those below this range as small and above as large. The CTDIvol,dose-length-product (DLP) and size-specific dose estimates (SSDE) of all adult patients undergoing CT examinations in 8 CT facilities for 11 months (Dec. 2019 - Oct. 2020) were evaluated. The 75th and 50th percentile values were compared with national and international values. ResultsOf the total of 69,434 CT examinations, nearly 80% fell within average size. The 75th percentile values of CTDIvol and DLP for small patients for abdomen-pelvic exams were nearly half of average sized patients. Similarly, the 75th percentile values for large patients were nearly double. Similar findings were not found for chest exams. Analysis of image quality and dose factors such as noise, mean axial length, slice thickness, mean number of sequences, use of iterative reconstruction and tube current modulation (TCM) resulted in identification of opportunities for improvement and optimization of different CT facilities. ConclusionsDRLs for adult patients were found to vary widely with patient size and thus establishing DRLs only for standard sized patient is not adequate. Simplified and intuitive methods for size classification was shown to provide meaningful information for optimization for patients outside the standard size adult.

Indications for computed tomography use and frequency of traumatic abnormalities based on real-world data of 2405 pediatric patients with minor head trauma.

Background: In pediatric patients with minor head trauma, computed tomography (CT) is often performed beyond the scope of recommendations that are based on existing algorithms. Herein, we evaluated pediatric patients with minor head trauma who underwent CT examinations, quantified its frequency, and determined how often traumatic findings were observed in the intracranial region or skull.Methods: We retrospectively reviewed the medical records and neuroimages of pediatric patients (0–5 years) who presented at our hospital with minor head trauma within 24 h after injury.Results: Of 2405 eligible patients, 1592 (66.2%) underwent CT examinations and 45 (1.9%) had traumatic intracranial hemorrhage or skull fracture on CT. No patient underwent surgery or intensive treatment. Multivariate analyses revealed that an age of 1–5 years (vs. <1 year; P < 0.001), Glasgow Coma Scale (GCS) score of 14 (vs. a score of 15; P = 0.008), sustaining a high-altitude fall (P < 0.001), using an ambulance (P < 0.001), and vomiting (P < 0.001) were significantly associated with the performance of CT examination. In addition, traumatic abnormalities on CT were significantly associated with the combination of an age of under 1 year (P = 0.042), GCS score of 14 (P < 0.001), and sustaining a high-altitude fall (P = 0.004).Conclusion: Although slightly broader indications for CT use, compared to the previous algorithms, could detect and evaluate minor traumatic changes in pediatric patients with minor head trauma, over-indications for CT examinations to detect only approximately 2% of abnormalities should be avoided and the indications should be determined based on the patient’s age, condition, and cause of injury.

Value of Quantitative CTTA in Differentiating Malignant From Benign Bosniak III Renal Lesions on CT Images.

The aim of this study was to investigate whether computed tomography texture analysis can differentiate malignant from benign Bosniak III renal lesions on computed tomography (CT) images. This retrospective case-control study included 45 patients/lesions (22 benign and 23 malignant lesions) with Bosniak III renal lesions who underwent CT examination. Axial image slices in the unenhanced phase, corticomedullary phase, and nephrographic phase were selected and delineated manually. Computed tomography texture analysis was performed on each lesion during these 3 phases. Histogram-based, gray-level co-occurrence matrix, and gray-level run-length matrix features were extracted using open-source software and analyzed. In addition, receiver operating characteristic curve was constructed, and the area under the receiver operating characteristic curve (AUC) of each feature was constructed. Of the 33 extracted features, 16 features showed significant differences (P < 0.05). Eight features were significantly different between the 2 groups after Holm-Bonferroni correction, including 3 histogram-based, 4 gray-level co-occurrence matrix, and 1 gray-level run-length matrix features (P < 0.01). The texture features resulted in the highest AUC of 0.769 ± 0.074. Renal cell carcinomas were labeled with a higher degree of lesion gray-level disorder and lower lesion homogeneity, and a model incorporating the 3 most discriminative features resulted in an AUC of 0.846 ± 0.058. The results of this study showed that CT texture features were related to malignancy in Bosniak III renal lesions. Computed tomography texture analysis might help in differentiating malignant from benign Bosniak III renal lesions on CT images.

Diagnostic reference levels for head and abdominal computed tomography of adult patients in selected states in South-South Nigeria

Context: Diagnostic reference level (DRL) is the first step in the optimization process to manage patient dose corresponding with the medical purpose. Aim: The objective of this study was to develop local DRL for computed tomography (CT) of the head and abdomen in adult patients in four CT centers in South-South Nigeria. Materials and Methods: A prospective, cross-sectional study of 546 adult patients that underwent CT examination of the head and abdomen from 2018 to 2020 using four different CT scanners. Volume CT dose index (CTDIvol) and dose length product (DLP) of contrast and non-contrast CT examinations of the head and abdomen were collated and the 50th percentile DRL was determined and compared to other published DRLs. Results: The 50th percentile CTDIvol/DLP for non-contrast head CT examination for centers A, B, C, and D was 75.3 mGy/1776.6 mGy.cm, 21.8 mGy/457 mGy.cm, 17.4 mGy/373.6 mGy.cm, and 29.6 mGy/628.5 mGy.cm, respectively. The 50th percentile CTDIvol/DLP for contrast head CT examination for centers A, B, C, and D was 150.6 mGy/3326.2 mGy.cm, 41.4 mGy/832.4 mGy.cm, 35.6 mGy/653.6 mGy.cm, and 77.9 mGy/1458.4 mGy.cm, respectively. The 50th percentile CTDIvol/DLP for non-contrast abdomen CT examination for centers A and B was 22.8 mGy/1488.5 mGy.cm and 7.9 mGy/302.3 mGy.cm, respectively. The 50th percentile CTDIvol/DLP for contrast abdomen CT examination for centers B and C was 19.6 mGy/825.7 mGy.cm and 31.5 mGy/1555.5 mGy.cm, respectively. There was correlation between contrast and non-contrast CTDI (P = 0.003) and DLP (P = 0.025) for the head. Conclusion: Wide variations CTDIvol and DLP values were observed among the centers for similar body part CT examinations.

Computed tomography in the diagnosis of intraperitoneal effusions: The role of texture analysis.

The morphological changes suggesting peritoneal carcinomatosis are inconsistent and may be visible only at later stages of the disease. However, malignant ascites represents an early sign, and this fluid exhibits specific histological characteristics. This study aimed to quantify the fluid properties on computed tomography (CT) images of intraperitoneal effusions through texture analysis and evaluate its utility in differentiating benign from malignant collections. Fifty-two patients with histologically proven benign (n=29) and malignant (n=23) intraperitoneal effusions who underwent CT examinations were retrospectively included. Texture analysis of the fluid component was performed on the non-enhanced phase of each examination using dedicated software. Fisher and the probability of classification error and average correlation coefficients were used to select two sets of ten texture features, whose ability to distinguish between the two types of collections were tested using a k-nearest-neighbor classifier. Also, each of the selected feature’s diagnostic power was assessed using univariate and receiver operating characteristics analysis based on the calculation of the area under the curve. The k-nearest-neighbor classifier was able to distinguish between the two entities with 71.15% accuracy, 73.91% sensitivity, and 68.97% specificity. The highest-ranked texture parameter was Inverse Difference Moment (p=0.0023; area under the curve=0.748), based on which malignant collections could be diagnosed with 95.65% sensitivity and 44.83% specificity. Although successful, the texture assessment of benign and malignant collections is less effective in reflecting the cytological differences between the two groups.

Associations of MTA1 expression with CT features, pathology and prognosis of elderly patients with non-small cell lung cancer.

Associations of metastasis-associated protein 1 (MTA1) expression with computed tomography (CT) features, pathology and prognosis of elderly patients with non-small cell lung cancer (NSCLC), and its clinical significance were explored. A total of 98 elderly patients with NSCLC were selected and underwent CT examination. The expression of MTA1 in carcinoma tissues and para-carcinoma normal tissues was detected via immunohistochemistry, and its associations with CT features, pathology and prognosis were analyzed. The results manifested that the expression of MTA1 in carcinoma tissues was significantly higher than that in para-carcinoma normal tissues, and it was associated with the degree of differentiation, stage and lymph node metastasis (P<0.05). Besides, the high expression of MTA1 was also related to the spicule sign, pleural indentation and lymph node metastasis (P<0.05) as well as the CT perfusion parameter capillary permeability (PMB) (P<0.05), but not to blood volume (BV), blood flow (BF) or time to peak (TTP). Moreover, the patients with high expression of MTA1 had significantly shorter survival time and a remarkably lower 5-year survival rate than those with low expression of MTA1 (P<0.05). In conclusion, MTA1 plays a certain role in the occurrence and development of NSCLC in elderly patients and has an association with their prognosis, which can provide references for the treatment and prognosis of NSCLC, with important clinical significance.

Correlation analysis of organ doses determined by Monte Carlo simulation with dose metrics for patients undergoing chest-abdomen-pelvis CT examinations

ObjectivesThis study aimed to determine organ doses based on Monte Carlo (MC) simulations for individual patients undergoing routine adult chest abdomen-pelvis computed tomography (CT) examinations and to evaluate the correlations of organ doses with patient size and dose metrics. MethodsMC simulations were performed by reading detailed descriptions of the CT scanner, scanning parameters, and CT images of phantoms and patients into the simulation software. The simulation models were validated by comparing the simulated doses with the doses measured by in-phantom dosimetry using radiophotoluminescent glass dosimeters and an adult anthropomorphic phantom, and organ doses for 80 patients were determined from the simulation results. To obtain patient size and dose metrics, body mass index and volume computed tomography dose index (CTDIvol) data were collected. Water equivalent diameter (WED) was calculated from the CT images of each patient. Size-specific dose estimates (SSDE) were calculated using CTDIvol and average WED over the scan range, and organ specific SSDE were calculated using the average CTDIvol and WED over each organ position. The correlations of organ doses with dose metrics were evaluated using coefficients of determination. ResultsOrgan doses increased with patient size, and the doses for obese were approximately two to three times higher than those for underweight patients. Organ doses exhibited stronger linear relationships with organ specific SSDE (R2 ≥ 0.82) than other dose metrics. ConclusionsThe linear regression fits between organ doses determined by MC simulation and organ-specific SSDE are valuable for simplified and accurate organ dose estimation for individual patients undergoing CT examinations.

Novel coronavirus disease 2019: predicting prognosis with a computed tomography-based disease severity score and clinical laboratory data.

Currently, there are known contributing factors but no comprehensive methods for predicting the mortality risk or intensive care unit (ICU) admission in patients with novel coronavirus disease 2019 (COVID‑19). The aim of this study was to explore risk factors for mortality and ICU admission in patients with COVID‑19, using computed tomography (CT) combined with clinical laboratory data. Patients with polymerase chain reaction-confirmed COVID‑19 (n = 63) from university hospitals in Tehran, Iran, were included. All patients underwent CT examination. Subsequently, a total CT score and the number of involved lung lobes were calculated and compared against collected laboratory and clinical characteristics. Univariable and multivariable proportional hazard analyses were used to determine the association among CT, laboratory and clinical data, ICU admission, and in‑hospital death. By univariable analysis, in‑hospital mortality was higher in patients with lower oxygen saturation on admission (below 88%), higher CT scores, and a higher number of lung lobes (more than 4) involved with a diffuse parenchymal pattern. By multivariable analysis, in‑hospital mortality was higher in those with oxygen saturation below 88% on admission and a higher number of lung lobes involved with a diffuse parenchymal pattern. The risk of ICU admission was higher in patients with comorbidities (hypertension and ischemic heart disease), arterial oxygen saturation below 88%, and pericardial effusion. We can identify factors affecting in‑hospital death and ICU admission in COVID-19. This can help clinicians to determine which patients are likely to require ICU admission and to inform strategic healthcare planning in critical conditions such as the COVID‑19 pandemic.

Additional CTA-Subtraction Technique in Detection of Pulmonary Embolism-a Benefit for Patients or Only an Increase in Dose?

Latest advantages in computed tomography (CT) come with enhanced diagnostic imaging and also sophisticated dose reduction techniques. However, overall exposure to ionizing radiation of patients in Germany rises slightly, which is mainly based on the growing number of performed CT scans. Furthermore, new possibilities in modern imaging, including 4D scans or perfusion protocols, offer new medical insights but require additional scans.In this study, we reevaluated data sets from patients undergoing CT examinations because of suspected pulmonary embolism and compared doses and diagnostic results of the standard protocol to the additional modern CT subtraction technique. Two groups of single-blinded radiologists were provided with CT data sets from 50 patients. One group (G1) had access to full datasets including CT subtraction with perfusion map. The other group (G2) only evaluated conventional CT angiography. Results were compared to final clinical diagnosis. Dose length product (DLP) of CT angiography was compared to CT subtraction technique, which consists of an additional non-contrast-enhanced scan and perfusion map. Effective dose was calculated using a Monte Carlo simulation-based software tool (ImpactDose). Inter-rater agreement of both groups was strong in G1 with κ = .896 and minimal in G2 (κ = .307). Agreement to final diagnosis was strong in both groups (G1, κ = .848; G2, κ = .767). Doses applied using the CT subtraction technique were 34.8% higher than for CT angiography alone (G1 DLP 337.6 ± 171.3 mGy x cm; G2 DLP 220.2 ± 192.8 mGy x cm; p < .001). Calculated effective dose was therefore significantly higher for G1 (G1 4.82 ± 2.20 mSv; G2 3.04 ± 1.33 mSv; p < .001). Our results indicate a benefit of the CT subtraction technique for the detection of pulmonary embolisms in clinical routine, accompanied by an increase in the dose administered. Although CT protocols should always be applied carefully to specific clinical indications in order to maximize the potential for dose reduction and keep the administered dose as low as reasonably achievable, one should never lose sight of the diagnostic benefit, especially in vital clinical indications.

Trauma-Associated Pulmonary Laceration in Dogs-A Cross Sectional Study of 364 Dogs.

In this study, we describe the computed tomography (CT) features of pulmonary laceration in a study population, which included 364 client-owned dogs that underwent CT examination for thoracic trauma, and compared the characteristics and outcomes of dogs with and without CT evidence of pulmonary laceration. Lung laceration occurred in 46/364 dogs with thoracic trauma (prevalence 12.6%). Dogs with lung laceration were significantly younger than dogs in the control group (median 42 months (interquartile range (IQR) 52.3) and 62 months (IQR 86.1), respectively; p = 0.02). Dogs with lung laceration were significantly heavier than dogs without laceration (median 20.8 kg (IQR 23.3) and median 8.7 kg (IQR 12.4 kg), respectively p < 0.0001). When comparing groups of dogs with thoracic trauma with and without lung laceration, the frequency of high-energy motor vehicle accident trauma was more elevated in dogs with lung laceration than in the control group. No significant differences were observed between groups regarding tge frequency and length of hospitalization and 30-day mortality. Similar to the human classification scheme, four CT patterns are described in dogs in this study: Type 1, large pulmonary laceration located deeply in the pulmonary parenchyma or around an interlobar fissure; Type 2, laceration occurring in the paraspinal lung parenchyma, not associated with vertebral fracture; Type 3, subpleural lung laceration intimately associated with an adjacent rib or vertebral fracture; Type 4, subpleural lesions not associated with rib fractures. Complications were seen in 2/46 dogs and included lung abscess and collapse.

Stifle Joint Rotational Variation in Extended Stifles in Healthy Dogs Undergoing Computed Tomography Examinations.

The aim of this study was to evaluate stifle joint rotational stability in response to body position and repositioning in dogs undergoing computed tomography (CT). Nine dogs (18 stifles) with no history or clinical signs of stifle injury undergoing CT examinations for other reasons were included in the study. Dogs were positioned in alternating dorsal and sternal recumbency with the pelvic limbs extended caudally and unrestrained, for a total of four examinations. Scans included the entire tibia and distal femur. Using defined landmarks on the tibia and femur, stifle joint rotational angles were measured from multiplanar reconstructions made by two independent observers, and repositioning effects and intra- and interobserver agreement evaluated. Repositioning produced repeatable stifle joint rotational angles (pooled within-subject standard deviations of 0.9° and 1.4°) and intraobserver repeatability was good (within-subject standard deviations 1.4°), but interobserver agreement was poor. Dorsal and sternal positioning produced equivalent results. The results indicate that little rotation occurs in the healthy extended canine stifle joint during positioning for CT and support CT as a method for assessing limb alignment around the stifle joint, provided that the limb distal to the femorotibial joint is unrestrained. Clinically, it is likely that measured changes in rotational angles across (and distant to) the stifle joint are real, rather than being due to rotation artefact during imaging.

Computed tomography evaluation of early post-operative complications of the Whipple procedure.

PurposePancreaticoduodenectomy (the Whipple procedure) is the only potential curative treatment for periampullary tumours. Although mortality due to the procedure is gradually decreasing, the morbidity rates remain high. This study aimed to evaluate early computed tomography (CT) findings in patients suspected of complications following the Whipple procedure.Material and methodsThe CT images of patients who underwent the conventional Whipple procedure between January 2015 and January 2019 and underwent CT examination for the detection of early postoperative complications were retrospectively evaluated by two radiologists.ResultsThe Whipple operation was performed to 65 patients, and the CT scans of 45 patients (30 males, 15 females) were included in the study. There were no complications in 21 patients. Complications were present in 24 patients (53.33%), of whom 13 had more than one complication. Eight patients had fluid collection in the operation site, two had haematoma, 10 had an abscess, and five had a pancreatic fistula. In addition, a hepatic abscess was detected in one patient, delayed gastric emptying in six patients, anastomotic leakage from the gastrojejunostomy line in two patients, superior mesenteric vein (SMV) thrombosis in two patients, and intraluminal haemorrhage and active extravasation in one patient. Mortality due to complications occurred in one patient in the early postoperative period. Other complications were treated by spontaneous, surgical or percutaneous interventional procedures.ConclusionsDespite the decreasing mortality rates in recent years, the Whipple procedure is risky and has high morbidity even when performed in experienced centres. CT is the adequate imaging modality for the evaluation of this anatomically altered region and detection of complications.

The effect of patient positioning on adrenal gland linear measurements estimated from computed tomographic images in healthy beagle dogs

Considering that recumbency can lead to a change in localization, detectability of distinct margins and thus measurement of the organs and reconstruction quality, it is of value to evaluate the effect of positioning on the objective evaluation of abdominal organs in computed tomography (CT). The objective of the present study was to evaluate the effect of patient decubitus on adrenal gland CT biometry. For this purpose, 6 clinically healthy adult beagle dogs underwent CT examination in 4 recumbencies. The various adrenal gland's size measurements were performed by 2 observers. Statistical analyses revealed that repeatability and reproducibility was the highest on the ventral and right lateral recumbencies, respectively. Significant differences were found in the left adrenal gland's length between the different positions (P < 0.001) and the left adrenal gland's width of the cranial pole measured in the dorsal plane (P < 0.04). The measurements on the parasagittal images differed significantly for the left adrenal length (P = 0.01), cranial pole height (P = 0.03), the right adrenal gland's lateral limb's length (P = 0.05) and medial limb's caudal poles height (P < 0.01). The caudal pole height of the right adrenal gland's medial limb was significantly different (P < 0.01) in all positions on the transverse images. In addition, the adrenal position differed significantly, except for the left adrenal gland relative to the nearest renal vessel (P = 0.1). According to these results, it is recommended to perform a CT of adrenal glands always in the same recumbency. If adrenal glands are evaluated on images taken in various recumbencies, we suggest relying on the measurements made on transverse plane images.

Morphological characteristics of radicular cysts using computed tomography.

The purpose of this study was to evaluate computed tomography (CT) findings of radicular cysts with a focus on location, size, and condition of the surrounding bone. Subjects comprised 60 men and 86 women (mean age 47.2years) with histopathologically confirmed radicular cysts who underwent CT examination between 2012 and 2014. Mesiodistal and buccolingual diameters were measured at the location where the lesion appeared to be largest on CT axial images. Of the 146 cases, 103 lesions were in the maxilla and 43 were in the mandible. Mesiodistal diameter of the maxillary lesions was significantly larger than that of the mandibular lesions. However, the ratio of mesiodistal diameter to buccolingual diameter in the mandible was significantly larger than that in the maxilla. Bone expansion was more significant in the maxilla than in the mandible. Mesiodistal and buccolingual diameters in only the maxilla and perilesional sclerotic radiolucency in images of both jaws were significantly associated with the severity of clinical symptoms. The findings suggest that radicular cysts in the maxilla are accompanied by bone expansion in the mesiodistal and buccolingual directions and those in the mandible progress in the mesiodistal direction without bone expansion. Clinical acute symptoms (pain and swelling) are correlated with lesion size in the maxilla; such a correlation is not clear for mandibular lesions, and discovery of mandibular lesions may, therefore, be delayed.