Common Computed Tomography Research Articles

CT patterns and serial CT Changes in lung Cancer patients post stereotactic body radiotherapy (SBRT)

BackgroundTo evaluate computed tomography (CT) patterns of post-SBRT lung injury in lung cancer and identify time points of serial CT changes.Materials and methodsOne hundred eighty-three tumors in 170 patients were evaluated on sequential CTs within 29 months (median). Frequencies of post-SBRT CT patterns and time points of initiation and duration were assessed. Duration of increase of primary lesion or surrounding injury without evidence of local recurrence and time to stabilization or local recurrence were evaluated.ResultsPost-SBRT CT patterns could overlap in the same patient and were nodule-like pattern (69%), consolidation with ground glass opacity (GGO) (41%), modified conventional pattern (39%), peribronchial/patchy consolidation (42%), patchy GGO (24%), diffuse consolidation (16%), “orbit sign” (21%), mass-like pattern (19%), scar-like pattern (15%) and diffuse GGO (3%). Patchy GGO started at 4 months post-SBRT. Peribronchial/patchy consolidation and consolidation with GGO started at 4 and 5 months respectively. Diffuse consolidation, diffuse GGO and orbit sign started at 5, 6 and 8 months respectively. Mass-like, modified conventional and scar-like pattern started at 8, 12 and 12 months respectively. Primary lesion (n = 11) or surrounding injury (n = 85) increased up to 13 months. Primary lesion (n = 119) or surrounding injury (n = 115) started to decrease at 4 and 9 months respectively. Time to stabilization was 20 months. The most common CT pattern at stabilization was modified conventional pattern (49%), scar-like pattern (23%) and mass-like pattern (12%). Local recurrence (n = 15) occurred at a median time of 18 months.ConclusionDifferent CT patterns of lung injury post-SBRT appear in predictable time points and have variable but predictable duration. Familiarity with these patterns and timeframes of appearance helps differentiate them from local recurrence.

Establishing diagnostic reference levels for CT examinations in the south region of Saudi Arabia

This study aims to establish local diagnostic reference levels (DRLs) for the most common computed tomography (CT) examinations in the southern region of Saudi Arabia. Data has been collected from 399 adult patients (234 males and 165 females) and 76 paediatric patients (51 males and 25 females) undergoing different CT procedures. These procedures are as follows: CT chest (adults: 107, paediatrics: 10), abdomen (adults: 121, paediatrics: 11), pelvis (adults: 74), brain (adults: 48, paediatrics: 55), abdominopelvic (AP) (adults: 17), liver Tri-phase (adults: 12), and chest abdomen pelvis (CAP) CT scan (adults: 20). For adult patients, the CTDIvol for chest, abdomen, pelvis, brain, AP, CAP, and liver tri-phase procedures ranged from 3.74 to 22.61 mGy, 2.52–51.40 mGy, 9.53–38.63 mGy, 5.72–5109.0 mGy, 2.54–17.16 mGy, 3.93–29.14 mGy, and 12.35–40.55 mGy, respectively. Similarly, CTDIvol for chest, abdomen, and brain paediatric procedures ranged from 3.15 to 5.25 mGy, 3.23–224.32 mGy, and 16.47–109.08 mGy, respectively. For adult patients, the study observed that dose length product for chest, abdomen, pelvis, brain, AP, CAP, and liver tri-phase procedures ranged from 136.50 to 1124.13 mGy cm, 137.70–1403.66 mGy cm, 244.14–1205.30 mGy cm, 98.20–1163.0 mGy cm, 6.43–893.60 mGy cm, 284.10–2216.70 mGy cm, and 415.20–2055.90 mGy cm, respectively. Similarly, dose length product for chest, abdomen, and brain paediatrics procedures ranged from 122.81 to 175.34 mGy cm, 5.34–553.51 mGy cm, and 333.60–2084.0 mGy cm, respectively. Radiation doses varied between hospitals, with wide variation in technical settings suggesting an urgent need for establishing a national DRL as a necessary part for dose optimisation.

Feline upper respiratory tract disease - Computed tomography and laboratory diagnostic.

Background and Aim:Upper respiratory tract disease (URTD) is prevalent in cats, and diagnosis can be challenging. This study aimed to determine the most common causes of cat URTD in Latvia and describe computed tomography (CT) and laboratory diagnostic findings.Materials and Methods:The present retrospective study included a total of 94 cats who were diagnosed with URTD. All cats underwent CT, and 50 of them had additional diagnostic tests, such as histology and respiratory infection polymerase chain reaction (PCR) testing.Results:The most common CT finding was rhinosinusitis (55.32%) followed by nasal neoplasia (26.6%) and nasopharyngeal polyp (14.89%), but in three cats, a cause of respiratory symptoms was larynx neoplasia, nasal dermoid cyst, and an oronasal fistula. PCR test showed that the most cause of rhinosinusitis was Mycoplasma felis. Nasopharyngeal polyp as the primary diagnosis was identified in 14 cats from 3 months to 6 years, with an average age of 1.85 ± 1.915 years, and 54% of cats were female. Nasal neoplasia as a primary CT diagnosis was determined in 25 cats at the age of 5–18 years, with an average age of 10.56 ± 3.416 years. Histology diagnosis included four types of neoplasia – squamous cell carcinoma, sarcoma, adenocarcinoma, and aplastic carcinoma.Conclusion:This study describes the most common CT and laboratory findings in cats with URTD. Included information will be helpful for general veterinary practitioners and researchers and will update their knowledge on feline URTD.

Role of Computed Tomography in The Evaluation of Focal Liver Lesions

The liver lesions have marked differences across geographic regions and ethnic groups. In order to avoid inappropriate diagnosis and unnecessary surgery, Computed Tomography (CT) being a non-invasive imaging modality and with high sensitivity, provides better detection and distinguishing benign from malignant focal liver tumor lesions. Objective: To determine the role of Computed Tomography in the evaluation of focal liver lesions. Methods: A descriptive study was conducted at Government Kot Khawaja Saeed Teaching Hospital, Lahore, Pakistan. A sample size of 124 patients of both genders, age ranging from 22-90 years were enrolled in this study with a convenient sampling technique. Pregnant females and patients having renal insufficiency were excluded. The variables used to obtain data were: Age, Gender, Presenting complex clinical risk factors, CT findings, and other diagnoses. Toshiba Aquilion 16 CT scanner with KV 80-135 and MAs 500 was used. Injections of 1.5ml/kg IV contrast were given to patients, with a total dosage of 80-100ml at 4.5ml/sec through an 18G intravenous catheter. After contrast injection liver was scanned at 3 different time points or phases. All of the factors mentioned above were documented and kept in each patient's individual case record form (CRF). Data was gathered during the time frame specified. To examine the acquired data and arrange and compile the results, the statistical tool SPSS version 24 was used. Descriptive statistics and a Chi-square test was applied to check the comparison. Results: Among 124 individuals, 77 (62.1%) individuals were males, and 47 (37.9%) individuals were female. Average age of patients was 53.85±13.50 years. Multiple lesions were observed in 79 (63.7%) individuals had multiple lesions while 45 (36.3%) individuals had a single lesion. 94 (75.8%) individuals had malignant lesions while 30 (24.2%) had benign lesions. Lesions were more common in males than in females. The most common presenting complex clinic risk factor was hepatitis C virus with 45 individuals (36.3%) with Hepatitis C +ve. The most common CT finding was Hepatocellular Carcinoma with 41(33.1%). Conclusions: The study concluded that Computed Tomography being a non-invasive imaging modality and with high sensitivity, provides better detection and differentiation between benign and malignant focal liver lesions.

Glenoid Version Assessment When the CT Field of View Does Not Permit the Friedman Method: The Robertson Method.

Background:To improve spatial resolution, current clinical shoulder cross-sectional imaging studies reduce the field of view of the shoulder, excluding the medial scapula border and preventing glenoid version measurement according to the Friedman method.Purpose:To evaluate a method to accurately and reliably measure glenoid version on cross-sectional shoulder images when the medial scapula border is not included in the field of view, and to establish measurements equivalent to the Friedman method.Study Design:Controlled laboratory study.Methods:Sixty-five scapulae underwent computed tomography (CT) scanning with an optimal shoulder CT-positioning protocol. Glenoid version was measured on CT images of the full scapula using the Friedman method. We developed a measurement method (named the Robertson method) based on the glenoid vault version from partial scapula images, with a correction angle subtracted from the articular-surface-glenoid vault measurement. Comparison with the Friedman method defined the accuracy of the Robertson method. Three observers tested inter- and intraobserver reliability of the Robertson method. Accuracy was statistically evaluated with t tests and reliability with the intraclass correlation coefficient (ICC).Results:The statistical distribution of glenoid version was similar to published data,–0.5° ± 3° [mean ± SD]. The initial measurement using the Robertson method resulted in a more retroverted angle compared with the Friedman method, and a correction angle of 7° was then applied. After this adjustment, the difference between the 2 methods was nonsignificant (0.1° ± 4°; P > .65). Reliability of the Robertson method was excellent, as the interrater ICC was 0.77, the standard error of measurement (SEM) was 1.1° with P < .001. The intrarater ICC ranged between 0.84 and 0.92, the SEM ranged between 0.9° and 1.2° with P < .01.Conclusion:A validated glenoid version measurement method is now available for current clinical shoulder CT protocols that reliably create Friedman-equivalent values.Clinical Relevance:Friedman-equivalent values may be made from common clinical CTs of the shoulder and compared with prior and future Friedman measurements of the scapula.

Post COVID-19 fitness to dive assessment findings in occupational and recreational divers.

It is now known that COVID-19 has long term effects that may not correlate with clinical severity of disease. The known pulmonary and cardiovascular changes as well as thrombotic tendency could predispose to diving accidents. We aimed to investigate COVID-19 related changes that may cause disqualification from diving among divers who recovered from the disease. Occupational and recreational divers who applied for fitness to dive (FTD) assessment after COVID-19 infection were included. Routine FTD assessments were performed. Details of COVID-19 history were evaluated. Lung computed tomography (CT) scans were advised if not previously performed or if there were COVID-19 related changes in previous scans. Divers with pathological findings were restrained from diving and followed prospectively. Forty-three divers were analysed. Thirteen divers were restrained from diving, all due to persistent COVID-19 related changes in lung CT. The prevalence of CT with at least one lung lesion was 68.2% at the time of diagnosis, 73.3% in the first three months after diagnosis and 19.2% later. The most common CT findings were glass ground opacities and fibrotic changes. Demographic characteristics and COVID-19 history of divers deemed 'unfit' were similar to those deemed 'fit'. Divers who recover from COVID-19 should undergo FTD assessments before resuming diving. A chest CT performed at least three months after diagnosis may be suggested.

Computed tomography findings and prognosis in older COVID-19 patients

BackgroundIn older and multimorbid patients, chronic conditions may affect the prognostic validity of computed tomography (CT) findings in COVID-19. This study aims at assessing to which extent CT findings have prognostic implications in COVID-19 older patients.Methods Hospitalized COVID-19 patients aged 60 years or more enrolled in the multicenter, observational and longitudinal GeroCovid study who underwent chest CT were included. Patients were stratified by tertiles of age and pneumonia severity to compare CT findings. Hierarchical clustering based on CT findings was performed to identify CT-related classificatory constructs, if any. The hazard ratio (HR) of mortality was calculated for individual CT findings and for clusters, after adjusting for potential confounders.Results380 hospitalized COVID-19 patients, with a mean age of 78 (SD:9) years, underwent chest CT scan. Ground glass opacity (GGO), consolidation, and pleural effusion were the three most common CT findings, with GGO prevalence decreasing from younger to older patients and pleural effusion increasing. More severe the pneumonia more prevalent were GGO, consolidation and pleural effusion. HR of mortality was 1.94 (95%CI 1.24–3.06) for pleural effusion and 13 (95%CI 6.41–27) for cluster with a low prevalence of GGO and a high prevalence of pleural effusion (“LH”), respectively. Out of the three CT based clusters, “LH” was the only independent predictor in the multivariable model.ConclusionsPleural effusion qualifies as a distinctive prognostic marker in older COVID-19 patients. Research is needed to verify whether pleural effusion reflects COVID-19 severity or a coexisting chronic condition making the patient at special risk of death.Trial registrationClinicalTrials.gov: NCT04379440

Diagnostic pitfalls in computed tomography of the chest.

Anatomical variants and imaging artifacts on thoracic computed tomography (CT), when unrecognized as such, can lead to radiological misinterpretation and erroneous diagnosis. This is a concise review of 15 common CT diagnostic pitfalls due to anatomical variants and imaging artifacts which have potential to be misinterpreted as significant pathology, such as neoplasia, infection, traumatic injury, interstitial lung disease, pleural disease, or vascular lesions.

Pancreatic body cancer presenting with dysphagia and palpable abdominal mass being mistaken for gastric gastrointestinal stromal tumor: "Case report".

Introduction and importanceBody and tail pancreatic cancers account for one third of pancreatic ductal adenocarcinomas (PDACs). Dysphagia is an extremely rare manifestation of pancreatic cancer that may follow direct invasion of primary pancreatic cancer to esophagus. Pancreatic cancer can be confused with either pancreatic or peripancreatic lesions like gastrointestinal stromal tumors (GISTs) on diagnostic computed tomography (CT) scans. Undifferentiated pancreatic cancer, which is a rare variant of pancreatic ductal adenocarcinoma rarely, present with palpable abdominal mass. The aim of this case report is to show the rare presentation of this deadly malignancy with dysphagia and palpable abdominal mass which was mistaken on CT scan for gastric gastrointestinal stromal tumor.Presentation of the caseA 60 years old male farmer presented with progressive dysphagia to solid food of 3 months duration. He has no history of smoking, diabetes or alcohol intake. Physical examination showed hard epigastric mass with poorly defined borders. Imaging suggested gastrointestinal stromal tumor found to be primary pancreatic body cancer at laparotomy. Biopsy later confirmed undifferentiated pancreatic cancer.DiscussionThe presentation of pancreatic ductal adenocarcinoma is nonspecific. Presence of clinical symptoms indicates advanced disease. Pancreatic body cancer has poor prognosis due to late presentation of the disease as compared to its counter pancreatic head cancer. CT scan has 85% diagnostic accuracy.ConclusionBoth surgeons and radiologists should be familiar with common and uncommon CT scan findings of pancreatic ductal adenocarcinoma as this can avoid unnecessary invasive investigation or treatment.

Establishment of national diagnostic reference levels for computed tomography procedures in Sri Lanka: first nationwide dose survey

The main purpose of this study was to establish for the first time national diagnostic reference levels (NDRLs) for common computed tomography (CT) procedures in Sri Lanka. Patient morphometric data, exposure parameters and dose data such as volume CT dose index (CTDI) and dose–length product (DLP) were collected from 5666 patients who underwent 22 types of procedure. The extreme dose values were filtered before analysis to ensure that the data come from standard size patients. The median of the dose distribution was calculated for each institution, and the third quartile value of the median distribution was considered as the NDRL. Based on the inclusion and exclusion criteria, data from 4592 patients and 17 procedure types were considered for establishment of a NDRL, covering 41% of the country’s CT machines. The proposed NDRLs based on CTDI and DLP were: non-contrast-enhanced (NC) head, 82.2 mGy/1556 mGy cm; contrast-enhanced (CE) head, 82.2 mGy/1546 mGy cm; chest NC, 7.4 mGy/350 mGy cm; chest CE, 8.3 mGy/464 mGy cm; abdomen NC, 10.5 mGy/721 mGy cm; abdomen arterial (A) phase, 13.4 mGy/398 mGy cm; abdomen venous (V) phase, 10.8 mGy/460 mGy cm; abdomen delay (D) phase, 12.6 mGy/487 mGy cm; sinus NC, 30.2 mGy/452 mGy cm; lumbar spine NC, 24.1 mGy/1123 mGy cm; neck NC, 27.5 mGy/670 mGy cm; high-resolution CT of chest, 10.3 mGy/341 mGy cm; kidneys ureters and bladder NC, 19.4 mGy/929 mGy cm; chest to pelvis (CAP) NC, 10.8 mGy/801 mGy cm; CAP A, 10.4 mGy/384 mGy cm; CAP V, 10.5 mGy/534 mGy cm; CAP D, 16.8 mGy/652 mGy cm. Although the proposed NDRLs are comparable with those of other countries, the observed broad dose distributions between the CT machines within Sri Lanka indicate that dose optimisation strategies for the country should be implemented for most of the CT facilities.

Prognostic findings for ICU admission in patients with COVID-19 pneumonia: baseline and follow-up chest CT and the added value of artificial intelligence.

Infection with SARS-CoV-2 has dominated discussion and caused global healthcare and economic crisis over the past 18 months. Coronavirus disease 19 (COVID-19) causes mild-to-moderate symptoms in most individuals. However, rapid deterioration to severe disease with or without acute respiratory distress syndrome (ARDS) can occur within 1–2 weeks from the onset of symptoms in a proportion of patients. Early identification by risk stratifying such patients who are at risk of severe complications of COVID-19 is of great clinical importance. Computed tomography (CT) is widely available and offers the potential for fast triage, robust, rapid, and minimally invasive diagnosis: Ground glass opacities (GGO), crazy-paving pattern (GGO with superimposed septal thickening), and consolidation are the most common chest CT findings in COVID pneumonia. There is growing interest in the prognostic value of baseline chest CT since an early risk stratification of patients with COVID-19 would allow for better resource allocation and could help improve outcomes. Recent studies have demonstrated the utility of baseline chest CT to predict intensive care unit (ICU) admission in patients with COVID-19. Furthermore, developments and progress integrating artificial intelligence (AI) with computer-aided design (CAD) software for diagnostic imaging allow for objective, unbiased, and rapid assessment of CT images.

Features on Computed Tomography That Correlate With Acute Appendicitis.

Background: The purpose of this study is to investigate the relevant findings in adult patients admitted to Cabell Huntington Hospital who were diagnosed with acute appendicitis. Methods: Patients who had the postoperative diagnosis of acute appendicitis and a preoperative computed tomography (CT) scan from January 2011 through December 2016 were included in this retrospective chart review. Results: There were 592 patients. A thick, edematous appendix was the most common CT finding in acute appendicitis. The average diameter was 12.6mm. The wall thickness correlated to the diameter of the appendix (P < 0.001). For comparison, we reviewed the CT scans of 50 trauma patients who had normal abdominal CT scans. The average diameter of a normal appendix was 4.9mm (SD 1.139) with a range of 4-7mm. Interestingly, the admission white blood cell count (P = 0.0372) as well as the thickness of the appendix (P < 0.0001) were strongly associated with increased length of stay. Conclusions: An appendiceal diameter greater than 9mm should be considered abnormal and associated with acute appendicitis. Appendiceal size, white blood cell count, and age correlate with length of stay. Early antibiotics and early surgical intervention may decrease length of stay.

Evaluation of thorax computed tomographic findings in COVID-19 variant cases.

BackgroundBecause of genetic mutations occurring during viral replication, new SARS-CoV-2 variants will continue to emerge. Throughout the COVID-19 pandemic, thorax computed tomographic (CT) findings have played a crucial role in the diagnosis and follow-up of patients with COVID-19. In this study, we compared the thorax CT findings of patients infected with SARS-CoV-2 variants (variant group) with those of patients infected with the non-variant strain (non-variant group) to assess if thorax CT findings may be utilized to discriminate between the groups. Furthermore, we compared demographic and laboratory data between the groups.MethodsThe study comprised a total of 77 patients who presented to our hospital with a preliminary diagnosis of COVID-19 based on clinical symptoms, a positive oropharyngeal/nasopharyngeal swab RT-PCR testing, and thorax CT examinations. Patients' laboratory and demographic features as well as thorax CT findings were retrospectively evaluated, and the results were grouped according to RT-PCR results.ResultsThere were 42 patients in the non-variant group and 35 patients in the variant group. The average age of patients infected with the non-variant strain, alpha variant, and gamma variant was 63.52 ± 14.87 years, 54.86 ± 14.31 years, and 59.4 ± 17.79 years, respectively. The average age of the variant group was significantly lower than that of the non-variant group. There was no significant difference in thorax CT findings between the groups, and consolidation, ground glass densities, and cobblestone pattern in the bilateral lower lobes and peripheral areas were the most common thorax CT findings in both the groups.ConclusionThere is no significant difference in thorax CT findings between the variant and non-variant groups. Therefore, clinical and laboratory characteristics should take precedence over thorax CT findings for distinguishing between patients infected with SARS-CoV-2 variants and the non-variant strain.

Computed tomography lung parenchymal descriptions in routine radiological reporting have diagnostic and prognostic utility in patients with idiopathic pulmonary arterial hypertension and pulmonary hypertension associated with lung disease.

BackgroundPatients with pulmonary hypertension (PH) and lung disease may pose a diagnostic dilemma between idiopathic pulmonary arterial hypertension (IPAH) and PH associated with lung disease (PH-CLD). The prognostic impact of common computed tomography (CT) parenchymal features is unknown.Methods660 IPAH and PH-CLD patients assessed between 2001 and 2019 were included. Reports for all CT scans 1 year prior to diagnosis were analysed for common lung parenchymal patterns. Cox regression and Kaplan–Meier analysis were performed.ResultsAt univariate analysis of the whole cohort, centrilobular ground-glass (CGG) changes (hazard ratio, HR 0.29) and ground-glass opacification (HR 0.53) predicted improved survival, while honeycombing (HR 2.79), emphysema (HR 2.09) and fibrosis (HR 2.38) predicted worse survival (all p<0.001). Fibrosis was an independent predictor after adjusting for baseline demographics, PH severity and diffusing capacity of the lung for carbon monoxide (HR 1.37, p<0.05). Patients with a clinical diagnosis of IPAH who had an absence of reported parenchymal lung disease (IPAH-noLD) demonstrated superior survival to patients diagnosed with either IPAH who had coexistent CT lung disease or PH-CLD (2-year survival of 85%, 60% and 46%, respectively, p<0.05). CGG changes were present in 23.3% of IPAH-noLD and 5.8% of PH-CLD patients. There was no significant difference in survival between IPAH-noLD patients with or without CGG changes. PH-CLD patients with fibrosis had worse survival than those with emphysema.InterpretationRoutine clinical reports of CT lung parenchymal disease identify groups of patients with IPAH and PH-CLD with significantly different prognoses. Isolated CGG changes are not uncommon in IPAH but are not associated with worse survival.

Establishing local diagnostic reference levels for adult computed tomography in Morocco

In Morocco, the radiation doses received by adult patients are increasing due to the number of CT examinations performed and the larger number of computed tomography (CT) scanners installed. The aim of this study was to evaluate the radiation doses received by patients for the most common adult CT examinations in order to establish local diagnostic reference levels (DRLs). Data from 1016 adult patients were collected during 3 months from four Moroccan hospitals. Dose length product (DLP) and volumetric computed tomography dose index (CTDIvol) were evaluated by determining the 75th percentile as diagnostic reference levels for the most common examinations including head, chest and abdomen. The DRL for each examination was compared with other studies. The established DRLs in Morocco in terms of CTDIvol were 57.4, 12.3 and 10.9 for CT examinations of the head, chest, abdomen, respectively. For DLP, they were 1020, 632 and 714, respectively. These established DRLs for CTDIvol were almost similar to the UK DRLs at all examinations, higher than the Egyptian DRLs and lower than the Japanese DRLs at the head CT examination, lower than the DRLs from Egypt and Japan at the CT abdomen examination. In terms of DLP, the DRLs were higher than those of the British studies, lower than those of the Egyptian and Japanese studies at the head CT examination were higher at chest CT and lower at abdominal CT than those of all selected studies. The higher level of established DRLs in our study demonstrates the requirement of an optimization process while keeping a good image quality for a reliable diagnosis.

Computed tomography scan in COVID-19: a systematic review and meta-analysis.

PurposeComputed tomography (CT) scan is a commonly used tool for the diagnosis of the novel coronavirus disease 2019 (COVID-19), similarly to reverse transcription-polymerase chain reaction (RT-PCR). Because of the limitations of RT-PCR, there is growing interest in the usability of the CT scan. The present systematic review and meta-analysis aims to summarize the available data on the CT scan features of COVID-19.Material and methodsWe conducted a systematic search in electronic databases to find eligible studies published between 1 December 2019 and 4 April 2020, which investigated the computed tomographic features of patients with COVID-19. All preprint and peer-reviewed articles were included. No language limitation was applied. For proportional data, pooled prevalence was calculated using a Freeman-Tukey double arcsine transformation, with a 95% confidence interval (CI).ResultsEighty-six studies were eligible to be included in the meta-analysis. For 7956 patients, the most common CT findings were bilateral pattern of involvement (78%; 95% CI: 0.73-0.82; p < 0.001), involvement of more than 1 lobe (75%; 95% CI: 0.68-0.82; p < 0.001), ground-glass opacities (GGO) (73%; 95% CI: 0.67-0.78; p < 0.001), and peripheral distribution of signs (69%; 95% CI: 0.61-0.76; p < 0.001). Only 5% of patients had a normal CT scan (95% CI:0.03-0.07; p < 0.001). The proportion of paediatric patients (age < 18 years) with unremarkable CT findings was higher (40%; 95% CI: 0.27-0.55; p < 0.001). Subgroup analysis showed that patients with the severe or critical type of COVID-19 were more likely to have pleural effusion (RR 7.77; 95% CI: 3.97-15.18; p < 0.001) and consolidation (RR 3.13; 95% CI: 1.57-6.23; p < 0.001). CT results in patients with COVID-19 were comparable with those of people having pneumonia from other causes, except for the lower incidence of consolidation (RR 0.81; 95% CI: 0.71-0.91; p < 0.001) and higher risk of showing GGO (RR 1.45; 95% CI: 1.13-1.86; p < 0.001). The mortality rate was slightly higher in patients with bilateral involvement (RR 3.19; 95% CI: 1.07-9.49; p = 0.04).ConclusionsOur study results show that COVID-19 shares some features with other viral types of pneumonia, despite some differences. They commonly present as GGO along with vascular thickening, air bronchogram and consolidations. Normal CT images, lymphadenopathies, and pleural effusions are not common. Consolidations and pleural effusions correlate with more severe disease. CT features are different between COVID-19 and non-COVID-19 pneumonia. Also, they differ by age, disease severity, and outcomes within COVID-19 patients.

Comparison of Radiation Dose in CT Examinations At PIMS with European Commission Reference Doses

OBJECTIVE - The purpose of this study was to assess the radiation dose levels from common computed tomography (CT) examinations performed in Radiology Department of Pakistan Institute of Medical Sciences (PIMS), and evaluate these according to diagnostic reference levels (DRLs) proposed by European Commission (EC) guidelines, and thus contributing towards the establishment of local and national DRLs. To the best of our knowledge, this is the first study of its kind to explore radiation doses from CT examinations in Pakistan.&#x0D; STUDY DESIGN - This was a quantitative study conducted at PIMS, Islamabad, spanning a duration of eight weeks. Scan parameters and dose profile data of 1506 adults undergoing examinations of head, neck, chest and abdomen-pelvis regions, comprising of single- and multi-phase, contrast-enhanced and unenhanced studies. Dose indicators utilized by EC guidelines for DRLs include volume CT dose index (CTDIvol) and Dose Length Product (DLP) for single slice and complete examination radiation doses, respectively.&#x0D; METHOD - Values of CTDIvol, DLP and scan lengths were extracted from the CT operators console. Other control variables included gender, contrast enhancement and phasicity of study. IBM SPSS package was used to obtain descriptive statistics such as mean and quartiles.&#x0D; RESULTS - DRLs calculated as 75th percentile of CTDIvol, DLP for various anatomical regions are by and far comparable to European DRLs.&#x0D; CONCLUSION – This study describes institutional diagnostic reference levels for common CT exams in Islamabad and provides benchmark values for future reference. Our DRL values are mostly comparable to European and international DRLs. Similar, albeit large scale, surveys are recommended for establishment of local and national DRLs, eventually contributing towards development of regional DRLs.&#x0D; KEYWORDS: CTDIvol, DLP, Diagnostic Reference Levels, Computed Tomography, Radiation Monitoring, Scan length

Severity and Predictors of Outcome of Motorcycle-Associated Head Injury: An Experience from a Regional Neurosurgery Centre in Northern Nigeria

Motorcycle-associated head injury is one of the leading causes of disability and deaths, with its main victims being the motorcyclists, passengers, and pedestrians in their young productive age group. This study determines the role of severity and some predictive factors on survival and mortality of motorcycle-associated head injury. This is a cross-sectional study using data of patients managed for motorcycle-associated head injuries between December 2014 and November 2016. The patients' biodata, clinical findings, and management outcomes were analyzed using Statistical Packages for the Social Sciences version20. A total of 184 patients were analyzed, most of whom (81%) were aged ≤40 years and with a male dominance of 6.7:1. Pupillary abnormality was seen in 43.5% of the patients, and severe head injury occurred in 34.2% of the patients. Hemorrhagic contusion was the most common computed tomography (CT) finding (16.3%). Among 20.8% of the patients who died, 63.2% had severe head injury. Motorcycle-associated head injury predominantly occurred among young men who used a motorcycle for commercial purposes. The survival rate was higher among patients who had brain CT scan performed, extra-axial clots, and operative treatment. However, high mortality was seen among patients who could not afford brain CT scan, and who had bilateral pupillary dilatation, CT findings of abnormalities that are not surgically amenable, and severe head injury.

Follow-up study of pulmonary sequelae in discharged COVID-19 patients with diabetes or secondary hyperglycemia

PurposeTo determine chest CT changes 6 months and 12 months after the onset of coronavirus disease 2019 (COVID-19) in patients with diabetes or hyperglycemia and the risk factors for these residual lung abnormalities. MethodsIn total, 141 COVID-19 patients were assigned to group 1 (diabetes), group 2 (secondary hyperglycemia) or group 3 (controls). Initial and six- and twelve-month follow-up computed tomography (CT) scans were performed 16 days, 175 days and 351 days after symptom onset, respectively. CT findings and clinical and peak laboratory parameters were collected and compared. Univariable and multivariable logistic regression analyses were performed to identify the independent predictors for the presence of residual lung abnormalities at the 6-month follow-up exam. Seven variables (age; the presence of acute respiratory distress syndrome; the duration of hospitalization; the peak levels of lactate dehydrogenase (LDH) and C-reactive protein; and the initial total CT score) were chosen in the final multivariable models. ResultsAt the six-month follow-up, abnormalities were still observed on chest CT in 77/141 (54.6%) patients. Reticular patterns (40/141, 28.4%) and ground-glass opacities (GGOs) (29/141, 20.6%) were the most common CT abnormalities on the follow-up CT scans. Patients in Groups 1 and 2 had significantly higher incidences of residual lung abnormalities than those in Group 3 (65.4% and 58.3%, respectively vs. 36.6%; p < 0.05). Twelve months after disease onset, the chest CT changes persisted in 13/25 (52.0%) patients. A duration of hospitalization > 20 days (OR: 5.630, 95% CI: 1.394–22.744, p = 0.015), an LDH level ≥ 317 U/L (OR: 7.020, 95% CI: 1.032–47.743, p = 0.046) and a total CT score > 15 (OR: 9.919, 95% CI: 1.378–71.415, p = 0.023) were independent predictors of residual pulmonary abnormalities in patients with diabetes or secondary hyperglycemia. ConclusionsA considerable proportion of surviving COVID-19 patients with diabetes or secondary hyperglycemia had residual pulmonary abnormalities six months after disease onset, and we found evidence of persistent chest CT changes at the one-year follow-up. Residual lung abnormalities were associated with longer hospital stays, higher peak LDH levels and higher initial total CT scores.

Prognosis and Clinical Characteristics of Patients with Pancreatic Ductal Adenocarcinoma Diagnosed by Endoscopic Ultrasonography but Indeterminate on Computed Tomography.

Background/AimsEndoscopic ultrasonography (EUS) provides high-resolution images and is superior to computed tomography (CT) scan in diagnosing small pancreatic ductal adenocarcinoma (PDAC). As a result, the use of EUS for early detection of PDAC has attracted attention. This study aimed to identify the clinical and radiological characteristics of patients with PDAC diagnosed by EUS but not found on CT scan.MethodsThe medical records of patients diagnosed with PDAC at 12 tertiary referral centers in Korea from January 2003 to April 2019 were reviewed. This study included patients with pancreatic masses not clearly observed on CT scan but identified on EUS. The clinical characteristics and radiological features of the patients were analyzed, and survival analysis was performed.ResultsA total of 83 patients were enrolled. The most common abnormal CT findings other than a definite mass was pancreatic duct dilatation, which was identified in 61 patients (73.5%). All but four patients underwent surgery. The final pathologic stages were as follows IA (n=31, 39.2%), IB (n=8, 10.1%), IIA (n=20, 25.3%), IIB (n=17, 21.5%), III (n=2, 2.5%), and IV (n=1, 1.4%). The 5-year survival rate of these patients was 50.6% (95% confidence interval, 38.8% to 66.7%). Elevated liver function testing and R1 resection emerged as significant predictors of mortality in the multivariable Cox regression analysis.ConclusionsThis multicenter study demonstrated favorable long-term prognosis in patients with PDAC diagnosed by EUS but indeterminate on CT scan. EUS should be considered for patients with suspected PDAC but indeterminate on CT scan.