Comparison of Low- and Standard-Dose CT for the Diagnosis of Acute Appendicitis: A Meta-Analysis

Misdiagnosis of Acute Appendicitis Cases in the Emergency Room

Acute appendicitis (AA) is one of the most frequent surgical emergencies, especially in pediatric populations, with its misdiagnosis in emergency settings presenting significant health risks. This misdiagnosis leads to various complications, such as delayed treatment or unnecessary surgeries. Factors such as age, gender, and comorbidities contribute to diagnostic errors, leading to complications such as peritonitis and increased negative appendectomy rates. This underscores the importance of accurate clinical assessment and awareness of common pitfalls, such as cognitive biases and over-reliance on laboratory tests. This review delves into the prevalence of AA misdiagnosis, its health burden, and the challenges inherent in the diagnostic process. It scrutinizes the effectiveness of different diagnostic approaches, including clinical assessment and imaging techniques. The treatment paradigms for AA are also explored, focusing on surgical interventions and the potential of conservative treatments using antibiotics. The review underscores the criticality of precise diagnosis in preventing adverse outcomes and ensuring effective treatment.

Up-to-Date Diagnostic CT Standards for Acute Appendicitis: Wall Thickness and Intraluminal Fluid Thickness

Acute appendicitis is a prevalent condition that requires accurate and timely diagnosis and management to avoid potential complications. Classically, the diagnosis of appendicitis is made using the appendicular outer-to-outer wall diameter. In this study, we examined the sensitivity and specificity of computed tomography (CT) scans for diagnosing acute appendicitis using wall thickness and lumen thickness rather than diameter. This study included data from 350 patients who presented to the emergency department with clinically suspected acute appendicitis. All patients underwent a CT scan, and 62 radiologically positive patients underwent surgery. A radiological diagnosis was made using the conventional outer-to-outer wall diameter with a cut-off of 6 mm for a positive diagnosis. These 62 positive CT scans were reviewed and compared with surgical results. The study showed that a threshold of 2.25 mm for appendicular lumen thickness is an excellent diagnostic tool for acute appendicitis, demonstrating a high sensitivity of 96.4% and a lower specificity of 67%. In contrast, 1.6 mm wall thickness indicates acute appendicitis, with 81.8% sensitivity and 84% specificity. However, the wall thickness remains inferior to the conventionally used measurement of 6.75 mm for appendicular diameter, with a sensitivity of 87.5% and a specificity of 100%.

A different way to diagnosis acute appendicitis: machine learning

<b><br>Indroduction:</b> Machine learning is a branch of artificial intelligence based on the idea that systems can learn from data, identify patterns, and make decisions with minimal human intervention.</br> <b><br>Aim:</b> Our aim is to predict acute appendicitis, which is the most common indication for emergency surgery, using machine learning algorithms with an easy and inexpensive method.</br> <b><br>Materials and methods:</b> Patients who were treated surgically with a prediagnosis of acute appendicitis in a single center between 2011 and 2021 were analyzed. Patients with right lower quadrant pain were selected. A total of 189 positive and 156 negative appendectomies were found. Gender and hemogram were used as features. Machine learning algorithms and data analysis were made in Python (3.7) programming language.</br> <b><br>Results:</b> Negative appendectomies were found in 62% (n = 97) of the women and in 38% (n = 59) of the men. Positive appendectomies were present in 38% (n = 72) of the women and 62% (n = 117) of the men. The accuracy in the test data was 82.7% in logistic regression, 68.9% in support vector machines, 78.1% in k-nearest neighbors, and 83.9% in neural networks. The accuracy in the voting classifier created with logistic regression, k-nearest neighbor, support vector machines, and artificial neural networks was 86.2%. In the voting classifier, the sensitivity was 83.7% and the specificity was 88.6%.</br> <b><br>Conclusions:</b> The results of our study show that machine learning is an effective method for diagnosing acute appendicitis. This study presents a practical, easy, fast, and inexpensive method to predict the diagnosis of acute appendicitis.</br>.

Diagnostic accuracy of computed tomography in adults with suspected acute appendicitis at the emergency department in a private tertiary hospital in Tanzania

INTRODUCTION

The increasing incidence of acute appendicitis in sub-Saharan Africa emphasizes the need for accurate and reliable diagnostic tools. However, the variability in the diagnostic performance of computed tomography for suspected acute appendicitis coupled with comparatively higher negative appendectomy rates in this setting highlight a possible concern regarding the diagnostic accuracy. This study evaluated the diagnostic accuracy of a computed tomography scan for suspected acute appendicitis at the emergency department in Tanzania.

METHODS

A retrospective diagnostic accuracy study was conducted from July to October 2020. All patients above 14 years of age who presented at the emergency department with right iliac fossa abdominal pain of fewer than ten days and underwent computed tomography for suspected acute appendicitis were evaluated, and the Alvarado score was computed. Histological diagnosis and clinical follow-up of 14 days were considered the reference standard. Ethical clearance was sought from the Aga Khan University Ethical review committee.

RESULTS

176 patients were included in this study. The sensitivity, specificity, and diagnostic accuracy were 100% (95% CI 91.8-100), 96.9% (95% CI 92.2-99.1), and 96.9% (95% CI 93.1-98.3), respectively. The mean Alvarado score in those without acute appendicitis was 4 (95% CI 3.7-4.3) compared to a mean score of 6.6 (95% CI 6.0-7.2) amongst those with acute appendicitis. The area under the receiver operator characteristics curve of computed tomography was 98.4%, and that of the Alvarado score was 84.1%.

CONCLUSIONS

The diagnostic performance of computed tomography in this study is similar to that established elsewhere. However, the Alvarado score is not routinely used for the initial screening of suspected acute appendicitis patients. A threshold of Alvarado score of 4 as a guide to conduct computed tomography for suspected acute appendicitis would have decreased computed tomography use by 50%, and missed 4 cases. Implementation studies that address Alvarado score use should be conducted.

Predicting the Severity of Acute Appendicitis in Children Using Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR)

Introduction

The ability to predict risk of perforation in acute appendicitis (AA) could direct timely management and reduce morbidity. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are surrogate severity markers in infections. This study investigates the use of PLR and NLR as a marker for distinguishing uncomplicated (UA) and complicated appendicitis (CA) in children.

Materials and methods

This retrospective single-center study collected data between January 1, 2014, and December 31, 2020. Children between five and 17 years of age with histologically confirmed appendicitis were included. Cut-off values for NLR and PLR were determined by employing the receiver operating characteristic (ROC) curve with sensitivity and specificity in addition to regression analysis.

Results

A total of 701 patients were included with a median age of 13 years. Out of which 52% of the cohort was female. The difference between the NLR and PLR ratios between UA and CA was significant (p=0.05, Kruskal-Wallis). For UA, the area under the ROC curve (AUC) and cut-off for NLR and PLR were 0.741, 3.80 with 95% CI of 0.701-0.781 and 0.660, 149.25 with 95% CI of 0.618-0.703, respectively. In CA, using NLR and PLR, AUC and cut-off were 0.776, 8.86 with 95%CI of 0.730-0.822 and 0.694, 193.67 with 95%CI of 0.634-0.755, respectively. All were significant with p<0.001.

Conclusions

NLR and PLR are reliable, synergistic markers predicting complicated appendicitis which can guide non-operative management in children.

Diagnostic, Therapy and Complications in Acute Appendicitis of 19,749 Cases Based on Routine Data: A Retrospective Multicenter Observational Study

Background: Acute appendicitis is one of the most common emergencies in general surgery. The gold standard treatment is surgery. Complications may occur during or after an appendectomy. In addition to age, clinically important factors for the outcome after appendicitis seems to be the comorbidities and the stage of the appendicitis at the time of the operation. Large observational data describing these facts are missing. Methods: In this retrospective multicenter observational study, all inpatients over the age of 17 years with a diagnosis of acute appendicitis in 47 hospitals of the Clinotel Hospital Group between 2010 and 2017 were included. Results: A total of 19,749 patients with acute appendicitis were operated on. The number of patients with more than five secondary diagnoses has increased from 8.4% (2010) to 14.5% (2017). The number of secondary diagnoses correlates with the ages of the patients and leads to a significantly longer hospital stay. Computer tomography (CT) has gained in importance in recent years in the diagnosis of acute appendicitis. A total of 19.9% of patients received a CT in 2017. Laparoscopic appendectomy increased from 88% in 2010 to 95% in 2017 (p < 0.001). The conversion rate did not change relevant in the study period (i.e., 2.3% in 2017). Appendicitis with perforation, abscess, or generalized peritonitis was observed in 24.8% of patients. Mortality was 0.6% during the observation period and was associated with age and the number of secondary diagnoses. The analysis is based on administrative data collected primarily for billing purposes, subject to the usual limitations of such data. This includes partially incomplete clinical data. Conclusions: Multimorbidity is increasingly present in patients with acute appendicitis. Mortality is still in an acceptably low range with no increase. A CT scan is necessary for a precise diagnosis in unclear clinical situations to avoid unnecessary operations and was performed more often at the end of the study than at the beginning.

Low-Dose Abdominal CT for Evaluating Suspected Appendicitis: Recommendations for CT Imaging Techniques and Practical Issues

A vast disparity exists between science and practice for CT radiation dose. Despite high-level evidence supporting the use of low-dose CT (LDCT) in diagnosing appendicitis, a recent survey showed that many care providers were still concerned that the low image quality of LDCT may lead to incorrect diagnoses. For successful implementation of LDCT practice, it is important to inform and educate the care providers not only of the scientific discoveries but also of concrete guidelines on how to overcome more practical matters. Here, we discuss CT imaging techniques and other practical issues for implementing LDCT practice.

De Garengeot hernias. Over a century of experience. A systematic review of the literature and presentation of two cases

De Garengeot hernia is a rare femoral hernia that contains the vermiform appendix. It has always been a subject of interest, mainly because of its uncommon entity, but also because of the diagnostic challenge it presents and the lack of consensus in its surgical management. It mainly presents as an emergency, with strangulation of the femoral hernia and acute inflammation of the appendix. The purpose of this study is to present two cases of De Garengeot hernias, the different surgical approach in each one and to perform a systematic literature review on all published accounts of De Garengeot hernias focusing on the surgical management of the hernias that contained an inflamed appendix. A literature search was performed using the keywords 'De Garengeot hernia' and 'appendicitis in femoral hernia'. All the published papers in the English language from 1898 to the end of 2019, as well as two patients from Lewisham and Greenwich NHS Trust, were included. There were 110 female vs 17 males. The majority of the described approaches were via either a Lockwood, or a transinguinal (Lothestein/McVay) incision. Most of the operations were done with an open incision. In the presence of an inflamed appendix, most hernias were repaired with sutures. Forty-one patients had their hernia repaired with non-absorbable sutures and four with absorbable. Most of the patients recovered without complications and were discharged after an average of 4.82 days.

Ultra-low-dose computed tomography and its utility in wrist trauma in the emergency department

BACKGROUND

The use and frequency of computed tomography (CT) are increasing day by day in emergency departments (ED). This increases the amount of radiation exposed.

PURPOSE

To evaluate the image quality obtained by ultra-low-dose CT (ULDCT) in patients with suspected wrist fractures in the ED and to investigate whether it is an alternative to standard-dose CT (SDCT).

MATERIAL AND METHODS

This is a study prospectively examining 336 patients who consulted the ED for wrist trauma. After exclusion criteria were applied, the patients were divided into the study and control groups. Then, SDCT (120 kVp and 100 mAs) and ULDCT (80 kVp and 5 mAs) wrist protocols were applied simultaneously. The images obtained were evaluated for image quality and fracture independently by a radiologist and an emergency medical specialist using a 5-point scale.

RESULTS

The effective radiation dose calculated for the control group scans was 41.1 ± 2.1 µSv, whereas the effective radiation dose calculated for the study group scans was 0.5 ± 0.0 µSv. The effective radiation dose of the study group was significantly lower than that of the control group (P < 0.01). The CT images in the study group showed no significant differences in the mean image quality score between observer 1 and observer 2 (3.4 and 4.3, respectively; P = 0.58). Both observers could detect all fractures using the ULDCT images.

CONCLUSION

ULDCT provides high-quality images in wrist traumas while reducing the radiation dose by approximately 98% compared to SDCT without any changes in diagnostic accuracy.

Low-Dose Abdominal CT for Evaluating Suspected Appendicitis in Adolescents and Young Adults: Review of Evidence

Due to its excellent diagnostic performance, CT is the mainstay of diagnostic test in adults with suspected acute appendicitis in many countries. Although debatable, extensive epidemiological studies have suggested that CT radiation is carcinogenic, at least in children and adolescents. Setting aside the debate over the carcinogenic risk of CT radiation, the value of judicious use of CT radiation cannot be overstated for the diagnosis of appendicitis, considering that appendicitis is a very common disease, and that the vast majority of patients with suspected acute appendicitis are adolescents and young adults with average life expectancies. Given the accumulated evidence justifying the use of low-dose CT (LDCT) of only 2 mSv, there is no reasonable basis to insist on using radiation dose of multi-purpose abdominal CT for the diagnosis of appendicitis, particularly in adolescents and young adults. Published data strongly suggest that LDCT is comparable to conventional dose CT in terms of clinical outcomes and diagnostic performance. In this narrative review, we will discuss such evidence for reducing CT radiation in adolescents and young adults with suspected appendicitis.

Impact of COVID-19 on the incidence of CT-diagnosed appendicitis and its complications in the UK and Sweden

AIM

To compare the number of appendicitis cases and its complications, during the first months of the COVID-19 pandemic in Sweden and the UK and the corresponding time period in 2019.

METHOD

Reports of emergency abdominopelvic CT performed at 56 Swedish hospitals and 38 British hospitals between April and July 2020 and a corresponding control cohort from 2019 were reviewed. Two radiologists and two surgeons blinded to the date of cohorts analyzed all reports for diagnosis of appendicitis, perforation, and abscess. A random selection of cases was chosen for the measurement of inter-rater agreement.

RESULT

Both in Sweden (6111) and the UK (5591) fewer, abdominopelvic CT scans were done in 2020 compared to 2019 (6433 and 7223, respectively); p < 0.001. In the UK, the number of appendicitis was 36% lower in April-June 2020 compared to 2019 but not in Sweden. Among the appendicitis cases, there was a higher number of perforations and abscesses in 2020, in Sweden. In the UK, the number of perforations and abscesses were initially lower (April-June 2020) but increased in July 2020. There was a substantial inter-rater agreement for the diagnosis of perforations and abscess formations (K = 0.64 and 0.77).

CONCLUSION

In Sweden, the number of appendicitis was not different between 2019 and 2020; however, there was an increase of complications. In the UK, there was a significant decrease of cases in 2020. The prevalence of complications was lower initially but increased in July. These findings suggest variability in delay in diagnosis of appendicitis depending on the country and time frame studied.

Expanding the Utilization of Low-Dose Computed Tomography in Plastic and Reconstructive Surgery Based on Validated Practices Among Surgical Specialties

INTRODUCTION

As computed tomography (CT) usage increases, so have concerns over radiation-induced malignancy. To mitigate these risks, low-dose CT (LDCT) has emerged as a versatile alternative by other specialties, although its use in plastic surgery remains sparse. This study aimed to investigate validated uses of LDCT across surgical specialties and extrapolate these insights to expand its application for plastic surgeons.

METHODS

A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using search terms "low dose CT" OR "low dose computed tomography" AND "surgery," where the name of each surgical specialty was substituted for word "surgery" and each specialty term was searched separately in combination with the 2 CT terms. Data on radiation dose, outcomes, and level of evidence were collected. Validated surgical applications were correlated with similar procedures and diagnostic tests performed routinely by plastic surgeons to extrapolate potential applications for plastic surgeons.

RESULTS

A total of 3505 articles were identified across surgical specialties, with 27 ultimately included. Depending on the application, use of LDCT led to a 25% to 97% reduction in radiation dose and all studies reported noninferior image quality and diagnostic capability compared with standard-dose CT. Potential identified uses included the following: evaluation of soft tissue infections, preoperative and postoperative management of facial and hand fractures, flap design, 3D modeling, and surgical planning.

DISCUSSION

Low-dose CT is a valid imaging alternative to standard-dose CT. Expanded utilization in plastic surgery should be considered to minimize the iatrogenic effects of radiation and to promote patient safety without compromising outcomes.

Diagnostic accuracy using low-dose versus standard radiation dose CT in suspected acute appendicitis: prospective cohort study

BACKGROUND

Contrast-enhanced CT is the reference standard used in diagnostic imaging for acute appendicitis in adults. The radiation dose has been of concern. This study aimed to assess whether a lower radiation dose would affect the diagnostic accuracy of CT.

METHODS

This was a prospective single-centre cohort study of patients (aged over 16 years) with suspected appendicitis evaluated for enrolment in concurrent APPAC II-III trials. The diagnostic accuracy of contrast-enhanced low- and standard-dose CT was compared with study protocols guiding imaging based on BMI; this enabled direct CT imaging comparison only in patients with a BMI below 30 kg/m2. The on-call CT diagnosis was compared with the final clinical diagnosis.

RESULTS

Among all 856 patients investigated, the accuracy of low-dose (454 patients) and standard-dose (402 patients) CT in identifying patients with and without appendicitis was 98·0 and 98·5 per cent respectively. In patients with a BMI under 30 kg/m2, respective values were 98·2 per cent (434 patients) and 98·6 per cent (210 patients) (P = 1·000). The corresponding accuracy for differentiating between uncomplicated and complicated acute appendicitis was 90·3 and 87·6 per cent in all patients, and 89·8 and 88·4 per cent respectively among those with a BMI below 30 kg/m2 (P = 0·663). The median radiation dose in the whole low- and standard-dose CT groups was 3 and 7 mSv respectively. In the group with BMI below 30 kg/m2, corresponding median doses were 3 and 5 mSv (P < 0·001).

CONCLUSION

Low- and standard-dose CT were accurate both in identifying appendicitis and in differentiating between uncomplicated and complicated acute appendicitis. Low-dose CT was associated with a significant radiation dose reduction, suggesting that it should be standard clinical practice at least in patients with a BMI below 30 kg/m2.

Conditional CT Strategy-An Effective Tool to Reduce Negative Appendectomy Rate and the Overuse of the CT

(1) Background: Diagnosis of acute appendicitis (AA) remains challenging; either computed tomography (CT) is universally used or negative appendectomy rates of up to 30% are reported. Transabdominal ultrasound (TUS) as the first-choice imaging modality might be useful in adult patients to reduce the need for CT scans while maintaining low negative appendectomy (NA) rates. The aim of this study was to report the results of the conditional CT strategy for the diagnosis of acute appendicitis. (2) Methods: All patients suspected of acute appendicitis were prospectively registered from 1 January 2016 to 31 December 2018. Data on their clinical, radiological and surgical outcomes are presented. (3) Results: A total of 1855 patients were enrolled in our study: 1206 (65.0%) were women, 649 (35.0%) were men, and the median age was 34 years (IQR, 24.5–51). TUS was performed in 1851 (99.8%) patients, and CT in 463 (25.0%) patients. Appendices were not visualized on TUS in 1320 patients (71.3%). Furthermore, 172 (37.1%) of 463 CTs were diagnosed with AA, 42 (9.1%) CTs revealed alternative emergency diagnosis and 249 (53.8%) CTs were normal. Overall, 519 (28.0%) patients were diagnosed with AA: 464 appendectomies and 27 diagnostic laparoscopies were performed. The NA rate was 4.2%. The sensitivity and specificity for TUS and CT are as follows: 71.4% and 96.2%; 93.8% and 93.6%. (4) Conclusion: A conditional CT strategy is effective in reducing NA rates and avoids unnecessary CT in a large proportion of patients. Observation and repeated TUS might be useful in unclear cases.

CT based Acute Appendicitis Severity Index for acute appendicitis and validate its effectiveness in predicting complicated appendicitis

AIM

To propose a CT-based scoring system called Acute Appendicitis Severity Index (AASI) for diagnosis of acute appendicitis and validates its effectiveness in predicting complicated appendicitis.

SUBJECTS AND METHODS

Retrospective analyses of CT images of 120 adult patients with pathologically proven uncomplicated (n = 64) and complicated (n = 56) acute appendicitis were performed. All patients had undergone a CT scan of the abdomen and pelvis using 320 multi-detectors computed tomography with Adaptive Iterative Dose Reduction 3D (AIDR 3D). CT image parameters were identified and used to develop a CT-based scoring system (AASI) to predict the severity of acute appendicitis and its outcome. All image analysis was performed by 2 radiologists and the total score was assigned to each patient based on the proposed CT scoring system. Validation of the effectiveness of the proposed scoring system (AASI) was done using statistical models.

RESULTS

The mean and standard deviation of AASI was found to be significantly higher (P value = 0.001) in the complicated appendicitis group (observer 1 = 10.2 ± 1.6 and observer 2 = 9.63 ± 2.3) as compared to that in uncomplicated acute appendicitis group (observer 1 = 7.09 ± 2.2 and observer 2 = 6.38 ± 1.9). There was an excellent interobserver agreement of the Acute Appendicitis Severity Index for both the uncomplicated and complicated appendicitis groups (K = 0.89, 95% CI = 0.87-0.92, P = 0.001). The cutoff value for AASI used to predict complicated appendicitis was taken as 9.5 and 8.5. This resulted in an AUC of 0.877 and 0.848, accuracy of 83% and 81%, the sensitivity of 75% and 80%, the specificity of 90% and 81%, the positive predictive value of 87% and 78%, and a negative predictive value of 81% and 83% by both reviewers respectively.

CONCLUSION

The proposed CT-based AASI is a reliable parameter for the prediction of complicated appendicitis.

The Value of PETRA in Pulmonary Nodules of <3 cm Among Patients With Lung Cancer

Objective

This study aimed to evaluate the visibility of different subgroups of lung nodules of <3 cm using the pointwise encoding time reduction with radial acquisition (PETRA) sequence on 3T magnetic resonance imaging (MRI) in comparison with that obtained using low-dose computed tomography (LDCT).

Methods

The appropriate detection rate was calculated for each of the different subgroups of lung nodules of <3 cm. The mean diameter of each detected nodule was determined. The detection rates and diameters of the lung nodules detected by MRI with the PETRA sequence were compared with those detected by computed tomography (CT). The sensitivity of detection for the different subgroups of pulmonary nodules was determined based on the location, size, type of nodules and morphologic characteristics. Agreement of nodule characteristics between CT and MRI were assessed by intraclass correlation coefficient (ICC) and Kappa test.

Results

The CT scans detected 256 lung nodules, comprising 99 solid nodules (SNs) and 157 subsolid nodules with a mean nodule diameter of 8.3 mm. For the SNs, the MRI detected 30/47 nodules of <6 mm in diameter and 52/52 nodules of ≥6 mm in diameter. For the subsolid nodules, the MRI detected 30/51 nodules of <6 mm in diameter and 102/106 nodules of ≥6 mm in diameter. The PETRA sequence returned a high detection rate (84%). The detection rates of SN, ground glass nodules, and PSN were 82%, 72%, and 94%, respectively. For nodules with a diameter of >6 mm, the sensitivity of the PETRA sequence reached 97%, with a higher rate for nodules located in the upper lung fields than those in the middle and lower lung fields. Strong agreement was found between the CT and PETRA results (correlation coefficients = 0.97).

Conclusion

The PETRA technique had high sensitivity for different type of nodule detection and enabled accurate assessment of their diameter and morphologic characteristics. It may be an effective alternative to CT as a tool for screening and follow up pulmonary nodules.

Final diagnosis and patient disposition following equivocal results on 2-mSv CT vs. conventional-dose CT in adolescents and young adults with suspected appendicitis: a post hoc analysis of large pragmatic randomized trial data

OBJECTIVE

To compare 2-mSv CT and conventional-dose CT (CDCT, typically 7-8 mSv) regarding final diagnosis and patient disposition following equivocal CT results in adolescents and young adults with suspected appendicitis.

METHODS

In total, 3074 patients of 15-44 years (28 ± 9 years, 1672 women) from 20 hospitals were randomized to undergo contrast-enhanced 2-mSv CT (n = 1535) or CDCT (n = 1539) from December 2013 through August 2016. One hundred sixty-one radiologists prospectively rated the likelihood of appendicitis in a Likert scale (i.e., grades 1-5). The final diagnosis was based on CT image, surgical, pathologic, and clinical findings. Post hoc analysis was performed for final diagnosis, surgical procedure, and delay in patient management following equivocal results (i.e., grade 3).

RESULTS

The 2-mSv CT and CDCT groups were comparable for final diagnosis following equivocal results, including confirmed appendicitis (1.2% [18 patients] vs. 1.2% [19], p > 0.99), negative appendectomy (0.1% [2] vs. 0.3% [4], p = 0.53), and perforated appendicitis (0.1% [1] vs. 0.2% [3], p = 0.53). More patients were confirmed as not having appendicitis following equivocal results in the CDCT group than in the 2-mSv CT group (2.2% [34] vs. 1.0% [16], p = 0.016). The two groups were comparable for the need of appendectomy (1.4% [22] vs. 1.5% [23], p > 0.99), need of additional imaging tests (0.7% [11] vs. 1.1% [17], p = 0.35), and delay in patient management following equivocal results.

CONCLUSION

2-mSv CT is comparable to CDCT regarding final diagnosis and patient disposition following equivocal CT results.

KEY POINTS

• Our results strengthen evidence justifying the use of low-dose CT instead of conventional-dose CT (CDCT) in adolescents and young adults with suspected appendicitis. • The 2-mSv CT and CDCT groups were comparable for final diagnosis following equivocal CT results, including confirmed appendicitis (1.2% vs. 1.2%, p > 0.99), negative appendectomy (0.1% vs. 0.3%, p = 0.53), and perforated appendicitis (0.1% vs. 0.2%, p = 0.53). • The two groups were comparable for the need for appendectomy (1.4% vs. 1.5%, p > 0.99), need for additional imaging tests (0.7% vs. 1.1%, p = 0.35), and delay in patient management, following equivocal CT results.

Low-dose CT for diagnosing intestinal obstruction and pneumoperitoneum; need for retakes and diagnostic accuracy

Background

One of the main concerns using low-dose (LD) CT for evaluation of patients with suspected intestinal obstruction or pneumoperitoneum is the potential need to make an additional standard-dose (SD) CT scan (retake) due to insufficient diagnostic accuracy of the LD CT.

Purpose

To determine the frequency of retakes and evaluate the diagnostic accuracy of LD CT for the assessment of intestinal obstruction and pneumoperitoneum.

Material and Methods

This retrospective study registered all LD CT scans over a one-year period at Aarhus University Hospital, Denmark in patients with suspected intestinal obstruction or perforation, comprising a total of 643 LD CT scans. A retake was defined as a SD CT scan of the abdomen and pelvis performed with or without intravenous contrast within 72 h after the initial LD CT due to either continued suspicion of intestinal obstruction or perforation or due to unclarified secondary findings. The sensitivity and specificity of LD CT for diagnosing intestinal obstruction and pneumoperitoneum compared to the discharge diagnoses of the scanned patients were determined.

Results

The frequency of retakes was 3%. The overall LD CT sensitivity and specificity for assessment of patients with suspected intestinal obstruction and pneumoperitoneum was 83% and 99%, respectively, but higher in certain subgroups.

Conclusions

LD CT led to few retakes and had a high diagnostic accuracy for diagnosing intestinal obstruction and pneumoperitoneum. Thus, LD CT can be recommended as the examination of choice in patients with suspected intestinal obstruction or perforation in order to reduce radiation dose.

Acute Appendicitis in Childhood and Adulthood

BACKGROUND

Acute appendicitis is the most common cause of the acute abdomen, with an incidence of 1 per 1000 persons per year. It is one of the main differential diagnoses of unclear abdominal conditions.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in the PubMed and Cochrane Library databases.

RESULTS

In addition to the medical history, physical examination and laboratory tests, abdominal ultrasonography should be performed to establish the diagnosis (and sometimes computed tomography [CT] or magnetic resonance imaging [MRI], if ultrasonography is insufficient). Before any treatment is provided, appendicitis is classified as either uncomplicated or complicated. In both types of appendicitis, the decision to treat surgically or conservatively must be based on the overall clinical picture and the patient's risk factors. Appendectomy is the treatment of choice for acute appendicitis in all age groups. In Germany, appendectomy is mainly performed laparoscopically in patients with low morbidity. Uncomplicated appendicitis can, alternatively, be treated conservatively under certain circumstances. A meta-analysis of five randomized, controlled trials has revealed that ca. 37% of adult patients treated conservatively undergo appendectomy within one year. Complicated appendicitis is a serious disease; it can also potentially be treated conservatively (with antibiotics, with or without placement of a drain) as an alternative to surgical treatment.

CONCLUSION

Conservative treatment is being performed more frequently, but the current state of the evidence does not justify a change of the standard therapy from surgery to conservative treatment.

Comparison on radiation effective dose and image quality of right coronary artery on prospective ECG-gated method between 320 row CT and 2nd generation (128-slice) dual source CT

This retrospective study was to compare the image quality of right coronary artery (RCA) and effective radiation dose on prospective ECG‐gated method between 320 row computed tomography (CT) and 2nd generation (128‐slice) dual source CT. A total of 215 candidates underwent CT coronary angiography using prospective ECG‐gated method, 120 patients enrolled in 320 row CT group, and 95 patients in dual source CT group. We divided RCA image quality scores as 1/2/3/4, which means excellent/good/adequate/not assessable and heart rates were considered, as well as the radiation dose. There is no statistically significant difference of RCA image quality of Score 1/2 between 320 row CT and 2nd generation dual source CT, but lower heart rate (<70/min) improved RCA image quality. Meanwhile, the 2nd generation dual source CT scan have significant lower radiation dose. For patients with high level heart rate variation, both prospective ECG‐gated method of 320 row CT scan (Toshiba) and 2nd generation dual source CT scan (Siemens) basically provided good image quality on RCA. There is an advantage of effective radiation dose reduction in prospective ECG‐gated method using the 2nd generation dual source CT scan. After the iodine contrast agent was injected into elbow vein, the threshold triggering method was used to carry out prospective gated scanning, and the acquired fault image was reconstructed by the standard post‐processing software of each manufacturer. The radiation dose value is obtained through the dose report automatically generated after each scan.

The Accuracy of Low-dose Computed Tomography Protocol in Patients With Suspected Acute Appendicitis: The OPTICAP Study

OBJECTIVE

To compare diagnostic accuracy of contrast enhanced low-dose computed tomography (CT) accomplished in the OPTICAP trial phantom phase to standard CT in patients with suspected acute appendicitis.

BACKGROUND

Increasing use of CT as the gold standard in diagnosing acute appendicitis has raised concerns regarding radiation exposure. Unenhanced low-dose CT protocols have shown similar diagnostic accuracy with standard CT for diagnosing appendicitis. To our knowledge, there are no other trials in which the same patient with suspected acute appendicitis underwent both standard and low-dose CT allowing interpatient comparison.

METHODS

OPTICAP is an interpatient protocol sequence randomized noninferiority single-center trial performed at Turku University Hospital between November, 2015 and August, 2016. Sixty patients with suspected acute appendicitis and body mass index <30 kg/m were enrolled to undergo both standard and low-dose contrast enhanced CT scans, which were categorized as normal, uncomplicated or complicated appendicitis by 2 radiologists in blinded manner. All patients with CT confirmed appendicitis underwent appendectomy to obtain histopathology.

RESULTS

The low-dose protocol was not inferior to standard protocol in terms of diagnostic accuracy; 79% [95% confidence interval (CI) 66%-89%) accurate diagnosis in low-dose and 80% (95% CI 67%-90%) in standard CT by primary radiologist. Accuracy to categorize appendicitis severity was 79% for both protocols. The mean radiation dose of low-dose CT was significantly lower compared with standard CT (3.33 and 4.44 mSv, respectively).

CONCLUSION

Diagnostic accuracy of contrast enhanced low-dose CT was not inferior to standard CT in diagnosing acute appendicitis or distinguishing between uncomplicated and complicated acute appendicitis in patients with a high likelihood of acute appendicitis. Low-dose CT enabled significant radiation dose reduction.

Randomized control trial comparing an Alvarado Score-based management algorithm and current best practice in the evaluation of suspected appendicitis

BACKGROUND

An objective algorithm for the management of suspected appendicitis guided by the Alvarado Score had previously been proposed. This algorithm was expected to reduce computed tomography (CT) utilization without compromising the negative appendectomy rate. This study attempts to validate the proposed algorithm in a randomized control trial.

METHODS

A randomized control trial comparing the management of suspected acute appendicitis using the proposed algorithm compared to current best practice, with the rate of CT utilization as the primary outcome of interest. Secondary outcomes included the percentage of missed diagnosis, negative appendectomies, length of stay in days, and overall cost of stay in dollars.

RESULTS

One hundred sixty patients were randomized. Characteristics such as age, ethnic group, American Society of Anesthesiologist score, white cell count, and symptom duration were similar between the two groups. The overall CT utilization rate of the intervention arm and the usual care arm were similar (93.7% vs 92.5%, p = 0.999). There were no differences in terms of negative appendectomy rate, length of stay, and cost of stay between the intervention arm as compared to the usual care arm (p = 0.926, p = 0.705, and p = 0.886, respectively). Among patients evaluated with CT, 75% (112 out of 149) revealed diagnoses for the presenting symptoms.

CONCLUSION

The proposed AS-based management algorithm did not reduce the CT utilization rate. Outcomes such as missed diagnoses, negative appendectomy rates, length of stay, and cost of stay were also largely similar. CT utilization was prevalent as 93% of the study cohort was evaluated by CT scan.

TRIAL REGISTRATION

The study has been registered at ClinicalTrials.gov (NCT03324165, Registered October 27 2017).

[Antibiotics alone as an alternative to appendectomy for uncomplicated acute appendicitis in adults: Changes in treatment modalities related to the COVID-19 health crisis]

La saturation intrahospitalière liée à l’arrivée massive de patients atteints du COVID-19 nécessitant une prise en charge urgente conduit à reconsidérer la prise en charge des autres patients. Différer au maximum les hospitalisations et les opérations chirurgicales non urgentes est un des objectifs des chirurgiens afin de désengorger autant que possible le système de soins. Alors que la majorité des opérations programmées sont annulées, la réduction de la chirurgie d’urgence est évidemment compliquée à proposer sans altérer la qualité de la prise en charge et conduire à une perte de chance pour le patient. Cependant, l’appendicite aiguë constitue une situation spécifique bien particulière et la fréquence de cette pathologie conduit à considérer ce cas particulier. En effet, tandis que le traitement recommandé de l’appendicite aiguë non compliquée est chirurgical, l’alternative non chirurgicale par antibiothérapie seule a été largement évaluée dans la littérature au cours de travaux de qualité. Dans la mesure où la limite principale du traitement médical exclusif de l’appendicite aiguë non compliquée est le risque de récidive à distance, cette option thérapeutique représente une alternative de choix pour réduire la surcharge intrahospitalière dans ce contexte de crise sanitaire. L’objectif de ce travail est donc de mettre à disposition des médecins et des chirurgiens un guide pratique issu d’une analyse de la littérature sur le traitement médical de l’appendicite aiguë non compliquée de l’adulte afin de pouvoir proposer ce traitement alternatif aux bons patients et dans des bonnes conditions, notamment lorsque l’accès au bloc opératoire est impossible.

Antibiotics alone as an alternative to appendectomy for uncomplicated acute appendicitis in adults: Changes in treatment modalities related to the COVID-19 health crisis

The massive inflow of patients with COVID-19 requiring urgent care has overloaded hospitals in France and impacts the management of other patients. Deferring hospitalization and non-urgent surgeries has become a priority for surgeons today in order to relieve the health care system. It is obviously not simple to reduce emergency surgery without altering the quality of care or leading to a loss of chance for the patient. Acute appendicitis is a very specific situation and the prevalence of this disease leads us to reconsider this particular disease in the context of the COVID-19 crisis. Indeed, while the currently recommended treatment for uncomplicated acute appendicitis is surgical appendectomy, the non-surgical alternative of medical management by antibiotic therapy alone has been widely evaluated by high-quality studies in the literature. Insofar as the main limitation of exclusively medical treatment of uncomplicated acute appendicitis is the risk of recurrent appendicitis, this treatment option represents an alternative of choice to reduce the intra-hospital overload in this context of health crisis. The aim of this work is therefore to provide physicians and surgeons with a practical guide based on a review of the literature on the medical treatment of uncomplicated acute appendicitis in adults, to offer this alternative treatment to the right patients and under good conditions, especially when access to the operating room is limited or impossible.

Diagnostic sensitivity and specificity of 2-mSv CT vs. conventional-dose CT in adolescents and young adults with suspected appendicitis: post hoc subgroup analysis of the LOCAT data

OBJECTIVES

To test whether the difference in sensitivity or specificity between 2-mSv CT and conventional-dose CT (CDCT) for the diagnosis of appendicitis differs across subgroups of adolescents and young adults with suspected appendicitis.

MATERIALS AND METHODS

We used the per-protocol analysis data of a trial conducted between Dec 2013 and Aug 2016, including 2773 patients (median age [interquartile range], 28 [21-35] years) and 160 radiologists from 20 hospitals. We defined subgroups by sex, body size, clinical risk scores for appendicitis, time of CT examination (i.e., working vs. after hours), CT machines, radiologists' experience, previous site experience in 2-mSv CT, and site practice volume. We drew forest plots and tested for additive or multiplicative interaction between radiation dose and subgroup attributes. If any subgroup had fewer than 200 patients, we considered the results from that subgroup not meaningful.

RESULTS

For most subgroups, the 95% CIs for the differences in sensitivity and specificity were 4.0 percentage points or narrower and contained the minute overall between-group differences. There was no significant interaction on sensitivity or specificity. A few subgroups, including those of extreme body sizes, high appendicitis inflammatory response scores, and hospitals with small appendectomy volume, were regarded to have insufficient numbers of patients.

CONCLUSIONS

There was no notable subgroup heterogeneity, which implies that 2-mSv CT can replace CDCT in diverse populations. Further studies are needed for the subgroups for which we had only small data.

KEY POINTS

• The minute difference in sensitivity or specificity between the 2-mSv CT and conventional-dose CT (typically 7 mSv) groups were consistent across various patient or hospital characteristics. • These results indicate that 2-mSv CT can replace conventional-dose CT in diverse populations. • Further studies are needed to confirm whether 2-mSv CT can replace conventional-dose CT in patients of extreme body sizes, high appendicitis inflammatory response scores, or hospitals with small appendectomy volume, as those subgroups in our data included limited numbers of patients.

Appendiceal Crohn's disease: a rare differential of right iliac fossa pain

A 30-year-old man with a history of severe right iliac fossa pain was referred to the surgical emergency unit. His symptoms began 3 days prior as mild, non-specific abdominal pain which progressively localised to the right iliac fossa and worsened in severity. Investigations were suggestive of acute appendicitis, and therefore a laparoscopic appendicectomy was planned. Laparoscopy revealed a thickened, necrotic appendix with a mass at the base of the appendix, in keeping with the appearance of an appendiceal malignancy. Subsequently a right hemicolectomy was performed. Histology revealed active chronic inflammation and granulomas highly suggestive of appendiceal Crohn's disease. Since, the patient has made a good recovery and presently shows no further signs of Crohn's disease. This case is demonstrative of one of many rare findings on histological examination of the appendix. It emphasises the need for a wide differential when investigating right iliac fossa pain.

Accuracy of Nonenhanced CT vs Contrast-Enhanced CT for Diagnosis of Acute Appendicitis in Adults

BACKGROUND

Acute appendicitis is one of the most common causes of acute abdominal pain requiring emergency intervention. It is often difficult for the clinician to make an accurate diagnosis due to nonspecific and overlapping clinical symptoms. Computed tomography (CT) has become the imaging modality of choice for the evaluation of suspected acute appendicitis. The main purpose of our study was to compare nonenhanced CT (NECT) with contrast-enhanced CT (CECT) for the diagnosis of acute appendicitis.

MATERIAL AND METHODS

A total of 140 patients were enrolled in the study. Two abdominal radiologists-masked to both the clinical information and the final diagnosis-retrospectively reviewed the computed tomographic findings and made an imaging diagnosis based on (1) NECT only, (2) CECT only, and (3) both NECT and CECT. With the final diagnosis as the reference standard, the accuracy of each CT technique was estimated.

RESULTS

The respective sensitivity, specificity, and accuracy for NECT, CECT, and NECT + CECT for the diagnosis of acute appendicitis were 80.7%, 86.7%, and 84.3%; 86.0%, 81.9%, and 83.6%; and, 87.7%, 80.7%, and 83.6%. There was no significant difference in the diagnosis of acute appendicitis among the 3 techniques. In order to make a correct diagnosis, the presence of at least 3 imaging findings for NECT or at least 4 for CECT had the best diagnostic accuracy. We also found that 9.25 mm was the optimal cut-off threshold for the detection of patients with acute appendicitis.

CONCLUSION

Our study allowed direct comparison between NECT, CECT, and NECT + CECT combined. There was no difference in the ability of each CT technique for diagnosing patients with acute appendicitis. For a patient whom iodinated contrast media is contraindicated or a patient who has an increased risk of severe adverse reaction, we would encourage the use of NECT because it provides comparable diagnostic accuracy without further exposing such patient to the contrast media.

Using 2-mSv Appendiceal CT in Usual Practice for Adolescents and Young Adults: Willingness Survey of 579 Radiologists, Emergency Physicians, and Surgeons from 20 Hospitals

OBJECTIVE

To survey care providers' willingness to use 2-mSv computed tomography (CT) in their usual practice for adolescents and young adults with suspected appendicitis.

MATERIALS AND METHODS

An ethical committee approved this prospective study. We introduced 2-mSv CT in 20 hospitals through a pragmatic clinical trial. At the final phase of the trial, we invited 698 potentially-involved care providers in the survey regarding their willingness to use 2-mSv CT. Multivariable logistic regression analyses were performed to identify factors associated with willingness. Nine months after the completion of the trial patient recruitment, we surveyed whether the hospitals were using 2-mSv CT in usual practice.

RESULTS

The analyses included responses from 579 participants (203 attendings and 376 trainees; 221 radiologists, 196 emergency physicians, and 162 surgeons). Regarding the willingness to immediately change their standard practice to 2-mSv CT, 158 (27.3%), 375 (64.8%), and 46 (7.9%) participants responded as "yes" (consistently), "partly" (selectively), and "no", respectively. Willingness varied considerably across the hospitals, but only slightly across the participants' departments or job titles. Willingness was significantly associated with attendings (p = 0.004), intention to maintain the dedicated appendiceal CT protocol (p < 0.001), belief in compelling evidence on the carcinogenic risk of conventional-dose CT radiation (p = 0.028), and hospitals having more than 1000 beds (p = 0.031). Fourteen of the 20 hospitals kept using 2-mSv appendiceal CT in usual practice after the trial.

CONCLUSION

Despite the extensive efforts over the years of this clinical trial, many care providers were willing to use 2-mSv CT selectively or not willing to use.

Reliability of standardized reporting system of acute appendicitis in adults at low-dose 320-rows CT

Aim

To assess the reliability of a standardized reporting system of acute appendicitis at low-dose 320-rows CT.

Subjects and Methods

Retrospective analysis CT of 78 patients with pathologically proven acute appendicitis. The study was performed at a low-dose 320-rows CT. The image analysis was performed by 2 radiologists according to a standardized reporting system of acute appendicitis.

Results

There was an excellent overall of the inter-observer agreement of both observers for the standardized reporting system of acute appendicitis (K = 0.89, 95 % CI = 0.87-0.92, P = 0.001). There was good inter-observer agreement for visualization of the appendix (K = 0.78, P = 0.001), the tip diameter (K = 0.75, P = 0.001), and a single wall thickness of appendix (K = 0.77, P = 0.001). There was excellent inter-observer agreement for outer to outer wall diameter (K = 0.82, P = 0.001), mucosal hyper-enhancement (K = 0.80, P = 0.001), appendicolith (K = 0.86, P = 0.001), gas in the appendix (K = 0.82, P = 0.001), surrounding fat stranding (K = 0.81, P = 0.001), focal cecal thickening (K = 0.85, P = 0.001), peri-appendiceal air (K = 0.87, P = 0.001), peri-appendicular fluid collection, phlegmon, or abscess (K = 0.82, P = 0.001), and right ovary cyst (K = 0.83, P = 0.001).

Conclusion

we concluded that excellent reliability of a standardized reporting system of acute appendicitis in the adults using low-dose 320-rows CT.

Computed tomography for diagnosis of acute appendicitis in adults

BACKGROUND

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not.

OBJECTIVES

Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy.

SEARCH METHODS

We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status.

SELECTION CRITERIA

We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity.

MAIN RESULTS

We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery.

AUTHORS' CONCLUSIONS

The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Reduced scan range abdominopelvic CT in patients with suspected acute appendicitis - impact on diagnostic accuracy and effective radiation dose

BACKGROUND

To evaluate a reduced range CT protocol in patients with suspected acute appendicitis as compared to standard abdominal CT regarding diagnostic performance, effective radiation dose and organ doses.

METHODS

In this study, we retrospectively included 90 patients (43 female, mean age 56.7 ± 17 years) with suspected acute appendicitis who underwent CT of abdomen and pelvis. From those CTs, we reconstructed images with a reduced scan range from L1 to the the pubic symphysis. Full range and reduced range datasets were assessed by two radiologists for i) coverage of the Appendix, ii) presence/absence of appendicitis and iii) presence of differential diagnoses. Furthermore, effective radiation doses as well as organ doses were calculated using a commercially available dose management platform (Radimetrics, Bayer HealthCare).

RESULTS

The Appendix was covered by the reduced range CT in all cases. In 66 patients CT confirmed the presence of appendicitis. In 14 patients, other relevant differential diagnoses were identified by CT, whereas in 10 patients no relevant findings were detected. Both readers identified all patients with appendicitis on both full and reduced range CT. For reduced range CT, total effective dose was 39% lower than for full range CT (reduced range: 4.5 [1.9-11.2] vs. full range: 7.4 [3.3-18.8] mSv; p ≤ 0.001). Notably, a remarkable reduction of organ dose in the female breasts by 97% (0.1 [0.1-0.6] vs. 3.8 [0.5-18.8] mSv; p ≤ 0.001) and in the testicles in males by 81% (3.4 [0.7-32.7] vs. 17.6 [5.4-52.9] mSv; p ≤ 0.001) was observed for reduced range CT compared to full range CT.

CONCLUSIONS

In patients with suspected acute appendicitis, reduced range abdominopelvic CT results in a comparable diagnostic performance with a remarkable reduction of total effective radiation dose and organ doses (especially breast dose in female and testicle dose in male patients) as compared to full range CT.

Low-Dose Computed Tomography Image Super-Resolution Reconstruction via Random Forests

Aiming at reducing computed tomography (CT) scan radiation while ensuring CT image quality, a new low-dose CT super-resolution reconstruction method based on combining a random forest with coupled dictionary learning is proposed. The random forest classifier finds the optimal solution of the mapping relationship between low-dose CT (LDCT) images and high-dose CT (HDCT) images and then completes CT image reconstruction by coupled dictionary learning. An iterative method is developed to improve robustness, the important coefficients for the tree structure are discussed and the optimal solutions are reported. The proposed method is further compared with a traditional interpolation method. The results show that the proposed algorithm can obtain a higher peak signal-to-noise ratio (PSNR) and structural similarity index measurement (SSIM) and has better ability to reduce noise and artifacts. This method can be applied to many different medical imaging fields in the future and the addition of computer multithreaded computing can reduce time consumption.

Optimising the antibiotic treatment of uncomplicated acute appendicitis: a protocol for a multicentre randomised clinical trial (APPAC II trial)

BACKGROUND

Based on epidemiological and clinical data acute appendicitis can present either as uncomplicated (70-80%) or complicated (20-30%) disease. Recent studies have shown that antibiotic therapy is both safe and cost-effective for a CT-scan confirmed uncomplicated acute appendicitis. However, based on the study protocols to ensure patient safety, these randomised studies used mainly broad-spectrum intravenous antibiotics requiring additional hospital resources and prolonged hospital stay. As we now know that antibiotic therapy for uncomplicated acute appendicitis is feasible and safe, further studies evaluating optimisation of the antibiotic treatment regarding both antibiotic spectrum and shorter hospital stay are needed to evaluate antibiotics as the first-line treatment for uncomplicated acute appendicitis.

METHODS

APPAC II trial is a multicentre, open-label, non-inferiority randomised controlled trial comparing per oral (p.o.) antibiotic monotherapy with intravenous (i.v.) antibiotic therapy followed by p.o. antibiotics in the treatment of CT-scan confirmed uncomplicated acute appendicitis. Adult patients with CT-scan diagnosed uncomplicated acute appendicitis will be enrolled in nine Finnish hospitals. The intended sample size is 552 patients. Primary endpoint is the success of the randomised treatment, defined as resolution of acute appendicitis resulting in discharge from the hospital without the need for surgical intervention and no recurrent appendicitis during one-year follow-up. Secondary endpoints include post-intervention complications, late recurrence of acute appendicitis after one year, duration of hospital stay, pain, quality of life, sick leave and treatment costs. Primary endpoint will be evaluated in two stages: point estimates with 95% confidence interval (CI) will be calculated for both groups and proportion difference between groups with 95% CI will be calculated and evaluated based on 6 percentage point non-inferiority margin.

DISCUSSION

To our knowledge, APPAC II trial is the first randomised controlled trial comparing per oral antibiotic monotherapy with intravenous antibiotic therapy continued by per oral antibiotics in the treatment of uncomplicated acute appendicitis. The APPAC II trial aims to add clinical evidence on the debated role of antibiotics as the first-line treatment for a CT-confirmed uncomplicated acute appendicitis as well as to optimise the non-operative treatment for uncomplicated acute appendicitis.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT03236961, retrospectively registered on the 2nd of August 2017.

A randomised placebo-controlled double-blind multicentre trial comparing antibiotic therapy with placebo in the treatment of uncomplicated acute appendicitis: APPAC III trial study protocol

INTRODUCTION

Recent studies show that antibiotic therapy is safe and feasible for CT-confirmed uncomplicated acute appendicitis. Spontaneous resolution of acute appendicitis has already been observed over a hundred years ago. In CT-confirmed uncomplicated acute diverticulitis (left-sided appendicitis), studies have shown no benefit from antibiotics compared with symptomatic treatment, but this shift from antibiotics to symptomatic treatment has not yet been widely implemented in clinical practice. Recently, symptomatic treatment of uncomplicated acute appendicitis has been demonstrated in a Korean open-label study. However, a double-blinded placebo-controlled study to illustrate the role of antibiotics and spontaneous resolution of uncomplicated acute appendicitis is still lacking.

METHODS AND ANALYSIS

The APPAC III (APPendicitis ACuta III) trial is a multicentre, double-blind, placebo-controlled, superiority randomised study comparing antibiotic therapy with placebo in the treatment CT scan-confirmed uncomplicated acute appendicitis aiming to evaluate the role of antibiotics in the resolution of uncomplicated acute appendicitis. Adult patients (18-60 years) with CT scan-confirmed uncomplicated acute appendicitis (the absence of appendicolith, abscess, perforation and tumour) will be enrolled in five Finnish university hospitals.Primary endpoint is success of the randomised treatment, defined as resolution of acute appendicitis resulting in discharge from the hospital without surgical intervention within 10 days after initiating randomised treatment (treatment efficacy). Secondary endpoints include postintervention complications, recurrent symptoms after treatment up to 1 year, late recurrence of acute appendicitis after 1 year, duration of hospital stay, sick leave, treatment costs and quality of life. A decrease of 15 percentage points in success rate is considered clinically important difference. The superiority of antibiotic treatment compared with placebo will be analysed using Fisher's one-sided test and CI will be calculated for proportion difference.

ETHICS AND DISSEMINATION

This protocol has been approved by the Ethics Committee of Turku University Hospital and the Finnish Medicines Agency (FIMEA). The findings will be disseminated in peer-reviewed academic journals.

TRIAL REGISTRATION NUMBER

NCT03234296; Pre-results.

Comprehensive review of typical and atypical pathology of the appendix on CT: cases with clinical implications

Acute appendicitis is the most common abdominal surgical emergency in the United States with approximately 250,000 cases annually. Computed Tomography (CT) has emerged as the most accurate diagnostic test to triage these patients for emergent surgery. Although the radiology search pattern is prioritized to detect an inflamed appendix, not all appearances equate to a typical surgical appendicitis. There are a select set of atypical pathologies involving the appendix that have subtle differences on CT, but can have catastrophic complications if treated with emergent appendectomy. This paper will review the spectrum of CT appearances and clinical management for typical and atypical appendiceal pathologies.

Diagnostic performance of emergency physician-performed point-of-care ultrasonography for acute appendicitis: A meta-analysis

OBJECTIVE

To assess the sensitivity and specificity of emergency physician-performed point-of-care ultrasonography (EP-POCUS) for diagnosing acute appendicitis (AA).

MATERIAL AND METHODS

The PubMed and EMBASE databases were searched, and the diagnostic performance of EP-POCUS was evaluated using bivariate modeling and hierarchical summary receiver operating characteristic curves. Subgroup analysis was performed for pediatric patients to compare EP-POCUS and radiologist-performed ultrasonography (RADUS). Meta-regression analyses were performed according to patient and study characteristics.

RESULTS

In 17 studies (2385 patients), EP-POCUS for diagnosing AA exhibited a pooled sensitivity of 84% (95% confidence interval [CI]: 72%-92%) and a pooled specificity of 91% (95% CI: 85%-95%), with even better diagnostic performance for pediatric AA (sensitivity: 95%, 95% CI: 75%-99%; specificity: 95%, 95% CI: 85%-98%). A direct comparison revealed no significant differences (p = 0.18-0.85) between the diagnostic performances of EP-POCUS (sensitivity: 81%, 95% CI: 61%-90%; specificity: 89%, 95% CI: 77%-95%) and RADUS (sensitivity: 74%, 95% CI: 65%-81%; specificity: 97%, 95% CI: 93%-98%). The meta-regression analyses revealed that study location, AA proportion, and mean age were sources of heterogeneity. Higher sensitivity and specificity tended to be associated with an appendix diameter cut-off value of 7 mm and the EP as the initial operator.

CONCLUSION

The diagnostic performances of EP-POCUS and RADUS were excellent for AA, with EP-POCUS having even better performance for pediatric AA. Accurate diagnoses may be achieved when the attending EP is the initial POCUS operator and uses a 7-mm cut-off value.

Super-resolution CT Image Reconstruction Based on Dictionary Learning and Sparse Representation

In this paper, a single-computed tomography (CT) image super-resolution (SR) reconstruction scheme is proposed. This SR reconstruction scheme is based on sparse representation theory and dictionary learning of low- and high-resolution image patch pairs to improve the poor quality of low-resolution CT images obtained in clinical practice using low-dose CT technology. The proposed strategy is based on the idea that image patches can be well represented by sparse coding of elements from an overcomplete dictionary. To obtain similarity of the sparse representations, two dictionaries of low- and high-resolution image patches are jointly trained. Then, sparse representation coefficients extracted from the low-resolution input patches are used to reconstruct the high-resolution output. Sparse representation is used such that the trained dictionary pair can reduce computational costs. Combined with several appropriate iteration operations, the reconstructed high-resolution image can attain better image quality. The effectiveness of the proposed method is demonstrated using both clinical CT data and simulation image data. Image quality evaluation indexes (root mean squared error (RMSE) and peak signal-to-noise ratio (PSNR)) indicate that the proposed method can effectively improve the resolution of a single CT image.