Acute colonic diverticulitis: visualization in magnetic resonance imaging

Magnetic Resonance Imaging for the diagnosis and management of acute colonic diverticulitis: a review of current and future use

Diverticular disease is one of the most common causes of outpatient visits and hospitalisations across Australia, North America and Europe. According to the Gastroenterological Society of Australia (GESA, 2010), approximately 33% of Australians over 45 years of age and 66% over 85 years of age have some form of colonic diverticulosis. Patients with colonic diverticulosis are known to develop subsequent complications such as acute colonic diverticulitis (ACD), and when more than one attack of diverticulitis occurs, there is a 70-90% chance that the individual will experience ongoing problems and recurring infections throughout their lifetime. Medical imaging is fundamental in the diagnosis, treatment and ongoing management of ACD and its complications, with Computed Tomography (CT) identified as the prevailing gold standard in the last few decades. Cross-database searching highlighted a large gap in the literature regarding the effectiveness of Magnetic Resonance Imaging (MRI) as a non-ionising radiation alternative imaging tool for ACD imaging after the mid-2000s, despite ongoing technological advancements in this modality. This narrative review identified 13 key publications (11 primary prospective cohort studies, 1 systematic review and 1 meta-analysis) that evaluate MRI for ACD imaging, of which five were published within the last decade. Several existing MRI protocols are deemed suitable for ACD imaging, and it is recommended they be re-evaluated in larger cohorts. Future studies should consider the rapidly growing technological improvements of MRI, its cost efficiency and its applicability in modern day healthcare settings when addressing ACD management. This is especially important considering the gradual rise in radiation dose among the Australian population attributable to increased CT referrals, alongside increased reporting of ACD cases in younger individuals.

Signal Recognition Based on APSO-RBF Neural Network to Assist Athlete's Competitive Ability Evaluation

The advanced analysis and research methods of big data will provide theoretical support for the integration of athletes' talent training. The advanced technological methods of big data will also give full play to the advantages of tapping the potential of talents and actively improve the success rate of grassroots young athletes. This paper proposes an improved Adaptive Particle Swarm Optimization (APSO) algorithm for the optimization of radial basis function (RBF) neural network parameters. The basic structure of RBF neural network is introduced, and the influence of parameters on the performance of RBF neural network is analyzed. The optimization method of RBF neural network parameters is analyzed, and Particle Swarm Optimization (PSO) algorithm is selected as the parameter optimization method of RBF neural network. In addition, an improved APSO algorithm is proposed according to the advantages and disadvantages of PSO and compared with other PSO algorithms. Experimental results show that the improved PSO algorithm has better accuracy. The improved PSO algorithm is applied to the parameter optimization of RBF neural network, and the experimental results prove the superiority of the proposed method. By weighting the second-level indicators, the weights of the second-level indicators of athletes' competitive ability are in order of skill, athletic quality, psychological ability, and artistic expression. Skills are the main factors that determine the level of competitive ability. Sports quality and psychological ability are important guarantees for supporting the normal performance of skills. Artistic expressiveness is a supplementary factor for competitive ability. The various elements cooperate with each other and interact with each other. The indicators do not exist alone but cooperate with each other to support the formation of the entire athletic ability system. In the content of the competitive ability index of excellent athletes, technical ability is the core, and sports quality, psychological ability, and artistic performance ability ultimately exist to serve the improvement of technical ability. The competition scores of the 100 athletes counted in this article are all above 9.0 points. The difference between APSO-RBF's action quality scores of 100 athletes and the real value is less than 3%. In terms of movement difficulty, the APSO-RBF evaluated athletes' scores are close to 1.65 points, which is basically the same as the real value.

Characteristics and associated risk factors of diverticular disease assessed by magnetic resonance imaging in subjects from a Western general population

OBJECTIVES

Diverticular disease represents an increasing pathology and healthcare burden worldwide. Our aim was to study the prevalence, extent and distribution of asymptomatic diverticular disease assessed by magnetic resonance imaging (MRI) in a sample of a Western population.

METHODS

Subjects from a population-based cohort study who underwent 3-T MRI were analyzed for the prevalence and extent of diverticula of the colon using an isotropic VIBE-Dixon gradient-echo sequence. The extent of diverticular disease was categorized according to the number of diverticula in each colonic segment. Univariate and adjusted analyses were performed to assess associated characteristics and risk factors.

RESULTS

Among 393 subjects included in the analysis (56.4 ± 9.2 years, 57.5% males), 164 (42%) had diverticular disease, with the highest prevalence in the left-sided colonic segments (93% diverticular disease in the descending and sigmoid segment). Subjects with advanced diverticular disease were older (62.1 vs. 54.4 years) and had a higher body mass index (BMI), LDL cholesterol levels and systolic blood pressure (30.2 ± 5.1 vs. 27.8 ± 4.9 kg/m², 149.8 ± 29.3 vs. 135.2 ± 32.9 mg/dl and 128.2 ± 14.1 vs. 118.4 ± 16.1 mmHg, respectively; all p > 0.003) compared with subjects without diverticular disease. In contrast, no significant correlation could be found for gender, physical activity, smoking status and alcohol consumption (all p > 0.31). Intra-rater reliability was excellent for all colonic segments (intra-class correlation [ICC] = 0.99-1.00), and inter-rater reliability was excellent for left- and right-sided colonic segments (ICC = 0.84-0.97).

CONCLUSIONS

These findings provide insights into the disease mechanism of asymptomatic diverticular disease and may help to improve prevention of diverticulosis and its associated complications.

KEY POINTS

• Overall prevalence of asymptomatic diverticular disease assessed by MRI was 42%, affecting predominantly the left-sided colon. • Asymptomatic diverticular disease was associated with age and cardiometabolic risk factors. • Magnetic resonance imaging reveals insights into the pathophysiologic mechanism of asymptomatic diverticular disease.

Anatomo-radiological correlation using 18-FDG-PET in abdominal sepsis model in rats. A preliminary study

Purpose:

To examine a correlation of micro-PET images with photographic images of the digestive organs in abdominal sepsis model.

Methods:

Male Wistar rats weighing 265±18g were used. Abdominal sepsis was induced by ligature and cecal puncture. Micro-PET Images from abdominal cavity septic foci were obtained using 18-Fluoro-deoxyglucose, looking for a correlation with photographic images of abdominal cavity organs. Pearson's correlation test was used.

Results:

The mean standard uptake values (SUV) and lesion areas were 2.58±0.63SUVbwg/ml and 546.87±300.95mm2, respectively. There was a strong positive correlation between the two variables (r=0.863, p=0.137), which resulted in a coefficient of determination r2?0.75, meaning that 75% of SUV variation is explained by the lesion areas of digestive organs.

Conclusion:

Micro-PET allows high throughput assessment of lesion count and volume in pre-clinical rat model of CPL abdominal sepsis.

Guideline for the diagnostic pathway in patients with acute abdominal pain

INTRODUCTION

Diagnostic practice for acute abdominal pain at the Emergency Department varies widely and is mostly based on doctor's preferences. We aimed at developing an evidence-based guideline for the diagnostic pathway of patients with abdominal pain of non-traumatic origin.

METHODS

All available international literature on patients with acute abdominal pain was identified and graded according to their methodological quality by members of the multidisciplinary steering group. A guideline was synthetized, providing evidence-based recommendations together with considerations based on expertise of group members, patient preferences, costs, availability of facilities, and organizational aspects.

DEFINITION

Uniform terminology is needed in patients with acute abdominal pain to avoid difficulty in interpretation and ease comparison of findings between studies. We propose the use of the following definition for acute abdominal pain: pain of nontraumatic origin with a maximum duration of 5 days. Clinical diagnosis: Clinical evaluation is advised to differentiate between urgent and nonurgent causes. The diagnostic accuracy of clinical assessment is insufficient to identify the correct diagnosis but can discriminate between urgent and nonurgent causes. Patients suspected of nonurgent diagnoses can safely be reevaluated the next day. Based on current literature, no conclusions can be drawn on the differences in accuracy between residents and specialists. No conclusions can be drawn on the influence of a gynecological consultation. In patients suspected of an urgent condition, additional imaging is justified. CRP and WBC count alone are insufficient to discriminate urgent from nonurgent diagnoses. Diagnostic imaging: There is no place for conventional radiography in the work-up of patients with acute abdominal pain due to the lack of added value on top of clinical assessment. Computed tomography leads to the highest sensitivity and specificity in patients with acute abdominal pain. Positive predictive value of ultrasound is comparable with CT and therefore preferred as the first imaging modality due to the downsides of computed tomography; negative or inconclusive ultrasound is followed by CT. Based on current literature, no conclusions can be drawn on the added value of a diagnostic laparoscopy in the work-up of patients with acute abdominal pain. Antibiotic treatment should be started within the first hour after recognition of sepsis. Administration of opioids (analgesics) decreases the intensity of the pain and does not affect the accuracy of physical examination.

Cancer and diverticulitis of the sigmoid colon. Differentiation with computed tomography versus magnetic resonance imaging: preliminary experiences

BACKGROUND

Both colon cancer and diverticular disease are common in the Western world. A challenge when patients present with clinical findings is that both diseases can present with symptoms that may mimic the other.

PURPOSE

To determine whether magnetic resonance imaging (MRI) could be helpful to differentiate between diverticulitis and cancer of the sigmoid colon compared to the differentiation offered by evaluation of multidetector computed tomography (CT) in a clinical situation.

MATERIAL AND METHODS

Thirty patients were consecutively included. Fifteen patients were under work-up for a recently diagnosed sigmoid cancer and 15 patients had recently been treated in hospital due to first-time acute sigmoid diverticulitis. All patients underwent CT, T2- weighted MRI and diffusion-weighted MRI. Anonymized examinations were retrospectively presented in random order to one experienced radiologist.

RESULTS

With contrast-enhanced CT, the sensitivity and specificity for diagnosis of cancer and diverticulitis were 66.7% (10/15) and 93.3% (14/15), respectively. Using T2-weighted and diffusion-weighted MR images, the sensitivity and specificity for diagnosis of cancer and diverticulitis were 100% (14/14) and 100% (14/14), respectively.

CONCLUSION

MRI provides information that may contribute to improve the differentiation between sigmoid cancer and diverticulitis that is offered by CT. These encouraging results need to be confirmed in a larger study.

MR imaging for acute lower abdominal and pelvic pain

Acute lower abdominal and pelvic pain is a frequent complaint of patients in the emergency room. Usually, the condition of these patients is assessed with computed tomography (CT) and ultrasonography (US). However, the need to reduce radiation doses of as much as 20 mSv at CT, especially in younger patients and possibly pregnant patients, and the operator dependence of US have led to an increased use of magnetic resonance (MR) imaging to assess those patients. MR imaging shows high accuracy in these patients and can be used to establish an accurate diagnosis quickly and reliably. A short imaging protocol of about 10 minutes, without the use of an intravenous contrast agent in most cases, allows investigation of these patients. The basic imaging protocol that localizes the diseased anatomic region needs to be complemented by focused anatomic imaging of the diseased area. Although MR imaging might not be the modality of choice for all patients, it may be beneficial for a subset of patients for whom CT is not warranted (pregnant patients or young patients) and US findings are inconclusive. In patients with acute abdominal and pelvic pain, the range of diseases and disorders that can be diagnosed with MR imaging is extremely broad. Therefore, MR imaging should be considered as an excellent imaging modality for the evaluation of these patients.

Giant colonic pseudo-diverticula importance of, and aids to radiological diagnosis: a case series

Introduction

This case series illustrates the clinical presentation and radiological findings of two patients in whom the diagnosis of a Giant Colonic Diverticulum (GCD) was histologically confirmed. We also discuss the pathogenesis and differential diagnosis.

Case presentation

In one case, the patient had no previous large bowel symptoms and intra operatively no other colonic diverticula were found. Both were treated with surgical resection.

Conclusion

The preoperative diagnosis of GCD is made radiographically, and the importance of the early recognition of radiological findings, especially in asymptomatic disease, is emphasised.

Prospective evaluation of the value of magnetic resonance imaging in suspected acute sigmoid diverticulitis

PURPOSE

The purpose of this study was to prospectively investigate patients with suspected acute colonic diverticulitis and to provide sensitivity, specificity, and interobserver agreement in a blinded trial.

METHODS

Fifty-five patients (29 men; 59 +/- 13 (range, 29-76) years) who reported to the emergency room with clinically suspected acute colonic diverticulitis were prospectively included in the study. All patients underwent magnetic resonance imaging scans of their abdomen before and after contrast agent administration. Two assessors blinded to all clinical, laboratory, and radiologic results evaluated the images separately.

RESULTS

The assessors reported colonic wall thickening, segmental narrowing of the colon, presence of diverticula, pericolic fatty infiltration, ascites, and abscesses. The assessors had to diagnose or rule out acute colonic diverticulitis. Sensitivities, specificities, positive, and negative likelihood ratios were derived. To determine interobserver agreement, a Cohen's kappa coefficient was calculated. The two assessors exhibited sensitivities of more than 94 percent, specificities of 88 percent, positive likelihood ratios of more than 7.5, and negative likelihood ratios of less than 0.07. The kappa coefficient showed a significant, strong correlation between both assessors (kappa = 0.68).

CONCLUSIONS

Magnetic resonance imaging is investigator independent and provides high sensitivity and specificity for the diagnosis of acute colonic diverticulitis.

Evaluation of optimized inversion-recovery fat-suppression techniques for T2-weighted abdominal MR imaging

PURPOSE

To test the theoretical benefits of a spectral attenuated inversion-recovery (SPAIR) fat-suppression (FS) technique in clinical abdominal MRI by comparison to conventional inversion-recovery (IR) FS combined with T2-weighted (T2W) partial Fourier single shot fast spin echo (SSFSE).

MATERIALS AND METHODS

1.5T MRI studies of the abdomen were performed in 28 patients with liver lesions (hemangiomas n = 14; metastases n = 14). T2W sequences were acquired using IR and SPAIR SSFSE. Measurements included retroperitoneal and mesenteric fat signal-to-noise (SNR) to evaluate FS; liver lesion contrast-to-noise (CNR) to evaluate bulk water signal recovery effects; and bowel wall delineation to evaluate susceptibility and physiological motion effects.

RESULTS

SPAIR-SSFSE images produce significantly improved FS and liver lesion CNR. The mean SNR of the retroperitoneal and mesenteric fat for SPAIR SSFSE was 20.5 +/- 10.2 (+/-1 SD) and 12.7 +/- 6.2, compared to 43.2 +/- 24.1 (P = 0.000006) and 29.3 +/- 16.8 (P = 0.0000005) for IR-SSFSE. SPAIR-SSFSE images produced higher CNR for both hemangiomas CNR = 164 +/- 88 vs. 126 +/- 83 (P = 0.00005) and metastases CNR = 75 +/- 27 vs. 53 +/- 19 (P = 0.007). Bowel wall visualization was significantly improved using SPAIR-SSFSE (P = 0.002).

CONCLUSION

The theoretical benefits of SPAIR over conventional IR FS translate into significant multiple improvements that can be measured on clinical abdominal MRI scans.

Diagnosis and management of diverticulitis and appendicitis

Diverticulitis and appendicitis are common infections of the gastrointestinal tract that require urgent medical and surgical attention. Successful management of these conditions requires a multidisciplinary approach among primary care providers, gastroenterologists, surgeons, and radiologists. The diagnosis of appendicitis, in particular, can be difficult. Advances in radiographic imaging have improved the diagnostic accuracy in these infections. Minimally invasive surgical techniques have improved the patient's postoperative recovery when surgery is necessary in the management of these conditions.

Pictorial review: magnetic resonance imaging of colonic diverticulitis

Magnetic resonance imaging (MRI) is rapidly emerging as a useful imaging modality for the evaluation of the gastrointestinal tract. Increasingly rapid sequences and improving hardware have significantly improved the visualisation of diseases of the colon. MRI has a major advantage over CT in that there is no ionising radiation. In our institution, MRI has increasingly been used as a complimentary imaging modality to CT in the diagnosis and evaluation of diverticulitis and its complications. In this review article, we illustrate the emerging role of MRI in the diagnosis and evaluation of colonic diverticulitis.

Magnetic resonance imaging based colonography for diagnosis and assessment of diverticulosis and diverticulitis

BACKGROUND AND AIMS

MRI-based colonography is a new minimally invasive imaging modality to assess the colon and abdomen. This new method which is applied mainly for polyp screening could be an integrative approach for colonic diverticulitis assessment. This study evaluated the feasibility of MRI-based colonography to assess diverticulosis or diverticulitis.

PATIENTS AND METHODS

Fourteen consecutive patients with clinically suspected diverticulitis were examined by MRI colonography on a 1.5-T scanner. All patients underwent abdominal CT as gold standard. N-Butyl-scopalamin was given intravenously to reduce bowel peristalsis. After rectal administration of a T1-positive enema T1- and T2-weighted acquisitions with additional intravenous contrast were obtained. A 3D FLASH sequence was acquired for virtual colonography. The results were compared with CT and biological parameters such as white blood cell count and C-reactive protein.

RESULTS

Of 56 bowel segments (sigmoid colon, descending colon, transverse colon, ascending colon) in all 14 patients 54 were assessed to have good to fair image quality. Having CT as standard of reference, all sigmoid diverticula were diagnosed based on MRI. Inflammation as judged by CT was identically assessed on MRI. 3D models of the colon revealed further diverticula in the remaining colon; additionally, the 3D models gave a comprehensive image for surgical planning.

CONCLUSION

In our preliminary study MRI colonography revealed the same diagnosis as CT in all patients without ionizing radiation. Additionally, 3D-rendered models and virtual colonoscopy can be performed. This comprehensive 3D models could replace presurgical planning barium enema with concurrent assessment of the residual colon.

Imaging of colonic diverticular disease

Diverticular disease affects approximately two thirds of the population over the age of 70. While only a small fraction of these patients will develop diverticulitis, adequate radiological evaluation of diverticulitis and its complications is imperative in determining proper medical and surgical treatment. Clinical examination and laboratory tests alone have been found to be inaccurate in defining many aspects of the disease in up to 60% of cases. Over the past 30 years, contrast enema, computed tomography, and ultrasound have all been used extensively to diagnose the complications of diverticular disease. More recently, magnetic resonance imaging has been studied in patients with complicated diverticulitis. This article reviews the use of these different radiological modalities in diagnosing acute colonic diverticulitis and its complications.

MR imaging in abdominal emergencies

The use of MR imaging in the emergency setting is evolving. Clear indications include situations in need of contrast media when iodinated contrast cannot be administered or to facilitate assessments in pregnant patients and children when exposure to ionizing radiation is considered unacceptable. The availability of rapid, motion-immune sequences now makes MR imaging a feasible study in less cooperative patients extending the range of patients for whom a diagnostic study can be achieved. Capitalizing on the unique benefits of MR imaging there is optimism that MR imaging can eliminate test redundancy and impact patient care in a cost-effective manner. Further investigations are needed to identify the diagnostic algorithms for which this favorable use holds true.