Acute cholecystitis: CT findings

Acute Cholecystitis: A Review

IMPORTANCE

Gallbladder disease affects approximately 20 million people in the US. Acute cholecystitis is diagnosed in approximately 200 000 people in the US each year.

OBSERVATIONS

Gallstone-associated cystic duct obstruction is responsible for 90% to 95% of the cases of acute cholecystitis. Approximately 5% to 10% of patients with acute cholecystitis have acalculous cholecystitis, defined as acute inflammation of the gallbladder without gallstones, typically in the setting of severe critical illness. The typical presentation of acute cholecystitis consists of acute right upper quadrant pain, fever, and nausea that may be associated with eating and physical examination findings of right upper quadrant tenderness. Ultrasonography of the right upper quadrant has a sensitivity of approximately 81% and a specificity of approximately 83% for the diagnosis of acute cholecystitis. When an ultrasound result does not provide a definitive diagnosis, hepatobiliary scintigraphy (a nuclear medicine study that includes the intravenous injection of a radiotracer excreted in the bile) is the gold standard diagnostic test. Following diagnosis, early (performed within 1-3 days) vs late (performed after 3 days) laparoscopic cholecystectomy is associated with improved patient outcomes, including fewer composite postoperative complications (11.8% for early vs 34.4% for late), a shorter length of hospital stay (5.4 days vs 10.0 days), and lower hospital costs. During pregnancy, early laparoscopic cholecystectomy, compared with delayed operative management, is associated with a lower risk of maternal-fetal complications (1.6% for early vs 18.4% for delayed) and is recommended during all trimesters. In people older than 65 years of age, laparoscopic cholecystectomy is associated with lower mortality at 2-year follow-up (15.2%) compared with nonoperative management (29.3%). A percutaneous cholecystostomy tube, in which a drainage catheter is placed in the gallbladder lumen under image guidance, is an effective therapy for patients with an exceptionally high perioperative risk. However, percutaneous cholecystostomy tube placement in a randomized trial was associated with higher rates of postprocedural complications (65%) compared with laparoscopic cholecystectomy (12%). For patients with acalculous acute cholecystitis, percutaneous cholecystostomy tube should be reserved for patients who are severely ill at the time of diagnosis; all others should undergo a laparoscopic cholecystectomy.

CONCLUSIONS AND RELEVANCE

Acute cholecystitis, typically due to gallstone obstruction of the cystic duct, affects approximately 200 000 people in the US annually. In most patient populations, laparoscopic cholecystectomy, performed within 3 days of diagnosis, is the first-line therapy for acute cholecystitis.

CT findings and outcomes of acute cholecystitis: is additional ultrasound necessary?

BACKGROUND

While ultrasound is often the preferred imaging modality for suspected acute cholecystitis (AC), CT is often the first line study when patients are being evaluated for abdominal pain. The diagnostic value of CT in the setting of AC is controversial, given the prevalent use of additional imaging.

PURPOSE

To evaluate the positive predictive value (PPV) of CT for diagnosing acute cholecystitis (AC) when used as a first line imaging study for evaluating abdominal pain and assess if additional imaging with ultrasound studies provides additional clinically useful information.

MATERIALS AND METHODS

Abnormal gallbladder findings in CT imaging studies were queried in a retrospective study over a 25-month period within a large urban health system. Sonographic (US) studies performed within 72 h of the initial CT were also included. Outcomes were determined by surgical pathology, fluid analysis, and clinical outcomes. Cases were stratified by the interpreting radiologist's subjective confidence level of diagnosing AC, and the PPVs were compared between cases using CT without US and cases with both CT and US.

RESULTS

Of the 468 CT studies meeting criteria, 192 were read as concerning for AC. PPV of CT was 44.7% without US and 50.5% when US was positive, which amounted to an insignificant gain (p = 0.41). When subdividing by confidence level, high-confidence positive CTs demonstrated no significant difference without ultrasound (80%) compared to with ultrasound (75%). Less confident reads in CT demonstrated potential gain from ultrasound; in the case of a "probable" CT impression, PPV increased from 45% without US to 90% with a high-confidence ultrasound impression.

CONCLUSION

Based on current practice within a large health system, CT examinations with high suspicion for AC demonstrated little gain from follow-up ultrasound. However, ultrasound may be of benefit when CT interpretations are less confident but still suspicious for AC.

Cholecystectomy for Complicated Gallbladder and Common Biliary Duct Stones: Current Surgical Management

Gallstone disease accounts for the vast majority of acute surgical admissions in the UK, with a major treatment being cholecystectomy. Practice varies significantly as to whether surgery is performed during the acute symptomatic phase, or after a period of recovery. Differences in practice relate to operative factors, patient factors, surgeon factors and hospital and trust wide policies. In this review we summarize recent evidence on management of gallstone disease, particularly with respect to whether cholecystectomy should occur during index presentation or following recovery. We highlight morbidity and mortality studies, cost, and patient reported outcomes. We speculate on barriers to change in service delivery. Finally, we propose potential solutions to optimize care.

Uncommon Presentation of Severe Empyema of the Gallbladder: Case Report and Literature Review

Patient: Male, 60-year-old

Final Diagnosis: Severe empyema of the gallbladder

Symptoms: Abdominal and/or epigastric pain • fever

Medication: —

Clinical Procedure: —

Specialty: Surgery

Emergent Treatment of Acute Cholangitis and Acute Cholecystitis

Acute pathology of the biliary tract including cholangitis and cholecystitis can lead to biliary sepsis if early decompression is not performed. This article provides an overview of the presenting signs and symptoms and role of interventional radiology in the management of patients with acute cholangitis or acute cholecystitis. It is especially important to understand the role of IR in the context of other treatment options including medical management, endoscopy, and surgery.

Infections of the Hepatobiliary System

Hepatobiliary infections account for a small but clinically important proportion of emergency department presentations. They present a clinical challenge due to the broad range of imaging characteristics on presentation. Recognition of complications is imperative to drive appropriate patient care and resource utilization to avoid diagnostic pitfalls and avert adverse patient outcomes. A thorough understanding of anatomy infectious pathology of hepatobiliary system is essential in the emergency setting to confidently diagnose and guide medical intervention. Many presentations of hepatobiliary infection have characteristic imaging features on individual imaging modalities with others requiring the assimilation of findings of multiple imaging modalities along with incorporating the clinical context and multispecialist consultation. Familiarity with the strengths of individual imaging modalities in the radiologists' arsenal is imperative to guide the appropriate utilization of resources, particularly in the emergent time sensitive setting. Accurate identification and diagnosis of hepatobiliary infections is vital for appropriate patient care and management stratification.

Combination of CT findings can reliably predict radiolucent common bile duct stones: a novel approach using a CT-based nomogram

OBJECTIVES

To identify CT features that reliably predict the presence of radiolucent common bile duct (CBD) stones.

MATERIALS AND METHODS

This retrospective study included 112 patients (mean age, 60.6 years) with clinically suspected CBD stones that were not visible on CT. All patients had undergone CT followed by endoscopic retrograde cholangiopancreatography (ERCP) to confirm the presence (n = 66) or absence (n = 46) of CBD stones. Two radiologists independently evaluated the CT images. Univariable and multivariable logistic regression analyses were performed to identify demographic, laboratory, and CT predictors for CBD stones. We developed a nomogram based on these results and assessed its performance.

RESULTS

In the multivariate analysis, CBD diameter ≥ 8 mm (odds ratio [OR], 10.12; p < 0.001), pericholecystic fat infiltration (OR, 3.76, p = 0.014), and papillitis (OR, 2.85; p < 0.049) were independent CT predictors of CBD stones. Combination of all three features had a specificity of 100%. Of these features, CBD diameter ≥ 8 mm was the best single predictor. The CT-based nomogram had an area under the curve (AUC) of 0.847 (95% confidence interval [CI], 0.777-0.916) and an accuracy of 77.7% (95% CI, 69.1-84.4%).

CONCLUSIONS

The combination of significant CT features (CBD diameter ≥ 8 mm, pericholecystic fat infiltration, and papillitis) translated into a nomogram allows a reliable estimation of CBD stone presence. It may serve as a decision support tool to determine whether to proceed to further diagnostic tests or treatment option.

KEY POINTS

• CBD diameter ≥ 8 mm (odds ratio [OR] = 10.12, p < 0.001), pericholecystic fat infiltration (OR = 3.76, p = 0.014), and papillitis (OR = 2.85, p = 0.049) were independent predictors of radiolucent CBD stones. • A CBD diameter ≥ 8 mm was the best predictor of CBD stones. • A nomogram based on a combination of these three CT signs predicted the presence of CBD stones and helped classify patients that should go immediately to ERCP, those who require a further investigation, and those who can safely be managed conservatively.

Pope's hat sign: another valuable CT finding of early acute cholecystitis

PURPOSE

To determine the diagnostic performance of minor computed tomography (CT) findings for acute cholecystitis and demonstrate the incremental benefit of pope's hat sign as an additional minor CT finding in patients suspected to have early acute cholecystitis.

MATERIALS AND METHODS

Two radiologists reviewed CT scans of 116 patients with early acute cholecystitis and 116 control patients. All cases in the patient group were surgically proven to have acute cholecystitis and preoperative dynamic CT scans. Evaluated CT parameters included major criteria (gallstone, distension of gallbladder (GB) lumen, GB wall edema, pericholecystic fat infiltration, and pericholecystic fluid collection) and minor criteria (GB bed hyperemia, tensile GB fundus sign, hyperdense GB wall sign, increased bile attenuation within GB, and pope's hat sign).

RESULTS

In a univariate analysis, among the minor criteria, GB bed hyperemia, tensile GB fundus sign, increased bile attenuation within GB, and pope's hat sign were more frequently observed (P < 0.05) in the early acute cholecystitis group. The optimal cut-off value of GB distension for discriminating between the two groups was 3.05 cm. In a multivariable analysis, GB bed hyperemia, pope's hat sign, and GB lumen > 3.05 cm were significant findings for differentiating the two groups (P < 0.001). Among all combinations of these findings, the combination of GB bed hyperemia and pope's hat sign exhibited the highest specificity (96.5%) and the combination of all three findings showed the highest sensitivity (94.0%).

CONCLUSION

Pope's hat sign is a new finding that could improve CT diagnostic performance for early acute cholecystitis in patients with RUQ pain in the emergency department. The combination of pope's hat sign with GB bed hyperemia or GB lumen distension > 3.05 cm may be even more helpful in the early stage or in mild forms of acute cholecystitis.

Imaging of acute cholecystitis and cholecystitis-associated complications in the emergency setting

Acute cholecystitis is a common cause of right upper quadrant pain in patients presenting at the emergency department. Early diagnosis and recognition of associated complications, though challenging, are essential for timely management. Imaging studies, including ultrasonography, computed tomography and magnetic resonance imaging, are increasingly utilised for the evaluation of suspected cases of cholecystitis. These investigations help in diagnosis, identification of complications and surgical planning. Imaging features of acute cholecystitis have been described in the literature and are variable, depending on the stage of inflammation. This article discusses the spectrum of cholecystitis-associated complications and their imaging manifestations. We also suggest a checklist for the prompt and accurate identification of complications in acute cholecystitis.

Acute cholecystitis is a common complication after allogeneic stem cell transplantation and is associated with the use of total parenteral nutrition

The incidence and risk factors for acute cholecystitis after allogeneic hematopoietic stem cell transplantation (HSCT) are not well defined. Of 644 consecutive adult transplants performed at our institution between 2001 and 2011, acute cholecystitis occurred in the first year of transplant in 32 patients (5.0%). We conducted 2 retrospective case-control studies of this population to determine risk factors for cholecystitis after HSCT and to evaluate the performance of different methods of imaging to diagnosis cholecystitis in patients undergoing HSCT compared with non-HSCT patients. In the HSCT population, development of cholecystitis was associated with an increased 1-year overall mortality rate (62.5% versus 19.8%, P < .001). The risk of developing cholecystitis was higher in patients who received total parenteral nutrition (TPN) (adjusted odds ratio, 3.41; P = .009). There was a trend toward more equivocal abdominal ultrasound findings in HSCT recipients with acute cholecystitis compared with nontransplant patients (50.0% versus 30.6%, P = .06). However, hepatobiliary iminodiacetic acid (HIDA) scans were definitively positive for acute cholecystitis in most patients in both populations (80.0% of HSCT recipients versus 77.4% of control subjects, P = .82). In conclusion, acute cholecystitis is a common early complication of HSCT, the risk is increased in patients who receive TPN, and it is associated with high 1-year mortality. In HSCT recipients with findings suggestive of acute cholecystitis, especially those receiving TPN, early use of HIDA scan may be considered over ultrasound.

Evidence-Based Management of Common Gallstone-Related Emergencies

Gallstone-related disease is among the most common clinical problems encountered worldwide. The manifestations of cholelithiasis vary greatly, ranging from mild biliary colic to life-threatening gallstone pancreatitis and cholangitis. The vast majority of gallstone-related diseases encountered in an acute setting can be categorized as biliary colic, cholecystitis, choledocholithiasis, and pancreatitis, although these diagnoses can overlap. The management of these diseases is uniquely multidisciplinary, involving many specialties and treatment options. Thus, care may be compromised due to redundant tests, treatment delays, or inconsistent management. This review outlines the evidence for initial evaluation, diagnostic workup, and treatment for the most common gallstone-related emergencies. Key principles include initial risk stratification of patients to aid in triage and timing of interventions, early initiation of appropriate antibiotics for patients with evidence of cholecystitis or cholangitis, patient selection for endoscopic biliary decompression, and growing evidence in favor of early laparoscopic cholecystectomy for clinically stable patients.

Acute cholecystitis: quantitative and qualitative evaluation with 64-section helical CT

BACKGROUND

Because of an expanded role for CT in the evaluation of patients with acute abdominal pain, it is not rare that acute cholecystitis is depicted by CT. However, the sensitivity and the specificity of a given CT variable for the diagnosis of acute cholecystitis is not known.

PURPOSE

To quantitatively and qualitatively analyze acute cholecystitis at 64-section helical CT with submilimeter and isotropic voxels using a retrospective case-control study.

MATERIAL AND METHODS

The 64-section helical CT examinations obtained with submilimeter and isotropic voxels in 40 patients with acute cholecystitis (25 men; mean age, 62.2 years) were quantitatively and qualitatively analyzed and compared to those of 40 control subjects matched for age and gender. Receiver-operating characteristic (ROC) curve analysis was used to determine the most discriminating cut-off values for quantitative variables. Comparisons of qualitative variables were made using univariate analysis.

RESULTS

Pericholecystic fat stranding, mural stratification, pericholecystic hypervascularity, spontaneous hyperattenuation of gallbladder wall, short (≥ 32-mm) and long (≥ 74-mm) gallbladder axis enlargement, and gallbladder wall thickening (≥ 3.6-mm) were the most discriminating and independent variables for the diagnosis of acute cholecystitis (P < 0.0001). Using cut-off values found at ROC curve analysis, gallbladder wall thickening, and short and long gallbladder axis enlargement were the most sensitive findings (sensitivity = 92.5%; 95%CI: 79.6%-98.4%) for the diagnosis of acute cholecystitis.

CONCLUSION

Acute cholecystitis is associated with myriad suggestive findings on 64-section helical CT. It can be anticipated that familiarity with these findings would result in more confident diagnosis of acute cholecystitis at 64-section helical CT.

An Inexpensive and Easy-to-Make Simulation Model of Biliary Ultrasound That Mimics Normal Anatomy and Abnormal Biliary Conditions

Simulation training in sonography has been shown be an effective method of teaching and assessing user competency in image acquisition/interpretation and performance of procedures. Gallbladder simulation models that are currently commercially available are entire torso section phantoms, are generally expensive to obtain, and require maintenance. We have developed a sonographic gallbladder simulation model constructed using readily available and inexpensive materials. Models were created of normal gallbladder anatomy as well as various gallbladder pathologies such as cholelithiasis, biliary sludge, and thickening of the gallbladder wall. This model can be used to train users both to obtain and interpret sonographic images of the gallbladder.

SPECT/CT unequivocally depicts dilated cystic duct sign on hepatobiliary scintigraphy in acute cholecystitis

The dilated cystic duct sign (DCDS) on hepatobiliary scintigraphy can lead to a false-negative test in patients with acute cholecystitis. Presented is a case of acute gangrenous cholecystitis with probable DCDS on the planar study that was unequivocally delineated on SPECT/CT imaging. SPECT/CT may be useful when planar findings suggest DCDS.

Complicated cholecystitis: the complementary roles of sonography and computed tomography

Acute cholecystitis is a common cause of abdominal pain in the Western world. Unless treated promptly, patients with acute cholecystitis may develop complications such as gangrenous, perforated, or emphysematous cholecystitis. Because of the increased morbidity and mortality of complicated cholecystitis, early diagnosis and treatment are essential for optimal patient care. Nevertheless, complicated cholecystitis may pose significant challenges with cross-sectional imaging, including sonography and computed tomography (CT). Interpreting radiologists should be familiar with the spectrum of sonographic findings seen with complicated cholecystitis and as well as understand the complementary role of CT. Worrisome imaging findings for complicated cholecystitis include intraluminal findings (sloughed mucosa, hemorrhage, abnormal gas), gallbladder wall abnormalities (striations, asymmetric wall thickening, abnormal gas, loss of sonoreflectivity and contrast enhancement), and pericholecystic changes (echogenic fat, pericholecystic fluid, abscess formation). Finally, diagnosis of complicated cholecystitis by sonography and CT can guide alternative treatments including minimally invasive percutaneous and endoscopic options.

The hot rim sign on hepatobiliary scintigraphy (HIDA) with CT correlation

An older male with multiple medical comorbidities presented to the emergency room after 3 days of worsening right upper quadrant pain. The patient had an elevated white blood cell count and mildly elevated liver functions. Initial ultrasound was equivocal and further imaging with CT scan was obtained. The CT scan was read as suggestive of cholecystitis, however a hepatobiliary scintigraphy (HIDA) scan was ordered for confirmation, as the patient was a poor operative candidate. The HIDA demonstrated no bile duct or small bowel activity on initial images or delays, however a classic 'hot rim' sign was present, confirming acute cholecystitis. The patient ultimately underwent percutaneous cholecystostomy with drainage for treatment where acute cholecystitis was confirmed. Upon retrospective review, the CT demonstrated hyperaemia surrounding the gallbladder fossa, which is the CT scan equivalent of a scintigraphic 'hot rim' sign. This is an uncommon example of a radiologic sign correlation between multiple imaging modalities.

Lessons learned from quality assurance: errors in the diagnosis of acute cholecystitis on ultrasound and CT

OBJECTIVE

The purpose of this article is to study errors in the diagnosis of acute cholecystitis reported in the online departmental quality assurance (QA) database.

MATERIALS AND METHODS

The departmental QA database was searched from October 2005 to April 2010 for cases of acute cholecystitis. Errors were classified into overcalls and undercalls.

RESULTS

We identified 14 cases of misdiagnosis involving acute cholecystitis. Three cases were classified as overcalls (21%) and eleven as undercalls (79%). Eight cases of misdiagnosis involved ultrasound studies (57%) and six cases involved CT studies (43%). Cases of overcall on ultrasound showed gallbladder wall edema, but none portrayed distention of the gallbladder. The final diagnosis in these cases included hepatitis, sepsis, and a case of chronic cholecystitis. All misinterpretations of CT cases were classified as undercalls. Contributing factors to misdiagnosis were lack of recognition of wall edema (n = 6), gallbladder distention (n = 4), absence of gallbladder wall edema (n = 1), lack of conclusion in the report (n = 2), and hospitalization in the ICU (n = 2). A possible case clustering was observed just after July almost every year.

CONCLUSION

An important pitfall in the diagnosis of acute cholecystitis is lack of recognition of gallbladder wall edema on CT. A relaxed (nondistended) gallbladder provides important evidence against the diagnosis of acute cholecystitis. Intensive care patients with sepsis often have no specific signs for diagnosis of acute cholecystitis, making diagnosis especially challenging.

The role of emergency ultrasound in the diagnosis of acute non-traumatic epigastric pain

The epigastrium is the site where pain coming from both abdominal and extra-abdominal organs is frequently referred. Although acute or chronic diseases of the stomach, duodenum, liver, pancreas and biliary tree are the most common causes of acute epigastric pain, several other entities, potentially more severe, should also be suspected and investigated. Clinical bedside ultrasonography (US) is actually the first-line imaging in acute epigastric pain patients presenting to the hospital Emergency Department (ED) because it is rapid, noninvasive, relatively inexpensive and focused, repeatable and reliable. Moreover, the systematic use of emergency US as a complement to routine management might save economic resources by avoiding further costs for complications and substantially reducing the time for making an accurate diagnosis. The purpose of this paper is to review the US spectrum of the most common diseases responsible for acute epigastric pain onset. We also propose a focused, well codified US protocol, that we call the "$ approach", based on our clinical experience and the current literature for acute non-traumatic epigastric pain evaluation in an emergency setting. Its systematic application by the emergency physician may reduce the wait for diagnosis and the over-usage of second-line radiological techniques, including computed tomography, as well as to increase the diagnostic accuracy with potential benefits for patient (safety), physician (efficacy) and the institution (efficiency).

Gallbladder imaging

The treatment of gallbladder disease has been revolutionized by improvements in laparoscopic surgery as well as endoscopic and radiologic interventional techniques. Therapeutic success is dependent on accurate radiologic assessment of gallbladder pathology. This article describes recent technical advances in ultrasonography, multidetector computed tomography, magnetic resonance imaging, positron emission tomography, and scintigraphy, which have significantly improved the accuracy of noninvasive imaging of benign and malignant gallbladder disease. The imaging findings of common gallbladder disorders are presented, and the role of each of the imaging modalities is placed in perspective for optimizing patient management.

CT findings of mild forms or early manifestations of acute cholecystitis

OBJECTIVE

The objective of this study was to determine the most predictive CT feature of the mild forms or early manifestations of acute cholecystitis.

MATERIALS AND METHODS

Two radiologists analyzed CT of 34 patients with mild or early acute cholecystitis and 34 control patients for pericholecystic increased attenuation on the arterial phase, indistinctness of the interface between the gallbladder (GB) and the liver, enhancement of the GB wall, and increased attenuation of the GB bile.

RESULTS

There were significant differences in the mean values for each CT feature but increased attenuation of the GB bile between patients and control group (P<.05). The most significant predictor of mild or early acute cholecystitis on CT was the presence of pericholecystic increased attenuation on the arterial phase (sensitivity, 82.4%), followed by indistinctness of the interface between the GB and liver (sensitivity, 38.0%), which were identified by both observers with good agreement (kappa=0.735 and kappa=0.687).

CONCLUSIONS

The pericholecystic increased attenuation on arterial phase CT was the most significant predictor of mild forms or early manifestations of acute cholecystitis.

Percutaneous gallbladder drainage for xanthogranulomatous cholecystitis

Xanthogranulomatous cholecystitis is a form of cholecystitis in which infected bile leaks into the gallbladder wall, forming extensive abscesses and infiltration. In this case, we demonstrate that at acute presentation, percutaneous radiologic-guided gallbladder drainage is a safe treatment, preceding elective cholecystectomy.

Three-dimensional mapping of gallbladder wall thickness on computed tomography using Laplace's equation

RATIONALE AND OBJECTIVES

Traditionally, maximum gallbladder wall thickness is measured at a single point on ultrasonography. The purpose of this work was to develop an automated technique to measure the thickness of the gallbladder wall over the entire gallbladder surface using computer tomography (CT).

MATERIALS AND METHODS

Subjects who had (5-mm) thick and thin (2.5-mm) reconstruction through the abdomen were selected from a research database. Their volumetric computed tomographic images were acquired using a multidetector GE Medical Systems LightSpeed 16 scanner at 120 kVp, approximately 250 mAs, with standard filter reconstruction algorithm and segmented in three dimensions. Two segmentation boundaries were obtained, an inner and an outer boundary of the gallbladder wall. The thickness of the wall was quantified by computing the distance between the boundaries over the entire volume using Laplace's equation from mathematical physics. The distance between the surfaces is found by computing normalized gradients that form a vector field, representing tangent vectors along field lines connecting both boundaries. The Laplacian technique was compared with the well-known Euclidean distance transformation (EDT) technique that provides a three-dimensional Euclidean distance mapping between the two extracted surfaces.

RESULTS

The technique was tested on 10 subjects who had thin- and thick-section computed tomographic datasets reconstructed from a single scan. The mean thickness for the thick- and thin-section CT using Laplace was 3.18 and 2.93 mm, respectively. The smooth transition between surfaces resulting from the Laplace technique resulted in a coefficient of variation that was less than 1% compared to EDT.

CONCLUSIONS

EDT technique is very sensitive to imperfect segmentations, resulting in higher variation compared to the Laplacian technique. The smooth transition between surfaces makes the Laplacian technique more robust compared to EDT for the measurement of CT gallbladder thickness.

Sixty-four–slice computed tomographic coronary angiography: will the “triple rule out” change chest pain evaluation in the ED?

Sixty-four-slice computed tomographic (CT) coronary angiography is a new technique for the noninvasive visualization of the coronary arteries. It enables noninvasive detection of coronary plaque and determination of severity without instrumentation of the heart. Although not yet commonly used in the emergency department setting, it stands poised to dramatically change the way that patients with chest pain are evaluated. In addition to evaluation of the coronary arteries, CT angiography has long been used to evaluate patients for other dangerous causes of chest pain such as aortic dissection and pulmonary embolus. Although these new scanners excel at all of these diagnostic modalities, the true excitement is in the possibility of combining several different protocols into one, allowing for multiple causes of chest pain to be "ruled out" simultaneously. This article describes the current state of the art of cardiac CT, current state of research, and current areas of controversy.

Recurrent cholangitis associated with biliary sludge and Phrygian cap anomaly diagnosed by magnetic resonance imaging and magnetic resonance cholangiopancreatography despite normal ultrasound and computed tomography

A 31-year-old woman presented with a one and half years' history of intermittent right upper quadrant (RUQ) pain, high fever and severely painful, warm and reddish swollen skin lesions on the fingers. Acute attack resolution occurred within 2 weeks after treatment with non-specific antibiotics. Low-grade fever (around 37.5 degrees C) and less painful swellings continued for 6 months after each attack. Abdominal ultrasound and computed tomography (CT) scans did not show any abnormality during the attacks. Biopsy of the skin lesions after the second attack revealed lymphocytic vasculitis. All laboratory studies including rheumatologic serology panel were normal. One month after the complete resolution of the second attack, the patient was observed to have high fever, the same skin lesions on the fingers as at the initial stage, nausea and marked abdominal pain in the RUQ. Routine laboratory studies including complete blood count, liver function tests and serum amylase and lipase levels were normal. An abdominal CT scan revealed a slight thickening of the gallbladder wall (3.9 mm). Two weeks later, abdominal magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) were performed because of persistent abdominal pain. They revealed both biliary tract and pancreatic gland alterations consistent with past cholangitis and pancreatitis with coexisting Phrygian cap anomaly and biliary sludge on the neck of the gallbladder.

Minimum training for right upper quadrant ultrasonography

The objective of this study was to assess if 10 right upper quadrant (RUQ) ultrasound (US) examinations could be used as a minimum standard for training. This was a retrospective review of patients with suspected gallbladder pathology who underwent resident-performed RUQ US before operative or department of radiology evaluation. Two hundred twenty-four patients were examined using resident-performed RUQ US followed by gold standard evaluations. One hundred seventy-eight patients were evaluated by 13 residents who met the "minimum training" standard of 10 prior examinations. The results of resident-performed RUQ US for gallstones and/or cholecystitis are shown subsequently. Previous suggestions that 10 examinations could be used as a minimum standard for training in focused abdominal sonography for trauma examinations cannot be used for RUQ US. The ACEP 2001 guidelines for 25 examinations are more consistent with the learning curve suggested by our data.

Hyperdense gallbladder wall sign

We reviewed the unenhanced computer tomography (CT) scans of 53 patients with surgically proven acute cholecystitis, where 27 patients presented with hyperdense gallbladder wall. To our knowledge, this sign was never reported before. Because mucosa is highly sensitive to ischemia, early mucosal necrosis and hemorrhage may result in CT-detectable high density. Similar episode may also occur in acute cholecystitis. This sign also reflects high probability for acute gangrenous cholecystitis. We suggest that patients with this sign should have urgent treatment.

Ultrasound and CT evaluation of emergent gallbladder pathology

Ultrasound is the initial imaging modality of choice for the evaluation of suspected acute gallbladder disorders, and is often sufficient for correct diagnosis. CT also plays a vital role, however, in the evaluation of acute gallbladder pathology. CT is particularly useful in situations where ultrasound findings are equivocal. CT is also extremely valuable in the assessment of suspected complications of acute cholecystitis, particularly emphysematous cholecystitis, hemorrhagic cholecystitis, and gallbladder perforation, which are often very difficult diagnoses to establish at sonography. If CT is the initial imaging test performed in a patient with abdominal pain of uncertain etiology, recognition of the various disorders described in this article may eliminate the need for further imaging and facilitate appropriate management.

CT of a thickened-wall gall bladder

This pictorial article reviews the various clinical entities that may cause mural thickening of the gall bladder encountered on contrast enhanced CT.

Imaging benign and malignant disease of the gallbladder

This article reviews the imaging of various benign and malignant diseases of the gallbladder. Clinical findings and imaging features using ultrasound, CT, and MR for the detection and evaluation of gallstones, acute cholecystitis, xanthogranulomatous cholecystitis, adenomyomatosis, and carcinoma of the gallbladder among other disorders are discussed.

CT findings in acute gangrenous cholecystitis

OBJECTIVE

The purpose of this study was to determine the CT findings in acute gangrenous cholecystitis.

MATERIALS AND METHODS

Four observers retrospectively reviewed CT scans in 75 patients (23 with acute gangrenous cholecystitis, 25 with acute non-gangrenous cholecystitis, and 27 without cholecystitis). The following findings were evaluated: distention, mural thickening, wall enhancement, irregular wall, wall striation, intraluminal membranes, pericholecystic inflammation, gallstones, pericholecystic fluid, enhancement of liver parenchyma, pericholecystic abscess, and gas in the wall or lumen. Sensitivity and specificity of CT for gangrenous cholecystitis and for each finding were calculated. Two reviewers in consensus measured gallbladder dimension and wall thickness. Logistic regression models were used to predict gangrenous versus non-gangrenous cholecystitis.

RESULTS

Sensitivity, specificity, and accuracy of CT for acute cholecystitis were 91.7%, 99.1%, and 94.3%, respectively, and for acute gangrenous cholecystitis were 29.3%, 96.0%, and 64.1%, respectively. Findings with the highest specificity for gangrenous cholecystitis were gas in the wall or lumen (100%), intraluminal membranes (99.5%), irregular or absent wall (97.6%), and abscess (96.6%). The difference between the mean gallbladder wall thickness and the short-axis dimension for the two groups with cholecystitis was statistically significant. In three patients with gangrenous cholecystitis, no mural enhancement was seen. Pericholecystic fluid also achieved statistical significance for the diagnosis of gangrene. Multivariate logistic regression analysis showed that the overall accuracy of CT for gangrenous cholecystitis was 86.7%.

CONCLUSION

CT findings most specific for acute gangrenous cholecystitis are gas in the wall or lumen, intraluminal membranes, irregular wall, and pericholecystic abscess. Gangrenous cholecystitis is associated with a lack of mural enhancement, pericholecystic fluid, and a greater degree of gallbladder distention and wall thickening.

Imaging the patient with right upper quadrant pain

A variety of high-resolution imaging techniques are currently available for the evaluation of patients with RUQ pain. In these patients, an imaging approach that is based on identifying the presence of certain clinical signs and symptoms can aid in choosing the appropriate imaging modality and establishing the diagnosis. For patients presenting with a positive Murphy sign, sonography and biliary scintigraphy are the most useful initial imaging techniques. In patients with fever and a negative Murphy sign, a combination of sonography and contrast-enhanced CT can establish the diagnosis in most cases. And finally, in patients without fever or a positive Murphy sign, CT and MR are appropriate first-line imaging techniques.