Radiologic diagnosis of an intra-abdominal abscess. Do multiple tests help?

Scoping review on diagnostic criteria and investigative approach in sepsis of unknown origin in critically ill patients

Background

Up to 11% of critically ill patients with sepsis have an unknown source, where the pathogen and site of infection are unclear. The aim of this scoping review is to document currently reported diagnostic criteria of sepsis of unknown origin (SUO) and identify the types and breadth of existing evidence supporting diagnostic processes to identify the infection source in critically ill patients with suspected SUO.

Methods

A literature search of Embase, MEDLINE and PubMed for published studies from 1910 to August 19, 2021 addressing the topic of SUO was performed. Study type, country of origin according to World Bank classification, diagnostic criteria of sepsis of unknown origin, and investigative approaches were extracted from the studies.

Results

From an initial 722 studies, 89 unique publications fulfilled the inclusion and exclusion criteria and were included for full text review. The most common publication type was case report/series 45/89 (51%). Only 10/89 (11%) of studies provided a diagnostic criteria of SUO, but a universally accepted diagnostic criterion was not identified. The included studies discussed 30/89 (34%) history, 23/89 (26%) examination, 57/89 (64%) imaging, microbiology 39/89 (44%), and special tests 32/89 (36%) as part of the diagnostic processes in patients with SUO.

Conclusions

Universally accepted diagnostic criteria for SUO was not found. Prospective studies on investigative processes in critically ill patients managed as SUO across different healthcare settings are needed to understand the epidemiology and inform the diagnostic criteria required to diagnose SUO.

Intramesenteric abscess caused by non-typhoidal Salmonella

Nontyphoidal Salmonella (NTS) is a common cause of gastroenteritis in humans and animals, but intra-abdominal abscesses or organ space surgical site infection (SSI) secondary to this organism has been rarely reported, making diagnosis and management difficult. Our case of intra-mesenteric abscess caused by NTS species is the only case reported in the literature. Immunocompromising conditions such as diabetes and human immunodeficiency virus (HIV) are important risk factors for invasive nontyphoidal Salmonella. Most patients are treated initially with intravenous antibiotics. Treatment often requires operative drainage by laparoscopy or laparotomy alone, although percutaneous drainage has been performed more frequently in recent years. Early clinical signs and radiographic features of intra-abdominal abscess may be diagnostically challenging. It is important for clinicians to have high index of suspicion based on history and symptomatology as prompt treatment is essential to prevent further morbidity and mortality.

IMPPACT (Intravenous Monotherapy for Postoperative Perforated Appendicitis in Children Trial): Randomized Clinical Trial of Monotherapy Versus Multi-drug Antibiotic Therapy

BACKGROUND

Perforated appendicitis is the most common cause of intraabdominal abscess (IAA) in children. The optimal postoperative antibiotic regimen to reduce IAA has evolved in the last decade from triple-drug to 2-drug therapy (CM). Recent retrospective studies show decreased infectious complications with monotherapy PT. To date prospective comparative data are lacking. Therefore, a prospective randomized trial comparing PT versus CM was conducted.

METHODS

A multi-institutional prospective randomized trial was performed in children with perforated appendicitis comparing postoperative antibiotic regimens PT or CM. The primary outcome was 30-day postoperative IAA formation. Perforation was strictly defined as a hole in the appendix or fecalith in the abdomen, documented with intraoperative photographs.

RESULTS

One hundred sixty-two patients were enrolled during the study period. No differences in age, weight, or duration of presenting symptoms were identified. In addition, length of stay, duration of intravenous antibiotic treatment, discharge oral antibiotic treatment, and antibiotic-related complications did not differ between groups. Compared to the CM group, the PT group had significantly lower IAA rate [6.1% vs 23.8%, odd ratio (OR) 4.80, P = 0.002], lower postoperative computed tomography imaging rate (13.9% vs 29.3%, OR 2.57, P = 0.030), and fewer emergency room visits (8.8% vs 26.4%, OR 3.73, P = 0.022). Multivariate logistic regression analysis found the use of CM versus PT (OR 9.21, P = 0.021) to be the most significant predictor for developing IAA.

CONCLUSIONS

In children with perforated appendicitis, postoperative monotherapy with PT is superior to standard 2-drug therapy with CM and does not increase antibiotic-related complications or antibiotic exposure duration.

Percutaneous drainage of retroperitoneal abscesses: variables for success, failure, and recurrence

PURPOSE

We aimed to evaluate the success and failure rates and minor and major complications of percutaneous drainage of retroperitoneal abscesses.

METHODS

Between 1990 and 2010, percutaneously drained 170 retroperitoneal abscesses in 150 patients (83 males, 67 females, median age 44.2 years, age range, 1-86 years) were included retrospectively. Percutaneous drainage of retroperitoneal abscesses was performed under the guidance of ultrasonography and fluoroscopy or computed tomography. Six abscesses were drained via single needle aspiration whereas 164 abscesses were drained via catheters of 6-14 F calibre using the Seldinger technique.

RESULTS

When all retroperitoneal abscesses are considered, success rates were found as follows: 75.3% cure (128/170), 7.7% temporization (13/170), 4.1% palliation (7/170). Failure rate was 12.9% (22/170). Recurrence rate was 10.6% (18/170), and 13 of the recurred abscesses were treated via second session percutaneous drainage. Mortality rate was 2.7% (4/150).

CONCLUSION

Percutaneous drainage is the first treatment option for retroperitoneal abscesses due to procedural reliability, elimination of need for general anesthesia, better tolerability, and lower morbidity and mortality rates compared with the surgical methods. High cure, temporization, or palliation rates can be obtained via imaging-guided percutaneous drainage for all retroperitoneal abscesses with a safe access route.

Imaging for infection: from visualization of inflammation to visualization of microbes

BACKGROUND

With the development of high-resolution cross-sectional imaging, anatomic identification of most areas of infection has become routine. Imaging a site of infection allows for diagnosis and treatment. In the past, molecular imaging for infection involved mainly the use of radiolabeled leukocytes for functional targeting at infection sites. With the recent development of functional nuclear imaging, bacterial and viral metabolism can also be imaged directly for potential identification of early infection.

METHODS

Review of pertinent English-language literature.

RESULTS

Cross-sectional imaging is used routinely to identify and treat sources of infection in patients with fever, leukocytosis, or unexplained hemodynamic instability. Although ultrasound is preferred for the identification of biliary or hepatic sepsis, computed tomography (CT) has proved to be accurate for the identification and treatment of intra-abdominal fluid collections and abscesses. Biologic imaging is a non-invasive technique that identifies sites of infection in cases in which no definite abnormality is identified via cross-sectional imaging. This is made possible by imaging the accumulation of radioisotopes that have been attached to white blood cells or glucose. Biologic imaging is useful for the identification of anatomic sites where there is inflammation or high metabolic demand. However, a drawback of biologic imaging is that it is not specific for infection. Techniques that image microbes directly increase the specificity of imaging results significantly and can be used to quantify and track infectious processes. For example, radiolabeling of antimicrobial proteins and antibiotics is one technique that has been demonstrated to identify areas of infection accurately in animals but is not currently being used clinically in humans. With the advent of gene therapy, many researchers are inserting the herpes viral thymidine kinase gene into both viruses and bacteria. This allows for tracking of the infectious process by imaging the accumulation of radiolabeled thymidine analogues.

CONCLUSION

This review summarizes standard imaging for infection as it is currently practiced clinically. We will also explore the promising new methods of microbial imaging that are likely to become standards in clinical care in the near future.

The value of Tc-99m (V) dimercaptosuccinic acid in detecting intra-abdominal infection: compared with gallium scan

OBJECTIVE

Gallium-67 (Ga-67) and labeled leukocytes are useful in the detection of an unknown infectious source. However, the delay in the diagnosis of a Ga-67 citrate scan (gallium scan) and the complicated labeling technique of a leukocyte scan are major drawbacks to their clinical use. Recently, Tc-99m (V) dimercaptosuccinic acid (DMSA) has been found to be very useful in the detection of infection. Tc-99m (V) DMSA is inexpensive, easy to prepare, and provides a result within hours. In this study, we evaluated the potential of Tc-99m (V) DMSA scan (DMSA scan) in the detection of intra-abdominal infection.

METHODS

A total of 33 patients who suffered from an unknown cause of fever after colorectal surgery were enrolled in this study. All patients received both a gallium scan and a DMSA scan. DMSA scintigraphy was performed 3-4 h after an injection of 740 MBq (20 mCi) of Tc-99m DMSA. After completion of the DMSA image, 111 MBq (3 mCi) of Ga-67 citrate was injected intravenously. Gallium scintigraphy was performed after 24 h and later as needed.

RESULTS

Of the 33 patients, 17 (51.5%) were diagnosed with intra-abdominal abscesses. For DMSA scans, the sensitivity, specificity, and overall accuracy were 88.2%, 93.7%, and 90.9%, respectively. For gallium scans, the diagnostic sensitivity, specificity, and accuracy were 100%, 87.5%, and 93.9%, respectively. No statistical difference was found in the diagnostic accuracy between these two diagnostic modalities using Fisher's exact test.

CONCLUSIONS

DMSA scan is a useful alternative to gallium scan in the detection of intra-abdominal infection in patients with colorectal surgery because Tc-99m DMSA is inexpensive, easy to prepare, and most importantly the result can be obtained within hours.

Tc-99m(V)-DMSA in wound infection after closure of an ileostomy

We present a 71-year-old man who underwent closure of an ileostomy and had a fever seven days post surgery. Both Tc-99m(V)-dimercaptosuccinic acid (DMSA) and gallium-67 citrate scans showed increased tracer accumulation in the right lower quadrant of the abdomen. Tc-99m(V)-DMSA scintigraphy can be a rapid alternative tool in the detection of wound infection in patients after ileostomy closure.

A comparative study to validate the use of ultrasonography and computed tomography in patients with post-operative intra-abdominal sepsis

PURPOSE

To validate abdominal ultrasonography and helical computed tomography in detecting causes for sepsis in patients after abdominal surgery and to determine improved criteria for its use.

MATERIALS AND METHODS

Eighty-five consecutive surgical patients primarily operated for non-infectious disease were included in this prospective study. Forty-one patients were admitted to the intensive care unit. All patients were suspected of an intra-abdominal sepsis after abdominal surgery. Both ultrasonography (US) and helical abdominal computed tomography (CT) were performed to investigate the origin of an intra-abdominal sepsis. The images of both US and CT were interpreted on a four-point scale by different radiologists or residents in radiology, the investigators were blinded of each other's test. Interpretations of US and CT were compared with a reference standard which was defined by the result of diagnostic aspiration of suspected fluid collections, (re)laparotomy, clinical course or the opinion of an independent panel. Likelihood ratios and post-test probabilities were calculated and interobserver agreement was determined using kappa statistics.

RESULTS

The overall prevalence of an abdominal infection was 0.49. The likelihood ratio (LR) of a positive test-result for US was 1.33 (95% CI: 0.8-2.5) and for CT scan 2.53 (95% CI: 1.4-5.0); corresponding post-test probabilities for US 0.57 (95% CI: 0.42-0.70) and for CT 0.71 (95% CI: 0.57-0.83). The LR of a negative test-result was, respectively, 0.60 (95% CI: 0.3-1.3) and 0.18 (95% CI: 0.06-0.5); corresponding post-test probabilities for US 0.37 (95% CI: 0.20-0.57) and for CT 0.15 (95% CI: 0.06-0.32) were calculated.

CONCLUSION

Computed tomography can be used as the imaging modality of choice in patients suspected of intra-abdominal sepsis after abdominal surgery. Because of the low discriminatory power ultrasonography should not be performed as initial diagnostic test.

Ga-67 scan to detect intra-abdominal infection in patients after colorectal surgery

PURPOSE

Intra-abdominal infection is still an important issue in colorectal surgery. The Ga-67 scan is relatively inexpensive, but the delay in diagnosis and the intense physiologic bowel activity are considerable drawbacks to its use in abdominal investigations. In this study, the authors performed 24-hour Ga-67 scans and read the images with the surgeon to detect abdominal infection in patients who underwent colorectal surgery.

METHODS

Sixty-one patients who underwent colorectal surgery were enrolled in this study. Ga-67 scintigraphy was performed 24 hours, and later as needed, after the injection of 111 MBq (3 mCi) Ga-67 citrate. All scans were interpreted together by a nuclear medicine specialist and the surgeon. The intensity of Ga-67 uptake was recorded as grade 0: no uptake; grade 1: less than liver uptake; grade 2: equal to liver uptake; or grade 3: greater than liver uptake. When the intensity of Ga-67 uptake was equal to or greater than grade 2, the pattern of Ga-67 uptake was classified as changing or unchanging. A positive Ga-67 scan was defined as having an intensity of grade 2 or 3 with an unchanging pattern.

RESULTS

Nineteen abdominal infections were diagnosed, all by Ga-67 scans, for a diagnostic sensitivity rate of 100%. Of the 42 patients with no intra-abdominal infection, only 2 had positive Ga-67 scans. This resulted in a specificity rate of 95.2%. The overall accuracy of the Ga-67 scan in the detection of intra-abdominal infection after colorectal surgery was 96.7%.

CONCLUSIONS

The Ga-67 scan is useful for detecting intra-abdominal infection after colorectal surgery. Reading the images with the surgeon and using a lateral view can decrease the false-positive rate. A negative Ga-67 scan can rule out intra-abdominal infection, whereas a positive Ga-67 scan indicates the need for further patient evaluation after colorectal surgery.

Abdominal abscesses in patients having surgery: an application of Ga-67 scintigraphic and computed tomographic scanning

PURPOSE

Early detection of occult abscesses is important in patients with persistent fever after colorectal surgery. In this study, the authors evaluated the relative merits of computed tomographic (CT) and Ga-67 scans in the detection of intra-abdominal abscesses in patients who had just undergone colorectal surgery.

MATERIALS AND METHODS

Thirty-four patients who underwent colorectal surgery were enrolled in the study. Ga-67 and CT scans were obtained in all patients. Ga-67 scintigraphy was performed 24 hours, and later as needed, after the injection of 111 MBq (3 mCi) Ga-67 citrate.

RESULTS

Intra-abdominal abscesses were diagnosed in 16 of the 34 (47%) patients who had colorectal surgery. For CT scans, the overall accuracy, sensitivity, and specificity rates were 97.1%, 93.7%, and 100%, respectively. For the Ga-67 scans, the diagnostic accuracy, sensitivity, and specificity rates were 91.2%, 100%, and 95.2%, respectively. In addition, the whole-body Ga-67 scans successfully detected two cases of extra-abdominal infection, one case of pneumonia, and one case of cellulitis.

CONCLUSIONS

Computed tomographic and Ga-67 scans offer complementary information and play an important role in the investigation of sources of infection in patients after colorectal surgery.

Does bowel preparation improve the quality of abdominal gallium scintigraphy?

Physiological accumulation of gallium in the intestine is a major weakness of gallium scintigraphy in evaluating the abdomen. In this study, we used two different cathartics to evaluate the efficacy of bowel cleansing in improving the quality of abdominal gallium imaging. One hundred and fifty patients underwent gallium scintigraphy and were randomly divided into three groups. Group A received no bowel preparation, Group B received 30 ml of castor oil the night before imaging, and Group C received bisacodyl the night before imaging. Gallium activity in the intestine was rated on a three-point scale from 0 to II based on the anterior view of a delayed 48-h gallium image. Our data showed that the incidence of gallium accumulation in the small intestine was low. On the contrary, there was high prevalence of gallium activity in the colon. Forty-eight percent of Group A patients had obvious gallium activity in the colon. The percentage decreased significantly to 28% and 22% in Groups B and C, respectively. No significant difference was noted between Group B and Group C. In conclusion, our data suggest that the application of either castor oil or bisacodyl significantly improves the quality of 48-h abdominal gallium scintigraphy. There were no significant differences in the efficacy of bowel cleansing on gallium activity between these two laxatives.

Development and implementation of an appropriateness guideline for use of CT in cases of suspected intraabdominal abscess

RATIONALE AND OBJECTIVES

The purpose of this study was to develop an evidence-based guideline for use of computed tomography (CT) in the evaluation of suspected abdominal abscess. The goal of the guidelines was to decrease the absolute number of CT examinations performed for suspected abdominal abscess and to increase the rate of positive CT examinations while not missing clinically relevant abscesses.

MATERIALS AND METHODS

A multidisciplinary team developed an evidence-based guideline regarding use of CT to evaluate for suspected abscess. A control group consisted of patients scanned for suspected abscess during a 6-month period. The intervention group consisted of patients scanned in the 6 months after guideline implementation. Focal fluid collections depicted on CT scans were reviewed for both patient groups to determine if these collections were abscesses. The number and proportion of abscesses in each group were then compared.

RESULTS

During the control period, 263 CT examinations for suspected abscess were performed, 75 of which (28.5%; 90% confidence interval [CI], 24%, 33%) depicted focal fluid and 25 of which (9.5%; 90% CI, 7%, 12%) depicted abscess. During the intervention period, 238 CT examinations were performed, 54 of which (22.7%; 90% CI, 18%, 27%) depicted fluid and 41 of which (17.2%; 90% CI, 13%, 21%) depicted abscess.

CONCLUSION

A guideline was successful at decreasing the number of CT examinations and increasing the proportion of positive CT results for abdominal abscess. As with other inpatient utilization interventions, each practice must assess the cost-benefit trade-off of guideline implementation in complex clinical situations.

CT in searching for abscess after abdominal or pelvic surgery in patients with neoplasia: do abdomen and pelvis both need to be scanned?

PURPOSE

This prospective study was undertaken to determine the incremental yield of combined abdominal and pelvic CT in searching for clinically suspected postoperative abscess in oncologic patients.

METHOD

One hundred seventeen oncologic patients underwent CT to exclude a clinically suspected abscess within 30 days of abdominal or pelvic surgery during an 8 month period. Scans were evaluated for the presence of ascites, loculated fluid collections, or other possible sources of fever. The clinical course and any intervention in the abdomen or pelvis within 30 days after CT were recorded.

RESULTS

After abdominal surgery, 44 of 69 [64%; confidence interval (CI) 51-75%] patients had loculated fluid collections in the abdomen; no patient (0%; CI 0-5%) had a loculated fluid collection present only in the pelvis. After pelvic surgery, 22 of 48 (46%; CI 31-61%) patients had loculated fluid collections in the pelvis; no patient (0%; CI 0-7%) had a loculated collection present only in the abdomen. Loculated collections were present in both the abdomen and the pelvis in 4 of 69 (6%; CI 1.6-14%) patients after abdominal surgery and 3 of 48 (6%; CI 1.3-17%) after pelvic surgery.

CONCLUSION

Isolated pelvic abscesses after abdominal surgery and isolated abdominal abscesses after pelvic surgery appear to be very uncommon in oncologic patients. CT initially need be directed only to the region of surgery in this particular patient population.

Radiologic investigation and treatment of gastrointestinal fistulas

Diagnostic radiology has assumed an increasingly prominent role in the diagnosis, investigation, and treatment of gastrointestinal fistulas during the past 15 years. This development largely has been the result of the application of computed tomography and ultrasonography to the diagnosis of intra-abdominal inflammatory processes and the use of these cross-sectional imaging modalities to guide percutaneous abscess drainage by the interventional radiologist. Effective percutaneous techniques have been developed that allow many gastrointestinal fistulas to be managed nonoperatively with less morbidity and mortality.

Leucocyte scintigraphy or computed tomography for the febrile post-operative patient?

OBJECTIVE

The optimal initial investigation for the post-operative patient with suspected occult intra-abdominal sepsis is controversial, although the diagnostic accuracy of a variety of techniques is known. Our objective is to determine which investigation has the greatest positive effect on patient management.

METHODS AND PATIENTS

We reviewed 67 consecutive post-operative patients investigated for suspected occult sepsis retrospectively and analysed the sequence of investigations required to achieve the diagnosis depending on the choice of initial investigation, and the interval between between initiating investigations and performing definitive percutaneous drainage.

RESULTS

Forty patients had scintigraphy as the initial investigation and 21 of these went on to require CT. None of the 27 patients who had CT as the initial investigation required any other imaging (chi 2 = 20.6, P < 0.0001) and appropriate percutaneous drainage was offered immediately. Conversely, the average interval to drainage in those who had scintigraphy first was 3.1 days. Fourteen out of 20 patients (70%) who had scintigraphy as the initial investigation following recent surgery, and 7 of 20 (35%) following old surgery, needed subsequent CT. None of the 20 and 7 patients in the recent and old surgery groups respectively who had CT initially required further imaging.

CONCLUSION

Our results suggest recommending CT as the initial investigation in the early post-operative period as this will reduce the total number of investigations required to achieve the diagnosis and the time to definitive drainage. In the late post-operative period, scintigraphy will resolve the majority of problems.

Intra-abdominal sepsis

This article addresses controversial issues in the field of intra-abdominal sepsis with particular attention to major changes in management that have evolved during the past decade. In the area of diagnostics, scanning techniques have revolutionized the ability to detect loculated collections, although many of these techniques are of limited value in the early stages of inflammation. The greatest debate concerns the relative merits of scanning techniques; the author's choice is CT scans with contrast, although ultrasonography is preferred in patients who cannot be transported and is probably preferred for pelvic infections. In the area of therapeutics, virtually all studies seem to show that single-drug treatment is as effective as dual combinations or triple-combination therapy that has been standard practice in the past with the proviso that the drug used has activity versus Enterobacteriaceae and B. fragilis. The role of enterococcus remains enigmatic; this organism was readily discounted as an important pathogen in the great majority of cases 10 years ago, but it has subsequently become a major nosocomial pathogen that now commands newfound respect. P. aeruginosa is also controversial, but most studies show that antipseudomonad treatment is not necessary in the empiric selection of drugs and may not be necessary even when P. aeruginosa is found at infected sites; the corollary to this is that aminoglycosides may no longer be required in the dual drug treatment regimens. There is increasing resistance by B. fragilis and some other species of Bacteroides to some of the drugs considered "standard" in the past, including clindamycin, cefoxitin, and cefotetan; nevertheless, it has been difficult to demonstrate that resistance of these organisms correlates with antibiotic failure. It was demonstrated 20 years ago that elective colon surgery must be accompanied by preoperative antibiotics, and erythromycin plus neomycin has evolved as the regimen of choice according to recommendations of authoritative sources for the past 20 years. Nevertheless, surveys of practicing surgeons indicate that most actually combine this oral preparation with parenteral agents as well. The final controversy concerns percutaneous drainage, which has now become a standard technique for dealing with intra-abdominal abscesses in 50% to 90% of cases. This controversy has sometimes been seen as a territorial battle between surgeons and radiologists, and most cases are clearly the prerogative of one discipline or the other, but many are in a gray zone in which clearly defined indications are not readily available.

Management of intra-abdominal sepsis

The management of intra-abdominal sepsis includes drainage of septic foci, debridement of devitalized tissue, and prevention of continuing peritoneal contamination. An algorithm is presented as an aid to the thought process.

Imaging intraabdominal abscesses and nonoperative drainage procedures

With state-of-the-art imaging and interventional techniques, the diagnosis and management of intraabdominal abscesses have improved. Radionuclide scanning, ultrasound, and computed tomography are very accurate for the diagnosis and staging of intraabdominal abscesses, permitting the use of percutaneous drainage methods. Percutaneous abscess drainage (PAD) has gained wide acceptance and applications now include not only curative drainages but also certain palliative ones. Although some controversy exists relative to results and palliative procedures, PAD is now accepted as an effective alternative to operative drainage.

Correlative imaging in abdominal infection: an algorithmic approach using nuclear medicine, ultrasound, and computed tomography

A wide variety of focal and diffuse infectious processes involve the abdomen. At one extreme are diseases such as pyelonephritis, cystitis, and pelvic inflammatory disease, conditions usually diagnosed without imaging studies and treated without complications. At the other extreme are abdominal abscesses, which may defy clinical diagnosis, are associated with significant morbidity and mortality, and may remain undetected or insufficiently characterized in spite of multiple imaging studies. The limited diagnostic value of clinical evaluation and plain film radiography in abscess detection has lead to widespread use of sophisticated imaging techniques including Gallium-67 (67Ga) scintigraphy, Indium-111 WBC (111In-WBC) scintigraphy, computed tomography (CT), and ultrasonography (US). Abdominal abscesses occur in a wide variety of anatomic sites, may involve any abdominal organ system, and have a number of different causes. The heterogeneity of the disease process and the varying capabilities of the different imaging techniques (with respect to site and organ system) make reliance on a single technique undesirable. An algorithmic approach using 67Ga or 111In-WBC scintigraphy, CT, and US provides a logical and clinically practical approach to complicated abdominal infection. By recognizing differences in clinical presentation and by appreciating the diagnostic strengths and weaknesses of nuclear medicine, CT, and US, the algorithm provides a reliable and direct route to accurate diagnosis while minimizing unnecessary examinations.

Delayed pelvic abscess eight years after generalized peritonitis

Recently, during a locally severe epidemic of gastroenteritis, a young woman presented, with the symptoms prevalent in her community, harboring an intraabdominal abscess. The case is presented along with a discussion of unusual and delayed presentations of abscesses in the literature. Early diagnosis is imperative because of the very significant morbidity and mortality accompanying delayed treatment.

Gadolinium-DTPA enhanced MR imaging of intramuscular abscesses

Sterile, chemical and bacterial abscesses were induced in the paraspinal muscles of 16 rats before obtaining magnetic resonance (MR) images using a 0.35-T resistive system. Abscess intensity, T1 and T2 values were recorded before and after the intravenous administration of Gd-DTPA (0.2 mmol/kg). The MR appearances of the abscesses were correlated with histologic sections. Both sterile and bacterial abscess were detected on MR images without the use of contrast medium, particularly on the T2-weighted spin echo sequence (TE/TR 56/2000 ms). However, the inflammatory zones of abscesses markedly enhanced in intensity with a corresponding decrease in T1 values after the administration of Gd-DTPA (TE/TR 28/500 ms). A clear distinction between the necrotic center and the cellular periphery of each abscesses was evident only after contrast enhancement (TE/TR 28/500 ms). Thus paramagnetic Gadolinium-DTPA was beneficial for defining the histologic components of abscesses on spin echo MR images.