Infections of the neck leading to descending necrotizing mediastinitis: Role of multi-detector row computed tomography

Descending necrotizing mediastinitis is an acute, polymicrobial infection of the mediastinum, originating from odontogenic, oropharyngeal and cervical infections. Anatomical continuity of the fascial spaces between the neck and the mediastinum leads to an occasional mediastinal extension of deep neck infection as a serious sequela. An understanding of the anatomy of the deep spaces of the neck and familiarity with the imaging findings in descending necrotizing mediastinitis may allow rapid diagnosis and treatment of this rare and life-threatening complication of deep neck space infection. In this article, we discuss the current role of radiology in diagnosing descending necrotizing mediastinitis, in determining the level of infection and the pathways of spread of infections from the neck to the mediastinum and in planning a successful treatment.     

Determining optimum management of descending necrotizing mediastinitis with CT; experience with 32 cases

To determine the value of helical computed tomography (CT) in the diagnosis, management and outcome of patients suspected of having descending necrotizing mediastinitis (DNM). Thirty-two patients with suspected DNM were submitted to contrast-enhanced single detector-row helical CT, four detector-row CT and 16 detector-row CT of the neck and chest. In 10/32 patients (group 1) no abnormality was observed in the neck or in the chest spaces on CT scan. These patients were all treated non-operatively. In 12/32 patients (group 2) CT showed the presence in the neck spaces of fluid collections, fasciitis, cellulitis, myositis, jugular vein thrombosis and lymphadenopathy; in all these patients the chest was unaffected. A cervical drainage was performed in ten patients. In the remaining ten patients (group 3), the neck infection involved the mediastinal spaces in all the cases and the pleural and pericardial spaces; CT findings included mediastinal cellulitis and fluid collections, pleural and pericardial effusions, venous thrombosis and lymphadenopathy. In these patients, a cervico-mediastinal drainage was performed and antibiotics were administered. The CT provides a highly accurate depiction of the presence and the spread of DNM. The CT findings and the extension of disease are important factors in order to predict for patient management and outcome.Presented at the 16th ECR, Vienna, March 2004.     

Acute small bowel ischemia: spectrum of computed tomographic findings

Acute small bowel ischemia is an important clinical entity with significant morbidity and mortality. Since the clinical presentation is often nonspecific, abdominal computed tomography (CT) is frequently obtained for the evaluation of patients with equivocal or unsuspected intestinal ischemia. In this article, the direct and ancillary CT findings of acute small bowel ischemia are reviewed. Although the individual CT manifestations are rarely specific, awareness of the spectrum of CT findings of small intestinal ischemia can help to suggest the diagnosis and direct appropriate management.     

Acute epiploic appendagitis: CT findings in 33 cases

Acute epiploic appendagitis (AEA) is a benign self-limiting process presenting with acute abdominal pain often misdiagnosed clinically as either diverticulitis or appendicitis, but which has a pathognomonic CT appearance. The CT findings in 33 adult patients diagnosed by CT over a 33-month period as having AEA were retrospectively reviewed. The study group included 24 men and 9 women, with a mean age of 44.6 years. The mean age of the male patients was lower than that of the female patients, 40.9 vs 54.7 years. All patients presented with acute abdominal pain, mainly in the left (n=21) and right (n=9) lower quadrants, with localized tenderness in all patients and peritoneal irritation in 15 of them. Low-grade fever was found in 8 patients and mild leukocytosis in 16. Characteristic CT findings of an oval fatty mass with central streaky densities and surrounded by mesenteric stranding adjacent to the serosal surface of the colon were seen in all cases. Additional findings included mural thickening of the juxtaposed colon in 16 patients and peritoneal fluid in 7. One patient underwent surgery on the basis of an erroneous diagnosis of acute appendicitis. As CT is often used nowadays to evaluate various acute abdominal complaints, it may be the first imaging modality by which AEA is diagnosed. AEA should be included in the differential diagnosis in young male patients with localized left lower abdominal pain and tenderness. Electronic Publication     

Infectious mediastinitis after cardiovascular surgery: role of computed tomography

PURPOSE: The aim of this study was to evaluate the effectiveness of computed tomography (CT) findings in the diagnosis of mediastinitis after cardiovascular surgery with median sternotomy. MATERIAL AND METHODS: A total of 122 patients were divided into two groups: the early group (21 days after surgery). Among them, six patients were ultimately diagnosed with infectious mediastinitis. CT findings in each patient were evaluated. Mediastinal fluid collections or free gas bubbles were regarded as the primary findings of mediastinitis. RESULTS: In the early group, sensitivity and specificity of the primary CT findings were 100% and 39%, respectively. In the late group, the sensitivity was 100% and the specificity 85%. Mediastinal fluid collections were observed in all six patients with mediastinitis. CONCLUSION: Mediastinal fluid collections or free gas bubbles are not specific during the early postoperative period. However, after 2 21 days, these observations could be indicative of mediastinitis.     

Acute coronary syndrome on non-electrocardiogram-gated contrast-enhanced computed tomography

It is not rare for acute coronary syndrome (ACS) patients to present with symptoms that are atypical, rather than chest pain. It is sometimes difficult to achieve a definitive diagnosis of ACS for such patients who present with atypical symptoms, normal initial biomarkers of myocardial necrosis, and normal or nondiagnostic electrocardiograms (ECGs). Although cardiac CT allows for assessments of coronary artery stenosis as well as myocardial perfusion defect in patients with suspected ACS, it requires ECG gating and is usually performed with high-performance multislice CT for highly probable ACS patients. However, several recent reports have stated that ACS is detectable by myocardial perfusion defects even on routine non-ECG-gated contrast-enhanced CT. A growing number of contrast-enhanced CT scans are now being performed in emergency departments in search of pathologies responsible for a patient’s presenting symptoms. In order to avoid inappropriate management for this life-threatening event, clinicians should be aware that myocardial perfusion defect is more commonly detectable even on routine non-ECG-gated contrast-enhanced CT performed in search of other pathologies.     

Ureterolithiasis: classical and atypical findings on unenhanced helical computed tomography

Evaluation of patients with acute flank pain using helical computed tomography (CT) is a well-accepted, rapid, and safe procedure in the emergency setting. Various primary and secondary signs are described in the literature for evaluation of these patients. Our purpose is to demonstrate both the classical findings associated with ureteral calculi on unenhanced helical CT and atypical findings and potential pitfalls. We also provide readers with a systematic approach to interpreting unenhanced helical CT scans performed for acute flank pain. Electronic Publication     

Acute cardiac tamponade: Demonstration of altered hemodynamics by contrastenhanced computed tomography

We present a case of cardiac tamponade caused by blunt trauma to demonstrate the specific hemodynamic changes that can be demonstrated with contrast-enhanced computed tomography. Because the clinical diagnosis may be missed in the setting of multiple trauma, radiologists should familiarize themselves with these specific changes.     

Transverse colon volvulus: appearance on computed tomography

Transverse colon volvulus is a rare but potentially fatal cause of intestinal obstruction. We report the case of a 72-year-old woman presenting with clinically suspected intestinal obstruction. She underwent abdominal and pelvic computed tomography (CT). The diagnosis was obtained preoperatively: CT showed “the whirl sign”, indicative of a volvulus.     

Middle mesenteric artery: Angiographic and three-dimensional computed tomography findings

The middle mesenteric artery, also known as the third mesenteric artery, is a very rare anomaly. Several anatomical variations of middle mesenteric artery have been reported; in these reports, the right colic artery and/or middle colic artery often originate directly from the aorta. Here, we report a middle mesenteric artery in which the middle colic artery originated directly from the abdominal aorta. We also provide three-dimensional computed tomography and angiography findings and discuss anatomical and embryological considerations.     

CT features of descending necrotizing mediastinitis—a pictorial essay

Descending necrotizing mediastinitis (DNM) is a relatively rare condition caused by downward spread of neck infections into the mediastinum. This infection previously had a much worse prognosis. In recent years, prompt computer topography (CT) diagnosis has been recommended. CT scan provides the earliest means of detecting DNM for optimal management and early surgical intervention. This paper provides an illustrated summary of our extensive clinical experience with DNM, involving 36 documented cases with CT over a 5-year period.     

Dumbbell-shaped thoracic hibernoma: computed tomography and magnetic resonance imaging findings

Hibernoma is an uncommon, benign soft tissue tumor that arises in brown adipose tissue. The computed tomography (CT) and magnetic resonance imaging (MRI) findings of hibernomas are similar to those of well-differentiated liposarcoma or angiolipoma. We report the unique appearance of a rare thoracic wall hibernoma, which appeared as a dumbbell-shaped lipomatous tumor across an intercostal region. A dynamic contrast-enhanced study on MRI revealed early enhancement, which corresponded to the branching low-signal intensity on T2-weighted images of the mass.     

Focused helical appendiceal computed tomography: Technique and interpretation

This article reviews a focused helical appendiceal computed tomographic technique and discusses an approach to appendiceal computed tomographic interpretation.     

Spontaneous rupture of a necrotic hepatic angiosarcoma: findings on dual-phase computed tomography and angiography

We present dual-phase computed tomographic (CT) and angiographic findings of a ruptured hepatic angiosarcoma. These tumors can be divided into two types: those with and those without gross central necrosis with hemorrhage. In our case, the tumor had gross central necrosis, and CT and angiographic findings showed a small number of areas with a centripetal enhancement pattern and the rest of the tumor with avascular areas. We found that dual-phase CT and angiographic findings are able to distinguish angiosarcoma, which mimics a hemangioma, as these lesions show avascular areas that reflect a mass with gross central necrosis.     

Right lower quadrant pain: Imaging with computed tomography

Computed tomography (CT) is a fast and accurate way to evaluate patients with acute right lower abdominopelvic pain. In the emergency setting, appendicitis is the most common etiology. A tailored CT examination can visualize the normal or abnormal appendix with accuracy, confirming or excluding appendicitis in 90–95% of cases. If the appendix is normal, CT often identifies an alternative etiology for the pain. This exhibit reviews the CT appearance of the normal appendix, usual and unusual presentations of appendicitis and complicated appendicitis, and pitfalls in diagnosis. The CT appearance of other conditions included in the differential diagnosis of acute right lower quadrant pain and clinically mimicking appendicitis is also presented, including disorders arising from the gastrointestinal tract, genitourinary tract, and vascular and musculoskeletal systems.     

Leiomyosarcoma of the inferior vena cava: Angiographic and computed tomography findings

Leiomyosarcoma, a highly malignant tumor of the inferior vena cava, is rare. Only 55 cases have been reported in the world literature, and of these only 18 were evaluated with a special vascular procedure, either arteriography or inferior vena cavography. In two cases of leiomyosarcoma of the inferior vena cava, we performed arteriography and inferior vena cavography. In one, computed tomographic studies were also carried out. Cavography showed a lobulated filling defect in one case and complete caval occlusion with collateral circulation in the other. In the one case in which it was performed, computed tomography clearly demonstrated the tumor's size and its relationship to surrounding organs. Arteriographic studies, however, allowed only an indistinct delineation of the extent of tumor growth in one case. Venography followed by computed tomography should permit adequate assessment of most leiomyosarcomas of the inferior vena cava, with arteriography reserved for tumors involving the upper cava in which hepatic involvement must be evaluated.     

Timing of exposure in angiographic computed tomography

Visualization of heart chambers or the abdominal arterial phase on one of two CT-scans was achieved in 89.4% of 169 injections (91 patients) using only 30 ml of contrast medium (370 mg iodine/ml), when the start of scanning was accurately timed at predicted bolus peak concentration. Normal arrival times and numer of transit cycles to the bolus concentration maximum in the right (RV) and left ventricle (LV) after injection of a small radionuclide bolus of technetium-99 m were related to the patient's heart rate (HR) in a group of 200 patients. For the RV, mean arrival times varied significantly between 2.31 (HR: 90–109 beats per minute) and 3.46 seconds (HR: 50–59 beats per minute), mean number of transit cycles between 4.1 and 3.5. For the LV, mean arrival times varied significantly between 6.92 (HR: 90–109 beats per minute) and 11.37 seconds (HR: 50–59 beats per minute), and the mean number of transit cycles between 11.5 and 10.7. Washout from the LV lasted between an average of 9.2 (HR: 90–109 beats per minute) and 8.5 cycles (HR: 50–59 beats per minute). Contrary to actual transit times, there was no significant difference in the number of transit heart cycles for heart rates between 60 and 109 beats per minute, so that to determine the scan starting time, the patient's cycle length (60 divided by heart rate) had only to be multiplied by the corresponding normal value of transit cycles, i.e., four for the RV, 11 for the LV, and 13 for the abdominal arteries. By applying the estimated values, the result was negative on two successive scans in only 10.6% because of failure in coordination on the part of the operators or bolus transit delays (due to severe heart failure, severe lung disease, recent thoracotomy, or small veins disease). With automatic triggering of the scanner by a timer and injector and with a flush of saline after injection, results can be further improved. Radionuclide studies supported by grant of the Internal Department of the Government of the Federal Republic of Germany     

Chronic airspace disease: Review of the causes and key computed tomography findings

Chronic airspace diseases are commonly encountered by chest, body or general radiologists in everyday practice. Even though there is significant overlap in the imaging findings of different causes of chronic airspace disease, some key clinical, laboratory and imaging findings can be used to guide the radiologist to the correct diagnosis. The goal of this article is to review and compare these features.     

Limitations of computed tomography for diagnostic Neuroradiology

Summary The limitations of computed tomography for diagnostic Neuroradiology are pointed out. The relation of CT to the classical neuroradiological examinations are discussed.