A Rare Case of Spinal Epidural Abscess Following Urinary Tract Infection Caused by Escherichia coli in a Patient with Pre-existing Stress Fractures of the Lumbar Spine.

Spinal epidural abscess (SEA) caused by Escherichia coli is an uncommon condition. It usually occurs secondary to urinary tract infection (UTI), following hematogenous propagation. Disruption of spinal anatomic barriers increases susceptibility to SEA. Although rarely, such disruption can take the form of lumbar spine stress fractures, which can result from even innocuous activity. Here, we describe a case of SEA secondary to UTI in a patient with pre-existing stress fractures of the lumbar spine, following use of an automated massage chair. Successful treatment of SEA consisted of surgical debridement and a six-month course of antibiotic therapy.

Current Role of Computed Tomography in the Evaluation of Acute Coronary Syndrome.

This review article provides an overview regarding the role of computed tomography (CT) in the evaluation of acute chest pain (ACP) in the emergency department (ED), focusing on characteristic CT findings.

High prevalence of a linear valve-like structure on CT at the pulmonary artery terminus of patent ductus arteriosus in adult patients, mimicking endarteritis.

PURPOSE: A linear valve-like structure at the pulmonary artery terminus is identified on CT in some patients with patent ductus arteriosus (PDA) and can potentially be mistaken for endarteritis. The purpose of this study was to evaluate the differences in CT features between adult patients with PDA and a linear structure and those without. MATERIALS AND METHODS: We retrospectively evaluated ECG-gated cardiac CT of 38 patients with PDA dividing them into two groups [patients with linear symmetrical valve-like structure (group1, n = 16), and those without (group 2, n = 22)]. We analyzed CT findings of the PDA including length, minimal and maximal diameter, presence of calcification, and PDA type, comparing the two subgroups. The authors also investigated the prevalence of endarteritis. RESULTS: There was no difference in CT findings between the two groups in the prevalence of calcification and length, and minimal and maximal diameter of PDA. Notably the linear valve-like structure was only identified in type 1 PDA (cone-shaped PDA) (p = 0.04), while there were variable types of PDA in group 2. There was only one case of endarteritis as a complication of PDA in group 1. In contrast to a linear valve-like structure, asymmetrical nodular thickening was noted in the patient with endarteritis on CT overlying the pre-existing linear valve-like structure at the pulmonary end of PDA. CONCLUSION: A linear valve-like structure is frequently identified at the pulmonary end in type 1 PDA. This CT finding should not be mistaken for endarteritis in the absence of other clinical evidence.

Differences in the CT findings between vulnerable plaque and culprit lesions in acute coronary syndrome.

BACKGROUND: The CT finding of "vulnerable plaque" is widely regarded as similar to that of a culprit lesion in an acute coronary syndrome (ACS). However, this hypothesis may not be accurate, since "vulnerable plaques" may substantially change their morphology when they rupture to cause an ACS. METHODS: We retrospectively evaluated coronary CT angiography data sets of 25 patients with ACS who had vulnerable (n = 10) or culprit plaques (n = 15). We analyzed CT features including positive remodeling (PR), low attenuation plaque (LAP), the napkin ring sign (NRS), degree of stenosis (normal, <50%, 50-99%, 100%), and myocardial hypoperfusion in the left ventricle. RESULTS: There was no difference in the prevalence of PR, NRS, or LAP between vulnerable and culprit plaques. In contrast, a majority (80%, 8/10) of vulnerable plaques were associated with <50% luminal stenosis while total occlusion was identified in 47% (7/15) of culprit plaques (p = .037). In all patients with occlusion, myocardial hypoperfusion was demonstrated in the corresponding arterial territory on CT. CONCLUSION: CT features of vulnerable and culprit plaques differ in cases with thrombotic occlusion reflecting dynamic plaque changes related to the episode of ACS.

Diagnostic value of ultrasound and computed tomographic arthrography in diagnosing anterosuperior acetabular labral tears.

PURPOSE: This study investigated the sensitivity, specificity, and accuracy of ultrasound as well as the computed tomography arthrography (CTA) findings and arthroscopic findings for the diagnosis of anterosuperior acetabular tear and correlated tear types using the Lage classification system on ultrasound and CTA compared with the arthroscopic findings. METHODS: We retrospectively reviewed the results of ultrasonographic examinations conducted before injection and after injection of contrast for subsequent CTA in 36 hips (34 patients; 24 men [71%] and 10 women [29%]; mean age, 36 years). All patients had chronic groin pain and a positive impingement test. We analyzed the sensitivity, specificity, and accuracy before injection, after injection, and at CTA and compared these with findings with the arthroscopic findings. Interobserver agreement and intraobserver reproducibility of the presence of a tear and tear type in the anterosuperior quadrant of the acetabular labrum on ultrasonography and CTA were calculated by use of κ coefficients. RESULTS: The sensitivity, specificity, and accuracy for sonographic detection of labral tear before injection/after injection were 58%/79%, 67%/58%, and 61%/72%, respectively, for observer 1 and 75%/92%, 25%/42%, and 58%/75%, respectively, for observer 2. The sensitivity, specificity, and accuracy for CTA detection of labral tears were 96%, 92%, and 94%, respectively, for observer 1 and 88%, 92%, and 89%, respectively, for observer 2. When the sonographic classification was compared with the arthroscopic findings of observer 1 and observer 2, the accuracy before injection/after injection was only 53%/67% and 58%/75%, respectively. The accuracy of morphologic classification of CTA and arthroscopic findings of observer 1 and observer 2 was 83% and 75%, respectively. Interobserver correlation before injection and at CTA was poor (κ = 0.056) and moderate (κ = 0.642), respectively. CONCLUSIONS: Although intra-articular injection during sonographic examination could improve diagnosis of labral tears, sonographic examination as a diagnostic technique is still of limited use. However, CTA shows reliable validity in the diagnosis of acetabular labral tears. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

A case of a patient with protein C deficiency presenting with concurrent thromboses in the pulmonary arteries and innominate artery: a suggestive computed tomographic finding of thrombophilia.

The incidence of arterial thrombosis in patients with protein C deficiency is relatively low compared with that of venous thrombosis. To our knowledge, there is no previously published report of a protein C deficiency patient with simultaneous thromboses in the pulmonary artery and innominate artery in the English literature. We present a case of a protein C deficiency in which the presence of concurrent clots in the pulmonary arteries and innominate artery demonstrated on a pulmonary computed tomographic angiography provided an important clue permitting diagnosis of the deficiency.

Rarity of isolated pulmonary embolism and acute aortic syndrome occurring outside of the field of view of dedicated coronary CT angiography.

BACKGROUND: Although triple rule-out CT angiography (TRO) to simultaneously evaluate acute coronary syndrome (ACS), pulmonary embolism (PE), and acute aortic syndrome (AAS) is increasingly used in many institutions, TRO is inevitably associated with increased radiation exposure due to extended z-axis coverage compared with dedicated coronary CT angiography (DCTA). PURPOSE: To determine the frequency of exclusion of findings of AAS, PE, and significant incidental non-cardiac pathology that may be the cause of acute chest pain when using a restricted DCTA field of view (FOV). MATERIAL AND METHODS: We retrospectively reviewed CT images and charts of 103 patients with acute PE and 50 patients with AAS. Either non-ECG gated dedicated pulmonary or aortic CT angiography was performed using 16- or 64-slice multidetector CT (MDCT). We analyzed the incidence of isolated PE, AAS, or significant non-cardiac pathology outside of DCTA FOV (i.e. from tracheal carina to the base of heart). RESULTS: There were two cases of isolated PE (2/103, 1.9%) excluded from the FOV of DCTA. One case of PE was isolated to the subsegmental pulmonary artery in the posterior segment of the right upper lobe. In the second case, pulmonary embolism in the left main pulmonary artery was located out of the FOV of DCTA because the left main pulmonary artery was retracted upwardly by fibrotic scar in the left upper lobe due to prior tuberculosis. There was no case of AAS and significant non-cardiac pathology excluded from the FOV of DCTA. AAS (n = 50) consisted of penetrating atherosclerotic ulcer (n = 7), intramural hematoma (n = 5) and aortic dissection (n = 38). CONCLUSION: As isolated PE, AAS, and significant non-cardiac pathology outside of the DCTA FOV rarely occur, DCTA may replace TRO in the evaluation of patients with non-specific acute chest pain and a low pre-test probability of PE or aortic dissection.

Comparison of radiographic and computed tomographic measurement of pedicle and vertebral body dimensions in Koreans: the ratio of pedicle transverse diameter to vertebral body transverse diameter.

This study was designed to investigate the characteristics of pedicle transverse diameters (PD), vertebral body transverse diameters (VBD), especially the ratios of PD/VBD (CT ratio), which has never been discussed, in Koreans using computed tomography (CT) scans and to evaluate the possibility of obtaining more accurate estimations of PD from plain radiographs using the CT ratios in each spine level. The T1-L5 vertebrae of 50 participants were analyzed prospectively with CT scans (CT-VBD and CT-PD), and the T9-L5 vertebrae of the same participants were investigated with plain radiographs (X-VBD and X-PD). The CT ratio had a higher correlation with the CT-PD (r2 = 0.630) from T1 to L5, especially in the lower thoracic and lumbar spine (T9-L5, r2 = 0.737). The correlation of VBDs between the two radiologic tools (r2 = 0.896) was higher than that of the PDs (r2 = 0.665). Based on the data, equations for the estimation of a more accurate PD from plain radiographs were developed as follows: estimated PD = estimated VBD × [1.014 × (X-VBD) + 0.152] × the mean CT ratio at each spinal level. The correlation between the estimated PD and the CT-PD (r2 = 0.852) was improved compared with that (r2 = 0.665) between the X-PD and the CT-PD. In conclusion, the CT ratio showed a very similar changing trends to CT-PD from T1 to L5 regardless of sex and body mass, and the measurement error of PD from only plain radiographs could be minimized using estimated VBD and the mean CT ratio at each spinal level.

Can the extent of epicardial adipose tissue thickness or the presence of descending thoracic aortic calcification predict significant coronary artery stenosis in patients with a zero coronary calcium score on multi-detector CT?

OBJECTIVE: The purpose of this study was to evaluate whether the extent of epicardial adipose tissue (EAT) thickness or the presence of descending thoracic aortic calcification on multi-detector CT (MDCT) can predict the presence of significant coronary artery stenosis in patients with negative coronary artery calcium (CAC). METHODS: We enrolled 90 patients with negative CAC in whom both coronary CT angiography (CTA) and conventional angiography had been performed. Group 1 consisted of patients (n=27) with significant coronary artery stenosis (≥50%), whereas group 2 (n=63) had non-obstructive coronary artery stenosis (<50%) on conventional angiography. We analyzed whether or not there is a significant difference in EAT thickness or the incidence of calcification of descending thoracic aorta among the two groups. RESULTS: There was no significant difference between EAT thickness on MDCT among the two groups. There was also no significant difference in the incidence of descending thoracic aortic calcification between group 1 (7/27, 25.9%) and group 2 (14/63, 22.2%) (p>0.05). CONCLUSIONS: Neither the presence of abundant EAT nor calcification of descending thoracic aorta is a marker of significant coronary artery stenosis in patients with negative CAC.

Current Concepts in Cardiac CT Angiography for Patients With Acute Chest Pain.

This article presents specific examples of delayed diagnosis of acute coronary syndrome, acute aortic dissection, and pulmonary embolism resulting from evaluating patients with nonspecific acute chest pain who did not undergo immediate dedicated coronary CT angiography (CTA) or triple rule-out protocol (TRO). These concrete examples of delayed diagnosis may advance the concept of using cardiac CTA (i.e., dedicated coronary CTA versus TRO) to triage patients with nonspecific acute chest pain. This article also provides an overall understanding of how to choose the most appropriate examination based on the specific clinical situation in the emergency department (i.e., dedicated coronary CTA versus TRO versus dedicated pulmonary or aortic CTA), how to interpret the CTA results, and the pros and cons of biphasic versus triphasic administration of intravenous contrast material during TRO examination. A precise understanding of various cardiac CTA protocols will improve the diagnostic performance of radiologists while minimizing hazards related to radiation exposure and contrast use.

Acute hepatitis A: correlation of CT findings with clinical phase.

BACKGROUND/AIMS: The purpose of this study was to evaluate the incidences of various multi-detector CT (MDCT) findings in acute viral hepatitis A (AHA) and to determine if there are associations between these CT findings and the clinical phases of AHA. METHODOLOGY: Eighty-five patients with AHA were enrolled in this study. The patients were divided into three groups according to changes in their serum alanine aminotransferase and bilirubin levels before and after performing MDCT: group 1 (n = 16, prodromal phase); group 2 (n = 41, jaundice phase); group 3 (n = 28, recovery phase). RESULTS: Small lymph node enlargement in the hepatoduodenal ligament area, perihepatic fat infiltration, gallbladder (GB) changes (wall thickening, contraction, or an undulating inner margin), periportal edema, hepatomegaly, splenomegaly and pelvic fluid collection were noted in 98.8%, 76.5%, 75.3%, 43.5%, 22.4%, 52.9% and 56.5% of the patients, respectively. Fat infiltration, periportal edema, and pelvic fluid collection were most frequent in group 2. GB changes were least frequent in group 1. CONCLUSIONS: At least one of the CT findings suggestive of AHA was noted in 89.4% of the enrolled patients. These CT findings were more frequently identified in patients in the jaundice phase compared to another phases.

Characterization of spontaneous healing of chronic posterior cruciate ligament injury: Analysis of instability and magnetic resonance imaging.

PURPOSE: To explore the healing process of the injured posterior cruciate ligament (PCL) by evaluating instability measurements and magnetic resonance imaging (MRI) findings. MATERIALS AND METHODS: A retrospective cross-sectional study of 46 cases of complete PCL tear who obtained MRI more than two months after injury. RESULTS: A total of 13 cases (28%) showed nearly normal PCL contour, 20 cases (44%) showed continuity but deformed PCL contour, and 13 cases (28%) showed discontinuity. The duration from injury to MRI was not directly correlated with continuity. However, the group that obtained MRI more than six months after injury showed more continuity than the group that obtained MRI within six months of the injury (P < 0.01). The group with nearly normal continuity showed better stability results in the KT-1000 arthrometer and stress radiographs than the group with discontinuity (P < 0.05). The presence of other combined ligament injuries had a negative effect on regaining PCL continuity (P <0.05). CONCLUSION: More than two-thirds (72%) of chronic PCL injury cases showed ligamentous continuity on MRI, especially when the injury had occurred more than six months before. Stability may improve as continuity is regained. The presence of other combined ligament injuries appears to prohibit spontaneous PCL healing.

Sonographic diagnosis of a saccular aneurysm of the internal jugular vein.

Aneurysm of the internal jugular vein is an extremely rare condition. It is usually detected during childhood and is characterized by being more prominent during Valsalva maneuvers such as vomiting, coughing, and straining. Most of the cases reported in the English literature are fusiform aneurysms of the internal jugular vein. We report the case of a saccular aneurysm of the left internal jugular vein in a 59-year-old woman with no change in size of the aneurysm during a Valsalva manuever.

Counting ribs on CT by assessing costal attachments to the proximal xiphoid: is this method accurate?

OBJECTIVES: To evaluate the usefulness of the method of counting ribs by assessing anatomic variations of the attachments of costal cartilages to the proximal xiphoid. MATERIALS AND METHODS: From January to September 2005, 224 subjects (136 men, 88 women, age 13 to 89 years, mean age 55 years) underwent computed tomography examination of the chest. Axial images of the chest were obtained on a 16-slice multidetector computed tomography. Counting ribs was performed by using the medial clavicle as an anatomic landmark to identify the first costal cartilage. We analyzed variety and incidence of the attachment patterns of costal cartilages to the proximal xiphoid. RESULT: Out of the 224 patients, the last costal attachments to the proximal xiphoid were the sixth costal cartilages bilaterally for 2 (0.9%) subjects, one 6th and one 7th for 4 (1.8%) subjects, bilateral seventh for 191 (85.3%) subjects, one 7th and one 8th for 15 (6.7%) subjects, and bilateral eighth for 12 (5.4%) subjects. CONCLUSIONS: The method of counting ribs from the proximal xiphoid is inaccurate because the sixth, seventh, and eighth costal cartilages may each attach to the proximal xiphoid.

A case of nonsecretory multiple myeloma with atypical imaging features.

Multiple myeloma usually shows homogeneous enhancement on contrast-enhanced Magnetic Resonance imaging (MRI), and is accompanied by a monoclonal gammopathy in serum or urine. We report a case of nonsecretory myeloma, the diagnosis was difficult due to the absence of a monoclonal gammopathy and the presence of atypical imaging features.

Spontaneous diaphragmatic rupture after vomiting: rapid diagnosis on multiplanar reformatted multidetector CT.

Spontaneous rupture of the diaphragm is an extremely rare condition. We report a case of spontaneous rupture of the diaphragm that was caused by violent vomiting and immediately diagnosed by the imaging features before the operation. If there is a mass with an air-fluid level adjacent to the diaphragm on the chest radiograph in a patient who presents with sudden chest pain after violent vomiting, spontaneous rupture of the diaphragm should be suspected and multidetector CT with multiplanar reformatted images should be immediately performed.

Lithiasis in a heterotopic pancreas of the stomach.

A heterotopic pancreas is a relatively uncommon abnormality and usually of no clinical importance. A heterotopic pancreas is subject to various pathologic changes occurring in the pancreas, however, such as acute pancreatitis, cyst or abscess formation, pancreatic cancer, and islet cell tumor. We describe a rare case of a heterotopic pancreas presenting as a gastric submucosal mass with punctate calcifications occurring in a 43-year-old man.