Chondromyxoid fibroma of the temporal bone: CT and MRI findings

We present the case of a 44-year-old woman with chondromyxoid fibroma of temporal bone origin. Since this is the least common bone tumor of cartilaginous origin, it is highly unusual to find this tumor in the skull. In fact, the literature describes 18 cases of this form of neoplasia arising in the skull, only 4 of these having originated in the temporal bone. To date, the radiological features of these tumors, and especially features detected using the latest imaging modalities, have not been described in detail. This report is unique in that it is the first to present a case of chondromyxoid fibroma of the temporal bone accompanied by detailed CT and MRI findings. Received: 8 July 1999; Revised: 14 December 1999; Accepted: 20 December 1999     

Hydro-dynamic CT preoperative staging of gastric cancer: correlation with pathological findings. A prospective study of 107 cases

The aim of this study was to evaluate the accuracy of dynamic CT in the preoperative staging of gastric cancer. One hundred seven patients affected by gastric cancer diagnosed by endoscopic biopsy were prospectively staged by dynamic CT prior to tumor resection. After an oral intake of 400–600 ml of tap water and an intravenous infusion of a hypotonic agent, 200 ml of non-ionic contrast agent were administered by power injector using a biphasic technique. The CT findings were prospectively analyzed and correlated with the pathological findings at surgery. The accuracy of dynamic CT for tumor detection was 80 and 99 % in early and advanced gastric cancer, respectively, with overall detection rate of 96 % (103 of 107). Three early (pT1) and one advanced (pT2) cancers were undetected. Tumor stage as determined by dynamic CT agreed with pathological findings in 83 of 107 patients with an overall accuracy of 78 %. The accuracy of CT in detecting increasing degrees of depth of tumor invasion when compared with pathological TNM staging was 20 % (3 of 15) and 87 % (80 of 92) in early and advanced cancer, respectively. The sensitivity, specificity, and accuracy of CT in the preoperative staging (pT3–pT4 vs pT1–pT2) was 93, 90, and 91.6 %, respectively. The sensitivity, specificity, and accuracy of CT in assessing metastasis to regional lymph nodes was 97.2, 65.7, and 87 %, respectively. Computed tomography correctly staged liver metastases in 105 of 107 patients with an overall sensitivity of 87.5 % and specificity of 99 %. The sensitivity of peritoneal involvement was 30 % when ascites or peritoneal nodules were absent. Our findings show that dynamic CT can play a role in the preoperative definition of gastric cancer stage. The results can be used to optimize the therapeutic strategy for each individual patient prior to surgery, thus avoiding unnecessary intervention and allowing careful planning of extended surgery in eligible patients. Received: 29 June 1999, Revised: 20 October 1999, Accepted: 22 May 2000     

Evaluation of CT findings for diagnosis of pleural effusions

Computed tomography studies are usually used to assess patients with pleural effusions, and radiologists should be aware of the significance of different CT findings for the diagnosis of the effusion. The purpose of this study was to evaluate CT findings for etiological diagnosis of pleural effusions. Contrast-enhanced CT of the chest of 211 patients with pleural effusion of definite diagnosis were evaluated. The CT images were evaluated for the presence and extent of pleural effusion, thickening or nodules, extrapleural fat and other changes in the mediastinum or lung. The CT scans were read by two independent observers and correlation between them was evaluated. Comparison of CT findings between benign and malignant effusions, between exudates and transudates, and between empyemas and the other parapneumonic effusions were carried out. Kappa values for most CT findings were > 0.85. Loculation, pleural thickening, pleural nodules, and extrapleural fat of increased density were only present in exudative effusions. Multiple pleural nodules and nodular pleural thickening were the only pleural findings limited to malignant pleural effusions. The signs were also more frequently seen in empyemas than in other parapneumonic effusions. Computed tomography findings can help to distinguish between transudates and exudates. Although there is some overlap between benign and malignant pleural effusions, pleural nodules and nodular pleural thickening were present almost exclusively in the latter. Although differences between CT findings of empyemas and the other parapneumonic effusions exist, there is no finding which can definitely differentiate between them. Received: 27 January 1999; Revised: 24 June 1999; Accepted: 24 August 1999     

In vitro CT comparisons of dissected phleboliths and retrieved ureteral calculi

Purpose: This project was designed to assess the accuracy of radiologists in distinguishing between pelvic phleboliths and ureteral calculi by CT scanning in vitro. Materials and methods: Twenty-five phleboliths were dissected from autopsy specimens, and 23 ureteral calculi were retrieved intact and all calcifications made available for this study. Calcifications were suspended in ordinary butter and subjected to CT scanning using both bone and soft tissue windows. A panel of three radiologists blinded to the correct diagnoses independently assessed the images. The questions asked were: was the calcification a phlebolith or a stone? was it round or irregular? did it have a central “hole” or not? Confidence levels for each observer and each question were rated on a semicontinuous scale from 0 to 100 and receiver-operating characteristic (ROC) curves computed. Results: ROC curves for distinguishing between ureteral stones and calculi ranged from .78 to .99. As a subset, ROC curves for roundness alone, assuming phleboliths tended to be round and calculi not, ranged from .85 to .98. These ROC curves for roundness alone correlated closely with overall performance in distinguishing ureteral stones from phleboliths. ROC curves for determining central radiolucencies, however, although the latter were assumed to be hypothetically present in phleboliths, were degenerate for two observers, and only .57 for the third. Conclusions: Under optimal in vitro conditions, pelvic phleboliths and ureteral calculi do possess characteristics, especially shape, that many permit discrimination by CT scanning.     

Computed tomography of the small bowel in adult celiac disease: the jejunoileal fold pattern reversal

The aim of this retrospective study was to establish whether the distinctive intestinal fold pattern of celiac disease (CD), known by barium studies as jejunoileal fold pattern reversal (JFPR) may be recognized at CT. The number of intestinal folds per 2.5 cm, seen at CT, were counted in the jejunum and in the ileum of 22 adult patients with CD and compared with the folds of 30 consecutive subjects in whom an intestinal disease had been excluded. The results were submitted to statistical analysis by Student's t-test. In the control group the number of folds per 2.5 cm were 4.88 (SD ± 0.78) in the jejunum and 2.84 ( ± 0.62) in the ileum; in the CD group the number of folds were 2.42 ( ± 1.61) in the jejunum and 5.11 ( ± 1.24) in the ileum. There was a statistically significant difference in the number of jejunal and ileal folds between the CD patients and the control group (in both cases p < 0.001). The JFPR was seen in 15 patients with CD (68.2 %) but in none of the controls. Our study shows that JFPR is not a normal finding and can be demonstrated by CT in the majority of patients with CD. Received: 21 January 1999; Revised: 25 May 1999; Accepted: 26 May 1999     

CT and MR findings in neoplastic perineural spread along the vidian nerve

The aims of this article are to describe the findings of perividian tumor spread and to compare the accuracy of MRI and CT in diagnosing perineural metastasis along the vidian nerve. Moreover, the frequency of perividian metastasis in patients with head and neck cancer was evaluated. The CT and MR examinations of 98 consecutive untreated patients with histologically proven head and neck cancer were retrospectively reviewed. We considered as criteria for perineural tumor spread along the vidian nerve the following CT and MR findings: For CT (a) enlargement of the pterygoid canal, (b) erosion of its bony wall, and (c) obliteration of its normal fatty content; and for MR (a) enlargement of the vidian nerve, (b) enhancement of the nerve, and (c) obliteration of fat, particularly in the anterior part of the pterygoid canal. Ten patients met the selected criteria for perineural metastasis, which was bilateral in 3 patients, with a total of 13 vidian metastases. The CT scans demonstrated unilateral involvement of the vidian nerve in 9 patients. The MRI scans showed 13 perineural metastases. In 3 patients MR scans demonstrated involvement of four vidian nerves that appeared normal on CT examinations. The diagnostic difference between CT and MRI was statistically significant (Fisher's exact test; p = 0.04). Perineural spread along the vidian nerve is an event more frequent than previously reported and must be investigated with a careful imaging technique. Although a major limitation of our study is the lack of histological proof, the MR finding of a significant enhancement of the nerve, whether enlarged or normal in size, could be considered very suggestive of this kind of metastatic spreading, particularly if associated with simultaneous involvement of the neighboring structures (pterygopalatine fossa, foramen lacerum, trigeminal branches, etc.). Received: 5 January 1999; Revision received 11 May 1999; Accepted: 17 June 1999     

CT of radiatioe-indeced injury of the gastrointestinal tract spectrum of findings with barium studies correlation

Because of improvement in survival rate of patients with abdominal cancer, gastrointestinal complications following external radiation therapy are becoming more frequent. Thus, an increased number of patients are commonly investigated with imaging because of suspected radiation-induced injury of the gastrointestinal tract. This pictorial review highlights the spectrum of CT and barium study manifestations of radiation-induced injury of the gastrointestinal tract. The major role of CT in the evaluation and management of patients with radiation injury of the gastrointestinal tract is highlighted. Emphasis is placed on CT imaging signs that may help in distinguishing between radiation-induced injury and recurrent disease. Received: 19 October 1999; Accepted: 15 November 1999     

Dissecting aneurysm of the superior mesenteric artery associated with transomental hernia of the small bowel: helical CT findings

We present a case of intestinal obstruction caused by a transomental hernia with an associated finding of a dissecting aneurysm of the superior mesenteric artery. These two rare conditions both cause acute abdomen with similar symptoms. This case shows the possible diagnostic pitfalls of transomental hernia.     

Hepatic hemangiosarcoma: imaging findings and differential diagnosis

Primary hepatic angiosarcoma is a rare mesenchymal tumor of the liver that usually presents with nonspecific symptoms in elderly men. We present four cases of hepatic hemangiosarcoma and discuss the imaging characteristics of this entity. Our series shows that this tumor is not uncommon in younger patients with no associated risk factors such as previous exposure to thorotrast or vinyl chloride. Our experiences on a limited number of patients suggests that the combined use of angiography and dual-phase helical CT provides a better identification of the tumor and its complications. Analysis of imaging studies in patients with hepatic hemangiosarcoma reveals hypervascular lesions. Common complications were portal vein thrombosis, Budd-Chiari syndrome, as well as arterio-venous or arterio-portal shunts. Due to the vascularity of the tumor, percutaneous liver biopsy is hazardous. Received: 20 November 1998; Revised: 2 March 1999; Accepted: 12 April 1999     

Unenhanced helical CT: the “unbeatable” emergency examination for acute flank pain

Unenhanced helical CT has made the excretory urogram virtually obsolete in the evaluation of patients presenting to the emergency department with acute flank pain. A case is presented demonstrating yet another advantage of unenhanced helical CT: that of unmasking the clever malingerer who feigns renal colic in order to obtain controlled drugs.     

Nontraumatic dens fracture in a patient with lymphangiomatosis: radiographic, CT, and MR findings

Lymphangiomatosis is a rare condition characterized by benign angiomatous growth of lymphatic tissue. Bone infiltration may result in lytic lesions surrounded by sclerotic margins of varying thickness. We report a nontraumatic fracture of the dens in a female patient. Conventional radiographs and computed tomographic and magnetic resonance images are shown. The use of computed tomography and magnetic resonance imaging is highly recommended for investigating bone lesions of lymphangiomatosis, since, as occurred with our patient, conventional radiographs may not reveal all bone lesions in this disorder.     

CT diagnosis of strangulation in patients with small-bowel obstruction: current status and future direction

The pathophysiology of strangulating small bowel obstruction and the limitations of known CT criteria of strangulation are reviewed. The concept of coronal mapping of the course of the superior mesenteric vessels based on axial abdominal CT in order to aid the radiologic diagnosis of intestinal strangulation is introduced.     

CT evaluation of pediatric abdominal trauma: pitfalls and quandaries

CT of the pediatric abdomen after blunt trauma has become a widely accepted technique for evaluation of hepatic and splenic injury. However, detection of hollow viscus and pancreatic injury remains challenging and controversial. Detection of bowel rupture (extravasated oral contrast, bowel discontinuity), pancreatic injury (laceration, separation of fragments) and bladder rupture may be difficult, particularly with inadequate technique and lack of vigilance. This article reviews findings associated with several injuries which may present diagnostic pitfalls as well as technical factors relating to the administration of enteric contrast and CT cystography.     

Abdominal wall hernias: imaging with spiral CT

Computed tomography is an accurate method of identifying the various types of abdominal wall hernias, especially if they are clinically occult, and of distinguishing them from other diseases such as hematomas, abscesses and neoplasia. In this study we examined the CT images of 94 patients affected by abdominal wall hernias observed over a period of 6 years. Computed tomography clearly demonstrates the anatomical site of the hernial sac, the content and any occlusive bowel complications due to incarceration or strangulation. Clinical diagnosis of external hernias is particularly difficult in obese patients or in those with laparotic scars. In these cases abdominal imaging is essential for a correct preoperative diagnosis and to determine the most effective treatment. Received: 20 May 1999; Revised: 10 August 1999; Accepted: 13 August 1999     

The local spread of lower bile duct cancer: evaluation by thin-section helical CT

This study illustrates the local spread of lower bile duct cancer with thin-section helical CT in correlation with the surgical and pathological findings. Pathologically, 16 patients had pancreatic invasion, 4 had small bowel mesentery invasion, 7 had extrapancreatic nerve plexus invasion, and 3 patients had vascular invasion. On thin-section helical CT, pancreatic invasion was correlated to the clarity or non-clarity of the bile duct mass-pancreas border and the presence of an intrapancreatic mass. Cases with small bowel mesentery and extrapancreatic nerve plexus invasion showed mass or stranding around the superior mesenteric artery and/or inferior pancreatoduodenal artery. Vascular invasion was seen as tumor contiguity to these vessels. Received: 28 September 1998; Revised: 30 December 1998; Accepted: 2 April 1999     

Focal airtrapping at expiratory high-resolution CT: comparison with pulmonary function tests

This study was undertaken to determine prevalence, extent, and severity of focal airtrapping at expiratory high-resolution CT, and to compare focal airtrapping with age, gender, pulmonary function tests, and blood gas analysis. Two-hundred seventeen patients with and without pulmonary disease underwent paired inspiratory/expiratory high-resolution CT. Six scan pairs with corresponding scan levels were visually assessed for focal – not diffuse – airtrapping using a four-point scale. Pulmonary function tests and blood gas analysis were available for correlation in all patients (mean interval 5 days). Focal airtrapping with lower lung predominance was observed in 80 % of patients. Twenty-six of 26 patients with restrictive lung function impairment exhibited focal airtrapping (mean score 2.4), whereas only 72 of 98 (74 %) patients with obstruction did (mean score 1.5; p < 0.05). Fifty-eight of 70 (83 %) patients with normal lung function (mean score 1.8) and 19 of 23 (83 %) patients with mixed impairment (mean score 1.8) had focal airtrapping. Focal airtrapping showed negative correlations with static lung volumes (–0.27 to –0.37; p < 0.001) in all patients and moderate positive correlations with dynamic parameters (0.3–0.4; p < 0.001) in patients with obstruction. No significant correlations were found with age, gender, and blood gas analysis. Visual assessment of focal – not diffuse – airtrapping at expiratory high-resolution CT does not correlate with physiological evidence of obstruction as derived from pulmonary function tests since the perception of focal airtrapping requires an adequate expiratory increase in lung density. Received: 11 February 2000; Revised: 8 June 2000; Accepted: 9 June 2000     

Littoral cell angioma of the spleen: CT and MR imaging appearance

We report a case of littoral cell angioma (LCA) of the spleen, a recently described splenic pathology, which imaging characteristics and pathologic morphology have been discussed only by a few authors. The imaging findings in unenhanced and contrast-enhanced MRI and CT as well as histologic specimen are presented. Diagnosis was made after elective splenectomy. Differential diagnosis of splenic tumors as well as the imaging findings in this particular case are discussed. Received: 7 July 1999; Revised: 18 January 2000; Accepted: 19 January 2000     

Pseudomembranous aspergillus bronchitis in a double-lung transplanted patient: unusual radiographic and CT features

Pseudomembranous aspergillus bronchitis is considered as an early form of invasive pulmonary aspergillosis, a well-known airway infection in immunocompromised patients. Radiologic features concerning invasive aspergillosis of the airways have been reported. However, we describe here an unusual feature of invasive aspergillus bronchitis, never reported to date, observed in a double-lung transplanted patient. Chest radiograph and CT revealed significant peribronchial thickening without any parenchymal involvement. Received: 24 December 1999; Revised: 25 February 2000; Accepted: 28 February 2000     

Appendicitis after appendectomy: CT diagnosis

This article presents a case of appendicitis 7 years after open appendectomy. Together with the apparent CT findings we discuss the current literature of this issue. Received: 21 April 1999; Revised: 11 August 1999; Accepted: 13 August 1999