Sphenoid Sinus Epidermoid Cyst: A Case Report

We present an unusual case of an epidermoid cyst in the sphenoid sinus with extensive bony erosions and mass effect, compressing the optic nerve causing visual disturbances. Epidermoid cysts of the paranasal sinuses are extremely rare cases. They usually present as intradural, extraaxial, benign masses of the cerebellopontine angle but they should also be considered in the differential diagnosis of sphenoid sinus lesions. The typical imaging appearance of craniocerebral epidermoid cysts is demonstrated and pathophysiological considerations of formation in the paranasal sinuses are discusse

Metastases in Meckel's Cave: A Challenge of Differential Diagnosis

Metastases in Meckel's cave are a rare tumor entity and should be considered as important differential diagnosis, especially if the patient presents with trigeminal neuralgia and suffers from a known primary malignancy. We present three cases of patients with secondary trigeminal neuralgia caused by a metastasis in Meckel's cave, treated by microsurgery and fractionated radiation therapy. Differential diagnoses are discussed on the basis of preoperative neuroradiological imaging. MRI is the preferred diagnostic modality, whereas complementary CT may be needed for evaluation of early bone invasio

Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT

This study was conducted to determine the ability of multi-detector-row computed tomography (CT) to identify the source and etiology of acute gastrointestinal bleeding. Eighteen patients with acute upper (n = 10) and lower (n = 8) gastrointestinal bleeding underwent 4-detector-row CT (n = 6), 16-detector-row CT (n = 11), and 64-slice CT (n = 1) with an arterial and portal venous phase of contrast enhancement. Unenhanced scans were performed in nine patients. CT scans were reviewed to determine conspicuity of bleeding source, underlying etiology, and for potential causes of false-negative prospective interpretations. Bleeding sources were prospectively identified with CT in 15 (83%) patients, and three (17%) bleeding sources were visualized in retrospect, allowing the characterization of all sources of bleeding with CT. Contrast extravasation was demonstrated with CT in all 11 patients with severe bleeding, but only in 1 of 7 patients with mild bleeding. The etiology could not be identified on unenhanced CT scans in any patient, whereas arterial-phase and portal venous-phase CT depicted etiology in 15 (83%) patients. Underlying etiology was correctly identified in all eight patients with mild GI bleeding. Multi-detector-row CT enables the identification of bleeding source and precise etiology in patients with acute gastrointestinal bleedin

In vivo identification of uric acid stones with dual-energy CT: diagnostic performance evaluation in patients

Background: To prospectively investigate the in vivo diagnostic performance of dual-energy (DE) computed tomography (CT) for the differentiation between uric acid (UA)-containing and non-UA-containing urinary stones. Methods: DE CT scans were performed in 180 patients with suspected urinary stone disease using a dual-source CT scanner in the DE mode (tube voltages 80 and 140kV). Urinary stones were classified as UA-containing or non-UA-containing based on CT number measurements and DE software results. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) for the detection of UA-containing urinary stones were calculated using the crystallographic stone analysis as the reference standard. Results: DE CT detected 110/180 patients (61%) with urinary stone disease. In 53 patients, stones were sampled. Forty-four out of 53 stones (83%) were non-UA-containing; and nine stones (17%) were UA-containing. The software automatically mapped 52/53 (98%) stones. One non-UA-containing stone (UA, 2mm) was missed; one UA-containing stone (3mm) was misclassified by software analysis. The sensitivity, specificity, PPV, and NPV for the detection of UA-containing stones was 89% (8/9, 95% CI: 52-100%), 98% (43/44, 95% CI: 88-100%), 89% (8/9, 95% CI: 52-100%), and 98% (43/44, 95% CI: 88-100%). Conclusion: Our results indicate that DE dual-source CT permits for the accurate in vivo differentiation between UA-containing and non-UA-containing urinary stone

Prevalence and morphology of coronary artery ectasia with dual-source CT coronary angiography

To assess the prevalence and morphological characteristics of coronary artery ectasia (CAE) with CT coronary angiography (CTCA) in comparison to conventional catheterangiography (CCA). Dual-source CTCA examinations from 677 consecutive patients (223 women; median age 57years) were retrospectively evaluated by two blinded observers for the presence of CAE defined as a diameter enlargement ≥1.5 times the diameter of adjacent normal coronary segments. Vessel diameters and contrast attenuation within and proximal to ectatic segments were measured. CCA was used to compare measurements obtained from CTCA with the coronary flow velocity by using the thrombolysis in myocardial infarction (TIMI) frame count. CTCA identified CAE in 20 of 677 (3%) patients. CCA was performed in ten of these patients. CAE diameter measurements with CTCA (10.0 ± 5.4mm) correlated significantly (r = 0.92, p < 0.001) with the CCA measurements (8.8 ± 4.9mm), but had higher diameters (levels of agreement: −1.0 to 3.4mm). Contrast attenuation was significantly lower in the ectatic (343 ± 63 HU) than in the proximal (394 ± 60 HU) segments (p < 0.01). The attenuation difference significantly correlated with the CAE ratio (r = 0.67, p < 0.01) and the TIMI frame count (r = 0.58, p < 0.05). The prevalence of CAE in a population examined by CTCA is around 3%. Contrast attenuation measurements with CTCA correlate well with the flow alterations assessed with CC

Accuracy of dual-source computed tomography coronary angiography: evaluation with a standardised protocol for cardiac surgeons

Background: This study assesses the accuracy of the new dual-source computed tomography (DSCT) for detection of coronary artery disease (CAD) compared with invasive coronary angiography (ICA) with a specifically designed data presentation protocol for cardiac surgeons. Methods: Forty patients (30 males/10 females) underwent ICA and DSCT. Best-quality images were prepared by radiologists. Evaluation of 12 segments of significant coronary stenosis was done by two cardiac surgeons with a data presentation protocol including different coronary views in two-/three-dimensional (2D/3D) images. No beta-blockers were administered prior to DSCT. Results: ICA revealed CAD in 21 patients and valvular disease but no CAD in 19 patients. In DSCT, 20/21 patients were diagnosed with CAD (at least one significant stenosis per patient). In 11/21 patients, all 12 segments were assessed correctly; in 7/21 patients one segment and in 3/21 patients two segments were evaluated incorrectly. Of all 21 patients with CAD, 239/252 segments (95%) were correctly evaluated. In 18/19 patients without CAD, DSCT correctly ruled-out the ICA results in 226/228 segments (99%). In total, 465/480 segments were correctly assessed (97%). Of 480 segments, only six were considered not assessable. DSCT assessments of the segments showed a sensitivity of 91%, specificity of 99%, a positive predictive value of 92% and a negative predictive value of 99%. Conclusions: The accuracy of DSCT coronary angiography especially for exclusion of CAD is promising. The introduced data presentation protocol allows for the independent evaluation by cardiac surgeons after pre-arrangement from the radiologist