Prevalence and associated risk factors of coronary artery disease in patients with a zero coronary calcium score

PURPOSE

A zero coronary calcium score (CCS) is not able to provide a definite exclusion for coronary artery disease (CAD). The goal of this study was to determine the prevalence and associated cardiovascular risk factors of CAD in patients with zero CCS.

METHODS

Six hundred thirteen patients with zero CCS referred to coronary calcium score analysis (CCSA) and coronary computed tomography angiography (CCTA) with suspicion of CAD were included. The descriptive, univariate, and multivariate analyses were used to determine the prevalence and predictors of CAD presence.

RESULTS

Among 613 patients, 17 patients (2.7%) have NCCP, and obstructive CAD was found in 3 patients (0.48%). Multivariate analysis revealed that male gender and older age (≥50 years) were significantly associated with the presence of noncalcified coronary plaques (NCCP) (p < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the male gender and older age (≥50 years) model had 70.6% sensitivity and 84.2% specificity for predicting NCCP.

CONCLUSION

A non-negligible portion of patients with zero CCS had CAD. Male gender and older age (≥50 years) were independently associated with NCCP. Due to the high specificity value (84.2%) and negative predictive value (99.0%) of the male gender and older age (≥50 years) model, selective use of CCTA is recommended in <50 years old female patients to avoid unnecessary radiation exposure.

Evaluation of a two-image technique consisting of an axial and a coronal image generated by using the rib-flattening application: effect on reading time and diagnostic validity

Background/aim

When reading a chest CT, a radiologist needs to evaluate each rib one by one due to complex curvy shape, which makes reporting a tiresome and time-consuming task. A new curved planar reformat application that flattens ribs on a single plane may find a place in the radiology reporting room. This study aimed to evaluate the effect of a two-image set created by using the rib-flattening application on the performance of a radiologist in detecting sclerotic rib lesions in cancer patients.

Materials and methods

The local Institutional Review Board approved this retrospective study. Two radiologists with different experience levels reviewed chest CT examinations of 106 patients (76 men, 30 women). We divided the patients into group A (n = 54), reviewed by a standard method, and group B (n = 52), reviewed by a standard method and the two-image set created on the rib-flattening application. Reading times, validity indices, and agreement levels with reference data were evaluated for both readers.

Results

The median reading time of the junior examiner significantly decreased with the rib-flattening method (160.5 s vs. 70.0 s; P < 0.001). Diagnostic indices of the senior reader were improved significantly at per patient level (group A, AUC: 0.867; group B, AUC: 0.982; P = 0.046). The new method showed better agreement levels (kappa: 0.69 to 0.96) than the general method (kappa: 0.53 to 0.91).

Conclusion

Based on improved agreement levels, reading times, and diagnostic validity indices we conclude that a two-image set consisting of an axial and a coronal flattened-rib image may be used in conjunction with an ordinary exam.

Long-term vitamin-K antagonist use and coronary artery calcification

BACKGROUND

The aim of this study was to investigate the impact of vitamin K antagonist (VKA) therapy on coronary artery calcification (CAC) by comparing long-term VKA users with metallic prosthetic valves (MPVs) and VKA-free patients undergoing coronary calcium scoring for cardiovascular (CV) risk stratification.

METHODS

A total of 108 patients (43 VKA users with MPV and 65 gender-, age-, and risk-factor-matched VKA-free patients) were included in the study. CAC was determined via computed tomography (CT) and quantified on the basis of the Agatston score. The VKA group comprised patients who had an MPV for longer than 5 years, which entailed long-term VKA use.

RESULTS

Long-term VKA users had more calcified coronary arteries compared with the control group (178.1 ± 278 vs. 61.1 ± 130.6, p = 0.01). There was no difference between groups in terms of traditional CV risk factors. The mean duration of VKA use was 15 ± 7 years for the patients with MPV. There was no correlation between the duration of VKA use and mean Agatston score (r = 0.2, p = 0.215).

CONCLUSION

With its unique selection of patient groups, our study extends the findings of previous research that long-term VKA use is related to CAC as detected via CT scanning. The longer and more potent VKA regimen required for MPV patients is the primary cause of CAC in this group.

Frontal sinus osteoma associated with pneumocephalus

The most common causes of intracranial air are head trauma and neurosurgical procedures. Less common etiologies include infection due to gas-forming organisms, mucoceles, tumours, congenital neuroenteric cysts, and dural defects. Here, we present a case of a frontal sinus osteoma associated with longstanding pneumocephalus.

The role of late-phase pulse inversion harmonic imaging in the detection of occult hepatic metastases

OBJECTIVE

The purpose of this study was to investigate the efficacy of late-phase pulse inversion harmonic imaging (PIHI) in detecting occult metastases and to compare the results with helical computed tomography (CT) in a group of patients whose fundamental liver sonographic results were normal.

METHODS

Thirty-two patients (21 women and 11 men; age range, 20-87 years) with a known primary malignancy were enrolled in the study. The patients were evaluated with conventional sonography, unenhanced PIHI, and PIHI 3 minutes after the injection of Levovist (SH U 508A; Schering AG, Berlin, Germany). All patients also underwent triphasic helical CT within 1 week after sonography. In 1 patient, mangafodipir-enhanced magnetic resonance imaging was performed as part of the clinical workup.

RESULTS

After Levovist injection, in 4 (12.5%) of 32 patients, at least 1 hypoechoic lesion was detected by PIHI; multiple lesions were shown in 1 patient. The mean diameter of newly detected lesions was 12 mm. Triphasic helical CT also showed all of the lesions that were detected by PIHI. The diagnoses were confirmed by biopsy and CT findings in 2 patients and by the typical CT and magnetic resonance imaging findings in 1 patient. For the fourth patient, the diagnosis was confirmed by follow-up and CT. Conclusions. Late-phase PIHI is comparable to helical CT for detecting occult hepatic metastases, but it protects patients from the potentially hazardous effects of radiation and iodinated contrast agents. Further series involving a larger number of patients are needed to determine its place in the evaluation of cancer staging and treatment planning.

Portal and systemic venous gas in a patient after lumbar puncture

The presence of portal and systemic venous gas is traditionally regarded as an ominous radiological sign indicating a grave prognosis. With advances in imaging technology, the incidence of its detection has increased along with its association with clinically benign disorders. We present a young patient with systemic and portal venous gas after traumatic lumbar puncture.

Evaluation of the normal appendix at low-dose non-enhanced spiral CT

PURPOSE

To evaluate the frequency of visualization, thickness and location of the normal appendix at non-enhanced spiral computed tomography (CT).

MATERIALS AND METHODS

Low-dose spiral CT scans obtained for renal colic assessment in 243 patients were retrospectively reviewed. The frequency of visualization, thickness and location of normal appendices were recorded without knowledge of the patients' history for the appendectomy.

RESULTS

Forty of 234 patients had a past history of appendectomy (17%). Sensitivity, specificity, positive and negative predictive values, and accuracy of visualization of the normal appendix were 71%, 85%, 96%, 37% and 73%, respectively. When no intraluminal content was visualized, this area was excluded from the measurement and the mean thickness was 3.4 mm+/-0.66.

CONCLUSION

The normal appendix is frequently seen at nonenhanced spiral CT. Knowing the normal thickness of the appendix can help reduce false positive and false negative diagnoses of acute appendicitis when reviewing non-enhanced spiral CT.

[Assessment of mandibular vascular canals by dental CT]

PURPOSE

Sublingual artery and its branches run in the floor of the mouth and prone to substantial bleeding when injured during an implantation procedure. These branches enter the mandible from the lingual side and run through bony canals in the mandible. The purpose of this investigation is to evaluate the frequency, diameter, direction and position of lingual canals by dental CT.

MATERIALS AND METHODS

26 patients who underwent dental CT of the mandible before implantation were included in this study. Tomographic examination was performed in a transverse plane parallel to the mandibular base by bone algorithm. Multiplanar reconstructions were obtained in the sagittal and coronal oblique planes.

RESULTS

All patients demonstrated at least one canal, and 8 patients had two or more canals. Two of the patients presented with four canals. The typical lingual canal locations were the middle of the mandible and the premolar regions. The mean diameter of the lingual canals was 0.8 mm +/- 0.2 mm in the middle, 0.6 mm +/- 0.1 mm in the premolar regions. The direction of median canal was anterior and slightly caudal. Lateral canals were directed in a medial manner.

CONCLUSION

Before the dental implantation procedure, beside the relationships of implant with the important anatomic structures, lingual vascular canals should also be evaluated. Dental CT examination easily demonstrates the presence, position, direction and size of the lingual canals. By ensuring that radiologists and dentists are aware of these canals and their importance, bleeding complications during the placement of implants could be avoided.

[Case report: Complex composite odontoma: Plain radiography and computed tomography findings]

Complex composite odontoma is a rare benign odontogenic hamartoma seen in association with a primary tooth. Although it is seen most frequently between 10-19 years of age, here we present a lesion of unusual size in the mandible of a 6-year-old boy and report its clinical, radiographic, CT and histologic findings. Also, we discuss the value of three dimensional images.

Detection and differential diagnosis of hepatic masses using pulse inversion harmonic imaging during the liver-specific late phase of contrast enhancement with Levovist

PURPOSE

The purpose of this study was to investigate whether late-phase pulse inversion harmonic imaging (PIHI) increases conspicuity in hepatic masses, helps to differentiate benign from malignant lesions, and demonstrates a greater number of and smaller metastatic lesions than do conventional (fundamental) sonography and helical CT.

METHODS

Thirty patients (17 women and 13 men; age range, 35-77 years; mean age, 54 years) with known or suspected liver masses were evaluated using both fundamental sonography and contrast-enhanced PIHI during the liver-specific late phase of Levovist. The patients also underwent contrast-enhanced triphasic helical CT examinations within 1 week after sonography. In 4 of the patients, gadolinium-enhanced MRI was also performed as a part of their clinical work-up.

RESULTS

The increase in the lesions' conspicuity on PIHI compared with fundamental sonography was significantly greater in malignant lesions than in benign lesions (p< 0.001). An echogenic rim was observed on PIHI in 8 (53%) of 15 malignant lesions. The mean number of metastatic lesions visualized on PIHI (5.5 +/- 5.3) was significantly higher than the mean number visualized on fundamental sonography (2.5 +/- 2.1, p < 0.05). Although lesions as small as 3 mm were observed on PIHI, the mean sizes of the smallest lesions demonstrated using fundamental sonography, PIHI, and helical CT were not significantly different.

CONCLUSIONS

Late-phase PIHI is a useful technique for characterizing hepatic lesions and demonstrating both a greater number of and smaller metastases. It may help to differentiate benign from malignant liver masses and may obviate unnecessary and expensive further imaging.

Morphological characteristics of styloid process evaluated by computerized axial tomography

Morphological characteristics of styloid process and ossified stylohyoid ligament and their overall relationships to age and sex were studied by using computerized axial tomography images. The styloid process and ossified stylohyoid ligaments were classified into seven groups according to their shapes and lengths. The styloid process of a length of 25-40 mm, was the most frequently encountered. The elongated styloid process was mostly seen in males. There was no overall correlation between the types of SP and sex. The progressive increase in length with age was not seen in our study.

Renal infarct: contrast-enhanced power Doppler sonographic findings

Power Doppler sonography (PDUS) is a promising technique for the diagnosis of renal infarcts. PDUS's efficacy may be enhanced by using sonographic contrast agents. We evaluated 3 cases of renal infarction using PDUS and the sonographic contrast agent Levovist. The findings were compared with those of other imaging modalities, such as scintigraphy, CT, and angiography. In case 1, PDUS showed a patent interlobar artery only in the lower part of the right kidney and no other perfusion of the right renal parenchyma. Contrast-enhanced PDUS showed patchy areas of preserved perfusion in the lower and middle-upper anterior portions of the kidney. In case 2, PDUS showed diffuse and patchy perfusion defects in the anterolateral portion of the right kidney. On contrast-enhanced PDUS, no signal enhancement was seen in these areas, but the perfusion defects were better delineated. In case 3, PDUS showed no perfusion in the upper pole of the kidney; the nonperfused area extended to the posterior upper portion of the kidney but could not be distinguished from normal tissue. After injection of the contrast agent, there was no enhancement of the posterior extension of the upper pole infarct, but Doppler signals from the surrounding normal parenchyma were enhanced, so the area was more clearly demarcated. The administration of the contrast agent facilitated the visualization of the infarcts in all 3 cases.

Evaluation of osteoporosis in thalassemia by quantitative computed tomography: is it reliable?

This study was conducted to quantify the degree of osteoporosis in thalassemic patients by single energy quantitative computed tomography (SEQCT) and to test the reliability of this method. On 38 thalassemic patients with osteoporosis and 38 normal control subjects, bone mineral density (BMD) measurements were done by SEQCT. BMD and standard deviation (SD) of the x-ray attenuation numbers of pixels within region of interest (ROI) of the measurement areas were compared between two groups. Mean BMD values for thalassemic patients and control group were 173.4 and 158.2 mg/cm3, respectively. Mean BMD value for thalassemic patient group was significantly higher. Mean SD values of ROI for control group and thalassemic patients were 41.4 and 71.1, respectively. The difference between the SD values was also statistically significant. Positive correlation was noted between SD values and patients' ages in the thalassemic group. Results of SEQCT method may not reflect the clinical and conventional radiographic findings of osteoporosis seen in thalassemic patient group and should be used cautiously. Other methods of BMD measurement, such as photon absorbsiometry and x-ray absorbsiometry, should also be investigated for their accuracy in this patient group.

Single photon emission computerised tomography in chronic alcoholism. Antisocial personality disorder may be associated with decreased frontal perfusion

BACKGROUND

We examined the functional and structural cerebral changes in chronic alcoholics, analysing their association with personality features and alcohol drinking habits.

METHOD

Forty patients with alcohol dependency, including 15 with antisocial personality disorder (ASP) as defined in DSM-III-R and 10 age and sex matched healthy controls were studied after termination of withdrawal symptoms, using high resolution single photon emission tomography (SPECT), cranial computerised tomography (CT) and brainstem auditory evoked potentials (BAEP).

RESULTS

We found significant reductions in regional cerebral blood flow (rCBF) measurements of alcoholic patients. Low flow in frontal regions encountered in 67.5% of the patients was associated with the duration of alcohol consumption, while no such relation existed with the amount of daily intake. Patients with ASP exhibited more marked frontal hypoperfusion. Significant brain atrophy detected by CT was present in 40% of the patients and did not correlate with frontal hypoperfusion.

CONCLUSIONS

Patients with ASP are more sensitive to toxic effects of alcohol. Alternatively chronic alcoholism leads to frontal lobe dysfunction recognised as ASP in the clinical setting.

Bilateral perirenal urinoma with mediastinal extension

We report a unique case of adult-type polycystic kidney disease (PKD) having bilateral chronic perirenal fluid collection with unusual extension. Fluid collections at both sides are connected across the midline anterior to the abdominal aorta and inferior vena cava. In addition, supradiaphragmatic extension through aortic hiatus was well demonstrated by computed tomography (CT). Antomical boundaries and relations between two perirenal spaces are evaluated.

Digital subtraction sialography: technique, advantages and results in 107 cases

Sialographic examinations with the digital subtraction technique were performed in 107 salivary glands (90 parotid and 17 submandibular) of 99 patients. Diagnostic and technical advantages of the digital imaging and subtraction for sialography were investigated. Superior quality enabled detailed imaging of the entire ductal system. Reduced radiation exposure, short examination time and almost painless examinations with good patient tolerance proved to be the major advantages of digital subtraction sialography as a diagnostic tool.