Coronary calcium scoring with MDCT: the radiation dose to the breast and the effectiveness of bismuth breast shield

OBJECTIVE: The purpose of our study was to determine the breast radiation dose during coronary calcium scoring with multidetector computerized tomography (MDCT). We also evaluated the degree of dose reduction by using a bismuth breast shield when performing coronary calcium scoring with MDCT. MATERIALS AND METHODS: The dose reduction achievable by shielding the adult (35 years or older) female breasts was studied in 25 women who underwent coronary calcium scoring with MDCT. All examinations were performed with a 16-MDCT scanner. To compare the shielded versus unshielded breast dose, the examinations were performed with (right breast) and without (left breast) breast shielding in all patients. With this technique the superficial breast doses were calculated. To determine the average glandular breast radiation dose, we imaged an anthropomorphic dosimetric phantom into which calibrated dosimeters were placed to measure the dose to the breast. The phantom was imaged using the same protocol. Radiation doses to the breasts with and without the breast shielding were measured and compared using the Student's t-test. RESULTS: The mean radiation doses with and without the breast shield were 5.71+/-1.1 mGy versus 9.08+/-1.5 mGy, respectively. The breast shield provided a 37.12% decrease in radiation dose to the breast with shielding. The difference between the dose received by the breasts with and without bismuth shielding was significant, with a p-value of less than 0.001. CONCLUSION: The high radiation during MDCT greatly exceeds the recommended doses and should not be underestimated. Bismuth in plane shielding for coronary calcium scoring with MDCT decreased the radiation dose to the breast. We recommend routine use of breast shields in female patients undergoing calcium scoring with MDCT.     

Lumbosacral osseous tumors in children

A wide variety of benign and malignant neoplasms in children involve the lumbosacral region. When a solitary lesion of the lower spine occurs, tumors or tumor-like lesions represent an important group of entities for diagnostic consideration. Diagnostic investigation should begin with a patient history, physical examination, laboratory testing, and radiography. Roentgenograms, which demonstrate bone deviations, should be used as an initial examination. The results should direct further imaging studies, such as computed tomography (CT), magnetic resonance imaging (MRI), and bone scintigraphy. CT should be the chosen modality for delineating tumoral osteoid matrix formation. MRI shows soft-tissue masses and medullary infiltration better than any other radiological modality. A multimodal radiological approach is helpful in the overall evaluation and differential diagnosis of vertebral lesions in children. Although imaging features, especially of benign lesions, may yield a high percentage of accurate diagnoses, in cases with radiological findings highly suggestive of malignancy, a specific diagnosis cannot always be made, and histopathological findings are essential to achieve the diagnosis that will guide the therapy.     

MR imaging findings of spinal dural involvement with Wegener granulomatosis

Involvement of the brain and meninges is rare in cases of Wegener granulomatosis, occurring in 2% to 8% of cases. Meningeal involvement in association with Wegener granulomatosis has scarcely been reported as being confined to the dura mater of brain on images and is thought to represent granulomatous infiltration. There are a few reported cases of Wegener granulomatosis that document involvement of dura at the level of the spinal cord. We present the case of a 52-year-old man with Wegener granulomatosis involving the cervical spinal dura and include detailed MR imaging findings.     

Treatment of iatrogenic internal carotid artery laceration and carotid cavernous fistula with endovascular stent-graft placement

The risk of fatal injury of the internal carotid artery (ICA) and surrounding anatomy during transsphenoidal surgery for pituitary adenoma is the most severe potential complication associated with this particular approach. We present a case in which iatrogenic injury to a patient's ICA and resultant carotid cavernous fistula and massive hemorrhage was successfully managed with the emergency placement of an endovascular stent-graft. Both findings in the relevant literature and practical considerations concerning both stent-grafts and other more commonly used options for the treatment of iatrogenic ICA injury are discussed.     

Utilization of low-dose multidetector CT and virtual bronchoscopy in children with suspected foreign body aspiration

Background Foreign body aspiration is common in children, especially those under 3 years of age. Chest radiography and CT are the main imaging modalities for the evaluation of these children. Management of children with suspected foreign body aspiration (SFBA) mainly depends on radiological findings. Objective To investigate the potential use of low-dose multidetector CT (MDCT) and virtual bronchoscopy (VB) in the evaluation and management of SFBA in children. Materials and methods Included in the study were 37 children (17 girls, 20 boys; age 4 months to 10 years, mean 32 months) with SFBA. Chest radiographs were obtained prior to MDCT in all patients. MDCT was performed using a low-dose technique. VB images were obtained in the same session. Conventional bronchoscopy (CB) was performed within 24 h on patients in whom an obstructive abnormality had been found by MDCT and VB. Results Obstructive pathology was found in 16 (43.25%) of the 37 patients using MDCT and VB. In 13 of these patients, foreign bodies were detected and removed via CB. The foreign bodies were located in the right main bronchus (n = 5), in the bronchus intermedius (n = 6), in the medial segment of the middle lobe bronchus (n = 1), and in the left main bronchus (n = 1). In the remaining three patients, the diagnosis was false-positive for an obstructive pathology by MDCT and VB; the final diagnoses were secretions (n = 2) and schwannoma (n = 1), as demonstrated by CB. In 21 patients in whom no obstructive pathology was detected by MDCT and VB, CB was not performed. These patients were followed for 5–20 months without any recurrent obstructive symptomatology. Conclusions Low-dose MDCT and VB are non-invasive radiological modalities that can be used easily in the investigation of SFBA in children. MDCT and VB provide the exact location of the obstructive pathology prior to CB. If obstructive pathology is depicted with MDCT and VB, CB should be performed either for confirmation of the diagnosis or for the diagnosis of an alternative cause for the obstruction. In cases where no obstructive pathology is detected by MDCT and VB, CB may not be clinically useful.     

Coronary artery calcifications in children with end-stage renal disease

Coronary artery calcification (CAC) is common in adults with end-stage renal disease (ESRD), but little is known about the prevalence and the extent of it in children. We used multidetector spiral computed tomography (MDCT), echocardiography, and carotid and brachial high-resolution ultrasonography to screen for the presence and predisposing factors of CAC in 53 children with ESRD [15 hemodialysis (HD) patients, 24 peritoneal dialysis (PD) patients, and 14 renal transplant (rTx) recipients]. CAC was present in 15% of patients (three HD patients, three PD patients, and two rTx). The mean age of the patients with CAC was 16.4 years (range: 11.0–21.2 years), and their median CAC score was 101.3, ranging from 8.5 to 4,322 according to the Agatston method. The patients with CAC had longer duration of total dialysis (P=0.005), had higher time-integrated serum phosphorus (P<0.001), calcium-phosphate (CaxP) product (P=0.012), intact parathyroid hormone (P=0.010), vitamin B₁₂ levels (P=0.010), the amount of cumulative calcium-containing oral phosphate binders (OBPs) (P<0.001), and calcitriol intake (P<0.001), and had lower serum hemoglobin level (P=0.014). Interventricular septum systolic thickness (P=0.033) was significantly higher, relative wall thickness (P=0.062) tended to be higher, and flow-mediated endothelium-dependent dilatations (P=0.071) were lower without reaching statistically significant levels in those with CAC. A stepwise logistic regression analysis revealed that serum phosphorus (P=0.018) and the cumulative exposure to calcium-containing OPBs (P=0.016) were the most significant independent predictors in the development of CAC. These results indicate that even adolescents and children with ESRD may have coronary calcifications. We concluded that impaired divalent ion metabolism is the main factor in the formation of CAC in this age group.