The utility of radiographic assessment of the internal mammary arteries in chest wall irradiated patients.

PURPOSE: The internal mammary arteries (IMA's) are historically recognized to be protected against atherosclerosis. Whether chest wall-irradiation for breast cancer leads to significant IMA damage remains unclear. The utility of computed tomography (CT) and mammography to detect radiation-induced damage to the IMA's and its branches is not known. The objective of this study is to assess the susceptibility of IMA's to radiation-induced atherosclerosis, and the utility of CT scan and mammography in the assessment of IMA and its branches. METHODS: A retrospective analysis of breast cancer patients who received chest wall-radiotherapy was performed. Patients with CT scans and/or mammograms ≥5 years post-radiotherapy were included. Baseline characteristics, coronary artery calcification (CAC), the presence of IMA damage assessed by CT scan, and IMA branch calcifications by mammography were recorded. RESULTS: None of the 66 patients with CT scans post-radiotherapy revealed IMA atherosclerosis. There were 28 (42.4%) patients with CAC, of which four (14.3% of CAC subgroup or 6.1% of the total cohort) had calcifications on either side on mammogram (Chi-square test, p = 0.74). Out of the 222 patients with mammograms, 36 (16.2%) had IMA branch calcifications. Two hundred and ten patients received unilateral radiotherapy, and 27 (12.9%) of these patients had calcifications on the irradiated side, and 26 patients (12.4%) had calcifications on the contralateral side (OR = 1.0). CONCLUSION: IMA's do not exhibit signs of radiation-induced atherosclerosis when evaluated by CT scan. In addition, there is no association between radiotherapy for breast cancer and the presence of IMA branch calcification on mammograms.

PET/MRI Evaluation of Gynecologic Malignancies and Prostate Cancer.

PET combined with cross-sectional anatomical imaging is an essential part of workup for most malignancies, in which CT or MRI provides anatomical context to the functional information from PET. Hybrid imaging with PET/CT has been extensively researched and implemented clinically in the evaluation and management of patients with gynecologic malignancies. Lately, integrated PET/MR scanners have become available. This new technology is fast gaining a role in clinical applications in the fields of oncology, neurology, and cardiology. MRI provides excellent soft tissue contrast especially in the pelvis and has been proven very useful for imaging prostate and female genital pathologies. The ability of PET to provide accurate functional imaging data with high sensitivity combined with the strength of MRI to provide accurate depiction of anatomy with high contrast and spatial resolution renders combined PET/MRI a desirable method for evaluation of gynecologic malignancies and other pelvic cancers such as prostate cancer. The goal of this article is to provide an overview of the published literature using PET/MRI in gynecologic and prostate cancers.

Imaging of omphalomesenteric duct remnants and related pathologies in children.

The omphalomesenteric duct (OMD) or the vitelline duct (VD) is the embryologic communication between the yolk sac and the primitive midgut. OMD or VD anomalies are a group of defects resulting from failure of involution of the OMD. Meckel diverticulum is the most common anomaly that results from failure of resorption of the OMD. Other less common anomalies seen in children include OMD fibrous band, fistula, sinus tract, cyst, and umbilical polyps. These OMD remnants can have variable clinical manifestations such as umbilical discharge, small bowel obstruction, gastrointestinal tract bleeding, or acute abdomen. This pictorial essay reviews the clinical presentation and imaging findings of the common and not so common complications of OMD remnants in the pediatric population.

Evaluation of the use of automatic exposure control and automatic tube potential selection in low-dose cerebrospinal fluid shunt head CT.

INTRODUCTION: Cerebrospinal fluid shunts are primarily used for the treatment of hydrocephalus. Shunt complications may necessitate multiple non-contrast head CT scans resulting in potentially high levels of radiation dose starting at an early age. A new head CT protocol using automatic exposure control and automated tube potential selection has been implemented at our institution to reduce radiation exposure. The purpose of this study was to evaluate the reduction in radiation dose achieved by this protocol compared with a protocol with fixed parameters. METHODS: A retrospective sample of 60 non-contrast head CT scans assessing for cerebrospinal fluid shunt malfunction was identified, 30 of which were performed with each protocol. The radiation doses of the two protocols were compared using the volume CT dose index and dose length product. The diagnostic acceptability and quality of each scan were evaluated by three independent readers. RESULTS: The new protocol lowered the average volume CT dose index from 15.2 to 9.2 mGy representing a 39 % reduction (P < 0.01; 95 % CI 35-44 %) and lowered the dose length product from 259.5 to 151.2 mGy/cm representing a 42 % reduction (P < 0.01; 95 % CI 34-50 %). The new protocol produced diagnostically acceptable scans with comparable image quality to the fixed parameter protocol. CONCLUSION: A pediatric shunt non-contrast head CT protocol using automatic exposure control and automated tube potential selection reduced patient radiation dose compared with a fixed parameter protocol while producing diagnostic images of comparable quality.

Early pattern of degenerative changes in individual components of intervertebral discs in stressed and nonstressed segments of lumbar spine: an in vivo magnetic resonance imaging study.

STUDY DESIGN: A retrospective imaging review. OBJECTIVE: To assess differences in burden and pattern of disc degeneration in segments of lumbar spine with and without signs of increased mechanical stresses. SUMMARY OF BACKGROUND DATA: Young patients with magnetic resonance imaging signs of increased mechanical stress in pedicles or pars interarticularis provide an excellent in vivo model to study early effects of mechanical stresses on lumbar intervertebral discs without the confounding effects of genetics or environmental factors. Detailed in vivo evaluation for early degenerative changes in all individual disc components of stressed intervertebral discs has not been done. METHODS: Using magnetic resonance imaging, 2 radiologists assessed intervertebral discs around 93 stressed lumbar spinal segments in 87 patients (55 males, 32 females; mean age, 15.3 ± 3.3 yr; range, 5-25 yr) as well as lumbar discs in nonstressed segments for signs of degeneration in annulus fibrosus, nucleus pulposus, and endplates. Differences between stressed, control, and loading-matched control discs were assessed using Wilcoxon signed rank sum test. RESULTS: Burden of annular tears, radial tears, herniations, and nuclear degeneration was significantly higher in stressed discs (0.70 ± 0.34, 0.48 ± 0.39, 0.07 ± 0.19, and 0.17± 0.31, respectively) than control (0.29 ± 0.25, 0.09 ± 0.17, 0.01 ± 0.04, and 0.02 ± 0.08, respectively) or loading-matched control discs (0.44 ± 0.47, 0.16 ± 0.36, 0.01 ± 0.04, and 0.01 ± 0.11, respectively) (P < 0.01 for all). Stressed segments did not show any significant increase in endplate degeneration. CONCLUSION: Intervertebral discs in stressed spinal segments show an increased burden of disc degeneration involving annulus fibrosus and nucleus pulposus, but not the endplates. LEVEL OF EVIDENCE: N/A.

Magnetic resonance imaging-guided focused laser interstitial thermal therapy for intracranial lesions: single-institution series.

BACKGROUND: Surgical treatments for deep-seated intracranial lesions have been limited by morbidities associated with resection. Real-time magnetic resonance imaging-guided focused laser interstitial thermal therapy (LITT) offers a minimally invasive surgical treatment option for such lesions. OBJECTIVE: To review treatments and results of patients treated with LITT for intracranial lesions at Washington University School of Medicine. METHODS: In a review of 17 prospectively recruited LITT patients (34-78 years of age; mean, 59 years), we report demographics, treatment details, postoperative imaging characteristics, and peri- and postoperative clinical courses. RESULTS: Targets included 11 gliomas, 5 brain metastases, and 1 epilepsy focus. Lesions were lobar (n = 8), thalamic/basal ganglia (n = 5), insular (n = 3), and corpus callosum (n = 1). Mean target volume was 11.6 cm, and LITT produced 93% target ablation. Patients with superficial lesions had shorter intensive care unit stays. Ten patients experienced no perioperative morbidities. Morbidities included transient aphasia, hemiparesis, hyponatremia, deep venous thrombosis, and fatal meningitis. Postoperative magnetic resonance imaging showed blood products within the lesion surrounded by new thin uniform rim of contrast enhancement and diffusion restriction. In conjunction with other therapies, LITT targets often showed stable or reduced local disease. Epilepsy focus LITT produced seizure freedom at 8 months. Preliminary overall median progression-free survival and survival from LITT in tumor patients were 7.6 and 10.9 months, respectively. However, this small cohort has not been followed for a sufficient length of time, necessitating future outcomes studies. CONCLUSION: Early peri- and postoperative clinical data demonstrate that LITT is a safe and viable ablative treatment option for intracranial lesions, and may be considered for select patients.