Fully automated opportunistic screening of vertebral fractures and osteoporosis on more than 150 000 routine computed tomography scans.

OBJECTIVE: Osteoporosis is underdiagnosed and undertreated, although severe complications of osteoporotic fractures, including vertebral fractures, are well known. This study sought to assess the feasibility and results of an opportunistic screening of vertebral fractures and osteoporosis in a large database of lumbar or abdominal CT scans. MATERIAL AND METHODS: Data were analysed from CT scans obtained in 35 hospitals from patients aged 60 years or older and stored in a Picture Archiving and Communication System in Assistance-Publique-Hôpitaux de Paris, from 2007 to 2013. Dedicated software was used to analyse the presence or absence of at least 1 vertebral fracture (VF), and the radiodensity of the lumbar vertebrae was measured Hounsfield Units (HUs). A simulated T-score was calculated. RESULTS: Data were analysed from 152 268 patients [mean age (S.D.) = 73.2 (9.07) years]. Success rates for VF assessment and HUs measurements were 82 and 87%, respectively. The prevalence of VFs was 24.5% and increased with age. Areas under the receiver operating characteristic curves for the detection of VFs were 0.61 and 0.62 for the mean HUs of the lumbar vertebrae and the L1 HUs, respectively. In patients without VFs, HUs decreased with age, similarly in males and females. The prevalence of osteoporosis (sT-score ≤ -2.5) was 23.8% and 36.5% in patients without and with VFs, respectively. CONCLUSION: It is feasible on a large scale to screen for VFs and osteoporosis during opportunistic screening in patients 60 years or older having lumbar or abdominal CT.

Imaging of Skull Base and Orbital Invasion in Sinonasal Cancer: Correlation with Histopathology.

BACKGROUND: Pretreatment assessment of local extension in sinonasal cancer is essential for prognostic evaluation and surgical planning. The aim of this study was to assess the diagnostic performance of two common imaging techniques (CT and MRI) for the diagnosis of skull base and orbital invasion by comparing imaging findings to histopathological data. METHODS: This was a retrospective two-center study including patients with sinonasal cancer involving the skull base and/or the orbit operated on between 2000 and 2019. Patients were included only if pre-operative CT and/or MRI, operative and histopathologic reports were available. A double prospective blinded imaging review was conducted according to predefined radiological parameters. Radiologic tumor extension was compared to histopathological reports, which were considered the gold standard. The predictive positive value (PPV) for the diagnosis of skull base/orbital invasion was calculated for each parameter. RESULTS: A total of 176 patients were included. Ethmoidal intestinal-type adenocarcinoma was the most common type of cancer (41%). The PPV for major modification of the bony skull base was 78% on the CT scan, and 89% on MRI. MRI signs of dural invasion with the highest PPVs were: contact angle over 45° between tumor and dura (86%), irregular deformation of dura adjacent to tumor (87%) and nodular dural enhancement over 2 mm in thickness (87%). Signs of orbital invasion had low PPVs (<50%). CONCLUSIONS: This retrospective study provides objective data about the diagnostic value of pretreatment imaging in patients with sinonasal cancer.

Laser thermal therapy: real-time MRI-guided and computer-controlled procedures for metastatic brain tumors.

BACKGROUND AND OBJECTIVE: We report the final results of a pilot clinical trial exploring the safety and feasibility of real-time magnetic resonance-guided laser-induced thermal therapy (MRgLITT) for treatment of resistant focal metastatic intracranial tumors. STUDY DESIGN: In patients with chemotherapy, whole-brain radiation, and radiosurgery resistant metastatic intracranial tumors, minimally invasive stereotaxic placement of a saline-cooled interstitial fiberoptic laser applicator under local anesthesia was followed by laser irradiation during continuous magnetic resonance imaging (MRI) scanning. A computer workstation extracted real-time temperature-sensitive information for feedback control over laser delivery. A total of 15 metastatic tumors were treated in 7 patients. Patients were followed with physical exam and imaging for 30 months. RESULTS: In all cases, the procedure was well tolerated, and patients were discharged home within 24 hours. Follow-up imaging at up to 30 months showed an acute increase in apparent lesion volume followed by a gradual and steady decrease. No tumor recurrence within thermal ablation zones was noted. Kaplan-Meier analysis indicated that the median survival was 19.8 months. CONCLUSION: Real-time magnetic resonance (MR) guidance of laser-induced thermal therapy (LITT) offers a high level of control. This tool therefore enables a minimally invasive option for destruction and treatment of resistant focal metastatic intracranial tumors. MR-guided LITT appears to provide a safe and potentially effective treatment for recurrent focal metastatic brain disease. A larger phase II and III series would be of interest to quantify potential median survival advantage.

Real-time magnetic resonance-guided laser thermal therapy for focal metastatic brain tumors.

OBJECTIVE: We report the initial results of a pilot clinical trial exploring the safety and feasibility of the first real-time magnetic resonance-guided laser-induced thermal therapy of treatment-resistant focal metastatic intracranial tumors. METHODS: Patients with resistant metastatic intracranial tumors who had previously undergone chemotherapy, whole-brain radiation therapy, and radiosurgery and who were recused from surgery were eligible for this trial. Under local anesthesia, a Leksell stereotactic head frame was used to insert a water-cooled interstitial fiberoptic laser applicator inside the cranium. In the bore of a magnetic resonance imaging (MRI) scanner, laser energy was delivered to heat the tumor while continuous MRI was performed. A computer workstation extracted temperature-sensitive information to display images of laser heating and computed estimates of the thermal damage zone. Posttreatment MRI scans were used to confirm the zone of thermal necrosis, and follow-up was performed at 7, 15, 30, and 90 days after treatment. RESULTS: In all cases, the procedure was well tolerated without secondary effect, and patients were discharged to home within 14 hours after the procedure. Follow-up imaging showed an acute increase in apparent lesion volume followed by a gradual and steady decrease. No tumor recurrence within thermal ablation zones was noted. CONCLUSION: In this ongoing trial, a total of four patients have had six metastatic tumors treated with laser thermal ablations. Magnetic resonance-guided laser-induced thermal therapy appears to provide a new, efficient treatment for recurrent focal metastatic brain disease. This therapy is a prelude to the future development of closed-head interventional MRI techniques in neurosurgery.

[Follow-up brain imaging after strokes in internal medicine: frequently requested but rarely used for diagnosis or treatment]. / Imagerie cérébrale supplémentaire après un accident vasculaire cérébral en médecine interne: fréquemment demandée mais une rare implication diagnostique ou thérapeutique.

OBJECTIVE: To assess the interest of a second computed tomography (CT) scan of the brain during hospitalization of stroke patients in an internal medicine department and study the characteristics of these patients. METHOD: This retrospective study included 110 patients diagnosed with stroke between January 1, 2002, and August 31, 2004 in an internal medicine department. RESULT: All patients had a brain CT scan soon after admission - within three hours, on average, of arrival at the hospital; however, the mean delay between the onset of symptoms and hospital arrival was 40 hours. Mean hospital stay was 19 days. Eighty patients (73%) had at least one more scan. Indications for these scans were: no acute cerebral ischemia on the initial image (34%), routine follow-up or reason not specified (34%), worsening of neurologic status (15%), before oral anticoagulation (5%), to search a tumor (5%), to look for a cause (4%), and clinic-radiologic discordance (3%). Only 29% of the indications had any diagnostic or therapeutic reason. Among these 80 patients, the repeat brain scan resulted in a change in the initial diagnosis for 4 patients (5%) and in a change of therapy for 11 (14%). CONCLUSION: In our study, repeat CT imaging was frequently ordered in ischemic stroke, despite the not uncommon absence of any diagnostic or therapeutic reasons. To optimize the use of medical resources and avoid unnecessary imaging, it would be useful to identify subgroups of patients for whom repeat imaging might be of interest.