Evaluation of Adaptive Statistical Iterative Reconstruction-V Reconstruction Algorithm vs Filtered Back Projection in the Detection of Hypodense Liver Lesions: Reader Performance and Preferences.

OBJECTIVE: The aim of the study was to evaluate diagnostic accuracy and readers' experience in the detection of focal liver lesions on computed tomography with Adaptive Statistical Iterative Reconstruction-V (ASIR-V) reconstruction compared with filtered back projection (FBP) scans. METHODS: Fifty-five patients with liver lesions had FBP and ASIR-V scans. Two radiologists independently reviewed both sets of computed tomography scans, identifying and characterizing liver lesions. RESULTS: Adaptive Statistical Iterative Reconstruction-V scans had a reduction in dose length product (P < 0.0001) with no difference in image contrast (P = 0.1805); image noise was less for the ASIR-V scans (P < 0.0001) and contrast-to-noise ratio was better for ASIR-V (P = 0.0002). Both readers found more hypodense liver lesions on the FBP (P = 0.01) scans. Multiple subjective imaging scores were significantly less for the ASIR-V scans for both readers. CONCLUSIONS: Although ASIR-V scans were objectively better, our readers performed worse in lesion detection on them, suggesting a need for better education/experience with this technology during implementation.

Stroke: current concepts.

Cerebrovascular accidents (CVAs) are the leading cause of disability and the fourth leading cause of death in the U.S. The WHO defines stroke as "rapidly developing clinical signs of focal disturbance of cerebral function lasting more than 24 hours with no apparent cause other than of vascular origin." Strokes are subdivided into two major classifications: ischemic (80-87 percent) andhemorrhagic (13-20 percent). Ischemic strokes occur from thrombi, emboli, or global hypoperfusion. Hemorrhagic strokes are either parenchymal (10 percent of all strokes) or subarachnoid (3 percent of all strokes). There are a variety of recognized risk factors for stroke which include: age, race, family history, hypertension, diabetes mellitus, atherosclerosis, cardiac arrhythmias, prosthetic valves, hyperlipidemia, cigarette smoking, and others (drugs or hormones). The initial assessment of a patient suspected of stroke should be done quickly enough to ensure maximal reperfusion of brain tissue. The steps to achieve this goal are: 1) exclude an intracranial hemorrhage, 2) assess for contraindications to thrombolytics, 3) characterize the infarct. The workup for a patient should first include a history (especially the time when neurologic symptoms began), a physical exam (including the NIHSS), and imaging studies (to rule out hemorrhagic components). In addition, several lab studies can also be obtained including: PT/INR, glucose, complete blood count, metabolic panel, creatine kinase, ECG, echocardiogram, lipid panel, carotid Doppler, MRA or CTA. Acute management of a stroke is primarily focused on stabilizing the patient and allowing as much reperfusion as possible for at-risk brain tissue. Stroke management in the acute setting includes: use of thrombolytics if indicated, and re-assessment to monitor progression. Several trials have been completed in pursuit of safety and effectiveness of intra-arterial stroke therapy for patients outside the recommended thrombolytic time window, but so far they are only experimental treatment options. The best preventative measures for first time or recurrent stroke are: starting or switching antiplatelet therapy, treatment of cardiovascular risk factors (atrial fibrillation and carotid stenosis), optimization of hypertension, dyslipidemia and diabetes mellitus management, and smoking cessation.

Discitis and Osteomyelitis Caused by a Migrated Laparoscopic Adjustable Gastric Banding (LAGB) Catheter.

Laparoscopic adjustable gastric banding (LAGB) is a popular bariatric surgical procedure used to aid in weight loss. Although significant complications may occur after LAGB, they are rare. LAGB causing discitis and osteomyelitis are incredibly rare, with only one other reported case. In this case report, we describe the case of a middle-aged woman who experienced discitis and osteomyelitis due to a disengaged LAGB catheter, which had eroded through her stomach and a part of her cecum. Overall, this case highlights the rare but potential complication of LAGB causing discitis and osteomyelitis. Patients with a history of LAGB placement should be monitored for this possibility and further investigation is needed to identify and mitigate risk factors.

The different elements of the Urinary Tract Dilation (UTD) Classification System and their capacity to predict findings on mercaptoacetyltriglycine (MAG3) diuretic renography.

INTRODUCTION: The UTD Classification System risk stratifies postnatal UTD into three groups: low risk (UTD P1), intermediate risk (UTD P2), and high risk (UTD P3). In the original consensus document, a functional scan is not recommended for UTD P1 and is left to the discretion of the clinician for UTD P2 and P3. OBJECTIVE: This study aims to understand which patients with postnatal urinary tract dilation would benefit from a functional study. We investigated how different elements of the UTD classification system predict differential renal function (DRF) and diuretic half-life (T½) on MAG3 scan in infants undergoing evaluation for prenatally detected UTD. STUDY DESIGN: This is a multicenter retrospective chart review of infants 6 months of age or younger evaluated for prenatal UTD, correlating their first MAG3 scan and first postnatal renal ultrasound (RUS). Multivariable logistic regression was used to find UTD elements predictive of DRF < 40% and/or T½ > 20 min. RESULTS: A total of 517 patients met study criteria. Median age at time of RUS and MAG3 renal scan was 48 days (IGR 31-81) and 63 days (IQR 45-98), respectively. DRF < 40% was found in 6% of kidneys with UTD P2 and 35% of kidneys with UTD P3. T½ > 20 min was found in 31% of kidneys with UTD P2 and 79% of kidneys with UTD P3. An abnormal ureter (OR 2.7, 95% CI 1.2-6.0) and parenchymal thinning (OR 16, 95% CI 5.8-41.4) were significant at predicting DRF < 40%. Parenchymal thinning (OR 3.0, 95% CI 1.5-6.1) also predicted T½ > 20 min, as did each cm increase in the anterior-posterior renal pelvic diameter (APRPD) (OR 4.8, 95% CI 3.0-7.7). DISCUSSION: The UTD system discriminates well and correlates with the likelihood of finding adverse features on diuretic renography. Patients in the UTD P3 high-risk category had a significantly higher incidence of decreased differential renal function and delayed drainage than those in UTD P1 and P2. Of the individual components of the UTD Classification system, the presence of parenchymal thinning was the most important factor in predicting both decreased differential renal function and delayed drainage. CONCLUSION: Given the high incidence of poor function and delayed drainage seen in the UTD P3 group, we believe a functional study should be recommended in the evaluation of these patients. Our findings support leaving the performance of a functional study at the discretion of the physician for UTD P2.

PET/CT Evaluation of Head and Neck Cancer of Unknown Primary.

The diagnosis of carcinoma of unknown primary in the head and neck is made when there is a metastasis but no primary lesion is identified after physical exam and diagnostic CT or MR imaging. PET/CT is the first step in searching for a primary lesion, followed by more invasive techniques such as endoscopy and surgery. Knowledge of the different tumor histologic types, preferential locations of nodal spread, imaging pitfalls, and other special considerations such as cystic metastases can be helpful in the ultimate identification of primary tumors, which leads to improved overall patient survival.

Radiation-Induced Sarcoma on 18F-FDG PET/CT After Treatment of Gorham-Stout Disease of the Maxilla.

Gorham-Stout disease is a rare disorder characterized by proliferation of lymphatic and vascular channels within bone resulting in osteolysis. A 53-year-old man with Gorham-Stout disease involving the left maxilla underwent previous treatment including radiation therapy and intralesional chemotherapeutic injections. He later presented with anemia, facial pain, weight loss, and nasal cavity hemorrhage. CT imaging demonstrated a mass centered within the right maxillary sinus with locoregional involvement. PET/CT showed prominent FDG activity involving the mass centered in the right maxillary sinus with low-grade avidity involving the contralateral maxilla in regions of treated Gorham-Stout disease. Biopsy of the mass confirmed radiation-induced sarcoma.