Publications

OBJECTIVES: The aims of the study were to systematically analyze causes for radiation dose outliers in emergency department noncontrast head computed tomographies (CTs), to develop and implement standardized system solutions, and audit program success for an extended period of time.

METHODS: This study was performed in a large, tertiary academic center between January 2015 and September 2017. Four phases of radiation dose data collection with and without prior interventions were performed. Outliers from 5 categories were evaluated for appropriateness in consensus by 2 radiologists and a senior CT technologist.

RESULTS: A total of 275 ± 15 CTs per period were included. Fifty-seven inappropriate scanning parameters were found in 24 (9%) of 254 CTs during the first analysis, 27 in 21 (7%) of 290 CTs during the second, 11 in 10 (4%) of 276 during the third assessment (P = 0.006). After a year without additional intervention, the number remained stable (14 in 11/281 CTs, 4%).

CONCLUSIONS: Combining a dose reporting system, individual case analysis, staff education, and implementation of systemic solutions lead to sustained radiation exposure improvement.

BACKGROUND: Most patients with pineal cysts referred for neurosurgical consultation have no specific symptoms or objective findings except for pineal cyst size to help in management decisions. Our purpose was to assess the relationship between pineal cyst size and aqueductal CSF flow using PC-MRI.

METHODS: Eleven adult patients with pineal cysts (>1 cm) referred for neurosurgical consultations were included. Cyst volume was calculated using 3D T1 images. Phase contrast magnetic resonance imaging (PC-MRI) in axial plane with velocity encoding of 5 cm/sec was used to quantitatively assess CSF flow through the cerebral aqueduct to determine the aqueductal stroke volume, which was then correlated to cyst size using Pearson's correlation. Pineal cysts were grouped by size into small (6/11) and large (5/11) using the median value to compare aqueductal stroke volume using Mann-Whitney test.

RESULTS: Patients were 39±13 years (mean±SD) of age, and 10/11 (91%) were female. There was significant negative correlation between cyst volume and aqueductal stroke volume (r=0.74; P=0.009). Volume of small cysts (4954±2157 mm3) was significantly different compared to large cysts (13,752±3738 mm3; P=0.008). The aqueductal stroke volume of patients harboring large cysts 33±8 μL/cardiac cycle was significantly lower than that of patients with small cysts 96±29 μL/cardiac cycle (P=0.008).

CONCLUSIONS: Aqueductal CSF flow appears to decrease with increasing pineal cyst size. Our preliminary results provide first evidence that even in the absence of objective neurological findings or hydrocephalus; larger pineal cysts already display decreased CSF flow through the cerebral aqueduct.

OBJECTIVE. The purpose of this study was to determine the relationship between background parenchymal enhancement (BPE) on contrast-enhanced mammography (CEM) and breast tissue density, menstrual status, endocrine therapy, and risk factors for breast cancer and also to evaluate interreader agreement on classification of BPE on CEM. MATERIALS AND METHODS. Five subspecialty-trained breast radiologists independently and blindly graded tissue density (with fatty tissue and scattered fibroglandular tissue classified as nondense tissue and with heterogeneously dense and extremely dense classified as dense tissue) and BPE (with minimal or mild BPE categorized as low BPE and moderate or marked BPE categorized as high BPE) on CEM examinations performed from 2014 to 2018. Electronic medical charts were reviewed for information on menstrual status, endocrine therapy, history of breast surgery, and other risk factors for breast cancer. Comparisons were performed using the Kruskal-Wallis test, Mann-Whitney test, and Spearman rank correlation. Interreader agreement was estimated using the Fleiss kappa test. RESULTS. A total of 202 patients (mean [± SD] age, 54 ± 10 years; range, 25-84 years) underwent CEM. Tissue density was categorized as fatty in two patients (1%), scattered fibroglandular in 67 patients (33%), heterogeneously dense in 117 patients (58%), and extremely dense in 16 patients (8%). Among the 202 patients, BPE was minimal in 77 (38%), mild in 80 (40%), moderate in 31 (15%), and marked in 14 (7%). Dense breasts, younger age, premenopausal status, no history of endocrine therapy, and no history of breast cancer were significantly associated with high BPE. Among premenopausal patients, no association was found between BPE and time from last menstrual period to CEM. Overall interreader agreement on BPE was moderate (κ = 0.41; 95% CI, 0.40-0.42). Interreader agreement on tissue density was substantial (κ = 0.67; 95% CI, 0.66-0.69). CONCLUSION. Women with dense breasts, premenopausal status, and younger age are more likely to have greater BPE. Targeting CEM to the last menstrual period is not indicated.

Background Tumor perfusion may inform therapeutic response and resistance in metastatic renal cell carcinoma (RCC) treated with antiangiogenic therapy. Purpose To determine if arterial spin labeled (ASL) MRI perfusion changes are associated with tumor response and disease progression in metastatic RCC treated with vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs). Materials and Methods In this prospective study (ClinicalTrials.gov identifier: NCT00749320), metastatic RCC perfusion was measured with ASL MRI before and during sunitinib or pazopanib therapy between October 2008 and March 2014. Objective response rate (ORR) and progression-free survival (PFS) were calculated. Perfusion was compared between responders and nonresponders at baseline, at week 2, after cycle 2 (12 weeks), after cycle 4 (24 weeks), and at disease progression and compared with the ORR by using the Wilcoxon rank sum test and with PFS by using the log-rank test. Results Seventeen participants received sunitinib (mean age, 59 years ± 7.0 [standard deviation]; 11 men); 11 participants received pazopanib (mean age, 63 years ± 6.6; eight men). Responders had higher baseline tumor perfusion than nonresponders (mean, 404 mL/100 g/min ± 213 vs 199 mL/100 g/min ± 136; P = .02). Perfusion decreased from baseline to week 2 (-53 mL/100 g/min ± 31; P < .001), after cycle 2 (-65 mL/100 g/min ± 25; P < .001), and after cycle 4 (-79 mL/100 g/min ± 15; P = .008). Interval reduction in perfusion at those three time points was not associated with ORR (P = .63, .29, and .27, respectively) or PFS (P = .28, .27, and .32). Perfusion increased from cycle 4 to disease progression (51% ± 11; P < .001). Conclusion Arterial spin labeled perfusion MRI may assist in identifying responders to vascular endothelial growth factor receptor tyrosine kinase inhibitors and may help detect early evidence of disease progression in patients with metastatic renal cell carcinoma. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Goh and De Vita in this issue.

Acute injuries to the shoulder girdle are common and frequently encountered by the practicing radiologist. The type of injury is highly dependent on the age of the patient and mechanism of trauma with injuries occurring at the site of greatest mechanical weakness. In this review, we discuss the main clinical features and key imaging findings for the most common shoulder injuries. For each injury, we also provide a section on the important features that the orthopedic surgeon needs to know in order to guide surgical versus nonsurgical management.

BACKGROUND: No large dataset-derived standard has been established for normal or pathologic human cerebral ventricular and cranial vault volumes. Automated volumetric measurements could be used to assist in diagnosis and follow-up of hydrocephalus or craniofacial syndromes. In this work, we use deep learning algorithms to measure ventricular and cranial vault volumes in a large dataset of head computed tomography (CT) scans.

METHODS: A cross-sectional dataset comprising 13,851 CT scans was used to deploy U-Net deep learning networks to segment and quantify lateral cerebral ventricular and cranial vault volumes in relation to age and sex. The models were validated against manual segmentations. Corresponding radiologic reports were annotated using a rule-based natural language processing framework to identify normal scans, cerebral atrophy, or hydrocephalus.

RESULTS: U-Net models had high fidelity to manual segmentations for lateral ventricular and cranial vault volume measurements (Dice index, 0.878 and 0.983, respectively). The natural language processing identified 6239 (44.7%) normal radiologic reports, 1827 (13.1%) with cerebral atrophy, and 1185 (8.5%) with hydrocephalus. Age-based and sex-based reference tables with medians, 25th and 75th percentiles for scans classified as normal, atrophy, and hydrocephalus were constructed. The median lateral ventricular volume in normal scans was significantly smaller compared with hydrocephalus (15.7 vs. 82.0 mL; P < 0.001).

CONCLUSIONS: This is the first study to measure lateral ventricular and cranial vault volumes in a large dataset, made possible with artificial intelligence. We provide a robust method to establish normal values for these volumes and a tool to report these on CT scans when evaluating for hydrocephalus.

BACKGROUND:  A distinct pattern of edema distribution is seen in breast cancer-related lymphedema. The area of edema sparing has not been characterized in relation to anatomy. Specifically, alternate lymphatic pathways are known to travel adjacent to the cephalic vein. Our study aims to define the location of edema sparing in the arm relative to the cephalic vein.

METHODS:  A retrospective review of patients who underwent magnetic resonance imaging (MRI) between March 2017 and September 2018 was performed. Variables including patient demographics, arm volumes, and MRI data were extracted. MRIs were reviewed to define the amount of sparing, or angle of sparing, and the deviation between the center of sparing and the cephalic vein, or angle of deviation.

RESULTS:  A total of 34 consecutive patients were included in the analysis. Five patients demonstrated circumferential edema (no sparing) and 29 patients demonstrated areas of edema sparing. Advanced age (69.7 vs. 57.6 years) and greater excess arm volume (40.4 vs. 20.8%) correlated with having circumferential edema without sparing (p = 0.003). In 29 patients with areas of edema sparing, the upper arm demonstrated the greatest angle of sparing (183.2 degrees) and the narrowest in the forearm (99.9 degrees; p = 0.0032). The mean angle of deviation to the cephalic vein measured 3.2, -0.1, and -5.2 degrees at the upper arm, elbow, and forearm, respectively.

CONCLUSION:  Our study found that the area of edema sparing, when present, is centered around the cephalic vein. This may be explained by the presence of the Mascagni-Sappey (M-S) pathway as it is located alongside the cephalic vein. Our findings represent a key springboard for additional research to better elucidate any trends between the presence of the M-S pathway, areas of sparing, and severity of lymphedema.

The Covid-19 pandemic surges of 2020 resulted in major operational, personal, and financial impacts on US radiology practices. In response, a series of strategic and intentional operational changes were implemented, varying by practice size, structure and model. In reviewing the many business lessons that we learned during the pandemic, it became clear that for a business to be successful, a host of additional supportive factors are necessary. In addition to timely expense reductions, optimizing revenue capture and close monitoring and management of cash and reserves available for use, we also consider effective leadership and communication strategies, maintenance of a healthy and adequately staffed team, support for a remote work environment and flexible staffing models. Other ingredients include effectively embracing digital media for communications, careful attention to current and new stakeholders and the service delivered to them, understanding federal and state regulatory changes issued in response to the pandemic, close collaboration with the Human Resources office, and an early focus on redesigning your future practice structure and function, including disaster and downtime planning. This review aims to share lessons to enable leaders of an imaging enterprise to be better prepared for similar and future surges.

Cough-associated headaches (CAHs) are thought to be distinctive for Chiari malformation type I (CMI) patients and have been shown to be related to the motion of cerebrospinal fluid (CSF) near the foramen magnum (FM). We used computational fluid dynamics (CFD) to compute patient-specific resistance to CSF motion in the spinal canal for CMI patients to determine its accuracy in predicting CAH. Fifty-one symptomatic CMI patients with cerebellar tonsillar position (CTP) ≥ 5 mm were included in this study. The patients were divided into two groups based on their symptoms (CAH and non-CAH) by review of the neurosurgical records. CFD was utilized to simulate CSF motion, and the integrated longitudinal impedance (ILI) was calculated for all patients. A receiver operating characteristic (ROC) curve was evaluated for its accuracy in predicting CAH. The ILI for CMI patients with CAH (776 dyn/cm5, 288-1444 dyn/cm5; median, interquartile range) was significantly larger compared to non-CAH (285 dyn/cm5, 187-450 dyn/cm5; p = 0.001). The ILI was more accurate in predicting CAH in CMI patients than the CTP when the comparison was made using the area under the ROC curve (AUC) (0.77 and 0.70, for ILI and CTP, respectively). ILI ≥ 750 dyn/cm5 had a sensitivity of 50% and a specificity of 95% in predicting CAH. ILI is a parameter that is used to assess CSF blockage in the spinal canal and can predict patients with and without CAH with greater accuracy than CTP.