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OBJECTIVE. Using the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS), this study sought to determine whether decreasing the point assignment for punctate echogenic foci in mixed solid and cystic nodules would reduce the number of benign mixed solid and cystic nodules that were biopsied and would not substantially increase the number of missed mixed carcinomas MATERIALS AND METHODS. A multiinstitutional database of 3422 pathologically proven thyroid nodules was evaluated to identify all mixed solid and cystic nodules with punctate echogenic foci. We determined the numbers of mixed benign and malignant nodules that would receive ACR TI-RADS recommendations of fine-needle aspiration, follow-up, and no further evaluation if the points assigned to punctate echogenic foci were changed from 3 points to 1 or 2 points. RESULTS. A total of 287 mixed nodules were adequately characterized for evaluation. When the number of points assigned to punctate echogenic foci was changed from 3 points to 1 point, the point categories changed for 198 mixed nodules. Seven carcinomas would not undergo biopsy, but six of those seven would receive follow-up, and 44 benign nodules would not undergo biopsy. When 2 points were assigned to punctate echogenic foci, the point categories changed for 66 mixed nodules. Three carcinomas would not undergo biopsy, but all three of these would receive follow-up, and eight benign nodules would not undergo biopsy. CONCLUSION. Consideration should be given to decreasing the number of points assigned to punctate echogenic foci in mixed solid and cystic thyroid nodules, given the substantial decrease in the number of benign nodules requiring biopsy and the recommendation of follow-up for any carcinoma 1 cm or larger that did not undergo biopsy.

Hands-on ultrasound training is included in the curriculum of many medical specialties and is increasingly incorporated into medical school curricula. Despite published curricula for ultrasound training in these specialties, there remains a dearth of such programs for radiology residency programs. At our institution, there has been a perceived decline in ultrasound scanning comfort and skill in trainees. The purpose of this project was to assess the utility and efficacy of a hands-on simulation-based ultrasound course for radiology residents.First-year radiology residents were enrolled in a 2-week simulation-based course for the instruction of hands-on ultrasound training. With the use of a customizable commercial simulation software platform, residents completed didactic modules, virtual simulations, and phantom scans for a 2-week rotation. A dedicated simulation center with scanning models and computer-based software was provided to all residents. Self-assessments and assignments provided benchmarks of performance. All radiology residents were surveyed at the start of the academic year to assess prior experience and comfort with ultrasound scanning. First-year residents were surveyed a second time upon course completion.Presurvey and postsurvey responses suggest that participation in the 2-week ultrasound scanning course contributed to an improvement in perceived scanning knowledge and comfort for participating residents. Based on our initial experience, the scanning curriculum presented here provides a comprehensive introductory course for first-year radiology residents both for ultrasound anatomy and for scanning technique. Continued education in hands-on ultrasound skills is a crucial factor in maintaining radiology's dominance in the modality.

This study evaluates the performance of convolutional neural networks (CNNs) in risk stratifying the malignant potential of thyroid nodules alongside traditional methods such as American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS). The data set consisted of 651 pathology-proven thyroid nodules (500 benign, 151 malignant) from 571 patients collected at a single tertiary academic medical center. Each thyroid nodule consisted of two orthogonal views (sagittal and transverse) for a total of 1,302 grayscale images. A CNN classifier was developed to identify malignancy versus benign thyroid nodules, and a nested double cross validation scheme was applied to allow for both model parameter selection and for model accuracy evaluation. All thyroid nodules were classified according to ACR TIRADS criteria and were compared with their respective CNN-generated malignancy scores. The best performing model was the MobileNet CNN ensemble with an area under the curve of 0.86 (95% confidence interval, 0.83-0.90). Thyroid nodules within the highest and lowest CNN risk strata had malignancy rates of 81.4% and 5.9%, respectively. The rate of malignancy for ACR TIRADS ranged from 0% for TR1 nodules to 60% for TR5 nodules. Convolutional neural network malignancy scores correlated well with TIRADS levels, as malignancy scores ranged from 0.194 for TR1 nodules and 0.519 for TR5 nodules. Convolutional neural networks can be trained to generate accurate malignancy risk scores for thyroid nodules. These predictive models can aid in risk stratifying thyroid nodules alongside traditional professional guidelines such as TIRADS and can function as an adjunct tool for the radiologist when identifying those patients requiring further histopathologic workup.

Clinicians need to better understand the value of computed tomography (CT) imaging and nonsurgical treatment options to manage acute left-sided colonic diverticulitis.To evaluate CT imaging, outpatient treatment of uncomplicated diverticulitis, antibiotic treatment, and interventional radiology for patients with complicated diverticulitis.MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, CINAHL, and ClinicalTrials.gov from 1 January 1990 through 16 November 2020.Existing systematic reviews of CT imaging accuracy, as well as randomized trials and adjusted nonrandomized comparative studies reporting clinical or patient-centered outcomes.6 researchers extracted study data and risk of bias, which were verified by an independent researcher. The team assessed strength of evidence across studies.Based on moderate-strength evidence, CT imaging is highly accurate for diagnosing acute diverticulitis. For patients with uncomplicated acute diverticulitis, 6 studies provide low-strength evidence that initial outpatient and inpatient management have similar risks for recurrence or elective surgery, but they provide insufficient evidence regarding other outcomes. Also, for patients with uncomplicated acute diverticulitis, 5 studies comparing antibiotics versus no antibiotics provide low-strength evidence that does not support differences in risks for treatment failure, elective surgery, recurrence, posttreatment complications, and other outcomes. Evidence is insufficient to determine choice of antibiotic regimen (7 studies) or effect of percutaneous drainage (2 studies).The evidence base is mostly of low strength. Studies did not adequately assess heterogeneity of treatment effect.Computed tomography imaging is accurate for diagnosing acute diverticulitis. For patients with uncomplicated diverticulitis, no differences in outcomes were found between outpatient and inpatient care. Avoidance of antibiotics for uncomplicated acute diverticulitis may be safe for most patients. The evidence is too sparse for other evaluated questions.Agency for Healthcare Research and Quality and American College of Physicians. (PROSPERO: CRD42020151246).

The objective was to evaluate the accuracy of 2D shear wave elastography (SWE) in predicting stages of liver fibrosis using five individual versus grouped measurements and different reliability criteria. This is a prospective study of 109 patients who underwent hepatic 2D SWE (Canon Aplio 500) prior to liver biopsy for varied indications. Liver fibrosis was staged using the METAVIR scoring system (F = 0–4). Propagation mapping was used to guide ten SWE measurements from the liver parenchyma: five individual measurements and five grouped measurements. IQR/median, SD/median, and SD/mean were examined as quality criteria for patient inclusion at various thresholds (IQR/median ≤ 0.15, 0.2, 0.3, 0.4, 0.5; SD/median ≤ 0.15, 0.2, 0.3; SD/mean ≤ 0.2, 0.3, 0.5). Threshold for clinically significant fibrosis (F ≥ 2) was determined with receiver operating characteristic (ROC) analysis. There was high agreement between individual and grouped measurements without statistically significant differences (intraclass correlation coefficient = 0.82; p = 0.26–0.96). When no quality criterion was used (n = 103), the optimal threshold was 11.3 kPa [AUROC 0.78, 95% CI (0.69, 0.88)] with sensitivity and specificity of 80% and 66%, respectively. All quality criteria were associated with equal or higher AUROC ranging from 0.78 to 0.87. IQR/median ≤ 0.5 (n = 88) achieved the highest sensitivity of 85% and only excluded a small subset of patients. The AUROC and specificity were 0.83 [95% CI (0.74, 0.92)] and 72%, respectively. Quality criterion IQR/median ≤ 0.5 increases sensitivity and specificity in prediction of clinically significant liver fibrosis while excluding only a small subset of patients. Grouped measurements are comparable to individual measurements and may help increase procedural efficiency.

Image-guided percutaneous cholecystostomy may be performed by a transhepatic or transperitoneal approach. We compared the short- and long-term outcomes of percutaneous cholecystostomy related to route of catheter placement.A retrospective observational study of image-guided percutaneous cholecystostomy was performed from 2004 to 2016. A search of the hospital's radiology information service was performed using the keywords "percutaneous cholecystostomy," "gallbladder drain," and "cholecystostomy tube" and the relevant Current Procedural Terminology codes. All search results were reviewed to identify the cohort of 373 patients who underwent initial percutaneous cholecystostomy catheter placement. Imaging was reviewed to determine the method and route of percutaneous cholecystostomy and complications. A chart review was performed to determine clinical outcomes. Differences were examined using a generalized linear model assuming a binary distribution and logit function.Percutaneous cholecystostomy catheter placement was performed using ultrasound guidance alone in 229 patients, ultrasound access with fluoroscopic guidance in 129 patients, CT guidance in 14 patients, and fluoroscopic guidance in one patient. The trocar technique was used for 183 patients, and the Seldinger technique was used for 190 patients. Two hundred eighteen percutaneous cholecystostomy catheters were placed via the transhepatic route, and 153 were placed via the transperitoneal route. The most common catheter sizes used were 8.5 French (n = 234) and 10 French (n = 124). No significant differences were observed between transperitoneal and transhepatic placement with regard to the frequency of pain, clogging, skin infection, bleeding, biloma, cholangitis, leakage, abscess, unplanned catheter removal, or need for replacement (p0.05).No evidence of a difference in outcomes was observed for transhepatic cholecystostomy tube placement over transperitoneal placement. The route that appears safer and less technically challenging should therefore be chosen.

Emerging data suggest that the location of thyroid nodules influences malignancy risk. The purpose of this study was to explore the impact of including location in American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) scoring. Four of five revised scoring algorithms that added 1 or 2 points to higher-risk locations were associated with lowered accuracy due to lower specificity. However, an algorithm that added 1 point to isthmic nodules did not differ significantly from ACR TI-RADS in accuracy; one additional isthmic cancer was diagnosed for each 10.3 additional benign nodules recommended for biopsy.

Ultrasound (US) imaging of the spinal canal is applied in early infants before formation of posterior spine bony elements. Here, we demonstrate for the first time in adult healthy subjects that excellent visualization of intrathecal structures at the level of C1-C2 is possible by transcutaneous US in flexion, extension, and neutral head positions through the soft tissue US window between C1-C2. We show with US that the posterior subarachnoid space increases significantly in head extension. Accordingly, C1-C2 US guidance can facilitate cervical myelography. In addition, we suggest that US of the C1-C2 spine level may offer an adjunct tool to diagnosing structural abnormalities in the setting of traumatic, congenital, or degenerative pathologies of the craniocervical junction.

OBJECTIVE The craniocervical junction (CCJ) is anatomically complex and comprises multiple joints that allow for wide head and neck movements. The thecal sac must adjust to such movements. Accordingly, the thecal sac is not rigidly attached to the bony spinal canal but instead tethered by fibrous suspension ligaments, including myodural bridges (MDBs). The authors hypothesized that pathological spinal cord motion is due to the laxity of such suspension bands in patients with connective tissue disorders, e.g., hypermobile Ehlers-Danlos syndrome (EDS). METHODS The ultrastructure of MDBs that were intraoperatively harvested from patients with Chiari malformation was investigated with transmission electron microscopy, and 8 patients with EDS were compared with 8 patients without EDS. MRI was used to exclude patients with EDS and craniocervical instability (CCI). Real-time ultrasound was used to compare the spinal cord at C1–2 of 20 patients with EDS with those of 18 healthy control participants. RESULTS The ultrastructural damage of the collagen fibrils of the MDBs was distinct in patients with EDS, indicating a pathological mechanical laxity. In patients with EDS, ultrasound revealed increased cardiac pulsatory motion and irregular displacement of the spinal cord during head movements. CONCLUSIONS Laxity of spinal cord suspension ligaments and the associated spinal cord motion disorder are possible pathogenic factors for chronic neck pain and headache in patients with EDS but without radiologically proven CCI.

OBJECTIVE. Compared with other guidelines, the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) has decreased the number of nodules for which fine-needle aspiration is recommended. The purpose of this study was to evaluate the characteristics of malignant nodules that would not be biopsied when the ACR TI-RADS recommendations are followed. MATERIALS AND METHODS. We retrospectively reviewed a total of 3422 thyroid nodules for which a definitive cytologic diagnosis, a definitive histologic diagnosis, or both diagnoses as well as diagnostic ultrasound (US) examinations were available. All nodules were categorized using the ACR TI-RADS, and they were divided into three groups according to the recommendation received: fine-needle aspiration (group 1), follow-up US examination (group 2), or no further evaluation (group 3). RESULTS. Of the 3422 nodules, 352 were malignant. Of these, 240 nodules were assigned to group 1, whereas 72 were assigned to group 2 and 40 were included in group 3. Sixteen of the 40 malignant nodules in group 3 were 1 cm or larger, and, on the basis of analysis of the sonographic features described in the ACR TI-RADS, these nodules were classified as having one of five ACR TI-RADS risk levels (TR1-TR5), with one nodule classified as a TR1 nodule, eight as TR2 nodules, and seven as TR3 nodules. If the current recommendation of no follow-up for TR2 nodules was changed to follow-up for nodules 2.5 cm or larger, seven additional malignant nodules and 316 additional benign nodules would receive a recommendation for follow-up. If the current size threshold (1.5 cm) used to recommend US follow-up for TR3 nodules was decreased to 1.0 cm, seven additional malignant nodules and 118 additional benign nodules would receive a recommendation for follow-up. CONCLUSION. With use of the ACR TI-RADS, most malignant nodules that would not be biopsied would undergo US follow-up, would be smaller than 1 cm, or would both undergo US follow-up and be smaller than 1 cm. Adjusting size thresholds to decrease the number of missed malignant nodules that are 1 cm or larger would result in a substantial increase in the number of benign nodules undergoing follow-up.

Objectives: In this study, we developed radiomic models that utilize a combination of imaging features and clinical variables to distinguish endometrial cancer (EC) from non-EC diagnoses on computed tomography (CT). Methods: A total of 926 patients consisting of 416 EC and 510 non-EC diagnoses were included. Uterus and the endometrium were manually segmented on CT. Fourteen feature selection and ten classification methods were manually examined to select the most optimized machine learning pipeline. Automatic machine learning using Tree-Based Pipeline Optimization Tool (TPOT) was performed. 847 patients were portioned into training, validation, testing sets, and another 79 patients were as our external testing set. The performance of the machine learning pipelines on the testing sets was compared to radiologists. Results: There was significant difference in age between the EC and non-EC groups (64.0 vs. 53.7, p

OBJECTIVE. The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) provides guidelines to practitioners who interpret sonographic examinations of thyroid nodules...

Thyroid nodules are a frequent finding on neck sonography. Most nodules are benign; therefore, many nodules are biopsied to identify the small number that are malignant or require surgery for a definitive diagnosis. Since 2009, many professional societies and investigators have proposed ultrasound-based risk stratification systems to identify nodules that warrant biopsy or sonographic follow-up. Because some of these systems were founded on the BI-RADS® classification that is widely used in breast imaging, their authors chose to apply the acronym TI-RADS, for Thyroid Imaging, Reporting and Data System. In 2012, the ACR convened committees to (1) provide recommendations for reporting incidental thyroid nodules, (2) develop a set of standard terms (lexicon) for ultrasound reporting, and (3) propose a TI-RADS on the basis of the lexicon. The committees published the results of the first two efforts in 2015. In this article, the authors present the ACR TI-RADS Committee's recommendations, which provide guidance regarding management of thyroid nodules on the basis of their ultrasound appearance. The authors also describe the committee's future directions.

Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Selection of the most appropriate modality for image guidance is essential for procedural success. We identified specific factors contributing to failure of ultrasound-guided procedures that were subsequently performed using CT guidance. This single-center, retrospective study included 164 patients who underwent a CT-guided biopsy, aspiration/drainage, or ablation after initially having the same procedure attempted unsuccessfully with ultrasound guidance. Review of the procedure images, reports, biopsy results, and clinical follow-up was performed and the reasons for inability to perform the procedure with ultrasound guidance were recorded. Patient cross-sectional area and depth to target were calculated. Differences in area and depth were compared using general linear modeling. Depth as a predictor of an unfavorable body habitus designation was modeled using logistic regression. US guidance was successful in the vast majority of cases (97%). Of the 164 procedures, there were 92 (56%) biopsies, 63 (38%) aspirations/drainages, and 9 (5%) ablations. The most common reason for procedure failure was poor acoustic window (83/164, 51%). Other reasons included target lesion being poorly discerned from adjacent tissue (61/164, 37%), adjacent bowel gas (34/164, 21%), body habitus (27/164, 16%), and gas-containing collection (22/164, 13%). Within the biopsy subgroup, patients for whom body habitus was a limiting factor were found to have on average a larger cross-sectional area and lesion depth relative to patients whose body habitus was not a complicating factor (p

The identification and removal of malignant central compartment lymph nodes (MCLN) is important to minimize the risk of persistent or recurrent local disease in patients with papillary thyroid cancer (PTC). While the diagnostic accuracy of preoperative ultrasound for the assessment of lateral compartment node metastases is well recognized, its role in the identification of central compartment node metastases in patients with PTC is less established. This study delineates the utility of high-resolution ultrasound (HUS) for the assessment of MCLN in patients with PTC.A retrospective chart review was performed of 227 consecutive patients who underwent total thyroidectomy for biopsy-proven PTC by a single endocrine surgeon in an academic tertiary care center between 2004 and 2014. Preoperative sonographic results were compared to postoperative pathology reports to determine the accuracy of HUS for the assessment of MCLN. Statistical analysis also included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).HUS identified abnormal central compartment nodes in 51 (22.5%) patients. All 227 patients underwent a careful central compartment node exploration. One hundred and four (45.8%) patients had MCLN identified by surgery, of whom 65 (62.5%) had a negative preoperative central compartment HUS. The sensitivity and specificity of preoperative HUS for the assessment of MCLN were 0.38 and 0.90, respectively. The PPV and NPV were 0.76 and 0.63, with an accuracy of 0.66.Preoperative HUS is quite specific for the identification of MCLN in patients with PTC. The present findings emphasize, however, that a negative HUS does not obviate the need for careful exploration of the central compartment to minimize the risk of persistent or recurrent local disease.

To retrospectively evaluate the safety and efficacy of microwave ablation (MWA) as treatment for single, focal hepatic malignancies.Institutional review board approval was obtained for this HIPAA-compliant study. From December 2003 to May 2012, 64 patients were treated with MWA for a single hepatic lesion, in 64 sessions. Hepatocellular carcinoma (HCC) was treated in 25 patients (geometric mean tumor size, 3.33-cm; 95% CI, 2.65-4.18-cm; range, 1.0-12.0-cm), metastatic colorectal cancer (CRC) was treated in 27 patients (geometric mean tumor size, 2.7-cm; 95% CI, 2.20-3.40-cm; range, 0.8-6.0-cm), and other histological-types were treated in 12 patients (geometric mean tumor size, 3.79-cm; 95% CI, 2.72-5.26-cm; range, 1.7-8.0-cm). Kaplan-Meier (K-M) method was used to analyze time event data. Chi-square and correlation evaluated the relationship between tumor size and treatment parameters.Technical success rate was 95.3% (61/64). Treatment parameters were tailored to tumor size; as size increased more antennae were used (p0.001), treatment with multiple activations increased (p0.028), and treatment time increased (p0.001). There was no statistically significant relationship between time to recurrence and tumor size, number of activations, number of antennae, and treatment time. At one-year, K-M analysis predicted a likelihood of local recurrence of 39.8% in HCC patients, 45.7% in CRC metastases patients, and 70.8% in patients with other metastases. Median cancer specific survivals for patients were 38.3 months for HCC patients, 36.3 months for CRC metastases, and 13.9 months for other histological-types. Complications occurred in 23.4% (15/64) of sessions.In our sample, tumor size did not appear to impact complete ablation rates or local recurrence rates for focal hepatic malignancies treated with MWA.

Background To determine the sensitivity and clinical application of 4-dimensional computed tomography (4D CT) for the localization of patients with primary hyperparathyroidism when ultrasonography (US) and sestamibi scans (STS) are negative. Methods We compiled a database of 872 patients with primary hyperparathyroidism who underwent parathyroid operation by a single surgeon from January 2003 to September 2013. Seventy-three patients who failed to have positive localization by US or STS were identified. Thirty-six underwent operation without a preoperative 4D CT, and 37 underwent operation after 4D CT. Results In patients not localized by US or STS, 4D CT was 89% sensitive in localizing an abnormal parathyroid gland when reviewed blindly by a radiologist specializing in endocrine localization studies, yielding a positive likelihood ratio of 0.89 and positive predictive value of 74%. Sensitivity, positive likelihood ratio, and positive predictive value for correct gland lateralization were 93%, 0.93, and 80%. The average size of parathyroid glands removed after preoperative localization by 4D CT was 404 mg and 0.57 cm 3 (SD = 280, 0.64), compared with 259 mg and 0.39 cm 3 (SD = 166, 0.21) in patients not localized by 4D CT. A focused, unilateral exploration was performed in 38% of patients with preoperative localization by 4D CT compared with 19% of patients without 4D CT (χ 2 = 3.0, P = .041). Conclusion 4D CT provided a positive localization in a clinically substantial number of patients not able to be localized by US or STS, which enabled an increased rate of successful, focused, unilateral operations compared with patients who did not undergo a 4D CT.

The purpose of our study was to determine if a textural analysis metric can be implemented to improve diagnosis of adenomyosis by ultrasound.We retrospectively identified 38 patients with a magnetic resonance imaging (MRI) diagnosis of uterine adenomyosis that also had a pelvic ultrasound within 6 months. We also identified 50 normal pelvic ultrasound examinations confirmed by a normal pelvic MRI within 6 months as a control group. A region of interest (ROI) was subsequently placed on the study population ultrasound image corresponding to the area of adenomyosis on MRI. An ROI was placed in the area of the junctional zone in the normal controls. The abnormal and normal ROIs were then compared against trained normal and abnormal distributions to determine the success rate, sensitivity, specificity, and negative and positive predictive values of our computer metric. The ultrasound reports performed before MRI were also reviewed to determine the radiologist correct/incorrect interpretation rate for comparison with our textural analysis metric.Using a training population of 50 normal ultrasound examinations (confirmed with a normal MRI) and 38 abnormal ultrasound examinations (MRI confirmed adenomyosis), we had an overall 75% (66/88 accurately diagnosed) success rate with a sensitivity, specificity, and negative and positive predictive values of 70%, 79%, 73%, and 76%, respectively (P < .0001). The sensitivity and false-negative rate of the initial ultrasound interpretation were 26% (10/38) and 74% (28/38), respectively.

Bone disease is prevalent among patients with inflammatory bowel disease (IBD), though bone density screening remains underutilized. We used CT scans performed for other indications in IBD patients to identify and monitor osteopenia using CT attenuation values at the lumbar spine. Significant rates of bone disease were detected which would have otherwise gone undiagnosed.Osteoporosis affects about 14-42% of patients with IBD. Though screening is recommended in IBD patients with risk factors, it remains underutilized. In patients with newly diagnosed IBD, we used CT scans performed for other indications to identify and monitor progression of osteopenia.Using the Ocean State Crohn's and Colitis Area Registry, we identified adult patients with one or more abdominal CT scans. Each patient had two age- and gender-matched controls. Radiologists measured attenuation through trabecular bone in the L1 vertebral body recorded in Hounsfield units (HU). Generalized estimating equations were used to measure how HU varied as a function of gender, type of IBD, and age.One hundred five IBD patients were included, and 72.4% were classified as "normal" bone mineral density (BMD) and 27.6% as potentially osteopenic: 8.6% with ulcerative colitis and 19.0% with Crohn's disease. We found a decrease in bone density over time (p 0.001) and that BMD decreases more in Crohn's disease than in ulcerative colitis (p 0.004). Sixty patients had two CT scans, and mean loss of 9.3 HU was noted. There was a non-significant decrease in BMD over time in patients exposed to 31 days of steroids and BMD was stable with 30 days of steroid exposure (p 0.09).Using CT scans obtained for other indications, we found low rates of osteopenia and osteoporosis that may otherwise have gone undiagnosed. Refinement of opportunistic screening may have advantages in terms of cost-savings and earlier detection of bone loss.

Guidelines for managing thyroid nodules are highly dependent on risk stratification based on sonographic findings. The purpose of this study is to evaluate the risk stratification system used by the American College of Radiology Thyroid Imaging Reporting and Data System (TIRADS).Patients with thyroid nodules who underwent sonography and fine-needle aspiration were enrolled in a multiinstitutional study. The sonographic nodule features evaluated in the study were composition, echogenicity, margins, and echogenic foci. Images were reviewed by two radiologists who were blinded to the results of cytologic analysis. Nodules were assigned points for each feature, and the points were totaled to determine the final TIRADS level (TR1-TR5). The risk of cancer associated with each point total and final TIRADS level was determined.A total of 3422 nodules, 352 of which were malignant, were studied. The risk of malignancy was closely associated with the composition, echogenicity, margins, and echogenic foci of the nodules (p0.0001, in all cases). An increased aggregate risk of nodule malignancy was noted as the TIRADS point level increased from 0 to 10 (p0.0001) and as the final TIRADS level increased from TR1 to TR5 (p0.0001). Of the 3422 nodules, 2948 (86.1%) had risk levels that were within 1% of the TIRADS risk thresholds. Of the 474 nodules that were more than 1% outside these thresholds, 88.0% (417/474) had a risk level that was below the TIRADS threshold.The aggregate risk of malignancy for nodules associated with each individual TIRADS point level (0-10) and each final TIRADS level (TR1-TR5) falls within the TIRADS risk stratification thresholds. A total of 85% of all nodules were within 1% of the specified TIRADS risk thresholds.

Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

This study was undertaken to define and evaluate echogenic foci and their posterior acoustic artifacts in thyroid nodules. Whether these findings were indicative of benignity or malignancy was assessed.Echogenic foci were classified into five types: no posterior artifact, large comet-tail artifact, small comet-tail artifact (≤1.0 mm), and posterior shadowing (subdivided into internal versus peripheral). Nodules were also classified into four parenchymal patterns: hypoechoic, hyperechoic,50% solid, and cystic. Results were compared with the cytologic or surgical findings.A total of 704 nodules had echogenic foci; 246 did not. The prevalence of malignancy ranged between 15.4% and 19.5% for all types of foci except large comet-tail artifacts (3.9%). Foci without posterior artifacts had a 21.9% rate of cancer in hypoechoic lesions and 15.8% in hyperechoic lesions. Foci with small comet-tail artifacts had a 27.6% rate of malignancy in hypoechoic nodules. For internal calcifications, no malignant nodules were found in either partially cystic group. Nodules with peripheral calcifications had prevalence rates of 20.0% in cystic nodules and 11.1% in predominately solid nodules. Identification of one additional type of high-risk focus increased the chance of malignancy 1.48 times.All categories of echogenic foci except those with large comet-tail artifacts are associated with high cancer risk. Identification of large comet-tail artifacts suggests benignity. Nodules with small comet-tail artifacts have a high incidence of malignancy in hypoechoic nodules. With the exception of nodules that have peripheral calcifications, the risk of malignancy is low when echogenic foci are present in partially cystic lesions.

To identify demographic and ultrasonographic (US) features associated with malignancy after initially nondiagnostic results of fine-needle aspiration (FNA) to help clarify the role of repeat FNA, surgical excision, or serial US in these nodules.This study was HIPAA compliant and institutional review board approved; informed consent was waived. Thyroid nodules (n = 5349) that underwent US-guided FNA in 2004-2012 were identified; 393 were single nodules with nondiagnostic FNA results but adequate cytologic, surgical, or US follow-up. Demographic information and diameters and volume at US at first biopsy were modeled with malignancy as outcome through medical record review. Exact logistic regression was used to model malignancy outcomes, demographic comparisons with age were made (Student t test, Satterthwaite test), and proportion confidence intervals (CIs) were estimated (Clopper-Pearson method).Of 393 nodules with initially nondiagnostic results, nine malignancies (2.3%) were subsequently diagnosed with repeat FNA (n = 2, 0.5%) or surgical pathologic examination (n = 7, 1.8%), 330 (84.0%) were benign, and 54 (13.7%) were stable or decreased in size at serial US (mean follow-up, 3.0 years; median, 2.5 years; range, 1.0-7.8 years). Patients with malignancies were significantly older (mean age, 62.7 years; median, 64 years; range, 47-77 years) than those without (mean age, 55.4 years; median, 57 years; range, 12-94 years; P = .0392). Odds of malignancy were 4.2 times higher for men versus women (P = .045) and increased significantly for each 1-cm increase in anteroposterior, minimum, and mean nodule diameter (1.78, 2.10, and 1.96, respectively). In 393 nodules, no malignancies were detected in cystic or spongiform nodules (both, n = 11, 2.8%; 95% CI: 1.4%, 5.0%), nodules with eggshell calcifications (n = 9, 2.3%; 95% CI: 1.1%, 4.3%), or indeterminate echogenic foci (n = 39, 9.9%; 95% CI: 7.2%, 13.3%).Very few malignancies were diagnosed with repeat FNA following nondiagnostic FNA results (two of 336, 0.6%); therefore, clinical and US follow-up may be more appropriate than repeat FNA following nondiagnostic biopsy results.

The purpose of this study was to evaluate the diagnostic accuracy of real-time shear-wave elastography for assessment of liver fibrosis in an unselected patient population, comparing shear-wave elastography measurements obtained at and remote from the site of random liver biopsy.In a prospective study of 50 patients (21 with and 29 without hepatitis C) referred for clinically indicated random liver biopsy for diffuse liver disease, shear-wave elastography measurements were taken from four locations before biopsy: one at the left lobe, two at the right lobe, and one at the biopsy location. The mean, minimum, maximum, and SD of shear-wave elastography were compared with pathologic grading. Steatosis and serum markers were analyzed using multiple logistic regression. Optimized shear-wave elastography thresholds were calculated using AUC analysis.The AUC (95% CI) at the biopsy site, ipsilateral lobe, and contralateral lobe were 0.82 (0.63-1.0), 0.84 (0.67-1.0), and 0.59 (0.19-0.99) in hepatitis C patients; 0.89 (0.75-1.0), 0.88 (0.73-1.0), and 0.93 (0.80-1.0) in nonhepatitis C patients; and 0.85 (0.74-0.96), 0.89 (0.79-0.99), and 0.80 (0.67-0.93) in all patients, respectively. Optimized biopsy site shear-wave elastography values for detecting Metavir score F2 or greater were 1.87 m/s (75% sensitivity and specificity), 2.00 m/s (80% sensitivity and specificity), and 1.89 m/s (76% sensitivity and specificity) in hepatitis C, nonhepatitis C, and all patients, respectively. Steatosis and serum markers were not significant.Real-time shear-wave elastography accurately predicted significant fibrosis (stage ≥ 2) in an unselected patient population with diffuse disease, including patients with and without hepatitis C. Shear-wave elastography best predicts pathologic grading when taken at the biopsy site or ipsilateral lobe in hepatitis C patients. Percentage steatosis was not predictive of shear-wave elastography results.

The objective of our study was to determine whether morphologic features of adrenal masses detected at initial contrast-enhanced MDCT can differentiate benign from malignant disease.Two hundred eleven adrenal masses (1-4 cm) detected during standard contrast-enhanced MDCT with a proven final diagnosis were retrospectively identified in 188 patients through a computer search of CT, PET/CT, and pathology reports. Three authors blinded to the diagnoses independently reviewed the contrast-enhanced MDCT images of the adrenal masses and evaluated their morphologic features: lesion margin (smooth, lobulated, or irregular), density (homogeneous or heterogeneous), and additional features of central low density and enhancing rim. Using these criteria, the readers categorized each mass as probably benign, indeterminate, or suspicious.There were 171 (81%) benign and 40 (19%) malignant adrenal masses. All malignant masses were metastases diagnosed in patients with known extraadrenal malignancy. For individual morphologic features in diagnosing malignancy, irregular margins had 30-33% sensitivity and 95-96% specificity and an enhancing rim had 5-13% sensitivity and 98-99% specificity. None of the imaging features was reliable in predicting benignity. When an adrenal mass was deemed suspicious by a reader, the sensitivities for malignancy ranged from 54% to 74% and specificities from 96% to 97%. Notably, no malignant lesions occurred in patients without a known history of cancer.At routine contrast-enhanced MDCT, adrenal masses with irregular margins or a thick enhancing rim are likely to be malignant. Smooth margins and homogeneous density can be seen in both benign and malignant adrenal masses and are insufficient for characterization.

In this work, we have proposed an on-line computer-aided diagnostic system called “UroImage” that classifies a Transrectal Ultrasound (TRUS) image into cancerous or non-cancerous with the help of non-linear Higher Order Spectra (HOS) features and Discrete Wavelet Transform (DWT) coefficients. The UroImage system consists of an on-line system where five significant features (one DWT-based feature and four HOS-based features) are extracted from the test image. These on-line features are transformed by the classifier parameters obtained using the training dataset to determine the class. We trained and tested six classifiers. The dataset used for evaluation had 144 TRUS images which were split into training and testing sets. Three-fold and ten-fold cross-validation protocols were adopted for training and estimating the accuracy of the classifiers. The ground truth used for training was obtained using the biopsy results. Among the six classifiers, using 10-fold cross-validation technique, Support Vector Machine and Fuzzy Sugeno classifiers presented the best classification accuracy of 97.9% with equally high values for sensitivity, specificity and positive predictive value. Our proposed automated system, which achieved more than 95% values for all the performance measures, can be an adjunct tool to provide an initial diagnosis for the identification of patients with prostate cancer. The technique, however, is limited by the limitations of 2D ultrasound guided biopsy, and we intend to improve our technique by using 3D TRUS images in the future.

Background Pre-transplantation living-donor kidney function determines remaining donor kidney function and significantly affects post-transplantation allograft function in the recipient. Few transplantation centers perform donor kidney function measurement owing to patient burden. A simplified method of glomerular filtration rate (GFR) measurement after angiographic procedures may facilitate more precise measurement of donor kidney function. Methods We evaluated the agreement between a simplified method of GFR measurement after renal computerized tomographic (CT) angiography (index GFR, 100 mL iohexol [350 mg/mL iodine]) and the reference GFR measurement with the use of iodinated radiocontrast media (5 mL bolus of iohexol [300 mg/mL iodine]) among 19 potential living kidney transplant donors. The 24-hour creatinine clearance and GFR estimation equations were additionally examined. Kidney lengths and total and segmented cortical kidney volumes were also measured. Results The index CT angiography GFR performed best with respect to the reference GFR with minimal bias (mean difference, −4 mL/min/1.73 m 2 ), good precision (SD of the difference, 9.8 mL/min/1.73 m 2 ), coefficient of determination ( R 2 ) of 0.74, narrow mean coefficient of variation (5% [range 1%–15%]), and high accuracy, with 100% of the values for the index test within 30% of the reference test. The 24-hour urine creatinine clearance values performed poorly. Kidney volumes and length did not significantly correlate with measured GFR. Conclusions The CT angiographic GFR measurement could be a useful and more convenient method of donor kidney function evaluation and maintains minimal bias, high precision, and accuracy compared with the reference GFR measurement.

Renal cell carcinoma accounts for 2%-3% of all visceral malignancies. Preoperative imaging can provide important staging and anatomic information to guide treatment decisions. Size of the primary tumor and degree of local invasion, such as involvement of perinephric fat or renal sinus fat, and tumor thrombus in renal veins and inferior vena cava are important detriments to local staging of primary tumor. Both kidneys are assessed for presence of other synchronous lesions. The ACR Appropriateness Criteria ® are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and application by the panel of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

We propose an adaptable framework for analyzing ultrasound (US) images quantitatively to provide computer-aided diagnosis using machine learning. Our preliminary clinical targets are hepatic steatosis, adenomyosis, and craniosynostosis. For steatosis and adenomyosis, we collected US studies from 288 and 88 patients, respectively, as well as their biopsy or magnetic resonanceconfirmed diagnosis. Radiologists identified a region of interest (ROI) on each image. We filtered the US images for various texture responses and use the pixel intensity distribution within each ROI as feature parameterizations. Our craniosynostosis dataset consisted of 22 CT-confirmed cases and 22 age-matched controls. One physician manually measured the vectors from the center of the skull to the outer cortex at every 10deg for each image and we used the principal directions as shape features for parameterization. These parameters and the known diagnosis were used to train classifiers. Testing with cross-validation, we obtained 72.74% accuracy and 0.71 area under receiver operating characteristics curve for steatosis ([Formula: see text]), 77.27% and 0.77 for adenomyosis ([Formula: see text]), and 88.63% and 0.89 for craniosynostosis ([Formula: see text]). Our framework is able to detect a variety of diseases with high accuracy. We hope to include it as a routinely available support system in the clinic.

Purpose The Charlson Comorbidity Index (CCI) has been shown to be a significant prognostic indicator in the treatment of many types of cancer. The aim of this study is to evaluate the degree to which the CCI predicts survival in patients with inoperable non-small cell lung cancer (NSCLC) treated with radiofrequency ablation (RFA). Materials and methods Eighty-two (34 men, 48 women) consecutive RFA treatments for medically inoperable NSCLC were performed at our institution from 1/1/2000 to 1/30/2009. With institutional IRB approval and in full HIPAA compliance, the medical records of these patients were examined for data relating to pre-treatment comorbid conditions, and a retrospective analysis was conducted. Survival curves were estimated by the Kaplan–Meier method. Risk factors for mortality were determined by single-factor comparisons of curves using Wilcoxon-weighted chi-square and multiple Cox regressions. Results The patients ranged in age from 59 to 91 years (mean: 75.5). Eighty-eight percent (72 patients) were tumor stage IA or IB. Patients were followed for a total of five years; three-year overall survival was 50.6%. Hospital mortality was 0%. Gender, stage, histology and CCI score were each associated with significantly impaired survival (p IB, squamous histology and gender, multiple Cox regressions showed that an increasing CCI score was significantly associated with an increased risk of death (HR 1.3, 95% CI 25.5, 58.2). Conclusions The CCI is validated as an important, independent predictor of patient survival, in cases of inoperable NSCLC treated with RFA.

The purpose of this study is to describe the prevalence and the characteristics of clinically important incidental extraurinary findings detected at MDCT urography performed for hematuria.A computer search of CT reports using the term "hematuria" identified 1209 reports of patients who had undergone MDCT urography. The results were retrospectively reviewed to determine unsuspected extraurinary findings that are clinically important or potentially important, warranting further imaging studies or medical or surgical intervention. We further categorized these important findings as acute (i.e., requiring immediate medical attention) or nonacute (i.e., requiring further evaluation in a nonurgent manner). By use of our electronic medical records, these findings were correlated to histologic diagnosis, further imaging evaluation, and clinical information.In 82 of 1209 patients (6.8%), 85 clinically important incidental extraurinary findings were identified. Follow-up evaluation was available for 43 of 85 (50.6%) findings by histologic diagnosis (n = 9), imaging evaluation (n = 31), or clinical information (n = 3). There were 11 (0.9%) examinations with acute findings, of which acute inflammation of the gastrointestinal tract and pancreaticobiliary system were the most common. Seventy-two (5.9%) examinations revealed 74 nonacute but important findings. Lung nodules were the most prevalent, followed by intraabdominal aneurysms and cystic ovarian masses. There were five (0.4%) histologically proven malignant neoplasms.The prevalence of clinically important incidental extraurinary findings at MDCT urography performed for hematuria was 6.8%.

Background and aims To evaluate the efficacy of MR enterography (MRE) in patients with known or suspected Crohn's disease without the use of anti-peristaltic pharmacologic agents compared to colonoscopy and histology. Methods A retrospective review of 850 consecutive patients who underwent routine MRE to evaluate known or suspected Crohn's disease was performed. Of these, 310 patients also underwent colonoscopy with biopsy(s) within 90 days. The results of the MRE were compared to the colonoscopy and pathology reports to determine the presence or absence of disease in evaluable bowel segments. Individual imaging parameters (including wall thickening, enhancement, T2 signal, mesenteric vascular prominence and adenopathy) were also separately analyzed to determine their independent predictive value. Results In 310 patients, the overall sensitivity and specificity of MRE (using endoscopy as a gold standard) were 85% and 80% respectively (kappa = 0.65). The sensitivity of MRE for detection of pathologically severe disease was 87% in the terminal ileum (TI) and 88% in the colon. In the subset of 162 patients who underwent colonoscopy within 30 days of MRE, the overall sensitivity remained 85% but the specificity increased to 85% (kappa = 0.69). Wall thickening and abnormal enhancement were sensitive indicators of Crohn's disease (75% and 78%), while abnormal T2 signal, mesenteric vascular prominence and adenopathy were specific (86%, 91% and 93%). Conclusion MRE compares favorably to colonoscopy for evaluation of known or suspected Crohn's disease noninvasively and without the exposure to ionizing radiation associated with CT enterography (CTE).

To determine whether placement of marking coils at biopsy of small renal neoplasms to facilitate localization at subsequent radiofrequency (RF) ablation is safe and can reduce fluoroscopy time during the ablative procedure.This retrospective study was approved by the hospital institutional review board and was compliant with HIPAA. The requirement to obtain informed consent was waived. A search of the renal RF ablation database (235 patients) identified 23 consecutive patients who had a marking coil placed at biopsy of a renal neoplasm (coil group) and 23 patients who did not have a marking coil placed at biopsy (control group). The patients were matched for tumor characteristics, including size, parenchymal position, location in the kidney, and laterality. All patients underwent subsequent RF ablation. The authors compared computed tomographic (CT) fluoroscopy times and technical success rates between the two groups. Statistical analyses were performed by using a single-tailed paired t test for comparison of CT fluoroscopy times, a two-tailed paired t test for comparison of age and tumor size, and a single-tailed McNemar test for comparison of the technical success rate of ablation.The mean CT fluoroscopy time for the RF ablation procedure was 28 seconds ± 11.7 (standard deviation) for the coil group and 66 seconds ± 85.8 for the control group (P = .025). There was no significant difference in the technical success rates of renal RF ablation.For small renal neoplasms that are poorly visualized at unenhanced CT, placement of a metallic marking coil at biopsy facilitates tumor localization, thus reducing CT fluoroscopy time and radiation dose for subsequent RF ablation procedures.

The objective of our study was to report the incidence of multiple sporadic primary renal cell carcinomas (RCCs) in patients referred for radiofrequency ablation (RFA).A retrospective search identified 162 patients (104 men and 58 women; mean age, 74 years) without a history of von Hippel-Lindau disease with a total of 175 tumors treated with RFA for biopsy-proven primary renal malignancies at our institution from 1998 to 2009. Three groups of patients with multiple RCCs were identified: patients with a history of nephrectomy for RCC who had been referred for RFA of a new renal tumor, patients who presented with multiple renal tumors at the time of referral for RFA, and patients who were shown to have developed a new renal tumor on follow-up imaging after RFA.Twenty-eight patients (17%) had multiple biopsy-proven RCCs. Eighteen patients (11%) had undergone prior nephrectomy for surgically proven RCC. The mean interval between prior nephrectomy and RFA referral was 122 months (range, 12-456 months). Seven patients (4%) without a history of nephrectomy presented with two biopsy-proven RCCs at RFA referral. Three patients (2%) who had not undergone nephrectomy and had a solitary RCC at the time of RFA had developed a new biopsy-proven RCC separate from the original treatment site on follow-up imaging after RFA. The mean time to diagnosis from the initial RFA treatment was 52 months (range, 25-89 months).Imaging surveillance of patients referred for renal RFA may be important not only to assess treatment success but also to detect new RCCs.

The objective of our study was to evaluate the accuracy of dynamic contrast-enhanced 4D MDCT in the preoperative identification of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT) and a history of failed surgery or unsuccessful localization on standard imaging.Thirty-four patients with PHPT underwent 4D CT. Retrospective blinded review of the 4D CT examinations was performed by three radiologists for the presence and location of a suspected parathyroid adenoma or adenomas. At the time of the study, 25 patients underwent surgical exploration after 4D CT. Twenty patients had solitary parathyroid adenomas, two patients had two adenomas resected, two patients did not have an adenoma, and one patient had mild four-gland hyperplasia. One patient did not have PHPT on repeat serum biochemistry. Surgical and pathology reports, adenoma enhancement, and biochemical and clinical follow-up were reviewed. Data were compared with 4D CT interpretations and interobserver reliability was calculated.The mean sensitivity and specificity of the three readers for the precise CT localization of adenomas was 82% (range, 79-88%) and 92% (range, 75-100%), respectively. Overall interobserver reliability was excellent (κ = 0.70; range, κ = 0.60-0.79). All adenomas resected at surgery showed a biochemical response and clinical response. The mean densities of the confirmed adenomas were 41, 128, 138, and 109 HU at 0, 30, 60, and 90 seconds, respectively. Level II lymph nodes identified in 10 patients showed significantly less enhancement at 30 (p = 0.0001) and 60 (p = 0.006) seconds compared with surgically proven adenomas.Occult parathyroid adenoma shows characteristic early enhancement. In this subset of patients, 4D CT may improve surgical outcomes and decrease morbidity.

Dramatic improvements in diagnostic imaging have developed with and enabled increasingly sophisticated treatments for metastatic colorectal cancer. Advances in therapeutic techniques, such as surgical resection and percutaneous therapies, demand that diagnostic imaging provide an accurate assessment of disease burden as well as precise localization. In this article, we present the current state-of-the-art of diagnostic imaging for evaluation of metastatic colorectal cancer. J. Surg. Oncol. 2010;102:909–913. © 2010 Wiley-Liss, Inc.

To review the recurrence patterns in patients with primary non-small cell lung cancer (NSCLC) treated with percutaneous image-guided radiofrequency (RF) ablation.This retrospective review was institutional review board approved and HIPAA compliant. Informed consent was waived. Data from all patients with primary NSCLC who underwent lung RF ablation from January 1998 to January 2008 were reviewed. Ninety-one patients were identified. Ten patients with no posttreatment imaging results and two patients with multiple treated lung cancers were excluded. There were 79 tumors in 79 patients (mean age, 75 years). Mean tumor size was 2.5 cm (range, 1-5.5 cm). Fifteen (19%) tumors were central, and 64 (81%) tumors were peripheral. Nineteen (24%) patients underwent adjuvant external beam radiation, and nine (11%) patients underwent concomitant brachytherapy. Correlation of computed tomography and positron emission tomography imaging studies with biopsy results, tumor size, location, and stage was performed. Patterns of recurrence were classified as local, intrapulmonary, nodal, mixed (local and nodal), and distant.Forty-five (57%) patients demonstrated no evidence of recurrence at follow-up imaging (range, 1-72 months; mean, 17 months). Recurrence was seen in 34 (43%) patients (range, 2-48 months; mean, 14 months). Recurrence after RF ablation was local in 13 (38%), intrapulmonary in six (18%), nodal in six (18%), mixed in two (6%), and distant metastases in seven (21%) cases. Median disease-free survival was 23 months. Sex, tumor location, and radiation therapy were not associated with risk of recurrence. Increasing tumor size (P = .02) and stage (P = .007) were related to risk of recurrence.The most common pattern of recurrence was local, which suggests that more aggressive initial RF ablation and adjuvant radiation may offer improvement in outcomes. Continued follow-up imaging is needed because new recurrences were seen throughout the 2 years following treatment.

To describe the incidence and clinical importance of the renal halo sign after percutaneous radiofrequency ablation (RFA) of renal neoplasms.Institutional review board approval was obtained for this HIPAA-compliant retrospective study. The study population consisted of 101 consecutive patients with 106 solid renal neoplasms that were treated with percutaneous RFA. Postablation computed tomographic (CT) and magnetic resonance (MR) images were retrospectively reviewed by three board-certified radiologists to determine the presence of the renal halo sign. Statistical analyses were performed to determine reader agreement and assess the effect that tumor size and location, radiofrequency (RF) applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed had on development of the renal halo sign.The renal halo sign developed in 79 (75%) of the 106 ablated tumors. Average imaging follow-up lasted 25 months (range, 1-98 months). The renal halo sign appeared, on average, 6 months (range, 1 month to 3 years) after RFA. The renal halo sign resolved in five (6%) of 79 tumors treated. Interobserver agreement for the presence of the renal halo sign was high. Tumor size and location, RF applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed were not independent predictors of renal halo sign development.The renal halo sign is seen in 75% of patients after percutaneous RFA of renal neoplasms. It may decrease in size over time; however, it rarely disappears. It is important to recognize this sign, as it can be mistaken for recurrent tumor or angiomyolipoma by radiologists who are not familiar with RFA.

Adrenal tumors represent a diverse group of neoplasms that include multiple etiologies, each with a different prognosis, malignant potential, and recommended treatment. Percutaneous techniques to treat adrenal neoplasms have been described including radiofrequency ablation, cryoablation, and chemical ablation. This article reviews the various adrenal neoplasms and the techniques of adrenal ablation.

To retrospectively evaluate the effectiveness and safety of tissue-type plasminogen activator (tPA) for drainage of abdominal and pelvic abscesses refractory to simple catheter drainage.This HIPAA-compliant study was approved by the Institutional Review Board; informed consent was waived. Forty-three patients (17 men, 26 women; mean age, 46 years; age range, 10-89 years) with a total of 46 abscesses underwent percutaneous drainage with 8.5-14-F catheters. Etiology was postoperative in 28 abscesses (60.9%) and varied in 18 (39.1%). Intracavitary tPA was initiated on the basis of viscous contents yielding minimal drainage at initial placement or if follow-up imaging showed a large residual collection despite satisfactory catheter position. A treatment cycle was 4-6 mg of tPA in 0.9% saline administered twice daily for 3 days. Drainage success was defined as evacuation of the abscess without surgery. Safety was evaluated on the basis of complications. Statistical analysis was performed by using the Student t test and Fisher exact test.Forty-six abscesses were initially drained by 51 catheters. Complete evacuation was achieved in 41 (89.1%) abscesses, whereas five (10.9%) required surgical drainage. Three (60%) of these five had a documented fistula, a higher (P = .02) percentage than in successfully drained abscesses. Three (6.5%) of the 46 abscesses recurred (12-95 days after catheter removal). There were no tPA-linked bleeding complications despite four patients receiving full systemic anticoagulation and 24 receiving prophylactic anticoagulation.Intracavitary tPA is safe and effective for draining complex fluid collections, with most patients avoiding surgery.

The objective of this study was to report the clinical outcome of patients with an appendicolith on computed tomography (CT) who did not undergo appendectomy on initial presentation. Reports from 45,901 abdominal CT examinations performed between March 2000-March 2004 containing the words "appendicolith" or "fecalith" were identified. Patients with appendicoliths not initially undergoing appendectomy were followed to assess re-presentation with abdominal pain ultimately requiring appendectomy. Seventy-four patients had an appendicolith on CT report, were discharged without surgery, and had clinical follow-up. Fifty-two of 74 (70%) patients had no appendiceal symptoms, were given an alternate diagnosis, and did not return with appendicitis. Twenty-two of 74 (30%) patients were discharged without acute appendicitis but with possible appendiceal symptoms. Five of these 22 (23%) patients returned with pathologically proven acute appendicitis, and all had possible appendiceal symptoms at initial presentation. An appendicolith may be a marker of increased risk for appendicitis but is not an indication for appendectomy.

Ultrasound is the most commonly used imaging technique for the evaluation of thyroid nodules. Sonographic findings are often not specific, and definitive diagnosis is usually made through fine-needle aspiration biopsy or even surgery. In reviewing the literature, terms used to describe nodules are often poorly defined and inconsistently applied. Several authors have recently described a standardized risk stratification system called the Thyroid Imaging, Reporting and Data System (TIRADS), modeled on the BI-RADS system for breast imaging. However, most of these TIRADS classifications have come from individual institutions, and none has been widely adopted in the United States. Under the auspices of the ACR, a committee was organized to develop TIRADS. The eventual goal is to provide practitioners with evidence-based recommendations for the management of thyroid nodules on the basis of a set of well-defined sonographic features or terms that can be applied to every lesion. Terms were chosen on the basis of demonstration of consistency with regard to performance in the diagnosis of thyroid cancer or, conversely, classifying a nodule as benign and avoiding follow-up. The initial portion of this project was aimed at standardizing the diagnostic approach to thyroid nodules with regard to terminology through the development of a lexicon. This white paper describes the consensus process and the resultant lexicon.

We propose a general ultrasound (US) texture-analysis and machine-learning framework for detecting the presence of disease that is suitable for clinical application across clinicians, disease types, devices, and operators. Its stages are image selection, image filtering, ROI selection, feature parameterization, and classification. Each stage is modular and can be replaced with alternate methods. Thus, this framework is adaptable to a wide range of tasks. Our two preliminary clinical targets are hepatic steatosis and adenomyosis diagnosis. For steatosis, we collected US images from 288 patients and their pathology-determined values of steatosis (%) from biopsies. Two radiologists independently reviewed all images and identified the region of interest (ROI) most representative of the hepatic echotexture for each patient. To parameterize the images into comparable quantities, we filter the US images at multiple scales for various texture responses. For each response, we collect a histogram of pixel features within the ROI, and parameterize it as a Gaussian function using its mean, standard deviation, kurtosis, and skew to create a 36-feature vector. Our algorithm uses a support vector machine (SVM) for classification. Using a threshold of 10%, we achieved 72.81% overall accuracy, 76.18% sensitivity, and 65.96% specificity in identifying steatosis with leave-ten-out cross-validation (p Extending this framework to adenomyosis, we identified 38 patients with MR-confirmed findings of adenomyosis and previous US studies and 50 controls. A single rater picked the best US-image and ROI for each case. Using the same processing pipeline, we obtained 76.14% accuracy, 86.00% sensitivity, and 63.16% specificity with leave-one-out cross-validation (p