Calcific Plaque Modification by Acoustic Shockwaves: Intravascular Lithotripsy in Cardiovascular Interventions.

PURPOSE OF REVIEW: To provide a review of recent literature on the treatment of moderate-to-severe calcification in coronary and peripheral vasculature with intravascular lithotripsy (Shockwave Medical, Santa Clara, CA). RECENT FINDINGS: Moderate-to-severe calcific plaques constitute a significant proportion of lesions treated with transcatheter interventions in the coronary and peripheral vascular beds and portend lower procedural success rates, increased periprocedural major adverse events, and unfavorable long-term clinical outcomes compared to non-calcific plaques. Intravascular lithotripsy (IVL) is a new technique that uses acoustic shock waves in a balloon-based system to induce fracture in the calcium deposits to facilitate luminal gain and stent expansion. IVL demonstrated high procedural success and low complication rates in the management of moderate-to-severe calcification in coronary and peripheral vascular beds and led to large luminal gain by modification of calcific plaque as assessed by optical coherence tomography. Further studies will determine the role of IVL in an integrated, protocolized approach to the treatment of severely calcified plaques in the coronary and peripheral vascular beds.

Substantial interreader agreement for biopsy with reduction in biopsy rate: A multireader diagnostic performance study of ACR TI-RADS.

PURPOSE: To assess diagnostic performance of ACR TI-RADS in thyroid cancer detection and evaluate interobserver agreement among radiologists with lower interpreting experience. METHODS: Four radiologists retrospectively assessed 295 biopsied thyroid nodules from ultrasound studies performed between 2009 and 2019, blinded to histopathology. Diagnostic performance for cancer detection was determined individually, and interobserver agreement among four readers was evaluated with Fleiss kappa coefficient (ⱪ). RESULTS: 245 (83.1%) benign and 50 (16.9%) malignant nodules were evaluated. Diagnostic performance based on final TR level was consistent and without significant difference among four readers, with excellent sensitivity (≥98.0%) and negative predictive value (NPV) [≥94.4%] for TR levels 3 to 5. Diagnostic performance based on recommendation to biopsy has moderate sensitivity (≥62%) and high NPV (≥84.7%). Retrospective scoring with established ACR TI-RADS criteria would have substantially reduced the number of biopsies performed, with 63.2% of malignancy not biopsied meeting criteria for sonographic surveillance. Interobserver agreement on TI-RADS scoring for final TR level was fair (ⱪ = 0.39, 95% CI 0.32, 0.47), with substantial agreement for recommendation to biopsy (ⱪ = 0.64, 95% CI 0.58, 0.70). CONCLUSIONS: Substantial reduction in biopsy rate (up to 48%) would have been achieved using the ACR TI-RADS criteria, with 63% of malignancy not biopsied meeting criteria for sonographic surveillance. Interobserver agreement was fair for TI-RADS level scoring and substantial for recommendation to biopsy.

Can obstructive urolithiasis be safely excluded on contrast CT? A retrospective analysis of contrast-enhanced and noncontrast CT.

PURPOSE: The aim of this study was to determine if contrast-enhanced CT can safely exclude obstructive urolithiasis in patients with flank plain. We performed a retrospective cohort analysis to compare the negative predictive values of contrast-enhanced and non-contrast CTs for the detection of obstructing urolithiasis. METHODS: Through report analysis, we identified all non-contrast and contrast-enhanced CT examinations of the abdomen and pelvis performed on adult patients in the emergency department at a single, multi-site academic medical institution in 2017 with an indication of flank pain. The prevalence of obstructive urolithiasis in each group was calculated. We subsequently analyzed 200 consecutive studies from each of these groups (reported negative for obstructive urolithiasis) for negative predictive value calculation. Follow up abdominal imaging within 7 days from original presentation was used as a reference standard for analysis. RESULTS: In the noncontrast group, 1 study out of 200 was false negative (negative predictive value = 99.5%). In the contrast-enhanced group, there were no false negatives (negative predictive value = 100%). The prevalence of obstructive urolithiasis was 44.0% (351/797) in the noncontrast group and 18.7% (86/459) in the contrast-enhanced group. CONCLUSION: Our results suggest that contrast-enhanced CT can safely exclude obstructing ureteral calculi in the setting of acute flank pain. This finding is of clinical relevance given the inherent benefit of IV contrast in diagnosing abdominopelvic pathology.

Utility of ultrasound after a negative CT abdomen and pelvis in the emergency department.

PURPOSE: The purpose of this study is to assess the utility of an abdominal and/or pelvic ultrasound (US) performed within 24 h after a negative CT of the abdomen and pelvis (CTAP) in the emergency department (ED). The secondary endpoint is to assess whether there is a significant increase in length of stay (LOS) in the ED due to immediate US reimaging. METHOD: We reviewed the imaging reports of 335 patients over the course of 3 years in our ED who had an US within 24 h after a negative CTAP. We then assessed type of US and whether the US showed any acute findings. We also evaluated LOS in the ED. RESULTS: Out of 335 patients, there were only three US cases suspicious for acute surgical pathology (3/335 or 0.9%). On 30-day clinical follow-up, only one of the three cases was confirmed as cholecystitis on pathology. The most common non-surgical findings on US not initially reported on CTAP were ovarian cysts (29/83) and gallstones (9/83). Additionally, the LOS for patients who received both a CTAP and US was 119 min longer than patients who only received a CTAP. CONCLUSION: US abdomen and/or pelvis reimaging within 24 h following a negative CTAP is unlikely to change surgical management in the acute setting. US reimaging can still be useful in diagnosing non-surgical pathology, which could serve to explain the patient's pain. US reimaging after negative CTAP is associated with an average increase in the ED LOS.

Rare imaging of a known entity: fat embolism seen on CT in lower extremity vein after trauma.

Fat embolism occurs in the vast majority of patients who have had trauma (approximately 90%). The most common occurrence is after long bone fracture. It has also been noted in cases after orthopedic surgery. Fat embolism is most often diagnosed when the clinical manifestations of fat embolism syndrome become apparent. Reported cases of fat emboli in transit are unusual. In our case, we present the rare finding of fat embolism seen on computed tomography in the lower extremity after a trauma.

Ultrasound to Detect Pressure-related Deep Tissue Injuries in Adults Admitted via the Emergency Department: A Prospective, Descriptive, Pilot Study.

Stage 4 pressure ulcers (PUs) start with tissue death at the level of the bone, also known as deep tissue injury (DTI). Studies have shown the appearance of DTI on the skin is delayed for several days after the original pressure-related injury to the deep soft tissues. Studies also suggest DTI can be seen using ultrasound (US) technology. A prospective, descriptive, correlational pilot study was conducted to evaluate the use of US technology to detect DTI in the soft tissues that are not visible on the skin upon hospital admission. Study participants included a convenience sample of 33 persons at risk for PUs (ie, Braden score <18) admitted through the emergency department. Each participant had US scans of 13 common PU body sites. All scans were documented in the radiologist report in the electronic medical record. Creatinine phosphokinase, calcium levels, and urine myoglobin levels also were assessed upon enrollment. Skin failure risk factors (SFRFs), including fever, hypotension, weight loss, coagulopathy, and acidosis/respiratory failure, also were documented. Patients were examined for skin PUs every day for 7 days after US scan. Twenty-three (23) patients completed the study. US scans identified pressure necrosis at 2 levels: bone (54 positive [US+]) and subcutaneous (SC); 79 US+, respectively). US+ bone sites resulted in 5 PUs appearing 6 to 7 days post-admission (sensitivity = 100%, specificity 84.7%, positive predictive value 10%, and negative predictive value 100%), indicating all DTI that later became purple skin DTI were detected by the US. US+ SC sites, located immediately under the skin, yielded 5 PUs appearing on day 2 after admission (sensitivity 100%, specificity 74.8%, positive predictive value 6.3%, and negative predictive value 100%). The participants with PU occurrence in both bone and SC groups had low Braden scores (bone group mean = 13.25, SC group mean = 11.2). Study patients who were positive for PU also had >4 SFRFs. Creatinine phosphokinase, calcium, and myoglobin levels were inconsistent and did not correlate with US+ scans. These observations warrant larger studies to confirm findings and optimize the validity of US screening for DTI in select populations, which may help improve protocols of care and PU admission documentation. The preliminary results suggest inclusion of the Braden Scale score and known PU risk factors may improve the positive predictive value of this test.

Elastography-targeted Thyroid Nodule Aspiration: A Novel Approach.

OBJECTIVES: Since 2009, the rate of nondiagnostic (ND) thyroid nodule fine-needle aspiration (FNA) has ranged from 2% to 20%. A ND result can cause further patient morbidity secondary to repeated procedures and delay in diagnosis. The use of real-time strain elastography (RTE) in determining nodule malignant risk has gained considerable focus recently. A less studied area where RTE may prove beneficial is its role in targeting areas for FNA. Our hypothesis is that FNA performed in concurrence with RTE will show a decreased rate of ND results leading to fewer repeated FNA. MATERIALS AND METHODS: The Institutional Review Board approval was obtained. A retrospective review of all thyroid nodule FNA from January 1, 2011, to January 1, 2014, was performed with review of nodule size, presence of microcalcifications, vascularity, solid components, patient age, and gender. Cases were separated based if RTE was done before FNA or not. Pathology reports were reviewed to assess for specimen adequacy. Statistical comparison was performed using SAS analysis software. RESULTS: A total of 221 specimens were reviewed, with RTE performed on 140 cases (63.4%). Both groups were similar in demographics and previously described nodule characteristics. The ND rate when RTE was not performed was 16% (13/68) compared to 10% when RTE was performed (14/126). The difference was not found to be statistically significant, P = 0.205. CONCLUSIONS: The presence of an elastogram failed to demonstrate a significant decrease in ND FNA rates although these results may be secondary to study design. Further evaluation with prospective trials using larger sample size may ultimately detect increased accuracy of RTE-targeted FNA.