Nontraditional Uses of US Contrast Agents in Abdominal Imaging and Intervention.

With the increasing availability of contrast-enhanced US (CEUS) worldwide and in the United States, the potential applications of this modality in abdominal imaging and intervention are continuing to expand. CEUS leverages the many inherent benefits of US with a safe and unique microbubble contrast agent. When injected intravenously, US contrast agents (UCAs) function as a pure blood pool agent, augmenting diagnostic US examinations such as vascular imaging. In the procedure suite, UCA can be used to improve needle visualization and depict active extravasation. UCA may also be injected through needles and tubes into various body spaces, allowing the assessment of the urinary system, indwelling catheters, and other tracts and cavities. Some venous and lymphatic lesions may be diagnosed with the direct injection of a UCA into these lesions. The authors highlight some of the many applications that are relevant to the abdominal imaging professional and interventional radiologist but should not be considered a complete list, and users of UCAs should continue to consider uses beyond those traditionally highlighted in recent literature. Online supplemental material is available for this article. ©RSNA, 2022.

Distance From Critical Pelvic Structures: Radiographic Comparison of High Submuscular and Space of Retzius IPP Reservoir Placement Techniques.

OBJECTIVE: To evaluate the distance from critical pelvic structures (CPS, defined as bladder and iliac vessels) among inflatable penile prosthesis (IPP) reservoirs placed into the space of Retzius (SOR) and high submuscular (HSM) locations using cross-sectional imaging. IPP reservoir placement into the HSM location has been proposed as a strategy to prevent injury due to greater distance from CPS. METHODS: Our institutional database was retrospectively reviewed to identify men who underwent IPP insertion between 2007 and 2020 and had available cross-sectional abdominopelvic imaging after the time of surgery. Patients were grouped based on reservoir placement technique (SOR vs. HSM). Staff radiologists blinded to placement technique evaluated reservoir position to determine the shortest distance between CPS and the reservoir and if a mass effect was present on CPS. Variables were analyzed using chi-squared, Fisher's exact, and student's T-tests as indicated. RESULTS: Among 1,010 IPP cases performed during the study interval, 139 (13%) were imaged. Compared with SOR reservoirs (n = 32), HSM reservoirs (n =107) were significantly less likely to induce a mass effect on the bladder (72 vs. 9%, P = <.01) or iliac vessels (34 vs. 4%, P = <.01) and were located roughly 5 times further from the bladder (10 ± 22 vs. 49 ± 36 mm, P = <.01) and iliac vessels (5 ± 9 vs. 23 ± 26 mm, P = <.01). CONCLUSION: This study radiographically confirms that IPP reservoirs are located significantly further away from CPS following HSM placement compared to SOR placement.

Radiographic Assessment of Inflatable Penile Prosthesis Reservoir Location Variability in Contemporary Practice.

BACKGROUND: Inflatable penile prosthesis (IPP) reservoirs are typically placed into the Space of Retzius (SOR) or alternative locations including the High Submuscular (HSM) space via transinguinal (TI) or counter incision (CI) techniques. A cadaver study showed variability in reservoir location after TI-HSM placement. AIM: To evaluate reservoir location using cross-sectional imaging following IPP insertion. METHODS: We retrospectively reviewed our institutional database and identified men who underwent virgin penoscrotal IPP insertion between 2007 and 2019. We then identified those men who subsequently underwent cross-sectional imaging prior to October 2019. Radiologists evaluated cross-sectional imaging in a blinded manner and categorized reservoir locations as follows: 1) submuscular; 2) posterior to the external oblique fascia and lateral to the rectus abdominis musculature; 3) preperitoneal; 4) retroperitoneal; 5) intraperitoneal; 6) inguinal canal; 7) subcutaneous. Patients were stratified by reservoir placement technique, transinguinal space of Retzius (TI-SOR), transinguinal high submuscular (TI-HSM), or counterincision high submuscular (CI-HSM). Clinical characteristics and outcomes were reviewed and compared. Statistical analysis was performed using Chi-squared and Fisher's exact tests. OUTCOMES: Variability exists in the TI placement of SOR and HSM reservoirs, CI-HSM reservoirs were associated with a low level of variability. RESULTS: Among 561 men who underwent virgin IPP insertion during the 12-year study period, 114 had postoperative cross-sectional imaging (29 TI-SOR, 80 TI-HSM, and 5 CI-HSM). Among the 114 patients imaged, TI-HSM reservoirs were more likely than TI-SOR to be located anterior to the transversalis fascia (48 vs 14%, P < .01) and were less likely to be located in the preperitoneal space (18 vs 62%, P < .01). Rates of intraperitoneal reservoir location were similar between the TI-HSM and TI-SOR groups (5 vs 7%, P = .66). Among imaged CI-HSM reservoirs, 4 (80%) were anterior to the transversalis fascia and 1 (20%) was within the inguinal canal. Among all 536 transinguinal cases (131 TI-SOR and 405 TI-HSM), rates of reservoir-related complications requiring operative intervention were similar between groups (5 vs 2%, P = .24). No complications were noted among the 25 patients in the CI-HSM cohort. CLINICAL IMPLICATIONS: The level of variability seen in this study did not seem to impact patient safety, complications were rare in all cohorts. STRENGTHS AND LIMITATIONS: This study is the first and largest of its kind in evaluating reservoir positioning in live patients with long-term follow-up. This study is limited in its retrospective and nonrandomized nature. CONCLUSIONS: Despite variability with both TI-HSM and TI-SOR techniques, reservoir related complications remain rare. Kavoussi M, Cook G, Nordeck S, et al. Radiographic Assessment of Inflatable Penile Prosthesis Reservoir Location Variability in Contemporary Practice. J Sex Med 2021;18:2039-2044.

Simulated radiographic bone and joint modeling from 3D ankle MRI: feasibility and comparison with radiographs and 2D MRI.

PURPOSE: The purpose of this work is to simulate radiographs from isotropic 3D MRI data, compare relationship of angle and joint space measurements on simulated radiographs with corresponding 2D MRIs and real radiographs (XR), and compare measurement times among the three modalities. MATERIALS AND METHODS: Twenty-four consecutive ankles were included, eight males and 16 females, with a mean age of 46 years. Segmented joint models simulating radiographs were created from 3D MRI data sets. Three readers independently performed blinded angle and joint space measurements on the models, corresponding 2D MRIs, and XRs at two time points. Linear mixed models and the intraclass correlation coefficient (ICC) was ascertained, with p values less than 0.05 considered significant. RESULTS: Simulated radiograph models were successfully created in all cases. Good agreement (ICC > 0.65) was noted among all readers across all modalities and among most measurements. Absolute measurement values differed between modalities. Measurement time was significantly greater (p < 0.05) on 2D versus simulated radiographs for most measurements and on XR versus simulated radiographs (p < 0.05) for nearly half the measurements. CONCLUSIONS: Simulated radiographs can be successfully generated from 3D MRI data; however, measurements differ. Good inter-reader and moderate-to-good intra-reader reliability was observed and measurements obtained on simulated radiograph models took significantly less time compared to measurements with 2D and generally less time than XR.

The Utility of Viscoelastic Testing in Patients Undergoing IR Procedures.

Whole-blood viscoelastic testing can identify patient-specific coagulation disturbances, allowing for targeted repletion of necessary coagulation factors and differentiation between coagulopathy and surgical bleeding that requires intervention. Viscoelastic testing complements standard coagulation tests and has been shown to decrease transfusion requirements and improve survival in bleeding patients. Viscoelastic testing also can be used to predict bleeding and improve the care of patients undergoing interventional radiology (IR) procedures.

Bone and joint modeling from 3D knee MRI: feasibility and comparison with radiographs and 2D MRI.

PURPOSE: The purpose was to evaluate feasibility of bone and joint segmentations from three-dimensional magnetic resonance imaging (3D MRI). METHODS: Segmented joint models from 3D MRI data set were obtained for 42 patients. Blinded angular and joint space measurements were performed on 3D MRI model, two-dimensional (2D) MRI, and radiography (XR). RESULTS: Medial joint space was similar on both XR and 3D MRI (P=.3). The XR measurements were statistically different but closer to 3D MRI for lateral patellar tilt angle, patellar tendon length, and lateral knee joint space, whereas 2D MRI measurements were closer to XR in terms of trochlear depth, sulcal angle, and patellar length. CONCLUSION: 3D bone and joint segmentations are feasible from isotropic MRI data sets.

Esophagectomy and Gastric Pull-through Procedures: Surgical Techniques, Imaging Features, and Potential Complications.

Esophagectomy takes the center stage in the curative treatment of local and local-regional esophageal cancer. It is a complex procedure with a high postoperative complication rate. When interpreting imaging studies, radiologists must understand the surgical techniques used and their potential complications. The most common surgical techniques are transthoracic esophagectomies, such as the Ivor Lewis and McKeown techniques, and transhiatal esophagectomy. Variations of these techniques include different choices of conduit (ie, stomach, colon, or jejunum) to serve in lieu of the resected esophagus. Postoperative imaging and accurate interpretation is vital in the aftercare of these patients. Chest radiographs, esophagrams, and computed tomographic images play an essential role in early identification of complications. Pulmonary complications and anastomotic leaks are the leading causes of postoperative morbidity and mortality secondary to esophagectomy. Other complications include technical and functional problems and delayed complications such as anastomotic strictures and disease recurrence. An esophagographic technique is described that is performed by using hand injection of contrast material into an indwelling nasogastric tube. Familiarity with the various types of esophagectomy and an understanding of possible complications are of utmost importance for radiologists and allow them to be key participants in the treatment of patients undergoing these complicated procedures.

3-D Isotropic MR Imaging for Planning Bone Reconstruction in Patients With Femoroacetabular Impingement.

BACKGROUND: Femoroacetabular impingement (FAI) is commonly seen in young or middle-aged patients. Early detection and correction of FAI-related bony deformities or pelvic realignment are essential to prevent the development or progression of hip osteoarthritis. DISCUSSION: Computed tomography (CT) and magnetic resonance (MR) imaging are the reference standards for the evaluation of bony anatomy and treatable internal derangement findings of the hip, respectively. Surgeons prefer CT imaging for preoperative bone delineation because of its 3-D isotropic capabilities and excellent multiplanar reconstructions. Three-Tesla (3T) MR scans enable high-resolution 3-D MR reconstructions for bone depiction similar to 3-D CT reconstructions and have the potential to eliminate the need for duplicate (CT and MR) scanning. CONCLUSION: This technical report illustrates the feasibility of such an approach and compares bone rendering obtained using isotropic data from 3-D MR with 3-D CT in the same patient.

Femoroacetabular impingement with chronic acetabular rim fracture - 3D computed tomography, 3D magnetic resonance imaging and arthroscopic correlation.

Femoroacetabular impingement is uncommonly associated with a large rim fragment of bone along the superolateral acetabulum. We report an unusual case of femoroacetabular impingement (FAI) with chronic acetabular rim fracture. Radiographic, 3D computed tomography, 3D magnetic resonance imaging and arthroscopy correlation is presented with discussion of relative advantages and disadvantages of various modalities in the context of FAI.

Comparative analysis of physician extender curricular requirements in radiology: a detailed view.

PURPOSE: This article provides a detailed analysis comparing the educational requirements for physician assistants, nurse practitioners, and radiologist assistants (RAs) working in radiology. The authors examine the curricular requirements as they pertain to radiology for each program and highlight the advantages and limitations of each within potential roles in radiology. METHODS: A literature review was performed using the following databases: CINAHL Plus, MEDLINE, and Academic Search Complete. The search parameters were English-language peer-reviewed articles published from 2002 through 2010. The search terms included "physician assistant," "nurse practitioner," "radiologist assistant," "radiology practitioner assistant," and "physician extender." The inclusion term applied was "radiology" to further hone results. RESULTS: The RA curriculum includes a core education that is comparable with the physician assistant and nurse practitioner curricula, with the exception of prescriptive authority and health promotion and disease prevention. The RA curriculum adds instruction in radiobiology, radiation safety, radiologic procedures, fluoroscopic unit operation and safety, and radiopharmaceuticals. CONCLUSIONS: The RA curriculum is specific for the radiologic imaging area and advantageous to radiologists, radiology managers, and patients undergoing diagnostic procedures.