Publications

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

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

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

PURPOSE: To develop a scheme to quantitatively assess localization accuracy of tomosynthesis-guided vacuum-assisted breast biopsy apparatus.

METHODS: A phantom containing a metallic pellet on a flexible plastic shaft was constructed and was tested in cranio-caudal (CC) and lateral (LAT) arm biopsy geometries following the standard clinical breast biopsy workflow. Three points were manually digitized on tomosynthesis images including: the center of the target, and the tip of the needle in pre- and postfire positions. The needle trajectory was determined and four error metrics were defined: (1) stroke length error (difference between the nominal and measured stroke lengths); (2) Euclidian distance between the target and center of trough (i.e., aperture); (3) longitudinal distance between target and center of trough; and (4) lateral distance between target and needle. The proposed methodology was also evaluated on a breast gel phantom and the complete biopsy procedure, including vacuum-assisted biopsy was performed.

RESULTS: Three biopsy geometries were investigated: (i) LAT arm on a prone table unit (Hologic, Affirm Prone), (ii) CC- and (iii) LAT arm in an upright unit (Hologic Affirm Upright). Both biopsy units passed the vendor-provided daily localization accuracy test, with <1 mm nominal error in each dimension. The aforementioned error metrics (1) to (4) were (0.6, 1.8, 0.4, 1.7) mm, (0.4, 4.2, 4.1, 1.1) mm, and (0.3, 2.4, 0.7, 2.3) mm, respectively, for geometry-I, -II, and -III. The gel phantom was tested on the upright unit with lateral arm and the error metrics (1) to (4) were 0.4, 2.5, 0.8, and 2.4 mm respectively.

CONCLUSIONS: A framework was developed to evaluate the tomosynthesis-guided breast biopsy localization error, allowing quantitative comparisons between different systems and biopsy configurations. The proposed framework can also be extended to the stereotactic breast biopsy units. We suggest that a quantitative tolerance level for localization accuracy of breast biopsy units be established.

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

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

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

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

PURPOSE: To prospectively validate electromagnetic hand motion tracking in interventional radiology to detect differences in operator experience using simulation.

METHODS: Sheath task: Six attending interventional radiologists (experts) and 6 radiology trainees (trainees) placed a wire through a sheath and performed a "pin-pull" maneuver, while an electromagnetic motion detection system recorded the hand motion. Radial task: Eight experts and 12 trainees performed palpatory radial artery access task on a radial access simulator. The trainees repeated the task with the nondominant hand. The experts were classified by their most frequent radial artery access technique as having either palpatory, ultrasound, or overall limited experience. The time, path length, and number of movements were calculated. Mann-Whitney U tests were used to compare the groups, and P < .05 was considered significant.

RESULTS: Sheath task: The experts took less time, had shorter path lengths, and used fewer movements than the trainees (11.7 seconds ± 3.3 vs 19.7 seconds ± 6.5, P < .01; 1.1 m ± 0.3 vs 1.4 m ± 0.4, P < .01; and 19.5 movements ± 8.5 vs 31.0 movements ± 8.0, P < .01, respectively). Radial task: The experts took less time, had shorter path lengths, and used fewer movements than the trainees (24.2 seconds ± 10.6 vs 33.1 seconds ± 16.9, P < .01; 2.0 m ± 0.5 vs 3.0 m ± 1.9, P < .001; and 36.5 movements ± 15.0 vs 54.5 movements ± 28.0, P < .001, respectively). The trainees had a shorter path length for their dominant hand than their nondominant hand (3.0 m ± 1.9 vs 3.5 m ± 1.9, P < .05). The expert palpatory group had a shorter path length than the ultrasound and limited experience groups (1.8 m ± 0.4 vs 2.0 m ± 0.4 and 2.3 m ± 1.2, respectively, P < .05).

CONCLUSIONS: Electromagnetic hand motion tracking can differentiate between the expert and trainee operators for simulated interventional tasks.

PURPOSE: To evaluate whether the recalculation of lung shunt fraction (LSF) is necessary prior to next-stage or same lobe repeat radioembolization.

MATERIALS AND METHODS: Retrospective chart review was performed for patients who underwent radioembolization between February 2008 and December 2018. Eighty of 312 patients had repeat mapping angiograms and LSF calculations. A total of 160 LSF calculations were made using planar imaging (155, [97%]) and single-photon emission computed tomography (5 [3%]) technetium-99m macroaggregated albumin hepatic arterial injection imaging. The mean patient age was 61.8 years ± 12.7; 69 (86%) patients had metastatic disease and 11 (14%) had hepatocellular carcinoma.

RESULTS: Patients had a median LSF of 5% (interquartile range [IQR] 3%-9%) with a median absolute difference of 1.25 (IQR 0.65-3.4) and a median of 76 days (IQR 42.5-120 days) between repeat LSF calculations. There was a median change in LSF of 0.2% between mapping studies (P = .11). There was no statistical significance between the repeat LSFs regardless of the arterial distribution (P = .79) or between tumor types (P = .75). No patients exceeded lung dose limits using actual or predicted prescribed dose amounts. The actual median lung dose was 2.6 Gy (IQR 1.8-4.4 Gy, maximum = 20.5) for the first radioembolization and 2.0 Gy (IQR 1.3-3.7 Gy, maximum = 10.1) for the second radioembolization.

CONCLUSIONS: No significant difference in LSF was identified between different time points and arterial distributions within the same patient undergoing repeat radioembolization. In patients who receive well under 30-Gy lung dose for the initial treatment and a 50-Gy cumulative lung dose, repeat radioembolization treatments in the same patient may not require a repeat LSF calculation.

PURPOSE: Non-contrast CT ASPECTS (NCCTasp) has an established role in determining eligibility for mechanical thrombectomy in centers without ready access to perfusion or DWI. Moreover, it has been suggested that CTA source ASPECTS (CTAasp) may be superior to NCCTasp in predicting final infarct volume (FIV). In this study, we hypothesized that CTA maximum intensity projection ASPECTS (MIPSasp) would be superior compared to both NCCTasp and CTAasp in predicting FIV as measured by DWI.

MATERIALS AND METHODS: In 41 consecutive patients with MCA territory infarcts, NCCTasp, CTAasp and MIPSasp were visually assessed by 2 neuroradiologists. Disagreements were adjudicated by a third neuroradiologist, and the reconciled data used for all further analysis. MR-DWI was used as the standard for FIV determination. Receiver operating characteristic curve analysis was used to compare the area under the curve for all three CT-based methods in predicting FIV ≥70 ml.

RESULTS: MIPSasp (AUC: 0.98, CI: 0.88-1.00) were statistically better than NCCTasp (AUC: 0.87, 95% CI: 0.72-0.95; p=0.01) in predicting FIV ≥70 ml. MIPSasp were also superior to CTAasp (AUC: 0.9, CI: 0.79-.98; p˂0.05). Optimal test performance for predicting FIV ≥70 ml for MIPSasp was ≤6 (sensitivity=100%, specificity=91.4%; Youden's J=0.98).

CONCLUSION: Our preliminary study suggests that a novel CTA-MIPS derived ASPECTS better predicts large MCA territory infarcts compared to CTA source and non-contrast ASPECTS. Thus, MIPSasp may be a promising technique for future studies aimed at improving ischemic stroke treatment in centers using ASPECTS for stroke management.

BACKGROUND: This study sought to examine the impact of nodule density on recurrence and survival in female patients with lung adenocarcinoma treated by lobectomy or sublobar resection.

METHODS: In this retrospective study of female patients who underwent surgical resection for pathologic stage IA adenocarcinoma, patients with preoperative imaging were included for analysis if the consolidation-to-tumor ratio was 0.5 (solid-predominant ground-glass opacity [GGO]) to 1.0 (solid). Kaplan-Meier curves were generated to estimate overall survival (OS) and disease-free survival (DFS). Risk estimates were calculated using multivariable Cox proportional hazards models.

RESULTS: For all 357 patients sublobar resection demonstrated worse 5-year DFS compared with lobectomy (76.4% vs 67.9%, P = .05). Multivariable modeling showed worse DFS with sublobar resection (hazard ratio, 1.55; P = .06) and tumors ≥ 2 cm (hazard ratio, 2.32; P = .05). On radiologic evaluation the solid-predominant GGO group (n = 81) demonstrated a smaller solid component compared with the solid nodule group (n = 163; 1.49 cm vs. 1.84 cm, respectively; P < .001) yet comparable total size. The solid-predominant GGO group showed improved 5-year OS (90.8 vs 76.8, P = .01) and DFS (79.3 vs 67.2, P = .05) compared with the solid nodule group. Additionally the solid-predominant GGO group demonstrated equivalent OS (90.8% vs 90.8%, P = .93) and DFS (76.0% vs 81.7%, P = .60) with sublobar resection compared with lobectomy.

CONCLUSIONS: In this report of female patients with stage IA adenocarcinoma, sublobar resection was associated with worse DFS compared with lobectomy in whole-group analysis. However patients with solid-predominant GGOs demonstrated improved 5-year OS and DFS compared with patients with solid nodules with equivalent outcomes regardless of resection type.