Pancreatic ductal adenocarcinoma (PDAC) regional nodal disease at standard lymphadenectomy: is MRI accurate for identifying node-positive patients?

OBJECTIVE: To determine the accuracy of qualitative and quantitative MRI features for the diagnosis of pathologic regional lymph nodes at standard lymphadenectomy in patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: All adult patients with pancreatic MRI performed from 2011 to 2021 within 3 months of a pancreaticoduodenectomy were eligible for inclusion in this single-center retrospective cohort study. Regional nodes at standard lymphadenectomy were independently reviewed by two fellowship-trained abdominal radiologists for the following qualitative features: heterogeneous T2 signal, round shape, indistinct margin, peri-nodal fat stranding, and restricted diffusion greater than the spleen. Quantitative characteristics including primary tumor size, largest node short- and long-axes length, number of regional nodes, absolute apparent diffusion coefficient (ADC) values, and ADC node-to-spleen signal index were assessed. Analysis was at the patient-level with surgical pathology as the reference standard. RESULTS: Of 75 patients, 85% (64/75) were positive for regional nodal disease on histopathology. None of the qualitative variables evaluated on MRI was associated with pathologic nodes. Median primary tumor maximum diameter was slightly larger for patients with pathologic nodes compared to those without (18 mm (10-42 mm) vs 16 mm (9-22 mm), p = 0.027). None of the other quantitative features was associated with pathologic nodes. Radiologist opinion was not associated with pathologic nodes (p = 0.520). Interobserver agreement was fair (kappa = 0.257). CONCLUSIONS: Lymph node morphologic features and radiologist opinion using MRI are of limited value for diagnosing PDAC regional nodal disease. Improved diagnostic techniques are needed given the prognostic implications of pathologic lymph nodes in these patients. KEY POINTS: • Multiple lymph node morphologic features routinely assessed on MRI for malignancies elsewhere in the body are likely not applicable when assessing for pancreatic ductal adenocarcinoma nodal disease. • Interobserver agreement for the presence or absence of pancreatic ductal adenocarcinoma lymph node morphologic features on MRI is fair (kappa = 0.257). • Many more lymph nodes are resected at PDAC standard lymphadenectomy than are detectable on MRI, median 25 vs 5 (p < 0.001), suggesting improved diagnostic techniques are needed to identify PDAC nodal disease.

MRI LI-RADS Version 2018: Impact of and Reduction in Ancillary Features.

OBJECTIVE. The purpose of this study is to determine the impact of LI-RADS ancillary features on MRI and to ascertain whether the number of ancillary features can be reduced without compromising LI-RADS accuracy. MATERIALS AND METHODS. A total of 222 liver observations in 81 consecutive patients were identified on MRI between August 2013 and December 2018. The presence or absence of major and ancillary features was used to determine the LI-RADS category for LR-1 to LR-5 observations. Final diagnosis was established on the basis of pathologic findings or one of several composite clinical reference standards. Diagnostic accuracy was compared with and without ancillary features by use of the z test of proportions. Decision tree analysis and machine learning-based feature pruning were used to identify noncontributory ancillary features for LI-RADS categorization. Interobserver agreement with and without ancillary features was measured using the Krippendorff alpha coefficient, and comparisons were made using bootstrapping. A p < .05 was considered statistically significant. RESULTS. Application of ancillary features resulted in a change in the LI-RADS category of seven hepatocellular carcinomas (HCCs), with the category of six of seven (86%) HCCs upgraded; 51 benign observations also had a change in LI-RADS category, with the category of 33 (65%) of these observations downgraded. When ancillary features were applied, the percentage of HCCs in each LI-RADS category did not differ significantly compared with major features alone (p = .06-.49). Decision tree analysis and the machine learning model identified five ancillary features as noncontributory: corona enhancement, nodule-in-nodule, mosaic architecture, blood products in mass, and fat in a mass, more than in adjacent liver. Interobserver agreement was high with and without application of ancillary features; however, it was significantly higher without ancillary features (p < .001). CONCLUSION. Although ancillary features are an important component of LI-RADS, their impact may be small. Several ancillary features likely can be removed from LI-RADS without compromising diagnostic performance.

Diagnostic Accuracy of Single-Phase Computed Tomography Texture Analysis for Prediction of LI-RADS v2018 Category.

OBJECTIVE: The aim of this study was to determine if texture analysis can classify liver observations likely to be hepatocellular carcinoma based on the Liver Imaging Reporting and Data System (LI-RADS) using single portal venous phase computed tomography. METHODS: This research ethics board-approved retrospective cohort study included 64 consecutive LI-RADS observations. Individual observation texture analysis features were compared using Kruskal-Wallis and 2 sample t tests. Logistic regression was used for prediction of LI-RADS group. Diagnostic accuracy was assessed using receiver operating characteristic curves and Youden method. RESULTS: Multiple texture features were associated with LI-RADS including the mean HU (P = 0.003), median (P = 0.002), minimum (P = 0.010), maximum (P = 0.013), standard deviation (P = 0.009), skewness (P = 0.007), and entropy (P < 0.001). On logistic regression, LI-RADS group could be predicted with area under the curve, sensitivity, and specificity of 0.98, 96%, and 100%, respectively. CONCLUSIONS: Texture analysis features on portal venous phase computed tomography can identify liver observations likely to be hepatocellular carcinoma, which may preclude the need to recall some patients for additional multiphase imaging.

Weightbearing CT scan of severe flexible pes planus deformities.

BACKGROUND: The three-dimensional relationships of the bones in the foot in a flatfoot deformity are difficult to assess with standard radiographs. CT scans demonstrate these relationships but are typically made in a nonweightbearing mode. Our objective was to assess the use of a weightbearing CT apparatus to image the feet in patients with severe flexible pes planus deformities and to better define the anatomical changes that occur. MATERIALS AND METHODS: A specialized device was designed and constructed to simulate weightbearing to the feet during CT examination. Eighteen normal feet and 30 painful severe and flexible pes planus feet were imaged in both the non weightbearing and weightbearing states, set at 50% of body weight. Several measurements of intertarsal relationships were made of the pes planus and normal feet. Navicular floor to skin distance, forefoot arch angle, and subtalar joint subluxation were measured in the coronal plane in both the weightbearing and nonweightbearing states. T-tests were used to analyze measurements of navicular floor to skin distance and forefoot arch angle. RESULTS: The weightbearing device had a significant effect on foot configuration for both normal and pes planus feet (p = 0.0008) and (p < 0.0001) respectively for both floor to skin distance and forefoot arch angle. There was a significant difference between normal feet and pes planus feet with regard to the forefoot arch angle in the nonweightbearing (p = 0.02) and weightbearing states (p = 0.01). Four of the pes planus patients had evidence of subtalar joint subluxation which was more pronounced in the weightbearing state. There was no significant difference between the navicular floor to skin distance in the normal versus pes planus feet in either the non weightbearing (p = 0.05) or the weightbearing states (p = 0.07). CONCLUSION: A device was designed and constructed to apply a weightbearing load equal to that of 50% body weight with minimal to no patient discomfort. The resultant effects on foot configuration were significant, and are useful for assessment of degree of flexible flat foot deformity, thus guiding clinical management. The measure which most significantly differed between pes planus patients and normal volunteers was the forefoot arch angle. Forefoot arch angle may therefore be the most useful measure for the imaging diagnosis of flexible pes planus, and the degree of planus deformity.

An unusual cause of pulmonary nodules in the emergency department.

We report a 51-year-old woman who presented to the emergency department with left-sided pleuritic chest pain 2 weeks after subtotal hysterectomy and bilateral salpingo-oophorectomy for a leiomyomatous uterus. Computed tomography scan of the chest revealed bilateral pulmonary nodules. Biopsy showed cytologically bland spindle cells without overt malignant features. Immunohistochemistry confirmed smooth muscle phenotype, in keeping with a clinicopathologic diagnosis of benign metastasizing leiomyoma (BML). BML does not frequently come to the attention of the emergency physician because it is rare and usually asymptomatic. When symptomatic, its clinical presentation depends on the site(s) of metastasis, number, and size of the smooth muscle tumors. Emergent presentations of BML are reviewed.

Persistent Mullerian duct syndrome associated with transverse testicular ectopia.

Persistent Mullerian Duct Syndrome (PMDS) associated with transverse testicular ectopia (TTE) is rare. Ten cases have been reported in the past. Accurate diagnosis with karyotype and histological analysis is crucial. Surgical management should be geared toward preservation of fertility when possible.

Sonography of full-thickness supraspinatus tears: comparison of patient positioning technique with surgical correlation.

OBJECTIVE: Sonography has become a popular technique for the assessment of musculoskeletal disorders. Patient positioning is crucial to a thorough and accurate assessment of rotator cuff tendons. Two positions, the Crass and modified Crass, have been routinely used in the research and clinical settings to examine the supraspinatus tendon. Our study was a prospective trial to determine whether the Crass or the modified Crass position affords the most accurate measure of supraspinatus tears when compared with surgical findings. SUBJECTS AND METHODS: Twenty-one patients with full-thickness supraspinatus tears underwent shoulder sonography in both the Crass and the modified Crass positions. Measurements of supraspinatus tears were performed in the sagittal and transverse dimensions. Patients subsequently underwent either arthroscopic or open supraspinatus repair. Intraoperative measurements were made in two dimensions and were compared with sonographic findings. RESULTS: Sonography had 100% specificity in detecting full-thickness supraspinatus tears. No statistically significant difference was seen between the size of supraspinatus tears in the Crass and modified Crass positions and surgical findings in the transverse plane (p = 0.55 and 0.61, respectively). In the sagittal dimension, no statistically significant difference was seen between surgical findings and the Crass position (p = 0.14); however, a difference existed when the modified Crass position was used (p = 0.03). CONCLUSION: Sonography reliably detects and quantifies supraspinatus tears. Both the Crass and the modified Crass positions reflected the true size of supraspinatus tears in the transverse plane. In the sagittal plane, the Crass position is the more useful to quantify supraspinatus tears because the modified Crass position overestimates the size of such tears.

Treatment of post-blepharoplasty lower lid retraction by free tarsoconjunctival grafting.

BACKGROUND: Blepharoplasty is probably the most commonly performed facial cosmetic procedure. Despite attempts to prevent its occurrence, post-blepharoplasty lower eyelid malposition with inferior scleral show and corneal exposure can occur, particularly with non-ophthalmologist surgeons. Since a repair must oppose the force of gravity and recurrent scarring, it is often difficult to achieve functional and esthetically pleasing surgical correction. A variety of authors have documented methods to correct post-blepharoplasty lower eyelid malposition. A review of such methods is presented. This is the first paper to analyze results from free tarsoconjunctival grafting specifically in cases of post-blepharoplasty lower lid retraction. METHODS: The present case-series report attempts to examine the efficacy of free tarsoconjuctival grafting in patients with post-blepharoplasty lower lid malposition. Ten patients, ranging in age from 48-75 years (mean = 58.7 years), presented with varied amounts of inferior scleral show and ocular symptoms, including epiphora, dry eye and ocular irritation. Varied amounts of lagophthalmos and superficial punctate keratitis were detected in five eyes and ten eyes, respectively. As described, each patient (20 eyes) underwent bilateral free conjunctival grafting from upper to lower eyelids. RESULTS: After a follow-up interval of 3-32 months (mean = 15 months), all patients experienced a decrease in inferior scleral show and symptomatology. The decrease in inferior scleral show ranged from 0.75 to 3 mm, with an average decrease of 1.61 mm; symptoms of epiphora, dry eye or discomfort persisted in only four eyes. The amount of lagophthalmos and superficial punctate keratitis also decreased postoperatively. Side effects were minimal. INTERPRETATION: We conclude that in the specific case of post-blepharoplasty lower lid retraction, free tarsoconjunctival grafting is both safe and effective.