Ultrasound-guided microwave ablation in the treatment of inguinal neuralgia.

Chronic groin pain can be due to a variety of causes and is the most common complication of inguinal hernia repair surgery. The etiology of pain after inguinal hernia repair surgery is often multifactorial though injury to or scarring around the nerves in the operative region, namely the ilioinguinal nerve, genital branch of the genitofemoral nerve, and the iliohypogastric nerve, is thought to be a key factor in causing chronic post-operative hernia pain or inguinal neuralgia. Inguinal neuralgia is difficult to treat and requires a multidisciplinary approach. Radiologists play a key role in the management of these patients by providing accurate image-guided injections to alleviate patient symptoms and identify the pain generator. Recently, ultrasound-guided microwave ablation has emerged as a safe technique, capable of providing durable pain relief in the majority of patients with this difficult to treat condition. The objectives of this paper are to review the complex nerve anatomy of the groin, discuss diagnostic ultrasound-guided nerve injection and patient selection for nerve ablation, and illustrate the microwave ablation technique used at our institution.

Characterizing T2 iso- and hypo-intense renal masses on MRI: Can templated algorithms improve accuracy?

PURPOSE: To assess if a templated algorithm can improve the diagnostic performance of MRI for characterization of T2 isointense and hypointense renal masses. METHODS: In this retrospective study, 60 renal masses with histopathologic diagnoses that were also confirmed as T2 iso- or hypointense on MRI were identified (mean ± standard deviation, range: 3.9 ± 2.5, 1.0-13.7 cm). Two semi-quantitative diagnostic algorithms were created based on MRI features of renal masses reported in the literature. Three body-MRI trained radiologists provided clinical diagnoses based on their experience and separately provided semiquantitative data for each components of the two algorithms. The algorithms were applied separately by a radiology trainee without additional interpretive input. Logistic regression was used to compare the accuracy of the three methods in distinguishing malignant versus benign lesions and in diagnosing the exact histopathology. Inter-reader agreement for each method was calculated using Fleiss' kappa statistics. RESULTS: The accuracy of the two algorithms and clinical experience were similar (70%, 69%, and 64%, respectively, p = 0.22-0.32), with fair to moderate inter-reader agreement (Fleiss's kappa: r = 0.375, r = 0.308, r = 0.375, respectively, all p < 0.0001). The accuracy of the two algorithms and clinical experience in diagnosing specific histopathology were also no different from each other (34%, 29%, and 32%, respectively, p = 0.49-0.74), with fair to moderate inter-reader agreement (Fleiss's kappa: r = 0.20, r = 0.28, r = 0.375, respectively, all p < 0.0001). CONCLUSION: Semi-quantitative templated algorithms based on MRI features of renal masses did not improve the ability to diagnose T2 iso- and hypointense renal masses when compared to unassisted interpretation by body MR trained subspecialists.

Transforming the Imaging Experience While Decreasing Sedation Rates.

OBJECTIVE: To evaluate the effect of the MRI-am-a-Hero program on sedation utilization for outpatient pediatric MRI studies. METHODS: The MRI-am-a-Hero program, which utilizes multimedia educational material and popular comic book characters to educate and support pediatric patients during MRI scan, was implemented at the radiology facility of a single tertiary care, academic medical center. The effect of the MRI-am-a-Hero program on sedation utilization for pediatric MRI was retrospectively evaluated using multivariate regressions yielding odds ratio of sedation before and after program implementation. The institutional review board approved the study with HIPAA compliancy. Effectiveness of the program was evaluated while controlling for age, neurological MRI examination, number of examinations in the case, and use of intravenous contrast. Further analysis was performed in subgroups categorized by age, neurological MRI versus nonneurological MRI, and the use of contrast. RESULTS: The percent of MRI cases with sedation decreased from 22.9% to 17.3% after the MRI-am-a-Hero program was implemented. When controlling for other variables, including patient age, neurological MRI, number of examinations in a case, and use of intravenous contrast, the odds of a study being performed with sedation after program implementation are 40% less than the odds before program implementation (odds ratio [OR] 0.60, P < .001). The effect of the program was greatest for patients aged 4 to 7 (OR 0.56, P < .001), followed by patients aged 8 to 11 (OR 0.64, P = .019). It was not statistically significant for patients aged 12 to 15 (OR 0.97, P = .919). CONCLUSION: MRI-am-a-Hero is a generalizable and inexpensive program for reducing sedation utilization for outpatient pediatric MRI studies, especially for patients aged 4 to 11.

MRI characterization of early CNS transport kinetics post intrathecal gadolinium injection: Trends of subarachnoid and parenchymal distribution in healthy volunteers.

PURPOSE: To quantify CSF transport kinetics and brain glymphatic distribution using MRI following intrathecal injection of gadolinium contrast in healthy adults. SUBJECTS AND METHODS: Eight completely healthy volunteer subjects underwent intrathecal injection of gadolinium via image guided lumbar puncture and serial MRI's at six subsequent time points up to 11 h post-injection. Rate of enhancement and deposition were calculated for various regions and lobes of the brain. RESULTS: Normalized cranial data revealed that gadolinium in the intracranial CSF spaces peaked within 1-3 h and started to decrease at 7 h. In some regions of the brain parenchyma, such as the cerebral cortex and white matter, enhancement was increasing after 11 h. Differential rates of uptake between the parietal and frontal (p = 0.0003), cingulate (p = 0.002) and temporal (p = 0.018) lobes were shown as well as a several fold change between various cortical regions. Lastly, a linear regression comparing laterality between 35 cortical regions yielded (R2 = 0.90, p < 0.001) with a slope of 1.01 showing symmetry in uptake. CONCLUSIONS: Gadolinium enhancement after lumbar intrathecal injection demonstrated differential CSF flow and brain parenchymal penetration, which illustrated the distributory function of the glymphatic system.

Juvenile granulosa cell tumor associated with Maffucci syndrome in pregnancy: A case report.

Juvenile granulosa cell tumor (JGCT) is an extremely rare ovarian tumor that has been associated with Maffucci syndrome. It both secretes hormone and has been postulated to grow in response to hormone. We present a case of a 33-year-old G1P0 asymptomatic woman with a history of Maffucci syndrome found to have a left adnexal mass on routine ultrasonography at 13 weeks gestation. This case demonstrates the sonographic and magnetic resonance imaging (MRI) features of JGCT, as well as the natural progression of the tumor during pregnancy. A follow-up ultrasound 3 weeks after initial diagnosis demonstrated marked growth in size and vascularity of the tumor, prompting unilateral salpingo-oophorectomy. Histopathological findings confirmed the diagnosis of JGCT.

Cough-induced costal cartilage fracture.

We present two cases of atraumatic costal cartilage fracture secondary to violent coughing. Although costal cartilage fractures due to trauma and bony rib fractures due to violent coughing have been described, to our knowledge there have been no prior reported cases of cough-induced costal cartilage fracture. It is important for radiologists to consider costal cartilage fractures, which are often more subtle than osseous injuries, in patients with chest pain, and understand that they may not always be preceded by direct trauma. Identifying this injury is clinically important and will prevent patients from undergoing unnecessary examinations to rule out a cardiac cause of chest pain or a pulmonary embolism.