Automatic needle tracking using Mask R-CNN for MRI-guided percutaneous interventions.

PURPOSE: Accurate needle tracking provides essential information for MRI-guided percutaneous interventions. Passive needle tracking using MR images is challenged by variations of the needle-induced signal void feature in different situations. This work aimed to develop an automatic needle tracking algorithm for MRI-guided interventions based on the Mask Region Proposal-Based Convolutional Neural Network (R-CNN). METHODS: Mask R-CNN was adapted and trained to segment the needle feature using 250 intra-procedural images from 85 MRI-guided prostate biopsy cases and 180 real-time images from MRI-guided needle insertion in ex vivo tissue. The segmentation masks were passed into the needle feature localization algorithm to extract the needle feature tip location and axis orientation. The proposed algorithm was tested using 208 intra-procedural images from 40 MRI-guided prostate biopsy cases, and 3 real-time MRI datasets in ex vivo tissue. The algorithm results were compared with human-annotated references. RESULTS: In prostate datasets, the proposed algorithm achieved needle feature tip localization error with median Euclidean distance (dxy) of 0.71 mm and median difference in axis orientation angle (dθ) of 1.28°, respectively. In 3 real-time MRI datasets, the proposed algorithm achieved consistent dynamic needle feature tracking performance with processing time of 75 ms/image: (a) median dxy = 0.90 mm, median dθ = 1.53°; (b) median dxy = 1.31 mm, median dθ = 1.9°; (c) median dxy = 1.09 mm, median dθ = 0.91°. CONCLUSIONS: The proposed algorithm using Mask R-CNN can accurately track the needle feature tip and axis on MR images from in vivo intra-procedural prostate biopsy cases and ex vivo real-time MRI experiments with a range of different conditions. The algorithm achieved pixel-level tracking accuracy in real time and has potential to assist MRI-guided percutaneous interventions.

Bending percutaneous drainage catheters to facilitate CT-guided insertion using curved trocar technique.

PURPOSE: To assess the safety and efficacy of placing thoraco-abdominal drainage catheters under CT-guidance using a curved trocar technique. METHODS: A retrospective study of 182 CT/CT-fluoroscopy-guided thoraco-abdominal catheter drainages was conducted; half were performed by residents or fellows under the supervision of one radiologist (Group 1) and the other half under the supervision of 10 other radiologists (Group 2). Group 1 procedures employed a curved catheter assembly placed using trocar technique (n = 44) or straight catheters placed with Seldinger technique (n = 47). Group 2 procedures employed a straight catheter placed using trocar technique (n = 16) or straight catheters placed with Seldinger technique (n = 75). Technical success, procedure time, radiation dose (CT Dose Index CTDIvol), and adverse events (Common Terminology Criteria for Adverse Events, 4.0) were compared between techniques and groups using Student's t test, Fisher's exact test or Chi-square analysis. RESULTS: All procedures in groups 1 and 2 were technically successful. Mean procedure time for Group 1 curved trocar technique (28 ± 8 min) was shorter than groups 1 and 2 Seldinger technique (37 ± 11 min, p = .00002). Mean CTDIvol for Group 1 curved trocar technique (107.8 ± 54.2 mGy) was lower than groups 1 and 2 Seldinger technique (136.1 ± 99.7 mGy, p = 0.032). Adverse event rates for curved trocar, straight trocar, and Seldinger techniques were 2.3% (1/44), 0% (0/16), and 3.3% (4/122), respectively (p = 1); all were grade 1 or 2, and no catheter malfunctions occurred. CONCLUSIONS: The curved catheter trocar technique is a safe and effective modification of the standard trocar technique that may facilitate CT-guided procedures impeded by CT gantry size limitations.

Self-embedding behavior: a new primary care challenge.

OBJECTIVE: The goal of this study was to define self-embedding behavior (SEB), develop a clinical profile of adolescents who engage in SEB, and emphasize the importance of rapid, targeted, and effective identification and intervention. METHODS: As part of a retrospective study with a database evaluating 600 patients percutaneously treated for soft-tissue foreign body removal, adolescents were identified with self-embedded soft-tissue foreign bodies. We describe patients' gender, age, and psychiatric diagnoses; SEB age of onset, frequency, and self-reported reasons; and the number, type, location of, and removal technique for objects. RESULTS: Eleven patients (9 females) who engaged in SEB were identified. Ten of the 11 patients were members of a group home or psychiatric facility at the time they engaged in SEB. All patients had previous and multiple psychiatric diagnoses. SEB mean age-of-onset was 16 years, and mean number of SEB episodes per patient was 1.9. The most common self-reported purpose for SEB was suicidal ideation (6 of 8 [75%]) versus nonsuicidal ideation (2 of 8 [25%]), with 3 cases lacking this documentation. The mean number of objects embedded in a single episode was 2.4, usually composed of metal and embedded in the arm. Seventy-six foreign bodies were percutaneously removed (using ultrasound or fluoroscopic guidance), including metal, glass, wood, plastic, graphite, and crayon. CONCLUSIONS: SEB is an extreme form of self-injury requiring aggressive and timely interdisciplinary assessment and treatment. An understanding of SEB allows medical professionals to pursue rapid, targeted, and effective intervention to interrupt the cycle of self-harm and institute appropriate long-term therapy.

Self-embedding behavior: radiologic management of self-inserted soft-tissue foreign bodies.

PURPOSE: To report on a series of self-embedding behavior (SEB), demonstrate the effectiveness and clinical effect of image-guided foreign body removal (IGFBR) in the treatment of embedded soft-tissue foreign bodies (STFBs), and evaluate the role of the radiologist in the clinical management of SEB. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. From a database of 600 patients treated with IGFBR with ultrasonographic (US) and/or fluoroscopic guidance, self-injury was identified in 11 (1.8%) mainly adolescent patients with a mean age of 16 years (age range, 14-18 years). Evaluated data included number of foreign bodies; number of repeat episodes of foreign body insertion; location, type, and size of foreign body; incision size; imaging modality; and success or failure of foreign body removal. RESULTS: Seventy-six foreign bodies were inserted into the arm (n = 69), neck (n = 4), ankle (n = 1), foot (n = 1), or hand (n = 1) in the 11 patients. The number of STFBs per case ranged from one to 15. Foreign body types included metal (n = 40), plastic (n = 15), graphite (n = 12), glass (n = 4), wood (n = 3), crayon (n = 1), and stone (n = 1). STFB dimensions were 2.5-160.0 mm in length by 0.25-3.0 mm in thickness. Sixty-eight of the 76 STFBs were removed in the interventional radiology section. Incision lengths ranged from 4 to 8 mm (mean, 6 mm). The STFBs were removed with US guidance (n = 43), fluoroscopic guidance (n = 15), or a combination of the two modalities (n = 10). IGFBR was successful in all 68 cases, without complications. CONCLUSION: Greater awareness of SEB may result in radiologists being the first physicians to identify SEB and rapidly mobilize an interdisciplinary team for early and effective intervention and treatment. Percutaneous radiologic treatment of self-imbedded STFBs is safe, precise, and effective for radiopaque and nonradiopaque foreign bodies.

Catheter-based drainage and agitation for definitive cytological diagnosis of a ciliated hepatic foregut cyst in a child.

Ciliated hepatic foregut cyst (CHFC) is an uncommon lesion, which rarely presents in the pediatric population. It is congenital in origin and manifests because of the migration of a bronchiolar bud of the foregut through the pleuroperitoneal canal. CHFC is accompanied by a broad list of differential diagnoses and is difficult to diagnose by means of radiologic evaluation. Therefore, fine-needle aspiration with cytology has been used in an attempt to diagnose this lesion. In previously reported cases, this approach has been moderately successful in the diagnosis of CHFC, while in others, no definitive diagnosis was achieved because of the retrieval of scattered, irregular cells insufficient for cytologic evaluation. We report a case of a 16-year-old girl who presented with a CHFC and discuss a promising alternative for obtaining large, intact cellular specimens to facilitate cytologic evaluation and definitive diagnosis.

Pulmonary hyalinizing granuloma and retroperitoneal fibrosis in an adolescent.

We describe a 15-year-old boy who developed pulmonary hyalinizing granuloma (PHG) and retroperitoneal fibrosis (RPF). His PHG and RPF were not associated with histoplasmosis or tuberculosis and appeared to represent idiopathic autoimmune phenomena. This is the first reported case of PHG in a pediatric patient and the fourth reported co-occurrence of PHG and RPF. The use of F-18 fluorodeoxyglucose positron emission tomography in the diagnostic and follow-up evaluation of PHG is reported.