Lack of Progression of Intraventricular Hemorrhage in Premature Infants: Implications for Head Ultrasound Screening.

Very preterm infants are at risk for germinal matrix hemorrhage- intraventricular hemorrhage (GH-IVH). Severe GH-IVH may cause death or severe neurodevelopmental disability while mild GH-IVH is considered a static, non-progressive disease. This retrospective study aimed to determine if infants with no GH-IVH or mild GH-IVH on initial screening head ultrasound (HUS) advanced to severe GH-IVH. A total of 353 eligible infants with birth gestational age ≤32 0/7 weeks who received a HUS during hospitalization were identified. Of the 343 (97%) infants who had mild GH-IVH (grade II or less) on initial screening, only 4 (1.2%) progressed to severe (grade III or IV). Each of these infants required mechanical ventilation for at least 40 days. Therefore, premature infants who have no GH-IVH or mild GH-IVH on initial routine screening HUS without other risk factors may not require follow-up HUSs. Infants with prolonged mechanical ventilation may require further screening despite reassuring initial HUS findings.

Still Coming Out of the Dark: Enduring Effects of Simulation-Based Communication Skills Training for Radiology Residents-Four-Year Follow-Up.

PURPOSE: To evaluate the long-term efficacy of simulation-based communication skills training for radiology residents. METHOD AND MATERIALS: The simulation-based communication skills training curriculum was developed in 2014. The curriculum included a teaching module based on the essential elements of communication. Two sets of 6 communication scenarios encountered by radiologist were created. First and fourth year radiology residents reviewed the teaching module and completed the 6 simulated scenarios. They then underwent debriefing sessions, received faculty and staff evaluations. Four years later, the former first year residents (now fourth years) reviewed the teaching module again and repeated the simulation. They again underwent debriefing sessions after the simulation. This time the residents' communication skills were evaluated by faculty and staff. RESULTS: A total of 5 residents participated in this simulation-based skills training. The resident performance 4 years after initial training show not only that residents maintained their improved scores, but also that their scores improved further as compared to after the initial training. The average overall score for all but 1 resident increased at the 4 year follow-up simulation. From 2014 to 2018, the average score of all the residents increased from 72.4% to 81.4%. Comparison of the average scores of each student across 6 stations from 2014 to 2018 showed a statistically significant difference between the scores after 4 years (P = 0.014). CONCLUSIONS: Simulation-based communication skills training is effective and long lasting.

Pediatric Elbow Injuries.

Elbow trauma in children is one of the most commonly encountered musculoskeletal injuries in pediatric radiology. However, elbow injuries in children can be misdiagnosed due to secondary ossification centers unique to pediatric patients. Familiarity of the normal elbow anatomy in children is crucial for an accurate diagnosis. This article seeks to improve diagnostic accuracy of these elbow injuries by reviewing the secondary ossification centers in the elbow in the pediatric population, followed by a discussion of commonly encountered acute and chronic fractures, dislocations or other injuries. While many elbow injuries are diagnosed with radiographs, there are situations where imaging with computed tomography, ultrasonography, and magnetic resonance imaging are essential in the diagnosis of these injuries.

Evaluation of the utility of 99m Tc-MDP bone scintigraphy versus MIBG scintigraphy and cross-sectional imaging for staging patients with neuroblastoma.

PURPOSE: Accurate staging of neuroblastoma requires multiple imaging examinations. The purpose of this study was to determine the relative contribution of 99m Tc-methylene diphosphonate (MDP) bone scintigraphy (bone scan) versus metaiodobenzylguanidine scintigraphy (MIBG scan) for accurate staging of neuroblastoma. METHODS: A medical record search by the identified patients with neuroblastoma from 1993 to 2012 who underwent both MIBG and bone scan for disease staging. Cross-sectional imaging was used to corroborate the scintigraphy results. Clinical records were used to correlate imaging findings with clinical staging and patient management. RESULTS: One hundred thirty-two patients underwent both MIBG and bone scan for diagnosis. All stage 1 (n = 12), 2 (n = 8), and 4S (n = 4) patients had a normal bone scan with no skeletal MIBG uptake. Six of 30 stage 3 patients had false (+) bone scans. In the 78 stage 4 patients, 58/78 (74%) were both skeletal MIBG(+)/bone scan (+). In 56 of the 58 cases, skeletal involvement detected with MIBG was equal to or greater than that detected by bone scan. Only 3/78 had (-) skeletal MIBG uptake and (+) bone scans; all 3 had other sites of metastatic disease. Five of 78 had (+) skeletal MIBG with a (-) bone scan, while 12/78 had no skeletal involvement by either MIBG or bone scan. In no case did a positive bone scan alone determine a stage 4 designation. CONCLUSION: In the staging of neuroblastoma, 99m Tc-MDP bone scintigraphy does not identify unique sites of disease that affect disease stage or clinical management, and in the majority of cases bone scans can be omitted from the routine neuroblastoma staging algorithm.

Graphic representation of clinical symptoms: a tool for improving detection of subtle fractures on foot radiographs.

OBJECTIVE: The purpose of this study was to assess changes in accuracy, degree of confidence, and evaluation time in radiography of subtle foot fractures when the text history is supplemented by a graphic indicating the site of pain. MATERIALS AND METHODS: Radiographs from 226 foot examinations (three views), including 126 examinations showing one subtle fracture (< 1-mm displacement) and 100 examinations with normal findings were selected. In the first interpretation session, only a text history was given for 112 examinations, and both text and a graphic indicating the site of pain for 114 examinations. Six months later, a graphic and text history were provided for the 112 cases interpreted without a graphic in the first session, and only text was provided for the other 114 cases. Seven radiologists evaluated the study sets. Sensitivity, specificity, degree of confidence (1-10 scale), and mean interpretation time in seconds were calculated. RESULTS: Use of a graphic increased overall sensitivity for any subtle fracture from 67% to 73% (p < 0.001), increased degree of confidence from 8.1 without a graphic to 8.4 with a graphic (p < 0.0001), and decreased the time for interpretation by 6%, from 53 seconds without a graphic to 50 seconds with a graphic (p = 0.006). Specificity changed from 93% without a graphic to 94% with a graphic (p = 0.33). Fractures of the third metatarsal were missed most frequently (74%); this percentage improved to 61% with use of a graphic. CONCLUSION: A graphic complements the text history by improving sensitivity, degree of confidence, and time for interpretation.

The radiographic appearance of split Blake drains: what you see is not necessarily what you get.

BACKGROUND: Two types of Blake chest drains are used by our cardiac surgeons for management of their patients after thoracic surgery. The drain can be longitudinally split by the surgeon resulting in a limb of the drain in each thoracic cavity. A split flat Blake drain has two radiopaque limbs and a split round Blake drain has a radiopaque limb and a less radiopaque limb. OBJECTIVE: To describe the radiographic appearance of these drains and promote their accurate radiologic identification and description. MATERIALS AND METHODS: We conducted a retrospective review of the ability of our radiologists to correctly identify the radiographic appearance of the two devices. We identified 48 cases; 30 contained two radiopaque limbs and 18 had a radiopaque and a less radiopaque limb. RESULTS: In 25 of the 30 (83%) cases the configuration of two radiopaque limbs was correctly identified; however, in 0 of 18 (0%) cases was the configuration of a radiopaque and a less radiopaque limb correctly identified. CONCLUSION: By improving awareness of different Blake drain configurations and appearances this study aims to promote proper identification, accurate reporting, and reduced cognitive errors arising from Blake drain misidentification.

Orbital Emphysema Following Ocular Trauma and Sneezing.

Orbital emphysema is typically a benign condition that occurs following forceful injection of air into the orbital soft tissue spaces. In many cases there is a history of trauma and fracture of an orbital bone, which permits air entry. However, other mechanisms of orbital emphysema have been reported including infection, pulmonary barotrauma, injury from compressed-air hoses, and complications from surgery including dental procedures. Here, we describe a report of a teenager who suffered an isolated medial orbital wall fracture while playing basketball, and several hours later developed orbital emphysema acutely after sneezing. We will review the radiological evaluation of orbital fractures and emphysema.

Critical functions of N-glycans in L-selectin-mediated lymphocyte homing and recruitment.

Lymphocyte homing is mediated by specific interaction between L-selectin on lymphocytes and the carbohydrate ligand 6-sulfo sialyl Lewis X on high endothelial venules. Here we generated mice lacking both core 1 extension and core 2 branching enzymes to assess the functions of O-glycan-borne L-selectin ligands in vivo. Mutant mice maintained robust lymphocyte homing, yet they lacked O-glycan L-selectin ligands. Biochemical analyses identified a class of N-glycans bearing the 6-sulfo sialyl Lewis X L-selectin ligand in high endothelial venules. These N-glycans supported the binding of L-selectin to high endothelial venules in vitro and contributed in vivo to O-glycan-independent lymphocyte homing in wild-type and mutant mice. Our results demonstrate the critical function of N-glycan-linked 6-sulfo sialyl Lewis X in L-selectin-dependent lymphocyte homing and recruitment.

Fever-range thermal stress promotes lymphocyte trafficking across high endothelial venules via an interleukin 6 trans-signaling mechanism.

Fever is an evolutionarily conserved response during acute inflammation, although its physiological benefit is poorly understood. Here we show thermal stress in the range of fever temperatures increased the intravascular display of two 'gatekeeper' homing molecules, intercellular adhesion molecule 1 (ICAM-1) and CCL21 chemokine, exclusively in high endothelial venules (HEVs) that are chief portals for the entry of blood-borne lymphocytes into lymphoid organs. Enhanced endothelial expression of ICAM-1 and CCL21 was linked to increased lymphocyte trafficking across HEVs. A bifurcation in the mechanisms controlling HEV adhesion was demonstrated by evidence that the thermal induction of ICAM-1 but not of CCL21 involved an interleukin 6 trans-signaling pathway. Our findings identify the 'HEV axis' as a thermally sensitive alert system that heightens immune surveillance during inflammation by amplifying lymphocyte trafficking to lymphoid organs.

A major class of L-selectin ligands is eliminated in mice deficient in two sulfotransferases expressed in high endothelial venules.

The interaction of L-selectin on lymphocytes with sulfated ligands on high endothelial venules leads to rolling and is critical for recruitment of lymphocytes into peripheral lymph nodes. Peripheral node addressin represents a class of L-selectin ligands recognized by the function-blocking monoclonal antibody MECA-79. Its epitope overlaps with sialyl 6-sulfo Lewis X, an L-selectin recognition determinant. Here, mice lacking two N-acetylglucosamine-6-O-sulfotransferases (GlcNAc6ST-1 and GlcNAc6ST-2) demonstrated elimination of both peripheral node addressin and sialyl 6-sulfo Lewis X in high endothelial venules, considerably reduced lymphocyte homing to peripheral lymph nodes and reduced sticking of lymphocytes along high endothelial venules. Our results establish an essential function for the sulfotransferases in L-selectin ligand synthesis and may have relevance for therapy of inflammatory diseases.

The S1P-analog FTY720 differentially modulates T-cell homing via HEV: T-cell-expressed S1P1 amplifies integrin activation in peripheral lymph nodes but not in Peyer patches.

Sphingosine-1-phosphate (S1P) and its receptor S1P1 control T-cell egress from thymus and secondary lymphoid organs (SLOs). To further define the role of S1P1 in lymphocyte trafficking, we performed adoptive transfer experiments and intravital microscopy (IVM) using both S1P1-/- lymphocytes and recipient wild-type (WT) mice treated with FTY720, an immunosuppressant that downmodulates S1P receptors. S1P1 deficiency and FTY720 caused rapid disappearance of T cells from blood, prolonged retention in SLOs, and accumulation in bone marrow, but did not alter interstitial T-cell motility in peripheral lymph nodes (PLNs) as assessed by multiphoton IVM. However, S1P1-/- lymphocytes displayed reduced short-term homing to PLNs due to attenuated integrin-mediated firm arrest in high endothelial venules (HEVs). By contrast, S1P1-/- T cells homed normally to Peyer patches (PPs), whereas S1P1-/- B cells had a marked defect in homing to PPs and arrested poorly in PP HEVs. Therefore, S1P1 not only controls lymphocyte egress from SLOs, but also facilitates in a tissue- and subset-specific fashion integrin activation during homing. Interestingly, FTY720 treatment enhanced accumulation of both S1P1 sufficient and S1P1-/- T cells in PPs by enhancing integrin-mediated arrest in HEVs. Thus, FTY720 exerts unique effects on T-cell traffic in PPs that are independent of T-cell-expressed S1P1.

Lymphocyte arrest requires instantaneous induction of an extended LFA-1 conformation mediated by endothelium-bound chemokines.

It is widely believed that rolling lymphocytes require successive chemokine-induced signaling for lymphocyte function-associated antigen 1 (LFA-1) to achieve a threshold avidity that will mediate lymphocyte arrest. Using an in vivo model of lymphocyte arrest, we show here that LFA-1-mediated arrest of lymphocytes rolling on high endothelial venules bearing LFA-1 ligands and chemokines was abrupt. In vitro flow chamber models showed that endothelium-presented but not soluble chemokines triggered instantaneous extension of bent LFA-1 in the absence of LFA-1 ligand engagement. To support lymphocyte adhesion, this extended LFA-1 conformation required immediate activation by its ligand, intercellular adhesion molecule 1. These data show that chemokine-triggered lymphocyte adhesiveness involves a previously unrecognized extension step that primes LFA-1 for ligand binding and firm adhesion.

Core 2 branching beta1,6-N-acetylglucosaminyltransferase and high endothelial cell N-acetylglucosamine-6-sulfotransferase exert differential control over B- and T-lymphocyte homing to peripheral lymph nodes.

Blood-borne lymphocyte trafficking to peripheral lymph nodes (PLNs) depends on the successful initiation of rolling interactions mediated by L-selectin binding to sialomucin ligands in high endothelial venules (HEVs). Biochemical analysis of purified L-selectin ligands has identified posttranslational modifications mediated by Core2GlcNAcT-I and high endothelial cell GlcNAc-6-sulfotransferase (HECGlcNAc6ST). Consequently, lymphocyte migration to PLNs of C2GlcNAcT-I(-/-) and HEC-GlcNAc6ST(-/-) mice was reduced; however, B-cell homing was more severely compromised than T-cell migration. Accordingly, intravital microscopy (IVM) of PLN HEVs revealed a defect in B-cell tethering and increased rolling velocity (V(roll)) in C2GlcNAcT-I(-/-) mice that was more pronounced than it was for T cells. By contrast, B- and T-cell tethering was normal in HEC-GlcNAc6ST(-/-) HEVs, but V(roll) was accelerated, especially for B cells. The increased sensitivity of B cells to glycan deficiencies was caused by lower expression levels of L-selectin; L-selectin(+/-) T cells expressing L-selectin levels equivalent to those of B cells exhibited intravascular behavior similar to that of B cells. These results demonstrate distinct functions for C2GlcNAcT-I and HEC-GlcNAc6ST in the differential elaboration of HEV glycoproteins that set a threshold for the amount of L-selectin needed for lymphocyte homing.

Lymphocyte-HEV interactions in lymph nodes of a sulfotransferase-deficient mouse.

The interaction of L-selectin expressed on lymphocytes with sulfated sialomucin ligands such as CD34 and GlyCAM-1 on high endothelial venules (HEV) of lymph nodes results in lymphocyte rolling and is essential for lymphocyte recruitment. HEC-GlcNAc6ST-deficient mice lack an HEV-restricted sulfotransferase with selectivity for the C-6 position of N-acetylglucosamine (GlcNAc). HEC-GlcNAc6ST-/- animals exhibit faster lymphocyte rolling and reduced lymphocyte sticking in HEV, accounting for the diminished lymphocyte homing. Isolated CD34 and GlyCAM-1 from HEC-GlcNAc6ST-/- animals incorporate approximately 70% less sulfate than ligands from wild-type animals. Furthermore, these ligands exhibit a comparable reduction of the epitope recognized by MECA79, a function-blocking antibody that reacts with L-selectin ligands in a GlcNAc-6-sulfate-dependent manner. Whereas MECA79 dramatically inhibits lymphocyte rolling and homing to lymph nodes in wild-type mice, it has no effect on HEC-GlcNAc6ST-/- mice. In contrast, in vitro rolling on purified GlyCAM-1 from HEC-GlcNAc6ST-/- mice, although greatly diminished compared with that on the wild-type ligand, is inhibited by MECA79. Our results demonstrate that HEC-GlcNAc6ST contributes predominantly, but not exclusively, to the sulfation of HEV ligands for L-selectin and that alternative, non-MECA79-reactive ligands are present in the absence of HEC-GlcNAc6ST.