Diagnosis of intrahepatic stones: superiority of MR cholangiopancreatography over endoscopic retrograde cholangiopancreatography

OBJECTIVE: The purpose of this study was to compare the efficacy of MR cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) for the diagnosis of intrahepatic stones. MATERIALS AND METHODS: Of the 318 patients who underwent MRCP examinations at our institution during an 18-month period, we identified 49 patients who subsequently underwent surgery or cholangioscopic stone removal with proof of intrahepatic stones. Thirty-four of these patients also underwent ERCP; they made up our study population. All images were interpreted for the presence of bile duct stones: MRCP images were interpreted independently by two reviewers, and ERCP studies were interpreted by one reviewer who was unaware of the MRCP findings. RESULTS: The sensitivity and specificity of MRCP for detecting intrahepatic stones were 97% and 93%, respectively, whereas those of ERCP were 59% and 97%, respectively. MRCP showed a significantly higher sensitivity than ERCP in the diagnosis of intrahepatic stones (p < 0.001). We found no significant difference between MRCP and ERCP in sensitivity or specificity for detecting calculi in the common duct or gallbladder. CONCLUSION: MRCP is a more effective diagnostic method than ERCP for the evaluation of intrahepatic stones.     

Intracranial and Spinal Ependymomas: Review of MR Images in 61 Patients

Objective

To compare the age distribution and characteristic MR imaging findings of ependymoma for each typical location within the neuraxis.

Materials and Methods

During a recent eleven-year period, MR images of 61 patients with histologically proven ependymomas were obtained and retrospectively reviewed in terms of incidence, peak age, location, size, signal intensity, the presence or absence of cyst and hemorrhage, enhancement pattern, and other associated findings.

Results

Among the 61 patients, tumor location was spinal in 35 (57%), infrartentorial in 19 (31%), and supratentorial in seven (12%). In four of these seven, the tumor was located in brain parenchyma, and in most cases developed between the third and fifth decade. Approximately half of the infratentorial tumors occurred during the first decade. The signal intensity of ependymomas was non-specific, regardless of their location. A cystic component was seen in 71% (5/7) of supratentorial, 74% (14/19) of infratentorial, and 14% (5/35) of spinal cord tumors. Forty-nine percent (17/35) of those in the spinal cord were associated with rostral and/or caudal reactive cysts. Intratumoral hemorrhage occurred in 57% (4/7) of supratentorial, 32% (6/19) of infratentorial, and 9% (3/35) of spinal cord tumors. In 17% (6/35) of spinal ependymomas, a curvilinear low T2 signal, suggesting marginal hemorrhage, was seen at the upper and/or lower margins of the tumors. Peritumoral edema occurred in 57% (4/7) of supratentorial, 16% (3/19) of infratentorial and 23% (8/35) of spinal cord tumors. Seventy-two percent (5/7) of supratentorial and 95% (18/19) of infratentorial tumors showed heterogeneous enhancement, while in 50% (17/34) of spinal cord tumors, enhancement was homogeneous.

Conclusion

Even though the MR imaging findings of ependymomas vary and are nonspecific, awareness of these findings, and of tumor distribution according to age, is helpful and increases the likelihood of correct preoperative clinical diagnosis.     

Conjoined lumbar nerve roots: a frequently underappreciated congenital abnormality

Nerve root anomalies are frequently underrecognized on advanced imaging studies and may account for some percentage of failed spinal surgical procedures. The conjoined nerve root represents the most common nerve root anomaly. It is a well-known cause of false-positive readings for bulging and herniated disks in patients with purely axial neuroimaging studies. A retrospective evaluation of consecutive microsurgical lumbar diskectomies in 80 patients during a 5-year period was undertaken. A total of four patients (5%) were found intraoperatively to have evidence of a conjoined nerve root by the classification of Neidre. None was diagnosed preoperatively. Coronal magnetic resonance imaging offers the best means of visualizing a conjoined nerve root. The chance for a successful operation can be significantly enhanced if the surgeon is prepared to encounter this pathology.     

Presence of Vesicoureteral Reflux in the Graft Kidney Does Not Adversely Affect Long-Term Graft Outcome in Kidney Transplant Recipients

Introduction

We studied the incidence of vesicoureteral reflux (VUR) in the graft kidney and its effect on the occurrence of urinary tract infection (UTI) and long-term graft function.

Methods

We performed a retrospective analysis of 64 adult kidney transplant recipients based upon voiding cystourethrography at 12 months post-transplantation. Patients underwent analysis of survival, incidence of UTIs beyond 1 year, and graft function.

Results

Thirty-seven male and 27 female patients in the study populations showed a mean age 42 years. VUR in the transplanted kidney at 12 months post-transplant occurred among 78.1% (50/64) of subjects: grade I (n = 6), grade II (n = 30), or grade III (n = 14) reflux. Patients followed for a median 61 months (range 44–74s) showed 11 cases of UTIs in 9 subjects. There were no significant differences in clinical characteristics or incidence of, UTIs according to the presence or severity of VUR (P = .81) or the Serum creatinine and estimated glomerular filtration rate values at 12, 36, 48, or 60 months post-transplantation.

Conclusions

VUR present in 78.1% of patients after kidney transplantation affected neither graft functions or graft survival. The incidence of UTI did not differ according to the presence of VUR.     

Injury of the corticobulbar tract in patients with dysarthria following cerebral infarct: diffusion tensor tractography study

Objectives: Little is known about injury of the corticobulbar tract (CBT) in stroke patients. We attempted to investigate injury of the CBT in patients with dysarthria following cerebral infarct, using diffusion tensor tractography (DTT). Methods: Eight patients with dysarthria following a corona radiata infarct and 12 control subjects were recruited for this study. Diffusion tensor imaging was performed at 14.3 days after onset and reconstruction of the CBT was performed using the probabilistic tractography method. Fractional anisotropy, mean diffusivity, and tract volume of the CBT were measured. Results: Reconstructed CBTs in the affected hemisphere of the patient group were thinner than those of the unaffected hemisphere of the patient group and the control group. Regarding the DTT parameters of the CBTs, fractional anisotropy and tract volume were significantly lower in the affected hemisphere of the patient group than in the unaffected hemisphere of the patient group and the control group (p < 0.05). However, we did not observe any difference in the mean diffusivity value (p > 0.05). Conclusions: We demonstrated injury of the CBT in patients with dysarthria following cerebral infarct in the corona radiata using DTT. This result indicates the importance of CBT evaluation for dysarthria in patients with cerebral infarct. Therefore, we suggest that evaluations of the CBT using DTT would be useful for patients with dysarthria following cerebral infarct.     

Evaluation of radial and ulnar blood flow after radial artery cannulation with 20- and 22-gauge cannulae using duplex Doppler ultrasound

This study evaluated ulnar and radial artery blood flow after radial artery cannulation during general anaesthesia using Doppler ultrasound. A total of 80 patients were randomly assigned to receive radial artery cannulation with either a 20‐G or 22‐G cannula. Arterial diameter, peak systolic velocity, end‐diastolic velocity, resistance index and mean volume flow were measured at four time points in both arteries: before anaesthesia; 5 min after intubation; immediately after cannulation; and 5 min after cannulation. After radial artery cannulation, ulnar diameters and blood flow were significantly increased, and persisted until 5 min after cannulation. Radial blood flow was decreased immediately after cannulation and recovered to pre‐cannulation values 5 min after cannulation. There were no statistical differences between groups at each time point. Radial artery cannulation causes compensatory increase in ulnar artery blood flow, and the difference in cannula size has minimal effect on this change.     

Utility of tibial tubercle osteotomy in the setting of periprosthetic infection after total knee arthroplasty

Purpose

This study reports radiographic and clinical treatment outcomes of tibial tubercle osteotomy (TTO) used for two-stage revision total knee arthroplasty (TKA) in the setting of periprosthetic infection.

Methods

Thirty-six patients with 51 TTOs used for infected TKA were retrospectively analysed from 2000 to 2010. In 15 of 36 patients, TTO was used in a sequential manner during both first and second stage procedures. The mean follow-up period was 57?months (range seven–126?months).

Results

The mean pre-operative range of knee motion was 40° (range 10–90°), and at latest follow-up it was 92° (range 50–140°). The Knee Society knee scores and function scores were 47 and 9 pre-operatively and 82 and 72 at latest follow-up, respectively. Bony union was achieved in all cases except one nonunion of an avulsion fragment of the osteotomy segment without functional deterioration.

Conclusions

TTO can be a useful extensile surgical approach for treatment of infected TKA with satisfactory clinical and radiographic outcomes.     

Misexpression of Dickkopf-1 in endothelial cells, but not in chondrocytes or hypertrophic chondrocytes, causes defects in endochondral ossification

Developing cartilage serves as a template for long-bone development during endochondral ossification. Although the coupling of cartilage and bone development with angiogenesis is an important regulatory step for endochondral ossification, the molecular mechanisms are poorly understood. One possible mechanism involves the action of Dickkopf (DKK), which is a family of soluble canonical Wnt antagonists with four members (DKK1-4). We initially observed opposite expression patterns of Dkk1 and Dkk2 during angiogenesis and chondrocyte differentiation: downregulation of Dkk1 and upregulation of Dkk2. We examined the in vivo role of Dkk1 and Dkk2 in linking cartilage/bone development and angiogenesis by generating transgenic (TG) mice that specifically express Dkk1 or Dkk2 in chondrocytes, hypertrophic chondrocytes, or endothelial cells. Despite specific expression pattern during cartilage development, chondrocyte- and hypertrophic chondrocyte-specific Dkk1 and Dkk2 TG mice showed normal developmental phenotypes. However, Dkk1 misexpression in endothelial cells resulted in defects of endochondral ossification and reduced skeletal size. The defects are caused by the inhibition of angiogenesis in developing bone and subsequent inhibition of apoptosis of hypertrophic chondrocytes and cartilage resorption.     

Opinions on the Preclinical Evaluation of Novel Therapies for Spinal Cord Injury: A Comparison between Researchers and Spinal Cord-Injured Individuals

Abstract We previously conducted a survey to gather the opinions and perspectives of scientific and clinical researchers on what levels of preclinical evidence were needed to justify translating a promising neuroprotective or neuroregenerative therapy in spinal cord injury (SCI) into a human clinical trial (Kwon et al., 2010 ). Here we conducted an analogous survey of individuals living with SCI in which we gathered their expectations for the levels of preclinical evidence achieved by researchers in substantiating the neuroprotective and neuroregenerative therapies being offered to them in clinical trials. In total, 214 individuals with SCI completed the survey, and their responses were compared to the responses of the 235 scientists and clinicians who completed our previous survey. SCI individuals were more likely than SCI researchers to opine that demonstrating efficacy and safety in rodent models of SCI alone is sufficient to proceed with clinical trials. However, SCI individuals also reported strong support for large animal and primate model studies, and in the case of the latter, were actually more in agreement for the need for primate studies than researchers. SCI individuals also reported strong support for independent replication studies. In general, individuals with SCI had high expectations for the levels of preclinical evidence required to justify translating novel therapies into clinical trials. These expectations should be considered in the decisions to translate specific experimental therapies for SCI.