胸腰椎爆裂性骨折损伤机制的生物力学研究

目的：探讨胸腰椎爆裂性骨折的损伤机制。方法：采用脊柱活动节段的三维有限元模型分析了脊柱在直立位、前屈位和后伸位的应力分布情况。结果：椎弓根以及椎体后上方与椎弓根相邻部分为应力集中区域。结论：胸腰椎爆裂性骨折的损伤机制与脊柱的应力集中有关。     

Imaging bowel obstruction: a comparison between fast magnetic resonance imaging and helical computed tomography

AIM: To compare the accuracy of fast magnetic resonance (MR) imaging using the half-Fourier single shot turbo spin echo (HASTE) sequence with helical computed tomography (CT) in diagnosing bowel obstruction. MATERIALS AND METHODS: Prospective evaluation of 44 patients with clinical evidence of bowel obstruction was conducted using various investigations including HASTE MR and helical CT. MR was performed with a Siemens 1.5 Tesla MR Imaging System and CT was performed with one of two Siemens ARHP CT systems using helical technique. MR acquisition allowed data to be gathered in 6-10 minutes and no contrast media were administered. CT imaging consisted of consecutive helical CT through the abdomen and pelvis with oral and intravenous contrast medium used when indicated. Bowel dilation along with the presence and level of obstruction were determined. RESULTS: Twenty-eight patients had bowel obstruction confirmed at laparotomy or by radiographic assessment. Of these, 25 had small bowel obstruction and three had colonic obstructions. The obstruction was due to fibrous adhesions in nine patients, metastases or primary carcinoma in seven, Crohn's disease in four, hernias in two, and inflammation or abscess in two. Other causes of obstruction included lymphoma, intussusception and anastomotic stricture. The cause of obstruction was correctly diagnosed by CT in 71%, and by MR in 95% of cases. The sensitivity, specificity and accuracy for HASTE MR imaging was 95%, 100% and 96% respectively as compared to 71%, 71% and 71% for helical CT. CONCLUSION: Fast MR imaging using the HASTE sequence is more accurate than helical CT in diagnosing bowel obstruction.     

Direct findings of aortic injury on contrast-enhanced CT in surgically proven traumatic aortic injury: a multi-centre review

OBJECTIVE: To review the contrast-enhanced CT findings in surgically proven traumatic aortic injury (TAI). MATERIALS AND METHODS: We searched the trauma registries of three academic medical centres from 1994 to 2000 and found 34 patients with surgically proven TAI that received pre-operative contrast-enhanced chest CT. Two chest radiologists recorded by consensus the size and location of direct (pseudoaneurysm, intimal flap) and indirect (mediastinal haematoma) findings of TAI. The imaging findings were correlated with surgical reports. RESULTS: Direct findings of aortic injury (pseudoaneurysm or intimal flap) were seen on contrast enhanced CT in all patients and confirmed at surgery. Specifically, a pseudoaneurysm was seen in 33 (97%), presenting either as a focal bulge in 22 (65%) or as more diffuse aneurysmal enlargement in 11 (32%). An intimal flap was identified in 31 cases (91%). A periaortic haematoma was seen in 31 cases (91%). In the three patients without periaortic haematoma, the only indications of aortic injury were a focal pseudoaneurysm in two (6%) and an intimal flap in one (3%). CONCLUSION: In this series of surgically proven TAI, direct findings of aortic injury were seen in all cases. Aortic tear occurred without mediastinal haematoma in 9% (3/34) of patients.     

Unusual presentation of Bouveret's syndrome

Received: September 8, 2000 / Accepted: April 13, 2001     

An unusual case of herniation of small bowel through an iatrogenic defect of the falciform ligament

Internal herniation through a congenital defect in the falciform ligament is extremely rare. We report an unusual observation of small bowel obstruction through an iatrogenic defect of the falciform ligament. Prompt diagnosis was made by helical CT, permitting a rapid surgical procedure to preserve the viability of the obstructed segment.     

0.5 T MR单激发快速自旋回波在胆系梗阻性病变诊断中的应用

目的评估0.5 T MR单激发半傅立叶采集快速自旋回波胰胆管水成像(HASTE-MRCP)的定位及定性准确性,并与三维快速自旋回波胰胆管水成像(3D-TSE-MRCP)进行比较.方法所有95例病人均行HASTE-MRCP及结合呼吸门控的3D-TSE-MRCP检查及最大信号强度投影(MIP)(设备为Philips 0.5 T T5-NT 磁共振成像系统).分析95例患者的胆管解剖显示情况、病变显示情况并与手术结果比较.结果 HASTE-MRCP胆总管及1～3级胆管的显示率为100.0%,4～5级胆管为94.7%,胆囊为74.1%,胰管为63.2%;结石部位显示100.0%,恶性病变及术后狭窄显示率100.0%.与3D-TSE-MRCP比较,对4～5级胆管、胆囊颈及结石,尤其泥沙样结石的显示率更高,统计学上两者间差异有显著性意义(χ2 值分别为3.92、6.62、11.76 及29.93,P<0.05 或<0.01);对恶性病变及术后狭窄的显示率均为100.0%.结石主要表现为胆道内呈低信号的"充盈缺损";恶性病变则表现为截断及梗阻征象,并可显示软组织轮廓.结论 HASTE-MRCP是优秀的胰胆管超快速成像技术,在0.5 T MR 也能非常好的运用;比较结合呼吸门控的3D-TSE-MRCP ,HASTE-MRCP在重症病人成像或显示小结石及泥沙样结石上有明显优势,建议对急诊、重症及临床疑为结石的病人,首先考虑选择HASTE-MRCP技术.     

Detection of common bile duct stones before laparoscopic cholecystectomy. Evaluation with MR cholangiography

Purpose:
To assess the diagnostic value of MR cholangiography (MRC) for detecting common bile duct (CBD) stones in candidates for laparoscopic cholecystectomy (LC). Material and Methods:
A series of 95 selected patients with gallstones and suspected CBD lithiasis (abnormal serum liver tests and/or CBD size ≥6.5 mm at US) were referred to our institution for MRC, before LC. MRC was performed on a 0.5 T magnet through a non-breath-hold, respiratory-triggered, fat-suppressed, thin-slab, heavily T2-weighted fast spin-echo sequence and through a breath-hold, thick-slab, single-shot T2-weighted sequence in the coronal plane. Axial T1- and T2-weighted sequences were first obtained. Two observers in conference reviewed source images and maximum intensity projections to determine the presence or absence of choledocholithiasis. MR findings were compared with endoscopic retrograde cholangiography and intraoperative cholangiography (IOC); IOC was always performed during LC. Results:
CBD calculi (single or multiple) were identified in 41 out of 95 patients (43%). Two false-positive and 4 false-negative cases were found on MRC. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of MRC for choledocholithiasis were 90%, 96%, 94%, 95%, and 93%, respectively. Conclusion:
MRC is a highly effective diagnostic modality for evaluation of patients with risk factors for CBD stones prior to LC.     

Recurrent gallstone ileus: a case report

Gallstone ileus is a rare complication of recurrent gallstone cholecystitis and usually occurs in elderly female patients. Recurrent gallstone ileus occurs in 5% of patients with a previous episode of gallstone ileus and is associated with a mortality of 20%. We present a 52-year-old female with recurrent gallstone ileus 1 year after her initial episode. Electronic Publication     

The Efficacy of Metallic Stent Placement in the Treatment of Colorectal Obstruction

Objective

To evaluate the efficacy of newly designed covered and non-covered coated colorectal stents for colonic decompression.

Materials and Methods

Twenty-six patients, (15 palliative cases and 11 preoperative) underwent treatment for the relief of colorectal obstruction using metallic stents positioned under fluoroscopic guidance. In 24 of the 26, primary colorectal carcinoma was diagnosed, and in the remaining two, recurrent colorectal carcinoma. Twenty-one patients were randomly selected to receive either a type A or type B stent; for the remaining five, type C was used. Type A, an uncovered nitinol wire stent, was lightly coated to ensure structural integrity. Type B (flare type) and C (shoulder type) stents were polyurethane covered and their diameter was 24 and 26mm, respectively. The rates of technical success, clinical success, and complications were analyzed using the chi-square test, and to analyse the mean period of patency, the Kaplan-Meier method was used.

Results

Thirty of 31 attempted placements in 26 patients were successful, with a technical success rate of 96.8% (30/31) and a clinical success rate of 80.0% (24/30). After clinically successful stent placement, bowel decompression occurred within 1-4 (mean, 1.58 ± 0.9) days. Five of six clinical failures involved stent migration and one stent did not expand after successful placement. In the preoperative group, 11 stents, one of which migrated, were placed in ten patients, in all of whom bowel preparation was successful. In the palliative group, 19 stents were placed in 15 patients. The mean period of patency was 96.25 ± 105.12 days: 146.25 ± 112.93 for type-A, 78.82 ± 112.26 for type-B, and 94.25 ± 84.21 for type-C. Complications associated with this procedure were migration (n=6, 20%), pain (n=4, 13.3%), minor bleeding (n=5, 16.7%), incomplete expansion (n=1, 3.3%), and tumor ingrowth (n=1, 3.3%). The migration rate was significantly higher in the type-B group than in other groups (p=0.038).

Conclusion

Newly designed covered and non-covered metallic stents of a larger diameter are effective for the treatment of colorectal obstruction. The migration rate of covered stents with flaring is higher than that of other types. For evaluation of the ideal stent configuration for the relief of colorectal obstruction, a clinical study involving a larger patient group is warranted.     

A Spanner in the works: the use of a new temporary urethral stent to relieve bladder outflow obstruction after prostate brachytherapy

PURPOSE: Assessment of the Spanner, a new temporary urethral stent to relieve bladder outflow obstruction and urinary symptoms after brachytherapy. METHODS AND MATERIALS: Five patients with unusually severe urinary morbidity after (125)I brachytherapy were recruited. The mean time after implant was 40 days (range 25-90). Spanner intraprostatic stents were introduced using topical anesthetic without complication. RESULTS: All patients were able to void spontaneously with no post-void residual volume of urine. The flow rates increased in all cases (p=0.03) and the International Prostate Symptom Scores were significantly improved after stent insertion in all patients (p=0.03). All patients experienced some degree of pain or dysuria during stent use. CONCLUSIONS: Bladder outflow obstruction was effectively treated with the Spanner intraprostatic stent, however pain limited the use of the device in the early post-brachytherapy patient group. Pharmacotherapy, stent design modification, or smaller stent diameter may increase the utility of stents after brachytherapy.