Computed Tomography-Based Preoperative Simulation System for Pedicle Screw Fixation in Spinal Surgery

Background@#A preoperative planning system facilitates improving surgical outcomes that depend on the experience of the surgeons, thanks to real-time interaction between the system and surgeons. It visualizes intermediate surgical planning results to help surgeons discuss the planning. The purpose of this study was to demonstrate the use of a newly-developed preoperative planning system for surgeons less experienced in pedicle-screw fixation in spinal surgery, especially on patients with anatomical variations. @*Methods@#The marching cubes algorithm, a typical surface extraction technique, was applied to computed tomography (CT) images of vertebrae to enable three-dimensional (3D) reconstruction of a spinal mesh. Real-time processing of such data is difficult, as the surface mesh extracted from high-resolution CT data is rough, and the size of the mesh is large. To mitigate these factors, Laplacian smoothing was applied, followed by application of a quadric error metric-based mesh simplification to reduce the mesh size for the level-of-detail (LOD) image. Taubin smoothing was applied to smooth out the rough surface. On a multiplanar reconstruction (MPR) cross-sectional image or a 3D model view, the insertion position and orientation of the pedicle screw were manipulated using a mouse. The results after insertion were then visualized in each image. @*Results@#The system was used for pre-planning pedicle-screw fixation in spinal surgery. Using any pointing device such as a mouse, surgeons can manipulate the position and angle of the screws. The pedicle screws were easy to manipulate intuitively on the MPR images, and the accuracy of screw fixation was confirmed on a trajectory view and 3D images. After surgery, CT scans were performed again, and the CT images were checked to ensure that the screws were inserted properly. @*Conclusion@#The preoperative planning system allows surgeons and students who are not familiar with pedicle-screw fixation to safely undertake surgery following preoperative planning. It also provides opportunities for screw-fixation training and simulation.

Hepatic Toxocariasis with Atypical CT and MR Imaging Findings: a Case Report

Hepatic toxocariasis is a type of visceral larva migrans caused by the migration of second-stage larvae of certain nematodes such as Toxocara canis to the liver. Histologically, the condition is characterized by granulomatous lesions containing eosinophils and inflammatory cells. We report a case of hepatic toxocariasis with atypical clinical and radiologic findings presenting as distinct, solitary hepatic nodule detected in a middle-aged woman.

Successful Transcatheter Embolization of Spontaneous Splenic Rupture in a Patient with Chronic Myeloid Leukemia / 대한내과학회지

We report a rare case of a patient who presented with pathological splenic rupture as the initial manifestation of chronic myeloid leukemia (CML) and was treated successfully by transcatheter arterial embolization. A 36-year-old man presented to the emergency department with a 1-day history of abdominal pain. Computed tomography showed gross hemoperitoneum with marked splenomegaly, with suspected focal rupture at the lower portion of the spleen and the extravasation of contrast material indicating active bleeding. Given the patient's hemodynamic stability, he was treated with partial splenic embolization by an interventional radiologist, and transfused with red blood cells. Examination of a bone marrow aspiration and biopsy led to a diagnosis of chronic phase CML. He was discharged from the hospital on day 13 post-embolization. Transcatheter arterial embolization should be considered as the initial treatment of spontaneous splenic rupture, especially in patients with hematological malignancies.

The Usefulness of Intensivist-Performed Bedside Drainage of Pleural Effusion via Ultrasound-Guided Pigtail Catheter / 대한구급학회지

BACKGROUND: There has been little data reporting the usefulness of intensivist-performed bedside drainage of pleural effusion via ultrasound (US)-guided pigtail catheter. The objective of this study is to clarify the usefulness and safety of these methods in comparison with radiologist-performed procedures. METHODS: Data of patients with pleural effusion treated with US-guided pigtail catheter drainage were analyzed. All procedures were performed from September 2012 to September. 2013 by a well-trained intensivist or radiologist. RESULTS: Pleural effusion was drained in 25 patients in 33 sessions. A radiologist performed 21 sessions, and an intensivist performed 12 sessions. Procedures during mechanical ventilation were performed in 15 (71.4%) patients by a radiologist and in 10 (83.3%) by an intensivist (p = 0.678). The success rate was not significantly different in radiologist- and intensivist-performed procedures, 95.2% (20/21) and 83.3% (10/12), respectively (p = 0.538). The average duration for procedures (including in-hospital transfer) was longer in radiologist-performed cases (p = 0.001). Although the results are limited because of the small population size, aggravation of oxygenation, CO2 retention, and decrease of mean arterial blood pressure were not statistically different in the groups. Pigtail-associated complications including hemothorax, pneumothorax, hepatic perforation, empyema, kink in the catheter, and subcutaneous hematoma were not found. CONCLUSIONS: Intensivist-performed bedside drainage of pleural effusion via ultrasound (US)-guided pigtail catheter is useful and safe and may be recommended in some patients in an intensive care unit.

Usefulness of Doppler Parameter in Patients with Renal Transplantation

PURPOSE: The purpose of this study is to assess the usefulness of Doppler parameters in transplanted kidney function. MATERIALS AND METHODS: Doppler parameters, including resistive index (RI), pulsatility index (PI), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured in the interlobar artery of 55 transplant recipients. Patients were grouped according to glomerular filtration rate (GFR): Group A (GFR or = 30 ml / min / 1.73 m2, n = 28). Doppler parameters were compared between groups and correlated with the GFR. RESULTS: GFR (40.1 +/- 26.9) showed a significant negative correlation with RI (0.69 +/- .08) (p = .002, r = -.414). RI (0.72 vs. 0.67), PI (1.42 vs. 1.23), and EDV (10.5 vs. 15.3) differed significantly between groups (p < .05), however, PSV was not (36.9 vs. 47.1). Patients in group A (n = 11) with a lower RI than the mean had significantly lower PSV (31.7 vs. 45.1; p = .027) and EDV (11.1 vs. 16.7; p = .017), compared with such patients in group B (n = 21). CONCLUSIONS: Doppler parameters are useful for evaluation of function of transplanted kidney. Even if the RI is normal, PSV and EDV may be used as hemodynamic indicators.

Ultrasonography-guided Transthoracic Cutting Biopsy of Pulmonary Lesion: Diagnostic Benefits and Safety

PURPOSE: To assess the safety and usefulness of ultrasonography-guided transthoracic cutting biopsy for lung lesions. MATERIALS AND METHODS: Eighty-eight patients (66 men, 22 women, mean age 59 years) with lung lesions underwent an ultrasonography(USG)-guided transthoracic cutting biopsy. The final diagnosis was based on the findings of surgery and clinical and radiological follow-ups. The histopathologic results and diagnostic accuracy of cutting biopsy were determined. Also, the complication rate was statistically evaluated according to the mass size, number of biopsies, and the presence or absence of pleural effusion. RESULTS: Biopsy specimens were successfully obtained in all patients. 79 of 88 lesions (89.8%) were established by histopathology. The final diagnosis was malignant in 58 and benign in 28. The remaining 2 patients were lost to follow-up. Diagnostic sensitivity for malignant lesions was 89.6% (52/58) and that for benign lesions was 96.4% (27/28). Procedure-related complications occurred in 9 patients (10.2%) including pneumothorax (n = 2) and hemoptysis (n = 7). And there was no significant difference according to mass size, number of biopsies, or presence of pleural effusion. CONCLUSION: USG-guided transthoracic cutting biopsy is a useful and safe method for technically-feasible lung lesions.

Intrahepatic Portosystemic Venous Shunt: Successful Embolization Using the Amplatzer Vascular Plug II

A 67-year-old woman presented with memory impairment and behavioral changes. Brain MRI indicated hepatic encephalopathy. Abdominal CT scans revealed an intrahepatic portosystemic venous shunt that consisted of two shunt tracts to the aneurysmal sac that communicated directly with the right hepatic vein. The large tract was successfully occluded by embolization using the newly available AMPLATZERTM Vascular Plug II and the small tract was occluded by using coils. The patient's symptoms disappeared after shunt closure and she remained free of recurrence at the 3-month follow-up evaluation.

Comparison of Internally Cooled Wet Electrode and Hepatic Vascular Inflow Occlusion Method for Hepatic Radiofrequency Ablation

BACKGROUND/AIMS: Various strategies to expand the ablation zone have been attempted using hepatic radiofrequency ablation (RFA). The optimal strategy, however, is unknown. We compared hepatic RFA with an internally cooled wet (ICW) electrode and vascular inflow occlusion. METHODS: Eight dogs were assigned to one of three groups: only RFA using an internally cooled electrode (group A), RFA using an ICW electrode (group B), and RFA using an internally cooled electrode with the Pringle maneuver (group C). The ablation zone diameters were measured on the gross specimens, and the volume of the ablation zone was calculated. RESULTS: The ablation zone volume was greatest in group B (1.82+/-1.23 cm3), followed by group C (1.22+/-0.47 cm3), and then group A (0.48+/-0.33 cm3). The volumes for group B were significantly larger than the volumes for group A (p=0.030). There was no significant difference in the volumes between groups A and C (p=0.079) and between groups B and C (p=0.827). CONCLUSIONS: Both the usage of an ICW electrode and hepatic vascular occlusion effectively expanded the ablation zone. The use of an ICW electrode induced a larger ablation zone with easy handling compared with using hepatic vascular occlusion, although this difference was not statistically significant.

Iatrogenic Left Internal Mammary Artery to Great Cardiac Vein Anastomosis Treated With Coil Embolization

Inadvertent left internal mammary artery (LIMA)-great cardiac vein (GCV) anastomosis is a rare complication of coronary artery bypass graft surgery. Patients with iatrogenic aortocoronary fistula (ACF) were usually treated surgical repair, percutaneous embolic occlusion with coil or balloon. We report a case of iatrogenic LIMA to GCV anastomosis successfully treated with coil embolization and protected left main coronary intervention through the percutaneous transfemoral approach.

Iatrogenic Left Internal Mammary Artery to Great Cardiac Vein Anastomosis Treated With Coil Embolization

Inadvertent left internal mammary artery (LIMA)-great cardiac vein (GCV) anastomosis is a rare complication of coronary artery bypass graft surgery. Patients with iatrogenic aortocoronary fistula (ACF) were usually treated surgical repair, percutaneous embolic occlusion with coil or balloon. We report a case of iatrogenic LIMA to GCV anastomosis successfully treated with coil embolization and protected left main coronary intervention through the percutaneous transfemoral approach.

Incidental Detection of Interstitial Pregnancy on CT Imaging

Ectopic pregnancy is a potentially life-threatening condition. Detection of ectopic pregnancy on CT images is rare. In this case, we describe the CT findings of interstitial pregnancy both before and after rupture. If CT images demonstrate the presence of a strong enhancing ring-like mass in the pelvis, ectopic pregnancy should be considered.

The placement of an Implantable Chemoport via the External Jugular Vein as a Primary Route

PURPOSE: To evaluate the usefulness and safety of the placement of an implantable chemoport via external jugular vein as a primary route for chemotherapy. MATERIALS AND METHODS: Between January 2006 and June 2007, a total of 108 implantable chemoports were placed on 325 patients for chemotherapy via the external jugular vein as a primary route. We placed a 9.6 F single lumen chemoport using a surgical procedure (n=89) and an interventional procedure (n=19), and evaluated the duration of catheterization days and treatment complications. RESULTS: An implantable chemoport was successfully installed in all cases. Furthermore, the duration of catheterization ranged from 2 to 461 days (mean: 187 days, total catheter days: 21,994). In addition, a total of 85 chemoports were removed due to complications (n=7) and termination of chemotherapy (n=78). A transient pulmonary air embolism occurring during a procedure was observed in one case. No pneumothorax or catheter malpositions were observed in the study subjects. Two chemoports were removed two days after implantation due to persistent tachycardia. In addition, five late complications occurred, which resulted in catheter occlusion (3 cases) (3%, 0.14/1000 catheter day) and infection in (2 cases) (2%, 0.09/1000 Catheter days). Lastly, no symptoms were attributed to a central vein thrombosis. CONCLUSION: The results of this study suggest that the implantation of chemoports via the external jugular vein is a safe procedure. Moreover, the selection of the external jugular vein as a primary route is useful in determining chemoport insertion locations.

Salvage Therapy for a Dysfunctional Arteriovenous Fistula for Hemodialysis

PURPOSE: Salvage procedures for a dysfunctional arteriovenous fistula (AVF) are defined as operation or percutaneous balloon angioplasty (PTA) for the AVF is inadequate for performing hemodialysis. This retrospective study was performed in order to identify the appropriate salvage treatment modality. METHODS: From April 2001 to October 2007, 132 salvage procedures in 100 patients were performed. We analyzed the overall cumulative patency rates of both the procedures and we compared them according to the type of primary AVF and the site and distribution of the stenoses. RESULTS: Fifty eight patients underwent operation, and 74 patients underwent PTA. The initial success rate was 77.59% for operation and 83.78% for PTA. The one year cumulative patency rates of operation and PTA were 46.11% and 21.62%, respectively (P=0.00). For the patients whose AVF had been created using autogenous vein, the one year cumulative patency rates of operation and PTA were 49.72% and 21.15%, respectively (P=0.04). According to the location and distribution of the stenoses, 56 patients (64.4%) with an autogenous AVF had juxta-anastomotic lesion. Among them, 23 patients underwent operation and 33 patients underwent PTA. The 1 year cumulative patency rates for these patients were 66.63% and 12.12%, respectively (P=0.00). For the treatment of the diffuse and multiple stenoses of the autogenous vein, PTA (n=14) showed a better patency rate than that of operation (P=0.00). CONCLUSION: Salvage therapy for a dysfunctional fistula prolonged their life span. Operation was superior to PTA for a juxta-anastomotic lesion of an autogenous AVF, but PTA had benefit over operation for the cases with diffuse and multiple stenoses.

Development of a World Wide Web-based Interactive Education Program to Improve Detectability of Pulmonary Nodules on Chest Radiographs

PURPOSE: To design and develop a World Wide Web-based education program that will allow trainees to interactively learn and improve the diagnostic capability of detecting pulmonary nodules on chest radiographs. MATERIALS AND METHODS: Chest radiographs with known diagnosis were retrieved and selected from our institutional clinical archives. A database was constructed by sorting radiographs into three groups: normal, nodule, and false positive (i.e., nodule-like focal opacity). Each nodule was assigned with the degree of detectability: easy, intermediate, difficult, and likely missed. Nodules were characterized by their morphology (well-defined, ill-defined, irregular, faint) and by other associated pathologies or potentially obscuring structures. The Web site was organized into four sections: study, test, record and information. RESULTS: The Web site allowed a user interactively to undergo the training section appropriate to the user's diagnostic capability. The training was enhanced by means of clinical and other pertinent radiological findings included in the database. The outcome of the training was tested with clinical test radiographs that presented nodules or false positives with varying diagnostic difficulties. CONCLUSION: A Word Wide Web-based education program is a promising technique that would allow trainees to interactively learn and improve the diagnostic capability of detecting and characterizing pulmonary nodules.

MR Imaging Findings of the Pituitary Gland in Patients with Transfusional Hemochromatosis: Two Case Reports

Hemochromatosis is a disorder caused by excessive iron deposition in parenchymal cells that leads to cellular damage and organ dysfunction. The excessive iron overload of secondary hemochromatosis is associated with chronic disorders of erythropoiesis that are treated with prolonged repeated blood transfusions. We experienced two cases of transfusional hemochromatosis involving the pituitary gland, and we report the findings of the MR imaging.

CT Findings of the Osteoma of the External Auditory Canal

PURPOSE: We wanted to report the CT image findings of the osteoma of the external auditory canal. MATERIALS AND METHODS: Temporal bone CT scanning was performed on eight patients (4 males and 4 females aged between 8 and 41 years) with pathologically proven osteoma of the external auditory canal after operation, and the findings of the CT scanning were retrospectively reviewed. Not only did we analyze the size, shape, distribution and location of the osteomas, we also analyzed the relationship between the lesion and the tympanosqumaous or tympanomastoid suture line, and the changes seen on the CT scan images for the patients who were able to undergo follow-up. RESULTS: All the lesions of the osteoma of the external auditory canal were unilateral, solitary, pedunculated bony masses. In five patients, the osteomas occurred on the left side and for the other three patients, the osteomas occurred on the right side. The average size of the osteoma was 0.6 cm with the smallest being 0.5 cm and the largest being 1.2 cm. Each of the lesions was located at the osteochondral junction in the terminal part of the osseous external ear canal. The stalk of the osteoma of the external auditory canal was found to have occurred in the anteroinferior wall in five cases (63%), in the anterosuperior wall (the tympanosqumaous suture line) in two cases (25%), and in the anterior wall in one case. The osteoma of the external auditory canal was a compact form in five cases and it was a cancellous form in three cases. One case of the cancellous form was changed into a compact form 35 months later due to the advanced ossification. CONCLUSION: Osteoma of the external auditory canal developed in a unilateral and solitary fashion. The characteristic image findings show that it is attached to the external auditory canal by its stalk. Unlike our common knowledge about its occurrence, osteoma mostly occurred in the tympanic wall, and this is regardless of the tympanosquamous or tympanomastoid suture line.

Normal Appendix in Adults: MDCT Findings about the Location, Thickness and the Presence or Absence of Intraluminal Gas

PURPOSE: We wanted to examine the usefulness of multi-detector CT (MDCT) with multiplanar reformations for evaluating the location, thickness and the presence or absence of intraluminal gas in the normal appendix of adults. MATERIALS AND METHODS: From December 2004 to June 2005, we evaluated normal appendices in 427 consecutive adult patients who were scanned with 16-slice MDCT. All these patients had no clinical findings of appendicitis. There were 251 men and 176 women. The age range was 19-84 years (mean age: 55 years). The contrast-enhanced MDCT scans during the portal phase were obtained with 0.75 mm detector collimation and they were reviewed with using the multiplanar reconstruction images (3 mm section thickness). The MDCT images of normal appendices on a PACS monitor were retrospectively analyzed. We analyzed the location, thickness and the presence or absence of intraluminal gas by consensus of two abdominal radiologists. The positions of normal appendices were classified as type I (postileal and medial paracecal), type II (subcecal), type III (retrocecal and retrocolic or laterocolic), type IV (preileal and medial colic) and type V (lower pelvic cavity). RESULTS: The five types of appendiceal locations were as follows; type I (n=187; 44%), type II (n=78; 18 %), type III (n=92; 22%), type IV (n=39; 9%) and type V (n=31; 7%). The appendiceal tips in 29 cases (7%) were unusually located in the right subhepatic space, the small bowel mesentery and the right adnexa. The mean thickness of 427 appendices was 5.8+/-0.9 mm (range: 3.8-9.2 mm). The appendiceal mean thickness was 5.9+/-0.9 mm in men and 5.7+/-0.9 mm in women (p < 0.05). 384 (90%) of 427 appendices had intraluminal gas and 43 (10%) had no intraluminal gas, and their mean thickness was 5.9 mm (range: 3.8-9.2 mm) and 5.3 mm (3.8-7.3 mm), respectively (p < 0.05). CONCLUSION: MDCT with multiplanar reformations was useful for evaluating the location, thickness and the presence or absence of intraluminal gas in normal appendix of adults. These MDCT findings may be helpful in diagnosing equivocal appendicitis or appendicitis with unusual location.

An Arteriovenous Malformation in the Suprapatellar Fat Pad of the Knee associated with Klippel-Trenaunay-Weber Syndrome: A Case Report

Klippel-Trenaunay-Weber syndrome (KTWS) is a vascular disorder that has significant arteriovenous malformation (AVM). We report a case of an AVM in the suprapatellar fat pad of the knee in a patient with the characteristic manifestations of KTWS, including cutaneous hemangioma, limb hypertrophy, and varicose veins. Magnetic resonance imaging, color Doppler sonography, and subsequent angiography demonstrated an AVM in the supra-patellar fat pad of the right knee causing painful swelling of the knee.

An Experience with Placement of a Stent-Graft in a Renal Artery Aneurysm via the Brachial Artery: A Case Report

We introduce here our case of a 4-cm, large saccular aneurysm in a patient with right flank pain that was treated by placement of a stent-graft via the left brachial artery. The large renal artery aneurysm was successfully occluded without any permanent sequela, although there were several complications that included intraprocedural renal arterial thrombosis, occlusion of the posterior segmental artery, a small thromboembolism in the left pons and a small arteriovenous fistula in the brachial artery. Stent-graft placement for treatment of renal arterial aneurysm is an effective and safe procedure, but the operator has to be cautious not to induce complications in case of using the brachial arterial approach.

A Case of Renovascular Hypertension Controlled by Renal Artery Embolization / 소아과

Renal artery stenosis is a major cause of renovascular hypertension and the most common cause of treatable secondary hypertension. There are several methods to treat renal artery stenosis, including surgery, percutaneous transluminal renal angioplasty(PTRA), and renal artery stenting(RAS). But, renal artery embolization can be tried in atherosclerotic stenosis, multiple stenosis, microaneurysm, and stenosis difficult to try PTRA or RAS. We report a case of renovascular hypertension in a 14-year-old female who had multiple segmental renal artery stenosis. Hypertension was controlled by renal ablation therapy with renal artery embolization.