Incidence and underreporting of osseous wrist and hand injuries on whole-body computed tomographies at a level 1 trauma center.

BACKGROUND: To investigate the incidence of osseous wrist and hand injuries on whole-body computed tomographies (WBCT) at an urban maximum-care trauma center, to report the number of missed cases in primary radiology reports, and to develop an algorithm for improved detection of these injuries. METHODS: Retrospective analysis reviewing all WBCT for a period of 8 months for osseous wrist and hand injuries. (1) Reconstruction of hands/wrists in three planes (thickness 1-2 mm) and analysis by a blinded musculoskeletal radiologist. (2) Scanning of primary radiology reports and comparison to the re-evaluation. (3) Calculation of the diagnostic accuracy of WBCT during primary reporting. (4) Search for factors potentially influencing the incidence (trauma mechanism, associated injuries, Glasgow Coma Scale, artifacts). (5) Development of an algorithm to improve the detection rate. RESULTS: Five hundred six WBCT were included between 01/2020 and 08/2020. 59 (11.7%) WBCT showed 92 osseous wrist or hand injuries. Distal intra-articular radius fractures occurred most frequently (n = 24, 26.1%); 22 patients (37.3%) showed multiple injuries. The sensitivity of WBCT in the detection of wrist and hand fractures during primary evaluation was low with 4 positive cases identified correctly (6.8%; 95% CI 1.9 to 16.5), while the specificity was 100% (95% CI 99.2 to 100.0). Forty-three cases (72.9%) were detected on additional imaging after clinical reassessment. Twelve injuries remained undetected (20.3%). Motorcycle accidents were more common in positive cases (22.0% vs. 10.1%, p = 0.006). 98% of positive cases showed additional fractures of the upper and/or lower extremities, whereas 37% of the patients without osseous wrist and hand injuries suffered such fractures (p < 0.001). The remaining investigated factors did not seem to influence the occurrence. CONCLUSION: Osseous wrist and hand injuries are present in 11.7% on WBCT after polytrauma. 93.2% of injuries were missed primarily, resulting in a very low sensitivity of WBCT during primary reporting. Motorcycle accidents might predispose for these injuries, and they often cause additional fractures of the extremities. Clinical re-evaluation of patients and secondary re-evaluation of WBCT with preparation of dedicated multiplanar reformations are essential in polytrauma cases to detect osseous injuries of wrist and hand reliably. TRIAL REGISTRATION: The study was registered prospectively on November 17th, 2020, at the German register for clinical trials (DRKS-ID: DRKS00023589 ).

Electrophysiological detection of electrode fold-over in perimodiolar cochlear implant electrode arrays: a multi-center study case series.

PURPOSE: It is important for the surgeon to determine the position of the CI electrode array during and after its placement within the cochlea. Most preferably, this should be within the scala tympani to obtain the best audiological outcome. Thus, misplacement into the scala vestibuli or tip fold-over should be prevented. Since there are different ways to ensure proper positioning of the electrode array within the scala tympani (e.g., intraoperative radiography, electrophysiological recordings), our study was aimed at detecting intraoperative electrophysiologic characteristics to better understand the mechanisms of those electrode tip fold-overs. MATERIAL AND METHODS: In a multi-centric, retrospective case-control series, patients with a postoperatively by radiography detected tip fold-over in perimodiolar electrodes were included. The point of fold-over (i.e., the electrode position) was determined and the intraoperative Auto-NRT recordings were analysed and evaluated. RESULTS: Four patients were found to have an electrode tip fold-over (out of 85 implantees). Significant changes of the Auto-NRT recordings were not detected. All tip fold-overs occurred in the most apical part of the electrodes. DISCUSSION: Cochlear implantation for hearing impaired patients plays a decisive role in modern auditory rehabilitation. Perimodiolar electrode arrays may fold over during the insertion and, hence, could have a negative impact on audiological outcome. Characteristic electrophysiologic changes to possibly predict this were not found in our series.

Superselective angiography of the wrist in patients with Kienböck's disease.

BACKGROUND: Microvascular problems like increased intraosseous pressure or venous congestion may influence the development of Kienböck's disease. We examined if wrist position modifies the blood flow in the nutrient vessels. METHODS: Retrospective analysis of 17 patients with Kienböck's disease who had a superselective microangiography of the radial, ulnar and interosseous artery in different wrist positions under general anaesthesia. We analysed the data with Fisher's exact and Wilcoxon-test. RESULTS: We found vessels that entered the bone, that ended at the bone edge, and that supplied a vascular plexus. The origins were the anterior interosseous artery in 10 of 17 cases, the radial artery in seven cases, and the ulnar artery in five cases. Movement of the wrist could reduce or stop the blood flow. Type of lunate configuration showed no significant influence on the blood supply in neutral position. CONCLUSION: The radial, ulnar, and anterior interosseous artery contribute to the vascular supply of the lunate bone in different combinations. Wrist movement can reduce blood flow to the lunate bone.

In vivo experiences with magnetic resonance imaging scans in Vibrant Soundbridge type 503 implantees.

OBJECTIVE: To observe the effects of magnetic resonance imaging scans in Vibrant Soundbridge 503 implantees at 1.5T in vivo. METHODS: In a prospective case study of five Vibrant Soundbridge 503 implantees, 1.5T magnetic resonance imaging scans were performed with and without a headband. The degree of pain was evaluated using a visual analogue scale. Scan-related pure tone audiogram and audio processor fitting changes were assessed. RESULTS: In all patients, magnetic resonance imaging scans were performed without any degree of pain or change in pure tone audiogram or audio processor fitting, even without a headband. CONCLUSION: In this series, 1.5T magnetic resonance imaging scans were performed with the Vibrant Soundbridge 503 without complications. Limitations persist in terms of magnetic artefacts.

MRI-Based Estimation of Scalar Cochlear-Implant Electrode Position.

The position of the cochlear-implant electrode is important to audiological outcomes after cochlear implantation. The common technique to evaluate the intracochlear electrode's position involves the use of ionized radiation in MSCT, DVT, or flat-panel tomography (FPT). Recent advances in knowledge regarding the handling of MRI artifacts in cochlear implantees indicate that estimating the intracochlear electrode's position with an MRI could be possible. This study's aim was to evaluate the ipsilaterally position of electrodes using MRI at 1.5 T. In a retrospective study of 10 implantees with postoperative need for MRI scanning, we evaluated the intrascalar electrode's position using a T2-weighted sequence at 1.5 T. We compared the resulting estimate of the intracochlear position with the estimates from the postoperative FPT scan and the intraoperative NRT ratio. For each ear, the MRI-estimated scalar position corresponded with the estimated positions from the FPT and NRT ratio. For eight ears, a scala tympani's position was observed in the MRI. In one case, an electrode scalar translocation was found. In one case, the scala vestibuli's position was observed. Thus, MRI-based estimation of the scalar position of a cochlear-implant electrode is possible. Limitations to this method include implant-specific magnet and fixation configurations, which can cause complications.

Postoperative imaging of the internal auditory canal : Visualization of active auditory implants.

BACKGROUND: Assessment of the internal auditory canal (IAC) and cochlea is of central importance in neurotology. The artefacts and visibility of active auditory implants on magnetic resonance imaging (MRI) vary because of their specific magnetic components. Knowledge of the size of MRI artefacts and the options for handling them is important for the auditory rehabilitation of specific diseases (e. g., vestibular schwannoma). METHODS: The current article is a literature review. RESULTS: MRI assessment of the IAC and cochlea after surgical placement of an active auditory implant is feasible only with a percutaneous bone-anchored hearing aid (BAHA, Ponto). When specific factors (implant position and MRI sequence) are taken into consideration, these structures can be visualized even after cochlear implantation. Complications such as magnet dislocation and pain may occur. CONCLUSION: The possibility of assessing the IAC and cochlea by MRI is an important aspect that needs to be taken into consideration when planning the auditory rehabilitation of patients after acoustic neuroma surgery.

[Postoperative imaging of the internal auditory canal : Visualization of active auditory implants. German version]. / Postoperative Bildgebung des inneren Gehörgangs : Darstellung aktiver auditorischer Implantate.

BACKGROUND: Assessment of the internal auditory canal (IAC) and the cochlea is of central importance in neurotology. The artefacts and visibility of the different types of active auditory implants in MRI vary, due to their specific ferromagnetic components. Knowledge of the size of MRI artefacts and the options for handling these is important for the auditory rehabilitation of specific diseases (e. g., vestibular schwannoma). METHODS: The current paper is a literature review RESULTS: MRI assessment of the IAC and cochlea after surgical placement of an active auditory implant is feasible only with a percutaneous bone-anchored hearing aid (BAHA, Ponto). When specific factors (implant position and MRI sequence) are taken into consideration, these structures can be visualized even after cochlear implantation. Complications such as magnet dislocation and pain may occur. CONCLUSION: The possibility of assessing the IAC and cochlea by MRI is an important aspect that needs to be taken into consideration when planning the auditory rehabilitation of patients after acoustic neuroma surgery.

[Diagnosis of the scaphoid bone : Fractures, nonunion, circulation, perfusion]. / Diagnostik des Skaphoids : Fraktur, Pseudarthrose, Durchblutung, Perfusion.

The clinical relevance of scaphoid bone fractures is reflected by their high incidence, accounting for approximately 60 % among carpal fractures and for 2-3 % of all fractures. With adequate therapy most scaphoid bone fractures heal completely without complications. Insufficient immobilization or undiagnosed fractures increase the risk of nonunion and the development of pseudarthrosis.X-ray examination enables initial diagnosis of scaphoid fracture in 70-80 % of cases. Positive clinical symptoms by negative x­ray results require further diagnostics by multi-slice spiral CT (MSCT) or MRI to exclude or confirm a fracture. In addition to the diagnosis and description of fractures MSCT is helpful for determining the stage of nonunion. Contrast enhanced MRI is the best method to assess the vitality of scaphoid fragments.

Electrophysiological detection of scalar changing perimodiolar cochlear electrode arrays: a long term follow-up study.

The position of the cochlear electrode array within the scala tympani is essential for an optimal hearing benefit. An intraoperative NRT-ratio was established, which can provide information about the intraoperative intracochlear electrode array position for perimodiolar electrodes. The aims of this study were to verify the longterm reliability for the NRT-ratio in perimodiolar electrodes. In a retrospective controlled study in a Tertiary Referral Center the electrophysiological data sets of 123 patients with implanted Nucleus Contour Advance electrodes were enclosed. Intraoperative and up to 1 year follow-up Auto-NRTs were evaluated. A NRT-ratio was calculated by dividing the average Auto-NRT data from electrode 16 to 18 with the average from electrode 5 to 7. Using a flat panel tomography system, the position of the electrode array was certified radiological. 31 patients with perimodiolar electrodes with 1 year follow-up data were included in the study. Eleven patients showed regular follow-up NRT-ratio with a correlated and radiologically confirmed electrode position. 20 patients showed mismatches between the NRT-ratio and the radiological position. These patients were highly variable in terms of duration of deafness and neural spectrum disorders. The NRT-ratio can be used to determine the intracochlear position of the electrode array for perimodiolar electrodes. Intraoperatively the NRT-ratio predicts the array position within the cochlea highly reliable for perimodiolar electrodes. We showed that after 6 months and a year, the NRT-ratio remains unchanged in most of the cases and shows a good correlation to the radiological determined position of the array. Nevertheless, the condition of the neural structures is highly important for reproducible responses. Limited validity is given in patients with degenerative and structural neural disorders.

[Obligation to operate splenic injuries in polytrauma patients using MS-CT criteria]. / Operationspflichtigkeit von Milzverletzungen bei Polytraumapatienten nach MSCT-Kriterien.

PURPOSE: The aim of this study is to evaluate the validity of multi-slice computed tomography (MS-CT) in predicting the need to operate on spleen injuries in polytrauma patients using selected grading systems; the Thompson screening test (TST) and the extended TST (ETST). PATIENTS AND METHODS: A retrospective evaluation of 2791 patients who presented spleen injuries in polytrauma MS-CTs in the period between 12/2002 and 06/2010 was undertaken. On the basis of CT morphology, and by using the above mentioned grading systems, the probability of the need to operate on a splenic injury was defined. RESULTS: From a sample of 2791 patients, an MS-CT polytrauma scan was used to identify 139 splenic injuries. In correlation with the actual interventions carried out on the spleen, the applied grading systems showed sensitivities of 91 % (TST) and 69 % (ETST) as well as specificities of 78 % (TST) and 93 % (ETST). Regarding interventions on a splenic injury, positive predictive values were 57 % (TST) and 76 % (ETST), and the accordant negative predictive values were 96 % (TST) and 91 % (ETST). Thereby we ascertained significantly lower results than Thompson et al. CONCLUSION: The applied grading systems based on the findings of MS-CT do not reliably predict the need to operate on spleen injuries in polytrauma patients.

Minimally invasive spinal surgery using nucleoplasty and the Dekompressor tool: a comparison of two methods in a one year follow-up.

OBJECT: The Disc Dekompressor and Nucleoplasty are 2 different, minimally invasive, percutaneous methods in the therapy for chronic discogenic low back pain. The aim of this study is to compare the effectiveness of both methods concerning the outcome one year after surgery. METHODS: We included patients with MRI-proven disc protrusion suffering from low back pain and/or radiating pain in the lower extremities. The pain perception of the patients was documented using the visual analogue pain scale (VAS). Furthermore, the patients were queried about analgesic consumption, disability in daily life and ability to work. Percutaneous minimally invasive nucleotomy using the Nucleoplasty or the Disc Dekompressor was carried out under fluoroscopic and CT-guidance. We carried out a follow-up examination at 6 and 12 months after the operation. RESULTS: From April 2005 to November 2007 a total of 126 patients underwent percutaneous minimally invasive nucleotomy using Nucleoplasty (April 2005 - December 2006) or the Disk Dekompressor (February 2006 - November 2007) and were followed up after 6 and 12 months. In the Nucleoplasty group the mean age of the 27 females (39%) and 42 males (61%) was 42 years (range: 18-74). In the Disc Dekompressor group the mean age of the 22 females (39%) and 35 males (61%) was 44 years (range: 16-76). The mean duration of symptoms in the Nucleoplasty group was 30.5 months (range: 1-120), and in the Disc Dekompressor group 16.3 months (range: 1-72). Statistically significant postoperative improvement concerning the VAS score was evident in both groups. Whereas the VAS score slightly increased in the Nucleoplasty group comparing the early postoperative score and the score after 12 months, the VAS score stayed on a low level in the Disc Dekompressor group. A statistically significant reduction in analgesic consumption, disability and occupational incapacitation was observed in the Nuceloplasty group and the Disc Dekompressor group. CONCLUSIONS: Both Nucleoplasty and Disc Dekompressor are effective therapies for chronic, discogenic back pain. Regardless of the different mechanism no significant differences in the outcomes were found. Both techniques result in significant reductions in levels of disability and incapacity for work as well as decreased analgesic consumption.

The role of cerebrospinal fluid flow study using phase contrast MR imaging in diagnosing idiopathic normal pressure hydrocephalus.

BACKGROUND: The purpose of this prospective study was to identify the ability of cerebrospinal fluid flow study using phase contrast MR imaging to replace the invasive methods currently used to establish the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). MATERIALS AND METHODS: Between January 2003 and April 2005, 61 patients with clinical symptoms fitting the Hakim triad and a dilated ventricular system on CT underwent a intrathecal infusion test and cerebrospinal tap test. All patients also had a phase contrast MRI to determine the CSF flow rate in the aqueduct. Shunted patients were followed postoperatively up to 12 months. The pre- and postoperative symptomatic condition was evaluated using the clinical Kiefer score. The outcome was calculated by the NPH Recovery Rate. FINDINGS: Patients were classified into 41 with iNPH and 20 patients with brain atrophy. Thirty-nine iNPH patients were shunted and two patients refused surgery. The mean Kiefer score of the shunted patients was statistically significantly lower after surgery. In patients screened for clinical symptoms and ventriculomegaly on CT imaging, an aqueduct-CSF flow rate greater than 24.5 ml/min was found to be statistically specific for a diagnosis of iNPH. CONCLUSIONS: The measurement of the CSF flow rate in the aqueduct by using the phase contrast MRI technique is a highly specific pre-selective method for diagnosing iNPH.

[Renal transplant: color duplex ultrasound and contrast-enhanced ultrasound in the evaluation of the early postoperative phase and surgical complications]. / Die Transplantatniere: Farbkodierte Duplex-Sonographie und kontrastmittelverstärkte Sonographie in der Beurteilung nephrologischer und chirurgischer Komplikationen.

Contrast ultrasound is a promising and straightforward method that is superior to established sonographic techniques such as conventional B-mode scanning which is used for volume measurement and hematoma demonstration. Color Doppler is important for the evaluation of rejection, the detection of perfusion defects, and complete vascularization in the diagnostic evaluation of kidney grafts. Moreover, contrast US has the potential for tumor characterization in transplanted kidneys. A single examination by contrast ultrasound can answer a variety of questions with respect to the early postoperative phase and chronic damage. New applications of contrast US will arise from the further technical development of ultrasound equipment. The rapid technical advances seen in recent years have been followed by the introduction of new software tools for the analysis of raw datasets or the improved visualization of microbubbles at very low energy. Initial studies show that efficient and early diagnosis of rejection is possible. Surgical complications like perfusion defects or hematoma can also be identified.

Neurotological and neuroanatomical changes in the connexin-26-related HID/KID syndrome.

The phenotype of the HID (hystrix-like ichthyosis, deafness)/KID (keratitis, ichthyosis, deafness) syndrome is primarily characterized by skin changes. However, the connexin 26 (Cx 26) autosomal dominant mutation underlying this syndrome is of special neurotological interest. In the present paper, the clinical pattern, audiovestibular and neuroimaging findings and the detailed genetic analysis of 4 patients with identical HID/KID-associated mutation D50N of Cx 26 are reported. The audiological test results demonstrated profound sensorineural hearing loss in all of the patients. Neurotological testing revealed inconsistent abnormalities in dynamic posturography (sensory organization test), but the vestibular ocular reflex upon caloric irrigation was normal in all patients. Vestibular-evoked myogenic potential testing for otolith function (saccule) showed a regular response in 1 patient and pathologic responses in 3 patients, while subjective haptic vertical (utricular function) testing was normal in all of the patients. CCT showed an extended (in length), but very thin (in diameter) bony lining between the basal portion of the internal auditory canal and the vestibule in the 3 scanned patients. Our study provides evidence for functionally intact semicircular canals and normal utricular function in subjects with the autosomal dominant D50N mutation of Cx 26, in contrast to saccular function which was generally compromised and hearing loss which was profound.

[The clinical use of the ISO-C(3D) imaging system in calcaneus fracture surgery]. / Die klinische Wertigkeit des ISO-C(3D) bei der Osteosynthese des Fersenbeins.

We compared in a prospective study including 82 patients treated with ORIF of an intraarticular calcaneus fracture the quality of fluoroscopy, intraoperatively Iso-C(3D) and postoperative CT-scans. Therefore the posterior facet of the calcaneus (PFOC) was divided into three sectors. Joint steps and fracture gaps were detected by two independent investigators and statistically analysed. Another focus was to evaluate if the findings due to intraoperatively Iso-C(3D) assessment performed by the surgeon were correct and subsequently influenced the surgical procedure. There were no statistically differences between the Iso-C(3D)- and CT findings concerning joint steps or fracture gaps in PFOC sectors I-III. With fluoroscopy an assessment of the PFOC sectors I and II was not possible. In six cases (7.3%), intraoperative reduction was redone after performing an Iso-C(3D) scan. In ten cases, 12 malpositioned screws were replaced (12.2%/14.6%). These results suggest that intraoperative 3D Iso-C(3D) imaging provides a high diagnostic reliability. By careful assessment of the images the surgeons receive information which could lead to a change of the operative strategy.

[Diagnosis of lunotriquetral instability]. / Diagnostik der lunotriquetralen Instabilität.

BACKGROUND: Lunotriquetral dissociation with rupture of the lunotriquetral ligament and the radiolunotriquetral and the radiodorsal ligament is usually recognized late. Cinematography, arthrography, magnetic resonance imaging and arthroscopy are the diagnostic procedures. Treatment includes nonoperative methods in the case of incomplete lesions but also closed reposition with temporary LT arthrodesis and open ligament repair. In many cases, definitive LT arthrodesis may become necessary. It is the aim to develop a diagnostic algorithm on the base of retrospective analysed data. MATERIAL AND METHODS: From January 1998 to July 2003, 97 cinematographies of the wrist were performed, 22 with the question for a dynamic or static VISI deformity as a sign for lunotriquetral instability. This group of patients was analysed retrospectively to evaluate the diagnostic reliability. Based on these datas, a diagnostical algorithm was established for prospective investigations. RESULTS: The combination of cinematography, arthrography and magnetic resonance imaging suspected lunotriquetral instability in ten cases so that an arthroscopy was arranged. This way LT-lesions were verified in nine cases. The mean interval between accident and first contact with our institution was five months. CONCLUSIONS: The management of lunotriquetral injuries is complicated by the long time from trauma to definitive diagnosis. A combination of refined clinical and apparative investigations can lead to a reliable diagnosis.

Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma.

BACKGROUND: Ultrasonography is regarded as the tool of choice for early diagnostic investigations in patients with suspected blunt abdominal trauma. Although its sensitivity is too low for definite exclusion of abdominal organ injury, proponents of ultrasound argue that ultrasound-based clinical pathways enhance the speed of primary trauma assessment, reduce the number of computed tomography scans and cut costs. OBJECTIVES: To assess the efficiency and effectiveness of trauma algorithms that include ultrasound examinations in patients with suspected blunt abdominal trauma. SEARCH STRATEGY: We searched MEDLINE, EMBASE, CENTRAL, CCMED, publishers' databases, controlled trials registers and the Internet. Bibliographies of identified articles and congress abstracts were handsearched. Trials were obtained from the Cochrane Injuries Group's trials register. Authors were contacted for further information and individual patient data. PARTICIPANTS: patients with blunt torso, abdominal or multiple trauma undergoing diagnostic investigations for abdominal organ injury. INTERVENTIONS: diagnostic algorithms comprising emergency ultrasonography (US). CONTROLS: diagnostic algorithms without US ultrasound examinations (e.g. primary computed tomography [CT] or diagnostic peritoneal lavage [DPL]). OUTCOME MEASURES: mortality, use of CT and DPL, cost-effectiveness, laparotomy and negative laparotomy rates, delayed diagnoses, and quality of life. STUDIES: randomised controlled trials (RCTs) and quasi-randomised trials (qRCTs). DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion, assessed methodological quality and extracted data. Where possible, data were pooled and relative risks (RRs), risk differences (RDs) and weighted mean differences, each with 95% confidence intervals (CIs), were calculated by fixed- or random-effects modelling, as appropriate. MAIN RESULTS: We identified two RCTs with US in the experimental arm and another with US in the control group. We also considered two qRCTs. Overall, trials were of moderate methodological quality. Few authors responded to our written inquiries seeking to resolve controversial issues and to obtain individual patient data. We were able to pool data from two trials comprising 1037 patients for primary endpoint analysis (i.e. mortality). The relative risk in favour of the no-US arm was 1.4 (95% CI 0.94 to 2.08). Because of a lack of details, the meaning of this observation remains unclear. There was a marginal benefit with US-based pathways in reducing CT scans (random-effects RD -0.46; 95% CI -1.00 to 0.13), offset by trials of higher methodological rigour. No differences were observed in DPL and laparotomy rates. AUTHORS' CONCLUSIONS: There is insufficient evidence from RCTs to justify promotion of ultrasound-based clinical pathways in diagnosing patients with suspected blunt abdominal trauma.

Does the ventricle size change after shunt operation of normal-pressure hydrocephalus?

OBJECTIVES: The aim of this study was to determine whether ventricular size correlates with a positive clinical outcome following shunt placement. Hydrostatic valves (Dual-Switch-Valves) were implanted in 80 patients with NPH at Unfallkrankenhaus Berlin between September 1997 and January 2002. One year postoperatively, these patients underwent computerized tomography scanning, and their ventricular size was ascertained using the Evans-Index. Among 80% of the patients who showed no postoperative change in ventricular volume, 59% nonetheless had good to excellent clinical improvements, 17% satisfactory clinical improvement, and 24% no improvement. Furthermore, a moderate reduction in ventricular size was observed in 14% of patients in this cohort. Among these, 36% experienced a good to excellent clinical improvement, 28% a satisfactory improvement, and 36% unsatisfactory improvement. A marked reduction in ventricular size was observed in 6% of the patients. Of this group, 60% demonstrated good to excellent outcomes, whereas 40% had unsatisfactory outcomes. Favourable outcomes following the implantation of a hydrostatic shunt in patients with NPH did not correlate with decreased ventricular volume 1 year after surgery. In fact, better clinical outcomes were observed in patients with little or no alteration in ventricular size, compared with those in patients with marked decrease in ventricular size. A postoperative change in ventricular volume should be assessed differently in patients with NPH compared with those suffering from hypertensive hydrocephalus.

Length and angle measurements of the lower extremity in digital composite overview images.

We here introduce a digital scanning method for determining leg length and angles. The leg length and angle measurements, image quality and radiation dose were evaluated. A composite overview image was reconstructed from a series of individual images. In 45 overview images, the total leg length and the femoro-tibial angle were determined by two radiologists, and the inter- and intra-observer variability was examined in the light of the measured values as well as the subjective assessment of the image quality. A dose comparison was carried out with a series of conventional whole leg images. The mean standard deviation of the multiple measurements of leg length was 0.4 mm for researcher I and 0.5 mm for researcher II. The difference in the mean values of the measured leg lengths between the researchers was 0.3 mm. The mean standard deviation of the multiple measurements of the femoro-tibial angle was 0.1 degrees for both researchers. The difference in the mean values of the measured femoro-tibial angle between the researchers was 0.03 degrees. On average, the marks for the image quality awarded by researcher II with an average score of 2 were very significantly worse than those awarded by researcher I with an average score of 1.5. The mean entrance dose value determined was 0.16 mGy lower in the digital system (0.49 mGy) than that of the comparative conventional series (0.65 mGy). Where there is a large number of possible length and angle measurements, the proposed procedure offers the advantages of good image quality, digital image processing, measurements that are easy to perform, reproducible and accurate, and lower radiation dose, and it is superior to conventional whole leg images.