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K W Preidler

Publications and source records attributed to K W Preidler.

At least 37 records · Page 2Linked to original sources
PubMed1997

Measurements of cortical thickness in experimentally created endosteal bone lesions: a comparison of radiography, CT, MR imaging, and anatomic sections.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of cortical measurements of experimentally created endosteal cortical lesions and to assess the sensitivity of radiography, CT, and MR imaging in the detection and measurement of such lesions. MATERIALS AND METHODS: Thirty-six cortical lesions were created in three fresh cadaveric femurs. After performing radiography, CT, and MR imaging, we sectioned the specimens in the axial plane. We then measured the remaining cortex at the lesions and the normal cortex adjacent to the lesions on all images and corresponding anatomic sections. The measurements of thickness of the cortex as seen with the different imaging methods and the anatomic sections were compared. Measurements were repeated to evaluate the influence of different window settings on the MR imaging measurements. RESULTS: When measured on radiographs, cortical thickness was overestimated in 58% of lesions. With CT, cortical thickness was overestimated by 0-15% in 94% of all lesions. With MR imaging, cortical thickness was uniformly underestimated by 3-17%. Measurements made on MR images varied according to different window settings. The proton density-weighted sequence yielded the highest sensitivity in the detection of shallow cortical lesions; the T1-weighted spin-echo sequence was the least sensitive of the MR sequences. CONCLUSION: In our cadaveric study, cortical thickness in the presence of endosteal lesions was overestimated on radiographs and CT scans and underestimated on MR images. Measurements derived from MR imaging are strongly influenced by the window setting. MR imaging with the proton density-weighted sequence is the most sensitive for detection of shallow cortical lesions and is more sensitive than CT.

Bone Neoplasms↗
PubMed1996

Comparison of mammographic image quality in various methods of reconstructive breast surgery.

The purpose of our study was to evaluate mammographic image quality of various methods of reconstructive breast surgery with specific reference to the possibility of diagnosis of recurrent tumors. A total of 39 patients who underwent breast reconstruction following modified radical mastectomy were subject to clinical and mammographic examination. Three groups were formed: (a) autonomous tissue reconstruction (TRAM-flap; n = 9), (b) submuscular silicon gel prostheses (n = 21), and (c) supramuscular silicon gel prostheses (n = 9). Mammographic image quality of the groups was compared by two radiologists working together using a point system where five specific criteria were valued and scored. The result was tabulated into three quality levels: good, acceptable, and limited. Mammograms were assessed as good, acceptable, or limited, respectively, as follows: group I: 7 (77.8%), 1 (11.1%), 1 (11.1%); group II: 4 (19%), 11 (52.4%), 6 (28.6%); group III: 3 (33.3%), 4 (44.5%), 2 (22.2%). The TRAM-flap method of reconstruction displays a high degree of mammographic image quality and therefore is preferable with respect to early diagnosis of recurrent tumors.

Adult↗
PubMed1996

Vascular complications in lumbar disk surgery: report of four cases.

Vascular injuries in lumbar disk surgery, although rare, are serious complications which may be overlooked due to a broad range of clinical manifestations. It is important that surgeons and radiologists be aware of these potentially fatal complications and develop an appropriate symptom-based diagnostic paradigm. We reviewed 8099 consecutive cases of lumbar disk surgery, performed over a 14-year period at a single institution, for postoperative vascular complications. We identified four patients (0.05%) with lumbar disk surgery-related vascular complications: intraoperative lacerations of the abdominal aorta and median sacral artery, an arteriovenous fistula between the left common iliac artery and vein detected 19 days postdiskectomy, and a partially thrombosed aortic aneurysm with an arteriovenous fistula between the aneurysm and the inferior vena cava, diagnosed 11 months after surgery. The majority of cases in the literature of vascular injury in lumbar disk surgery were reported prior to 1965. Diagnostic approaches described in that period do not reflect the great range of diagnostic techniques available today. Angiography remains the gold standard for diagnosis and guidance as to surgical repair. However, a high index of suspicion based on clinical signs and/or the use of sonography or CT is important in the detection of these complications.

Aged↗
PubMed1996

Osteoarthritis.

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Humans↗
PubMed1996

[Detection of perfusion of kidney transplants. Comparison between color-coded and amplitude-coded Doppler ultrasound].

OBJECTIVE: To evaluate the efficiency of colour Doppler energy (CDE) in comparison to conventional colour Doppler sonography (CDI) in the detection of renal blood flow signals in asymptomatic patients after renal transplantation. SUBJECTS AND METHODS: Fifteen asymptomatic volunteer patients after renal transplantation were examined with CDI and CDE. The examination parameters were kept constant; only the Doppler-receiver gain was varied. Assessment and comparison of blood flow signals were obtained with a self defined score system. RESULTS: CDI showed Doppler signals in the main stem vessels, segmental and interlobar vessels in all patients; in the arcuate arteries blood flow signals were detected in only 11 of 15 patients. There was no Doppler signal in peripherally located medullary and cortical vessels. CDE showed blood flow signals in the main stem, segmental and interlobar vessels and additionally in the arcuate, interlobular and medullary as well as in the cortical vessels in all patients. CONCLUSION: CDE is more sensitive than CDI and improves the detection of blood flow signals in peripheral medullary and cortical vessels of renal transplants.

Adult↗
PubMed1996

Distribution pattern of computed tomography findings in patients with bronchiolitis obliterans organizing pneumonia.

RATIONALE AND OBJECTIVES: The authors evaluated high-resolution computed tomography (HRCT) findings in 15 patients with biopsy-proven bronchiolitis obliterans organizing pneumonia (BOOP). Special attention was paid to lobar distribution to establish a predominant distribution pattern for this disease. SUBJECTS AND METHODS: Fifteen patients (average age, 61.8 years) with BOOP underwent computed tomography examinations. The examination technique included a slice thickness of 4 mm with a 4-mm interval; matrix size was 256 x 256 pixels. In all patients, additional HRCT images with a 2-mm slice thickness and a 10-mm interval (matrix, 512 x 512 pixels) were obtained. Interpretation included assessment of pulmonary, pleural, and mediastinal involvement. Special attention was paid to the distribution pattern of pulmonary abnormalities. RESULTS: High-resolution computed tomography in all patients demonstrated areas of air space consolidation in a multifocal but peripheral distribution. The right lower lobe was involved in 60% of the patients, the left lower lobe in 53%, the middle and right upper lobes in 20%, and left upper lobe in 23%. Five patients had ground-glass opacities in addition to the areas of air space consolidation, with the incidence in these patients being 100% in the right lower lobe. 80% in the left lower and middle lobes, 60% in the right upper lobe, and 20% in the left upper lobe. Nodules were found in two patients, and the left lower and middle lobes were affected in both. In one patient, the right lower lobe was affected. The interstitium was thickened in 66%, with axial involvement in 20%, septal thickening in 30%, and peripheral regions affected in 50%. Bronchiectasis was present in 60% of all patients studied, predominantly located in the lower lobes. CONCLUSION: Bronchiolitis obliterans organizing pneumonia presents a predominant peripheral, bilateral, and nonsegmental distribution, with the lower and middle lobes affected more than the upper lobes.

Adult↗
PubMed1996

Differentiation of delayed kidney graft function with gadolinium-DTPA-enhanced magnetic resonance imaging and Doppler ultrasound.

RATIONALE AND OBJECTIVES: The authors differentiate acute tubular necrosis from transplant rejection in patients with delayed kidney graft function using gadolinium (Gd)-DTPA enhanced magnetic resonance (MR) imaging. METHODS: Twenty-four patients after renal transplantation (10 with normal graft function, 14 with delayed graft function) underwent conventional and Doppler sonography and MR imaging examination after bolus application of Gd-DTPA. Within a time period of 512 seconds, 39 single-slice MR images were obtained. Measurements of signal intensity in three regions of interests (cortex, medulla, renal pelvis) resulted in a graphic description of the dynamics of the contrast enhancement. The time between the start of the scan and the peaks of the curves was measured. RESULTS: In patients with normal graft function the curves reached the peaks between 39 and 55 seconds (cortex), 44 and 61 seconds (medulla), and between 161 and 318 seconds (renal pelvis). Six patients with acute tubular necrosis showed normal values for the curves 1 and 2 but markedly prolonged time for curve 3 (between 420 and 512 seconds). In all patients with histologically proven transplant rejection, the peaks of all curves were not reached before the ends of the scans. CONCLUSION: The authors' preliminary results suggest that MR imaging seems to be a sensitive, noninvasive diagnostic tool to differentiate acute tubular necrosis from transplant rejection in the critical early postoperative period.

Adult↗
PubMed1996

Staging of cervical carcinomas. Comparison of body-coil magnetic resonance imaging and endorectal surface coil magnetic resonance imaging with histopathologic correlation.

RATIONALE AND OBJECTIVES: The authors evaluate the accuracy of magnetic resonance (MR) imaging with body coil and endorectal surface coil techniques in the staging of cervical carcinomas and compare these results with those obtained with clinical staging (International Federation of Gynecology and Obstetrics [FIGO] classification) and postsurgical histopathology. METHODS: Fifteen patients (average age, 48.6 years) with biopsy-proved cervical cancer were included in the study. After clinical staging (FIGO classification), MR imaging with body coil (BCMR) and subsequently with endorectal surface coil (ECMR) was performed. Using a 1.5-Tesla unit, axial and sagittal proton density weighted and spin echo T2-weighted and fast spin echo T2-weighted sequences were obtained with body and endorectal surface coil. During imaging analysis, special attention was paid to the uterine zones, the vaginal fornix, and the parametrial tissue. Ten patients were treated surgically (postsurgical histopathology was considered the gold standard), five patients, all clinically staged IIIb, underwent primary radiation therapy. RESULTS: Clinical staging with FIGO classification was accurate in 12 of 15 patients, and understaged in 2 and overstaged in 1 patient. Body coil MR showed accurate staging in 13 of 15 patients. Using this technique, understaging of 2 patients, both with only minimal tumor infiltration depth (< 8 mm), was performed. Endorectal surface coil MR was accurate in 14 of 15 patients missing minimal parametrial tumor infiltration in 1 patient. Histopathology (n = 10) revealed 3 patients with tumor stage T1b, 2 with stage T2a, and 5 patients with stage T2b. CONCLUSIONS: Although suggested by only a small number of patients, ECMR appears to be the most accurate modality for staging cervical carcinomas but seems to be unreliable in the detection of minimal tumor infiltration.

Adult↗
PubMed1996

Magnetic resonance imaging in patients with gestational trophoblastic disease.

RATIONALE AND OBJECTIVES: The authors describe the magnetic resonance (MR) imaging characteristics in patients with gestational trophoblastic disease (GTD) before and after therapy and to correlate these findings with human gonadotropin levels and the specific histology of GTD. METHODS: Thirteen women (mean age, 30.1 years) with elevated human chorionic gonadotropin (HCG) levels and histologically proven GTD underwent MR examinations of the pelvis. Magnetic resonance imaging was performed on a 1.5-tesla unit. Axial and sagittal proton density-weighted and T2-weighted and sagittal T1-weighted sequences were obtained. Four patients underwent follow-up studies after 4 and 8 weeks to monitor the response to therapy. Gestational trophoblastic disease was histologically proven with curettage in 11 patients and with hysterectomy in two cases. RESULTS: Nine patients had a diffusely enlarged uterus with pathologic signal intensities. In four patients, a focal tumor mass was observed. All patients showed loss of the zonal anatomy of the uterus in at least one local area. In 11 patients, no uterus zones could be identified throughout the entire uterus. Pathologic dilated tumor vessels were evident in all patients. In all four cases in which follow-up imaging studies were obtained, uterus size, signal intensities, identification of uterus zones, and uterus vessels returned to normal. CONCLUSION: Magnetic resonance imaging shows trophoblastic tumor infiltration as diffuse uterus enlargement, focal tumor masses, loss of zonal anatomy of the uterus, and pathologic uterine vasculature; this seems to be the most reliable MR imaging finding in patients with GTD. No correlation was found between MR imaging changes and HCG levels or specific histologic types of GTD.

Adolescent↗
PubMed1996

Coralline hydroxyapatite bone graft substitutes. Evaluation of bone density with dual energy x-ray absorptiometry.

RATIONALE AND OBJECTIVES: The authors evaluate whether dual-energy x-ray absorptiometry (DXA) is a reliable method to determine the density of natural coralline hydroxyapatite (HA) blocks used as bone graft substitutes. METHODS: To evaluate the basic density of HA blocks from the same coral heads with and without titanium meshes, densitometry of 12 HA-500 blocks (genus Goniopora) and 12 HA-200 blocks (genus Porites) was performed. In addition, density measurements of 30 HA blocks (HA-500, n = 15; HA-200, n = 15) from different coral heads were obtained to assess if the originating coral head influences the basic density of blocks within one coral genera. To assess standard deviation serial measurements on eight coralline HA blocks, four with titanium meshes and four without were performed. In the ex vivo study, densitometry of 12 HA blocks (HA-500, n = 4; HA-200, n = 8) used as bone graft substitutes in the mandibles and craniums of adult mongrel dogs was performed. Densities were measured after bone ingrowth for 2 and 4 months, respectively. All measurements were obtained with a Lunar DPX with scan mode "slow 750" in the spine program with the regions-of-interests selected manually. Bone ingrowth was assessed by computer-assisted histomorphometry, which was considered the gold standard. Statistical analysis was performed to correlate the densities of plain HA blocks with and without meshes to the specific weights of the blocks. RESULTS: Significant positive correlation was found between the density of each HA block (both coral species) with and without meshes and the calculated specific weights. Densitometry values showed no significant differences depending on the originating coral heads. Standard deviation ranged between +/- 3.8% and +/- 4.1% (HA-500) and between +/- 3.0% and +/- 3.8% (HA-200). Hydroxyapatite-500 blocks showed marked increased densities between 15% and 34% after 4 months in three specimens in which bone ingrowth between 16.9% and 21.1% was revealed by histomorphometry; no increase of density was observed in one specimen, which presented only minimal bone ingrowth and signs of infection. Despite bone invasion between 12% and 25.8%, no increased densities were observed for HA-200 implants. CONCLUSIONS: Dual-energy x-ray absorptiometry is an accurate and reproducible modality to assess the densities of plain coralline HA blocks and to monitor bone ingrowth into coralline HA-500 but not into HA-200 block implants.

Absorptiometry, Photon↗
PubMed1996

Sternoclavicular joint: MR imaging--anatomic correlation.

PURPOSE: To correlate magnetic resonance (MR) images of the sternoclavicular joint with anatomic sections. MATERIALS AND METHODS: MR imaging was performed on 14 sternoclavicular joints in seven specimens from cadavers (three men and four women 64-94 years of age at death; mean, 84 years). MR arthrography was performed in four specimens (eight joints), after injection of gadopentetate dimeglumine. After imaging, the specimens were frozen and cut into 3-mm-thick slices along the MR imaging planes. Images were correlated with the anatomic slices. RESULTS: MR imaging depicted the anatomy of the sternoclavicular joint and surrounding soft tissue. T2-weighted and proton-density-weighted images were superior to T1-weighted images in depiction of the intraarticular disk. MR arthrography depicted best the intraarticular disk and four of five perforations and delineated the joint capsule. All perforations also were depicted on T2-weighted images. CONCLUSION: MR imaging allows delineation of all structures of the sternoclavicular joint. MR arthrography allows delineation of perforations of the intraarticular disk.

Aged↗
PubMed1996

Enlargement of the third intercondylar tubercle of Parsons as a sign of osteoarthritis of the knee: a paleopathologic and radiographic study.

PURPOSE: To correlate presence and size of the third intercondylar tubercle of Parsons (TITP) with occurrence and severity of osteoarthritis of the knee. MATERIALS AND METHODS: In 100 paleopathologic tibial specimens and on 160 clinical knee radiographs, size of the TITP was correlated with osteoarthritis of medical and lateral femorotibial joints (FTJ) and with prominence of tibial spines. RESULTS: TITP size correlated significantly with osteoarthritis of the tibial plateau in the paleopathologic specimens (P<.0001). TITP size correlated significantly with osteoarthritis of medial FTJ and tibial spines on radiographs (P<.0001). Of 85 patients without osteoarthritis of the medial FTJ, 49 (58%) had no TITP, 33 (39%) had small TITPs, and three (4%) had medium or large TITPs. TITPs were found in 15 (88%) of 17 patients with pronounced osteoarthritis. CONCLUSION: Frequency and prominence of TITPs are increased in patients with osteoarthritis of the medial FTJ and prominent tibial spines. Prominent TITP is a secondary sign of osteoarthritis. At histologic examination, increasing size of TITPs represents osteophytosis or enthesopathy of the TITP.

Adolescent↗
PubMed1996

Tarsometatarsal joint: anatomic details on MR images.

PURPOSE: To evaluate the diagnostic capabilities of magnetic resonance (MR) imaging in the tarsometatarsal ([TMT] Lisfranc) joint with close anatomic correlation. MATERIALS AND METHODS: Six normal cadaveric feet were imaged by using T1-weighted spin-echo (oblique axial) and three-dimensional spoiled gradient-recalled acquisition in the steady state ([SPGR] coronal, sagittal) sequences. Subsequently, gadolinium-enhanced arthrography was performed in three specimens followed by T1-weighted spin-echo and SPGR MR imaging. Specimens were sectioned in all three planes followed by correlation of the MR imaging results with gross anatomic findings. RESULTS: In all specimens, the oblique axial and, less effectively, the coronal and sagittal planes allowed visualization of the Lisfranc ligament. Intermetatarsal ligaments were seen almost exclusively on the coronal images, and TMT ligaments on the sagittal images. Bone alignment could be assessed on the oblique axial images. CONCLUSION: MR imaging reliably depicts the anatomy of the TMT joint including ligamentous and osseous structures.

Cadaver↗
PubMed1996

Imaging of osseous and cartilaginous intraarticular bodies in the knee: comparison of MR imaging and MR arthrography with CT and CT arthrography in cadavers.

PURPOSE: To compare magnetic resonance (MR) imaging and MR arthrography with computed tomography (CT) and CT arthrography in the detection of intraarticular bodies in the knee. MATERIALS AND METHODS: Cuboid (3- or 6-mm-long sides) osseous and cartilaginous bodies were implanted in 16 cadaveric knee specimens. MR imaging was performed with T1-weighted spin-echo (SE), T2-weighted SE, proton-density-weighted SE, gradient recalled acquisition in the steady state (GRASS), and spoiled GRASS sequences. MR arthrography was performed in two phases with saline and 2 mmol/L gadopentetate dimeglumine. CT and CT arthrography were performed in the transaxial plane. RESULTS: MR arthrography yielded the highest accuracy for the detection of osseous and cartilaginous bodies combined (92%) and was significantly (P < .01) better than MR imaging (57%-70%), CT arthrography (80%), and CT (74%). Accuracy of CT arthrography was significantly better than that of MR imaging and that of CT. Accuracy of saline-enhanced MR arthrography was significantly inferior (P < .001) to that of gadolinium-enhanced MR arthrography. CONCLUSION: MR arthrography is the best imaging technique for detection of individual intraarticular bodies. CT arthrography is the second most accurate method. Spoiled GRASS and T2-weighted SE sequences are the most accurate at MR imaging. The presence of intraarticular fluid and performance of saline-enhanced MR arthrography improve detectability of intraarticular bodies.

Arthrography↗
PubMed1996

MR imaging of the tarsometatarsal joint: analysis of injuries in 11 patients.

OBJECTIVE: We evaluated how well MR imaging revealed ligamentous and bony abnormalities in patients with injuries of Lisfranc's joint. SUBJECTS AND METHODS: We evaluated the studies of 11 patients with plantar hyperflexion injuries of the foot who underwent MR imaging in all three planes using spinecho T1-weighted, fast spin-echo T2-weighted, and short inversion time inversion recovery sequences. In four of the 11 patients, a three-dimensional spoiled gradient-recalled acquisition in the steady-state volume sequence was performed in the coronal plane. For five of the 11 patients, radiographs were available for evaluation. RESULTS: Radiographs revealed tarsometatarsal joint malalignment in all five patients for whom plain films were available, metatarsal fractures in four of these patients, and tarsal fractures in the same four patients. MR imaging showed joint malalignment in all 11 patients and disruption of the Lisfranc's ligament in eight of the 11 patients. In the remaining three patients, normal Lisfranc's ligaments were associated with avulsion fractures of the second metatarsal bases or the medial cuneiform bones. On MR imaging, fractures of the metatarsal bases were evident in 10 of 11 patients. Fractures of the tarsal bones were seen in the same 10 patients. CONCLUSION: MR imaging allows the detection of disruption of the Lisfranc's ligament as well as tarsal and metatarsal fractures and therefore may be a valuable technique in assessing patients after trauma to the tarsometatarsal joints when results of routine radiographs are not conclusive.

Adult↗
PubMed1996

Shoulder impingement syndrome: influence of shoulder position on rotator cuff impingement--an anatomic study.

OBJECTIVE: The purpose of the study was to investigate the relationship of the distal supraspinatus tendon to the coracoacromial arch on radiographs and MR imaging at various shoulder positions. MATERIALS AND METHODS: Radiopaque and gadolinium-impregnated markers were sutured to the distal aspect of the supraspinatus tendon and along the coracoacromial ligament in three cadavers. While varying positions of the shoulder, we obtained gross anatomic visualization, radiographs, and MR images. RESULTS: Impingement of the distal aspect of the supraspinatus tendon between the acromion and the greater tuberosity of the humerus was well visualized during forward flexion and abduction of more than 30 degrees. Shoulder impingement was best seen at 60 degrees forward flexion, 60 degrees abduction, and internal rotation. CONCLUSION: MR imaging of different shoulder positions may help reveal the pathogenesis of shoulder impingement syndrome.

Aged↗