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Biomedical subjects

A Kaim

Publications and source records attributed to A Kaim.

At least 19 recordsLinked to original sources
PubMed2001

Acute appendicitis in a young adult with midgut malrotation: a case report.

Midgut malrotation is defined as a developmental anomaly that may cause atypical clinical symptoms in relatively common intestinal disorders due to altered anatomy. A 27-year-old woman presented with acute left-sided abdominal pain. Underlying type Ia malrotation prevented the correct clinical diagnosis of perforated, ulcerated appendicitis. Cross-sectional imaging demonstrated all the typical signs of this type of malrotation, i.e., right-sided duodenojejunal junction, left positioned cecum and ascending colon, inverted position of the superior mesenteric vessels, and hypoplasia of the uncinate process of pancreas, and surgical treatment was initiated.

Abdominal Pain↗
PubMed2001

Three-dimensional dynamic MR hysterosalpingography: a preliminary report.

The aim of this study was to evaluate the feasibility of three-dimensional dynamic MR hysterosalpingography (3D MR HSG) for visualization of the cavum uteri and demonstration of bilateral fallopian tube patency as an alternative to conventional hysterosalpingography. Five infertile female patients underwent 3D dynamic MR HSG prior to conventional hysterosalpingography. The MR protocol consisted of axial T1-weighted spin-echo (SE), axial/coronal T2-weighted fast SE (FSE), and 3D MR angiography sequences before, during, and after injection of a diluted gadolinium solution into the cavum uteri via a balloon catheter. Positioning of the catheter was feasible in all patients. In one patient the catheter slipped out during MRI and in one patient the catheter was placed far in the cavum uteri. In three patients catheter position was optimal at the level of the cervical canal. Evaluation of pelvic anatomy, myometrium, and ovaries was possible in all patients on the basis of T1-weighted SE and T2-weighted FSE. Three-dimensional visualization of the dilated cavum uteri was possible in four patients. In these four patients 3D MR HSG also proved bilateral fallopian tube patency which was confirmed in each patient by conventional hysterosalpingography. Three-dimensional MR HSG is feasible and further research should be done to determine if this technique can evolve into an alternative technique to conventional hysterosalpingography with the advantages of no radiation and additional visualization of the uterus wall and ovaries.

Adult↗
PubMed2000

Chronic post-traumatic osteomyelitis of the lower extremity: comparison of magnetic resonance imaging and combined bone scintigraphy/immunoscintigraphy with radiolabelled monoclonal antigranulocyte antibodies.

OBJECTIVE: A retrospective study of the validity of combined bone scintigraphy (BS) and immunoscintigraphy (IS) using (99m)Tc-labelled murine antigranulocyte antibodies (MAB) and magnetic resonance imaging (MRI) in chronic posttraumatic osteomyelitis. DESIGN AND PATIENTS: The results of MRI and combined BS/IS of 19 lesions in 18 patients (13 men, 5 women; mean age 45 years, range 27-65 years) were independently evaluated by two radiologists and one nuclear medicine physician with regard to bone infection activity and extent. The patient group was a highly selective collection of clinical cases: the average number of operations conducted because of relapsing infection was eight (range 2-27), the average time interval between the last surgical intervention and the present study was 6.5 years (range 3 months to 39 years), and from the first operation was 14 years (range 1.5-42 years). Interobserver agreement on MRI was measured by kappa statistics. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for MRI and the nuclear medicine studies. RESULTS: For MRI/nuclear medicine, a sensitivity of 100%/77%, a specificity of 60%/50%, an accuracy of 79%/61%, a PPV of 69%/58% and a NPV of 100%/71% were calculated. Four MR examinations were false positives because of postsurgical granulation tissue. A high degree of interobserver agreement was found on MRI (kappa=0.88). A low-grade infection was missed on two scintigrams, while four were false positive because of ectopic haematopoietic bone marrow, and in one examination the anatomical distortion resulted in an inaccurate assignment of the uptake leading to false positive findings. Image analysis was frequently hindered by susceptibility artefacts due to residual abrasions of metallic implants after removal of orthopaedic devices (15/18 patients); this led to limited assessment in 17% (3/18 patients). CONCLUSION: Acute activity in a chronic osteomyelitis can be excluded with high probability if the MRI findings are negative. In the first postoperative year fibrovascular scar cannot be distinguished accurately from reactivated infection on MRI and scintigraphy may improve the accuracy of diagnosis. MRI is more sensitive in low-grade infection during the later course than combined BS/IS. Scintigraphic errors due to ectopic, peripheral, haematopoietic bone marrow can be corrected by MRI.

Adult↗
PubMed2000

Retroisthmic cleft: a stress fracture of the lamina.

The retroisthmic cleft is a rarely diagnosed defect in the lamina of the lumbar spine. It has always been considered a congenital anomaly. This is the first report we are aware of showing radiological changes in a retroisthmic cleft over a period of time. The follow-up of this patient over a period of 6 years, the radiological and scintigraphic appearances and a review of the literature suggests that the retroisthmic cleft is a stress fracture of the lamina.

Adult↗
PubMed2000

Pitfalls and limitations of magnetic resonance imaging in chronic posttraumatic osteomyelitis.

The aim of this study was to evaluate pitfalls and technical limitations of MR imaging in diagnosing relapse of chronic posttraumatic osteomyelitis of the lower extremities. Retrospective analysis of MR examinations in 15 patients (17 body areas) with suspected relapse of chronic posttraumatic osteomyelitis (at least 1.5 years duration/mean number of surgical procedures per patient: 5.8). The MRI findings were compared with postoperative bacteriology (n = 11) and clinical follow-up (n = 4). Five patients had additional CT examination. Magnetic resonance imaging identified all infected areas correctly, but five uninfected regions were diagnosed false positive due to postoperative scarring/oedema in bone defects (n = 4) and soft tissue (n = 1). Specificity of MRI in diagnosing active bone infection was 63% and sensitivity 100%. Additional CT was preoperatively necessary in 5 patients (33%) to further examine osteomyelitic and reparative bone remodeling. Metal artefacts were present in 11 patients, rendering complete evaluation impossible (n = 2) or considerably more difficult (n = 4). Scarring/oedema in postoperative bone defects occurs up to 13 months postoperatively and represents a major pitfall leading to low specificity. Definitive evaluation of suspected fistula, bony fragments and mineralization by MRI may be limited in this special patient group and requires additional CT in one third of patients. Metal artefacts occur in most patients and may impair or even prevent correct film evaluation in 23 and 11%, respectively.

Adult↗
PubMed2000

A whole-body registration-free navigation system for image-guided surgery and interventional radiology.

RATIONALE AND OBJECTIVES: To develop and test an image-guided navigation system in which the base of reference is taken from the imaging modality, here, a helical CT scanner. METHODS: An optical digitizer together with a calibration device is used to measure the transformation matrix between the digitizer reference system and a CT reference system. During intervention, it tracks radiological and surgical tools with tool references. A specific software visually integrates the current tool position with the corresponding image information. In vitro accuracy tests were performed. RESULTS: With helical CT, freehand positioning accuracy was 1.9 +/- 1.1 mm (mean +/- SD) in vitro (n = 718). CONCLUSIONS: The navigation system developed by the authors appears to be feasible for radiological interventions as well as for minimally invasive surgery. It is not limited to a certain procedure, can be used in every region of the body, and is functional after imaging. Intraprocedural scans can be integrated immediately.

Equipment Design↗
PubMed1999

Cerebral veins: comparative study of CT venography with intraarterial digital subtraction angiography.

BACKGROUND AND PURPOSE: Our objective was to compare the reliability of CT venography with intraarterial digital subtraction angiography (DSA) in imaging cerebral venous anatomy and pathology. METHODS: In 25 consecutive patients, 426 venous structures were determined as present, partially present, or absent by three observers evaluating CT multiplanar reformatted (MPR) and maximum intensity projection (MIP) images. These results were compared with the results from intraarterial DSA and, in a second step, with the results of an intraobserver consensus. In addition, pathologic conditions were described. RESULTS: Using DSA as the standard of reference, MPR images had an overall sensitivity of 95% (specificity, 19%) and MIP images a sensitivity of 80% (specificity, 44%) in depicting the cerebral venous anatomy. On the basis of an intraobserver consensus including DSA, MPR, and MIP images (415 vessels present), the sensitivity/specificity was 95%/91% for MPR, 90%/100% for DSA, and 79%/91% for MIP images. MPR images were superior to DSA images in showing the cavernous sinus, the inferior sagittal sinus, and the basal vein of Rosenthal. Venous occlusive diseases were correctly recognized on both MPR and MIP images. Only DSA images provided reliable information of invasion of a sinus by an adjacent meningioma. CONCLUSION: CT venography proved to be a reliable method to depict the cerebral venous structures. MPR images were superior to MIP images.

Adult↗
PubMed1998

MR angiography in internal carotid artery dissection: improvement of diagnosis by selective demonstration of the intramural haematoma.

We studied eight consecutive patients with clinical and intra-arterial angiographic (DSA) diagnosis of internal carotid artery (ICA) dissection to analyse the accuracy of MRA in dissections, using a new technique with presaturation pulses. Spin-echo images of the head were followed by three-dimensional time-of-flight (TOF) MRA at the site of the dissection, with and without a special caudal saturation pulse in addition to the cranial one. The accuracy of MRA was assessed in 64 segments of 16 ICA, all examined with DSA and MRA. High-signal intramural haematoma in the ICA at the level of the dissection was observed in all patients either on the maximal-intensity projection (MIP) reconstructions or on the partitions with this presaturation pulse technique. MRA had a sensitivity to detect dissected vessels of 100%. Specificity for vessels correctly identified as not having a lesion was also 100%. There was good correlation between DSA and MRA in demonstrating the site of the dissected ICA segment and the degree of stenosis. In only two cases was there overestimation of the degree of stenosis on the MIP reconstructions of the 3-D MRA.

Adult↗
PubMed1998

Diameter of the common bile duct in the elderly patient: measurement by ultrasound.

We wanted to assess the width of the common bile duct (CBD) in an asymptomatic elderly (> 75 years) population, since no previous report has particularly considered the important age-related increase in CBD diameter for this patient group. CBD width of 92 asymptomatic people over 75 years of age (mean 84.7 years, range 75-96 years) without clinical or laboratory evidence for biliary, hepatocellular or pancreatic disease was measured by real-time high-resolution ultrasound of the upper abdomen. All examinations were performed by one experienced radiologist. Mean values were calculated for three groups: patients with and without cholecystolithiasis and after cholecystectomy. Statistical analysis was carried out by analysis of variance. Considering the measurements of all patients, the mean width (+/- SD) of the CBD was calculated as 6.5 +/- 2.5 mm. The difference between patients without cholecystolithiasis (6.2 +/- 2.3 mm) and patients after cholecystectomy (8.7 +/- 2.9 mm) was statistically significant (P < 0.0001). Cholecystolithiasis (6.0 +/- 1.6 mm) proves not to be an additional factor for CBD widening in comparison with patients without stone disease. The CBD of these very elderly subjects shows a considerable increase in comparison with the recommended borderline values in the ultrasound literature. An upper limit of 10 mm seems reasonable for patients with and without cholecystolithiasis. A significant increase in CBD width after cholecystectomy was found and measurements up to 14 mm may occur. Measurements have to be correlated with clinical and laboratory findings.

Aged↗
PubMed1998

Lung resection for invasive pulmonary aspergillosis in neutropenic patients with hematologic diseases.

Invasive pulmonary aspergillosis (IPA) is associated with a high mortality. In 27 consecutive neutropenic patients who underwent lung resection for suspected IPA, we analyzed preoperative diagnostic evaluation, operative procedure, perioperative management, histological findings, outcome concerning recurrence of aspergillosis, and survival to evaluate the morbidity and mortality of a surgical treatment of IPA. Seventeen patients with hematologic diseases had previously undergone high-dose chemotherapy and four stem cell transplantation. Six patients with aplastic anemia were treated with antilymphocyte globulin. IPA was suspected if localized infiltrates developed on thoracic CT scan, and fever persisted under antibiotic therapy in neutropenic patients. In only one case a diagnosis of IPA could be made preoperatively. Twenty patients underwent lobectomy and seven wedge resection. At day of surgery the neutrophil count was below 500 x 10(9)/L in 78% of patients, and the platelet count below in 50 x 10(9)/L in 58% of patients. Invasive fungal infection was confirmed histologically in 22 of 27 patients (81.5%); in five patients no fungal infection was documented. The median duration of surgery was 120 min. Postoperatively, patients stayed one night in the intensive care unit, and chest tubes were removed after 2 d. Within 7 d a median of four erythrocyte packs and two platelet packs per patient were replaced. Major surgical complications occurred in two patients (bronchial dehiscence; pleural aspergillosis). Minor surgical complications included prolonged chest tube drainage (recurrent pneumothorax, n = 2; air leakage, n = 1; hematothorax, n = 1), pleural effusion (n = 4), and seroma (n = 2). Postoperatively, two patients suffered from histologically proven disseminated aspergillosis (pleural aspergillosis, renal aspergilloma) and another patient from suspected orbital aspergillosis. At 30 d postoperative mortality was 11% and 3-mo survival was 77%. After lung resection, seven patients underwent stem cell transplantation without recurrence of IPA. In conclusion, we suggest lung resection is a therapeutic option for invasive pulmonary aspergillosis in neutropenic patients with hematologic diseases and is associated with a low surgery-related morbidity and mortality.

Adolescent↗
PubMed1998

Ectopic hematopoietic bone marrow in the appendicular skeleton after trauma.

METHODS: Combined bone scanning and immunoscintigraphy (IS) with 99mTc-monoclonal antigranulocyte antibodies were performed in two patients with suspected reactivation of chronic osteomyelitis of the lower extremity. Because bone scanning and IS were strongly positive, both patients underwent surgical intervention. RESULTS: Macroscopic findings did not show purulent infection and microbiologic results remained negative, but histology revealed unexpected ectopic bone marrow, explaining the strong uptake on IS. One patient exhibited active hematopoietic bone marrow at the former fracture site of the tibial bone. The second patient presented with interspersed bone marrow in the cortical bone of the femoral diaphysis after several intramedullary surgical procedures. CONCLUSION: Unexpected ectopic hematopoietic marrow may occur in the appendicular skeleton after trauma and repeated surgical interventions. The bone marrow shows a physiologic uptake with IS and may be misinterpreted as granulocyte accumulation due to infection. This may lead to false-positive diagnosis in cases of suspected osteomyelitis.

Adult↗
PubMed1997

Chronic complicated osteomyelitis of the appendicular skeleton: diagnosis with technetium-99m labelled monoclonal antigranulocyte antibody-immunoscintigraphy.

Chronic post-traumatic osteomyelitis (OM) represents a particular challenge for nuclear medicine and radiology since clinical and biochemical parameters are frequently unreliable. The aim of this study was to investigate the value of combined bone scan (BS) and immunoscintigraphy (IS) with technetium-99m labelled monoclonal antigranulocyte antibody (MAB) in patients with suspected chronic OM of the appendicular skeleton. Twenty-four patients (17 females and 7 males) with suspected chronic post-traumatic OM were evaluated with three-phase BS/99mTc-MAB-IS. The final diagnosis was established by means of bone culture and histology in 19 cases and clinical follow-up in five cases. The studies were reviewed by two independent and experienced observers; the interobserver agreement was calculated by kappa statistics. The sensitivity, specificity and accuracy of BS alone were 92%, 18% and 58%, respectively. Combined BS/99mTc-MAB-IS had a sensitivity, specificity and accuracy of 84%, 72% and 79%, respectively. Of 24 studies, 11 were true-positive, two false-negative, eight true-negative and three false-positive. Two patients presented with unexpected ectopic haematopoietic bone marrow in the appendicular skeleton that caused false-positive results. A high degree of interobserver agreement was found (kappa=0. 85). It is concluded that combined BS/99mTc-MAB-IS represents a very sensitive and reproducible method with an acceptable specificity for the investigation of chronic OM. Problems may occur in the differentiation of low-grade OM from aseptic inflammation. Another problem is ectopic marrow that may occur in the appendicular skeleton due to a chronic inflammatory stimulus. A former intramedullary intervention in the femur with displacement of haematopoietic marrow may also lead to an ectopic location.

Bone and Bones↗
PubMed1997

Foramen of Monro mass: MRI appearances permit diagnosis of cavernous haemangioma.

Cavernous haemangiomas are most commonly found in the subcortical white matter, the pons and the external capsule. We present a case of a cavernous haemangioma that appeared as an intraventricular mass at the foramen of Monro. Despite the unusual location the diagnosis was established by MRI because of the typical appearance. The differential diagnosis included primary and secondary neoplasms at the foramen of Monro.

Cerebral Ventricle Neoplasms↗
PubMed1996

Bone mineral density in patients receiving suppressive doses of thyroxine for differentiated thyroid carcinoma.

To determine bone mineral density in patients with differentiated thyroid carcinoma receiving thyroxine replacement therapy in suppressive doses, we studied 65 patients (47 women and 18 men; age 25-83 years, mean+/-SD 52.5+/-15.4 years). Patients were free of thyroid cancer in clinical and laboratory examinations at the time of the study. Bone mineral density of the lumbar spine and both hips was measured by dual-energy X-ray absorptiometry. There was no decrease in bone density in either 32 postmenopausal or 15 premenopausal women compared with an age- and sex-matched control group, nor was any decrease in bone density found in men. Our data suggest that thyroxine treatment in suppressive doses in patients with differentiated thyroid carcinoma is not a risk factor for the development of osteoporosis.

Adult↗
PubMed1996

Magnetic resonance imaging of vertebrobasilar ectasia in trigeminal neuralgia.

Vertebrobasilar ectasia is a rare cause of typical trigeminal neualgia. In a recently published large series only thirty-one (2%) of 1404 consecutive patients with vascularly determined neuralgia were found to have vertebrobasilar compression. We present three patients with trigeminal neuralgia caused by vertebrobasilar ectasia, who were evaluated with high resolution magnetic resonance imaging (MRI). MRI studies provided accurate information on the anatomical location and course of the ectatic vessel in the cerebellopontine angle and the caused mass effect on the brainstem. With gadolinium-enhancement vascular compression of the trigeminal nerve was demonstrated clearly. Surgery confirmed compression of the fifth nerve by an ectatic and tortuous vertebrobasilar artery in two cases. Following microvascular decompression neither patient experienced further pain. The third patient was treated with a ventriculoperitoneal shunt, as he developed occlusive hydrocephalus caused by the vertebrobasilar dolicho-ectasia. MRI is useful in the evaluation of trigeminal neuralgia as it excludes other aetiologies such as tumour or arteriovenous malformation, but also demonstrates cranial nerve compression by ectatic vertebral arteries.

Basilar Artery↗
PubMed1996

Value of repeat-angiography in cases of unexplained subarachnoid hemorrhage (SAH).

PURPOSE: To investigate the rate of false negative initial cerebral angiography in spontaneous SAH and to ascertain why aneurysms remain undetected. Furthermore to validate CCT in predicting the presence and site of an angiographically missed aneurysm. METHODS: Forty-two patients with spontaneous SAH were investigated, in whom initial cerebral angiography did not reveal any bleeding cause. Repeat-angiography was performed in all patients 5 to 55 days (mean 15 days) after the bleeding event. All patients underwent CCT scans within 48h after the ictus. RESULTS: In 8 of 42 patients (19%) repeat-angiography revealed an aneurysm missed on initial angiography. The aneurysms were located on the AcomA (n = 2), the MCA (n = 2), the ACA (n = 1), the PICA (n = 2) and the junction of ICA and PcomA (n = 1). Presumable reasons for missing an aneurysm were spasms detected in four of eight cases on initial angiography and thrombosis of the aneurysm found in two cases at surgery. In two cases, multiple additional views just revealed the aneurysm appearing different in size and shape on repeat-angiography. CCT blood distribution pattern in four cases indicated presence and site of an aneurysm, while blood distribution was non-specific in the other four cases. CONCLUSION: Repeat-angiography plays an important role in defining the site of an initially occult aneurysm and should be performed in all cases of unexplained SAH. It is of particular importance if vasospasm has compromised the initial angiogram or if one part of the vascular tree is not optimally seen.

Adult↗