PubMed Health⌕ Search

Biomedical subjects

D Liermann

Publications and source records attributed to D Liermann.

At least 19 recordsLinked to original sources

[Improvements in detection of rectal cancer recurrence by multiplanar reconstruction].

PURPOSE: To evaluate the advantages of multiplanar reconstruction and different axial slice thickness in diagnostic of rectal cancer recurrence after operation and radiotherapy. METHOD: We included 83 patients after operation and radiotherapy of rectal cancer in this study. All patients got a minimum of three CT-examinations in their follow-up program. A total of 294 CT-scans were evaluated. Each examination was reviewed by two experienced radiologists in respect to recurrence. Each examination was presented in axial reconstruction with a slice sickness of 8, 5, and 1.25 mm and in multiplanar reconstruction. The sensitivity, specificity, positive predictive value and accuracy were calculated. RESULTS: Multiplanar reconstructions showed better results for the detection of recurrence than axial reconstruction. A reduced slice thickness did not lead to better results in axial reconstruction. Multiplanar reconstruction showed a sensitivity of 0.88, a specificity of 0.98, an accuracy of 0.96 and a positive predictive value of 0,94, for axial reconstruction we calculated: 0.82, 0.97, 0.94 and 0.88, respectively. Sensitivity and accuracy showed a significant increase after the first and second examination. CONCLUSION: Multiplanar reconstructions allow a significant better detection of rectal cancer recurrence when compared to axial reconstructions. Thinner axial slice thickness shows no diagnostic advantage.

Germany↗

[Stents in the femoral artery: aid or problem?].

Percutaneous transluminal angioplasty (PTA) is a well-established technique in the treatment of symptomatic femoropopliteal artery stenoses and obstructions. It is a method of treatment with excellent initial technical and clinical results. However, the long-term results of PTA alone must be considered as unsatisfactory as recurrences are frequently observed. In the past, femoropopliteal stenting appeared to be a promising tool to prevent recurrence and to increase patency rates, but it did not produce better results than PTA alone. For this reason, alternative therapeutic strategies such as brachytherapy, drug-eluting pharmastents and gene therapy were developed. Several investigators are beginning to explore their potential use. This article reviews the present possibilities of PTA and stenting in the femoropopliteal region and considers potential future concepts. In this context, the current clinical literature is discussed.

Arterial Occlusive Diseases↗

[Observing the density increase curve after intravenous contrast medium administration using a bolus triggering system: a method for detection cardiovascular disorders?].

PURPOSE: Recently bolus tracking systems were developed to improve the timing of intravenous contrast media application in helical computed tomography. We investigated the benefit of this new method as a parameter of the cardiac function. MATERIAL AND METHODS: Retrospective analysis of 64 patients which incidentally underwent bolus triggered contrast enhanced helical CT and invasive investigation of the heart within one week. All examinations were performed on the CT scanner Somatom Plus 4 Volume Zoom (Siemens Corp., Forchheim, Germany) using the C.A.R.E. Bolus software. This performs repetitive low-dose test scans (e.g. for the abdomen: 140 kV, 20 mA, Tl 0.5 s) and measures the Hounsfield attenuation (increase over the baseline) in a preselected region of interest. The displayed increase of vascular density over the time after peripheral contrast media injection (75 ml lopromid (300 mg/ml), 2 ml/s) was categorised to three types: (a) rapid increase, (b) deceleration before a 100 HE threshold was reached and (c) one or more peaks. The findings of the invasive investigation of the heart were correlated to the findings of the bolus-tracking measurements. RESULTS: The examinations were categorized as follows: 19 type A, 34 type B, 11 type C. We found a high significant correlation between the type of the Hounsfield attenuation and systolic pressure in the left ventricle. There was no correlation between the type of the Hounsfield attenuation and the diastolic pressure in the left ventricle, the pressures related to the right ventricle or the ejection fraction. The bolus-tacking system showed a sensitivity of 53, a specificity of 82, an accuracy of 70%, a positive predictive value of 70% and a negative predictive value of 70% in detection of left heart failure. CONCLUSION: The bolus tracking system C.A.R.E.-bolus often shows atypical Hounsfield attenuation in cases of cardiac failure but is not suitable as a screening method of the cardiopulmonary function.

Absorptiometry, Photon↗

Stereoscopic 3D CT vs standard 3D CT in the classification of acetabular fractures: an experimental study.

The accuracy of stereoscopic and standard three-dimensional (3D) CT in the classification of acetabular fractures was compared. A receiver operating characteristic (ROC) analysis was performed by two radiologists and two surgeons blinded to the presence of acetabular fractures in an animal model (a total of 62 porcine hips, 40 with artificial acetabular fractures). Classification of acetabular fractures was adopted from the literature. Interpretation was performed on a workstation using two specific volume rendering algorithms; unshaded and shaded bone. The ROC analysis did not demonstrate any benefit in stereoscopic 3D CT compared with standard 3D CT.

Acetabulum↗

[Computerized tomography evaluation of local recurrence of operated and adjuvant radiation treated rectal carcinoma. Normal and pathological changes after operation and irradiation of rectal carcinoma in 956 CT examinations].

Colorectal carcinoma is one of the most common cancer in Germany. We want to evaluate the most reliable CT features indicating local recurrence of rectal cancer as early as possible. 232 patients suffering from rectal cancer being administered to our clinic from 1987-1998 were investigated. Criteria for inclusion: patients after surgery and radiotherapy of rectal cancer with a minimum follow-up of two years and at least 3 CT examinations. All CT examinations were analyzed standardized. The main target parameters for relapse were enlargement of a presacral mass, inhomogeneous appearance, asymmetric outlines, enlarged lymph nodes and infiltration of the surrounding structures. An unchanged appearance of the presacral space in more than three CT examinations after surgery correlated with freedom of recurrence.

Aged↗

Magnetic resonance imaging in the diagnosis of Fournier's gangrene.

Magnetic resonance imaging and ultrasound are the imaging modalities recommended in the early diagnosis of Fournier's gangrene. Because of the high mortality of this inflammatory disease early diagnosis is essential to initiate adequate surgical and medical treatment. In the clinical literature only a handful of cases, in which diagnosis of Fournier's gangrene is based on MRI findings, have been reported; therefore, we report another case which shows the ability of MRI especially to determine the point of origin and extension of disease.

Adult↗

["Phtisis atra"--a now seldom disease picture as a special disease course of silicosis].

Progressive massive fibrosis (PMF) of the lung is caused by coalescence of fibrotic nodules. The center of the PMF often displays necrotic areas. If the necrosis gets in contact to the bronchial system cavitation may occur. We report on a 68 year old patient suffering from severe silicosis of the lung and metastatic spread of a histologically proven lung cancer into the brain. The patient who was administered to the hospital under the intention of cerebral radiotherapy showed a colliquative PMF in the right upper lobe with cavitation and expectoration of large amounts of black-stained sputum (melanoptysis).

Adenocarcinoma↗

Prevention of radiographic-contrast-agent-induced reductions in renal function by acetylcysteine.

BACKGROUND: Radiographic contrast agents can cause a reduction in renal function that may be due to reactive oxygen species. Whether the reduction can be prevented by the administration of antioxidants is unknown. METHODS: We prospectively studied 83 patients with chronic renal insufficiency (mean [+/-SD] serum creatinine concentration, 2.4+/-1.3 mg per deciliter [216+/-116 micromol per liter]) who were undergoing computed tomography with a nonionic, low-osmolality contrast agent. Patients were randomly assigned either to receive the antioxidant acetylcysteine (600 mg orally twice daily) and 0.45 percent saline intravenously, before and after administration of the contrast agent, or to receive placebo and saline. RESULTS: Ten of the 83 patients (12 percent) had an increase of at least 0.5 mg per deciliter (44 micromol per liter) in the serum creatinine concentration 48 hours after administration of the contrast agent: 1 of the 41 patients in the acetylcysteine group (2 percent) and 9 of the 42 patients in the control group (21 percent; P=0.01; relative risk, 0.1; 95 percent confidence interval, 0.02 to 0.9). In the acetylcysteine group, the mean serum creatinine concentration decreased significantly (P<0.001), from 2.5+/-1.3 to 2.1+/-1.3 mg per deciliter (220+/-118 to 186+/-112 micromol per liter) 48 hours after the administration of the contrast medium, whereas in the control group, the mean serum creatinine concentration increased nonsignificantly (P=0.18), from 2.4+/-1.3 to 2.6+/-1.5 mg per deciliter (212+/-114 to 226+/-133 micromol per liter) (P<0.001 for the comparison between groups). CONCLUSIONS: Prophylactic oral administration of the antioxidant acetylcysteine, along with hydration, prevents the reduction in renal function induced by contrast agents in patients with chronic renal insufficiency.

Acetylcysteine↗

[Computerized tomography detection of portal vein air accumulation in severe gastroenteritis during chemotherapy].

Portal venous gas is caused by various pathological processes, both iatrogenic (complications of endoscopy) and non-iatrogenic (bowel ischemia, obstruction, perforated gastric ulcer, septicaemia). We report an immunocompromised patient suffering from metastatic cancer of the breast who developed severe gastroenteritis. Plain radiographs of the abdomen showed branching tubular lucencies that extended from the porta hepatis widely over the liver. A computed tomography performed to exclude air in the biliary tract demonstrated portal venous gas. Although the finding of portal venous gas has been associated with a high mortality rate and usually necessitates surgery, our patient survived without surgical intervention.

Adult↗

[Computed tomography and magnetic resonance tomography in tuberculous spondylitis. A review of the literature and the authors' own observations].

PURPOSE: The findings of tuberculous spondylitis in MRT have been described extensively. Nevertheless the diagnostic value of both methods in the diagnosis of this severe manifestation of the tuberculous disease was not yet defined definitely. MATERIALS: We performed a review of the recent literature and a retrospective analysis of the findings in ten patients with proven tuberculous spondylitis. Here we evaluated 10 CT and 6 MRT. RESULTS: Major findings in computed tomography (n = 10) were osseous sequestration (8/10), subperiosteal bone apposition (6/10), abscess of the surrounding tissue. (8/10) and calcification of the masses (3/10). In all cases which were examined by MRT (n = 6) marrow edema was seen. Affection of the soft tissue was described by means of MRT in 5/6 patients. All patients showed rim enhancement. CONCLUSIONS: MRT shows signs of infection (bone marrow edema) which is an early but rather unspecific finding. The commonness of osseous lesions in advanced tuberculous spondylitis suggests a benefit of computed tomography in the later stages. Both methods are complementary in the differential diagnosis of tuberculous and non-specific spondylitis.

Adult↗

Optimized enhancement in helical CT: experiences with a real-time bolus tracking system in 628 patients.

AIMS: Ultrafast detector technology enables bolus-triggered application of contrast media. In a prospective study we investigated the benefit of this new method with the intention of optimizing enhancement during examination of the chest and abdomen. MATERIALS AND METHODS: In total, we examined 548 patients under standardized conditions. All examinations were performed on a Somatom Plus 4 Power CT system (Siemens Corp., Forchheim, Germany) using the CARE-Bolus software. This produces repetitive low-dose test images (e.g. for the lung: 140 kV, 43 mA, TI 0.5 s) and measures the Hounsfield attenuation in a pre-selected region of interest. After exceeding a defined threshold, a diagnostic spiral CT examination was begun automatically. The data obtained from 321 abdominal CT and 179 lung CT examinations were correlated with different parameters such as age, weight and height of the patients and parameters of vascular access. In a group of 80 patients, the injection of contrast medium was stopped after reaching a pre-defined threshold of an increase of 100 HU over the baseline. Then, we assessed the maximal enhancement of liver, pulmonal artery trunk and aortic arch. RESULTS: There was no correlation between bolus geometry and age, body surface or weight. In helical CT of the abdomen the threshold was reached after a mean trigger time of 27 s (range 13-67 s) and only 65 ml (range 41-105 ml) of contrast medium were administered. In helical CT of the lung the threshold was reached after 21 s (range 12-48 s) and the mean amount of administered contrast medium was 48 ml (range 38-71 ml). CONCLUSION: Bolus triggering allows optimized enhancement of the organs and reduces the dose of contrast material required compared with standard administration.

Abdominal Neoplasms↗

[Duodeno-ileal fistula development due to retroperitoneal lymph node metastases of sigmoid carcinoma].

We report on a 75-year-old patient suffering from persistent diarrhea with consecutive weight loss of 50 kg over a nine month period. Three years ago the patient had been operated on a sigmoid cancer. Ultrasonography and CT-scan revealed retroperitoneal masses due to lymph node metastases. Enteroclysis demonstrated a fistula between the duodenum and the terminal ileum. Whereas duodenocolic fistulae due to malignancies are well known to the best of our knowledge a fistula between retroperitoneal parts of the duodenum and the intraperitoneal intestine have not descripted so far.

Aged↗

[Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

PURPOSE: Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MATERIAL AND METHODS: MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). RESULTS: In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). CONCLUSION: Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

Bronchoscopy↗

[Intramural pseudodiverticulosis of the esophagus. Diagnosis on second look].

HISTORY: Case 1. A 56-year-old man had experienced increasing dysphagia for 6 months, accompanied by a weight loss of 20 kg. A stenosing oesophageal carcinoma was suspected. Case 2. A 82-year-old man had been suffering intermittently from nausea for some years but had maintained his weight (80 kg; height 173 cm). Endoscopy 4 months before this admission had revealed a duodenal ulcer; its treatment briefly improved the symptoms. INVESTIGATIONS, DIAGNOSIS AND TREATMENT: Endoscopy in case 1 detected a severe oesophageal stenosis which could not be passed, and its cause could not be ascertained despite biopsy, barium swallow and computed tomography. After bougie dilatation an endoscope was finally passed and the typical picture of oesophageal pseudodiverticulosis (OPD) seen. In case 2, endoscopy at first indicated only marked Candida oesophagitis. But after antimycotic treatment a second endoscopy revealed OPD. No treatment is known nor necessary since OPD causes no clinical symptoms unless there are complications. CONCLUSIONS: OPD, a rare condition, presents in various ways, both in its symptoms and at endoscopy. In case of oesophageal stenosis of unknown cause or Candida oesophagitis repeat endoscopy my be necessary to establish the true diagnosis: OPD should be included in the differential diagnosis.

Aged↗

Brachytherapy with iridium-192 HDR to prevent from restenosis in peripheral arteries. An update.

The use of stents does not appreciably improve restenosis (usually resulting from intimal hyperplasia) as compared to percutaneous transluminal angioplasty (PTA) alone. The development of small-caliber probes for afterloading therapy in the biliary tract allowed us to use these for therapy in the vascular system. Using a special 9 F catheter, exact measurement of the length of the stented vascular segment and of the insertion length of the afterloading probe could be reproducibly performed. We used a Nucletron (Micro) Selectron HDR planning system version 10.10 for exact calculation, monitoring, and control of the afterloading procedure. Our source was iridium 192 (10 Ci) with a diameter of 1.1 mm. The program controls and monitors the insertion and removal of the iridium probe from the source into the special catheter through to the tip, and monitors the irradiation duration. The exposure time was around 200 seconds for a surface dose of 12 Gy. To date, a total of 40 patients have been treated with endovascular afterloading. All patients suffered from clinically relevant reocclusions or restenoses in stented vascular segments of the superficial femoral artery following successful PTA or laser treatment, within 6 to 8 months after the last therapy. In all patients it was possible to perform re-PTA treatment without remaining residual stenoses in the stented region. The additional time required as compared to PTA alone was approximately 45 minutes with most of this time spending for transportation between the cath lab and afterloading room. The follow-up period of the 40 patients ranged from 4 months to 71/2 years. In 33 patients, there was no deterioration of the clinical stage and no restenosis. One patient suffered from an acute thrombosis approximately 3 months after stent implantation, another patient had a stenosis 3 cm above the stented vascular segment 12 months after irradiation treatment. Follow-up examinations have revealed no evidence of nerve lesions following irradiation therapy. The tissue surrounding the artery showed no change following irradiation therapy, either in the CT, color-coded Doppler, endovascular ultrasonic scan or MRI. No complaints of discomfort were reported during or after irradiation. With the exceptions mentioned above, there was no evidence of any complications.

Aged↗