Interstitial involvement in children: "shaggy heart".
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Child, Preschool↗
Biomedical subjects
T J Vogl
Publications and source records attributed to T J Vogl.
Performance of Web-based image distribution: server-oriented measurements.
The aim of this study was to assess the performance of Web-based image distribution when multiple personal computers (PCs) are downloading images simultaneously for different server hardware configurations. Using specially developed software, the time-to-display (TTD) of different image types was measured with up to 16 concurrent PCs for various combinations of processor, random access memory (RAM), network connection and image compression. The TTD increased linearly with the number of concurrent PCs but remained under 5 s in most of the cases, even with 16 concurrent PCs. Only with a 10-Mbit/s network connection or with lossy compression were TTDs above 5 s obtained. Two processors instead of one led to a slight and constant improvement of the TTD. Reducing the amount of RAM increased the TTD mainly for computed radiography (CR) images. There was no difference between a 200- and 100-Mbit/s network, but 10 Mbit/s proved significantly worse. When increasing the number of clients lossless compression performed substantially better than lossy. A standard off-the-shelf server provides an appropriate download performance even with 16 concurrent clients. Processor speed and RAM amount are of minor importance, but it is highly recommended to use a 100-Mbit/s network connection and to avoid the application of on-demand lossy compression in a local area network.
Internet↗
Performance of Web-based image distribution: client-oriented measurements.
The aim of this study was to define a clinically suitable personal computer (PC) configuration for Web-based image distribution and to assess the influence of different hard- and software configurations on the performance. Through specially developed software the time-to-display (TTD) for various PC configurations was measured. Different processor speeds, random access memory (RAM), screen resolutions, graphic adapters, network speeds, operating systems and examination types (computed radiography, CT, MRI) were evaluated, providing more than half a million measurements. Processor speed was the most relevant factor for the TTD; doubling the speed halved the TTD. Under processor speeds of 350 MHz, TTD mostly remained above 5 s for 1 CR or 16 CT images. Here Windows NT with lossy compression were superior. Processor speeds of 350 MHz and over delivered TTD <5 s. In this case Windows 2000 and lossless compression were preferable. Screen resolutions above 1280 x 1024 pixels increased the TTD mainly for CR images. The RAM amount, network speed and graphic adapter did not have a significant influence. The minimum threshold for clinical routine is any standard off-the-shelf PC better than Pentium II 350 MHz, 128 MB RAM; hence, high-end PC hardware is not required.
Computers↗
Hepatocellular carcinoma with arterio-venous shunting: high incidence of hematogenous metastases?
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Adult↗
Phase II study of the efficacy and safety of cisplatin-epinephrine injectable gel administered to patients with unresectable hepatocellular carcinoma.
PURPOSE: To study the efficacy and safety of percutaneous cisplatin-epinephrine (CDDP-EPI) injectable gel in patients with localized unresectable hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Eligible patients had histologically proven HCC, no prior treatment except for surgery, and no more than three tumors (each measured < or = 7 cm, total tumor volume < or = 200 cm(3)). They were treated percutaneously under ultrasound or computed tomography (CT) guidance, with up to 10 mL of CDDP-EPI gel (1 mL contains 4 mg of CDDP and 0.1 mg of EPI) per treatment and four treatments in 6 weeks to a maximum of eight treatments. The primary end points were tumor response, defined by change of percentage of tumor necrosis according to CT criteria, and safety. Survival parameters were secondary end points. RESULTS: From June 1997 to April 2000, 58 patients (median age, 65 years) entered the study. All patients were assessable for safety, and 51 were assessable for efficacy. The median number of treatments was four (range, one to eight treatments). Objective response rate was 53% (27 of 51 patients), including 16 complete and 11 partial responses. Of the 27 responders, 14 (52%) subsequently developed progressive disease, but in most of them (93%), a new tumor arose at untreated liver sites. Median survival was 27 months (range, 18.4 to 35.7 months). The 1-, 2-, and 3-year survival rates were 79%, 56%, and 14% respectively. The procedure was well tolerated with only minor side effects. CONCLUSION: Percutaneous local ablation with CDDP-EPI injectable gel can induce significant tumor necrosis and local control for localized unresectable HCC, and the treatment is well tolerated.
Adult↗
[Importance of CT and MRI in the follow-up of patients with rectal cancer].
INDICATION: Presentation and evaluation of diagnostic procedures for the follow-up in patients with suspected local recurrence of rectal cancer. METHODS: Follow-up usually is performed using endoscopy and endosonography. Imaging techniques applied are also contrast enema as well as helical CT,MR imaging (MRI), and positron emission tomography (PET). RESULTS: The results demonstrate the difficulty of all available modalities to differentiate between early tumor recurrences from post-therapeutic alterations. Especially the differentiation of scar tissue and local tumor recurrence, the detection of lymph node as well as pulmonary or hepatic metastasis requires a large diagnostic effort with employment of various imaging modalities. Values determined for sensitivity and specificity for CT are 84% and 91% with a positive predictive value (PPV) of 78%. For MRI and PET the sensitivity are 94% and 98%,and the specificity 92% and 90% with a PPV of 93% for the PET. CONCLUSION: The results demonstrate the increasing importance of CT and MRI in the follow-up of patients with rectal cancer and enable an accurate and early diagnosis through employment of new examination strategies and sequence protocols.PET remains an add-on examination in uncertain local lesions.
Aged↗
[Diagnostic imaging and differential diagnosis of pathological processes of the sinus cavernosus].
To describe the different imaging modalities for the evaluation of pathological changes in the cavernous sinus as well as to compile criteria for differential diagnosis. Imaging of the cavernous sinus comprises the primary use of tomographic modalities such as CT or MRI. The continuing development of multislice-CT (MSCT) allows the depiction of bony structures of the cavernous sinus with a high resolution.Secondary reconstructions of the acquired data set allow a reliable evaluation especially of the bony topography including the foraminae of nerves and vessels. Uni- or bilateral structures can be visualized using contrast-enhanced CT.CT-angiography is capable of demonstrating the course of the internal carotid artery and its involvement in pathologies of the cavernous sinus, this recent achievement has only been made available by use of the current short scanning times. Contrast-enhanced MRI in axial and coronal orientation, optionally using fat saturation techniques as well as arterial and venous MRI-angiography (MRA) are used to depict the soft parts of the cavernous sinus. Care must be taken to cover all topographic detail including different signal intensities, as multiple inborn, neoplastic, infectious or traumatic changes can be present hampering the radiologic diagnosis of the cavernous sinus. Uni- and bilateral infiltration of the cavernous sinus as well as vascular involvement represent additional criteria leading to the differential diagnosis. The advent of dynamic sequences as well as diffusion and perfusion weighted MRI have broadened the spectrum of diagnostic modalities. Digital subtraction angiography as an invasive technique is used during therapeutic procedures such as the local treatment of aneurysms or carotid-cavernous fistulas.
Carotid Artery, Internal↗
[Early detection of colorectal tumors: CT or MRI?].
Cancer screening is currently offered for the organs breast, prostate, cervix and colorectum. With progressing technique in computerized tomography (CT) and magnetic resonance imaging (MRI) the colorectum can be increasingly better assessed. Because in CT and MRI also other organs are imaged with the colorectum, a colorectal screening automatically becomes a multiorgan screening. CT and MRI protocols designed for early detection of colorectal tumors are presented and discussed with regard to monoorganscreening (in CT: low dose, no i.v. contrast) and multiorganscreening (in CT: diagnostic dose for neighboured organs with i.v. contrast). More information under http://www.multiorganscreening.org.
Colonic Polyps↗
[Diagnosis of colorectal tumors].
With the introduction of multislice CT extensive volumetric data sets can be quickly acquired in high spatial resolution. The high spatial resolution reduces partial volume effects and enables multiplanar reconstructions. Regarding the colorectum this means that the colon can be assessed if the colon is sufficiently cleaned and distended, and that transmural infiltration of colorectal carcinoma and liver metastases can be better detected. T-staging of colon cancer is less important than T-staging of rectal cancer. Based on the higher contrast MRI is superior to CT in T-staging of rectal cancer and in the differentiation between scarring tissue and recurrence of carcinoma.
Colon↗
[Importance of coloncontrast enema].
Screening for colorectal cancer starts with digital exploration of the rectum and was extended in 1977 using the haemoccult test. It was referred to detect 24% of malignancies, but with a high number of false positive findings. Combination of regular follow up examinations and coloscopy reached a sensitivity of 80%. International studies demonstrated the need of a complete colon examination, so that the coloscopy is actually an important screening method in Germany. The coloncontrast examination is a safe, cost-effective method with a low complication rate. It is suitable especially for patients, in which the colonoscopic evaluation of the colon was not complete and provides additional morphological informations in many cases.
Adenomatous Polyps↗
[The role of stereotactic 11G vacuum biopsy for clarification of BI-RADS IV findings in mammography].
PURPOSE: To evaluate the potential of stereotactic vacuum breast biopsy in the histologic evaluation of suspicious mammographic findings ( BI-RADS IV). MATERIALS AND METHODS: In 221 patients with 227 probable mammographic lesions categorized as ( BI-RADS -IV), stereotactic biopsies were performed with an 11-gauge vacuum-assisted biopsy device (Mammotome). The evaluation included the histology of the specimens obtained with the Mammotome or with surgery, the time for the biopsy, the amount of bleeding, number of rotations and procured specimens, the extent of the resection and the complications. RESULTS: The biopsies were technically successful in 214 of the 227 probable mammographic lesions, with 176 lesions mostly resected and 34 lesions removed more than 50 %. No representative tissue was obtained from 4 lesions. All biopsies were performed without any clinically relevant complications and terminated after adequate material was obtained (O 28 specimens, 2.58 rotations). The mean time needed for performing the biopsy was 40.2 minutes. The histologic findings were DCIS (42 lesions), ADH (7 lesions), LCIS (3 lesions), ID-Ca (14 lesions, IL-Ca (3 lesions), and IDL-Ca (1 lesion). In 28 of 42 lesions with the initial DCIS histology, the surgical histology was also DCIS (n=28) or no residual tumor (n=10). In 4 lesions with an initial DCIS-histology, the surgical histology was invasive ductal cancer (9.5 %). The late follow-up examinations (up to 3 years) did not find any evidence of a false negative biopsy. CONCLUSION: Stereotactic vacuum breast biopsy ideally complements existing breast biopsy methods. The method is minimal invasive with a low rate of mostly minor complications.
Artifacts↗
[Interstitial photodynamic laser therapy for liver metastases: first results of a clinical phase I-study].
PURPOSE: Development and evaluation of a new photodynamic treatment technique for the laser therapy of liver malignancies MATERIAL AND METHODS: The combination with new catheter systems enables the use of the photodynamic therapy (PDT) to treat also tumors in parenchymal organs. So far it is mainly used to treat superficial or endoluminal tumors. The presented study is part of a multicenter phase I-study. We treated 5 patients with colorectal liver metastases with the new photosensitizer SQN 400 and following interstitial photodynamic laser treatment. Evaluation of tumors were performed by contrast-enhanced CT scans. RESULTS: In the contrast enhanced CT scans the development of a complete necrosis within a radius of 1 cm around every single fibre could be shown. Additional the ablation of tumors with the combined use of several fibres is possible. Severe complications or toxicities were not observed. CONCLUSION: The photodynamic laser therapy of liver malignancies is a minimal invasive procedure with little side effects which produces sharply defined yet small volumes of necrosis.
Aged↗
[MR-guided biopsies of undetermined liver lesions: technique and results].
PURPOSE: To evaluate safety and precision of liver tumor biopsies performed in an open low field system using different sequence techniques. MATERIALS AND METHODS: In 47 patients with liver tumors, MR-guided biopsies were performed in a low field system (0.2 Tesla, Magnetom Open, Siemens) using two different sequences. The procedure was monitored with T1-weighted FLASH sequences (TR/TE = 100/9; 70(3)) in all patients and with FISP-Rotated-Keyhole-sequence (TR/TE = 18/8; 90(3)) in additional 20 patients. After positioning of the needle tip in the tumors, 166 biopsy specimens were acquired with 16 G cutting needles (Somatex*). The diameter of the biopsied lesions ranged from 1 to 10 cm (mean diameter 3.2 cm). Visibility of the needles and precision of the biopsies were evaluated. RESULTS: All interventional biopsies were performed without vascular or organ injuries. Adequate specimens for histologic interpretation were obtained in 42 cases (89.3%). The biopsy results were non-specific in 2 patients (4.2%) and the lesions missed in 3 patients (6.3%). Mean in-room time was 35 minutes and the intervention time was 8.3 minutes. T1-weighted FLASH images proved optimal for confirming needle-tip placement during the biopsies or punctures. Organs, tumors and vessels were easily identified. The FISP sequence proved to be inferior in visualizing vessels and tumors. CONCLUSION: MR-guided liver biopsies are safely and precisely performed using T1-weighted FLASH-sequences with sufficient visualization of the lesions and might be complementary to US- or CT-guided biopsies.
Adult↗
[Transarterial chemoperfusion of inoperable pancreas carcinoma and local recurrence].
BACKGROUND: To evaluate the side effects and tumor response of a locoregional transarterial chemoperfusion with Mitomycin C and Gemcitabine in advanced pancreatic cancer. MATERIALS AND METHODS: Between October 2001 and August 2002, 16 patients were treated in 80 transarterial chemoperfusion sessions with a mean of 5 sessions per patient and a pause of 4 weeks between the sessions. The chemotherapy consisted of a combination of Mitomycin C (8.5 mg/m 2) and Gemcitabine (500 mg/m 2), administered within 1 hour. The tumor response was evaluated by MRT and CT and the quality of life by a patient questionnaire. RESULTS: All patients tolerated the procedure well. The therapeutic outcomes were as follows: in 50 % (n=8) of patients, minor response with a decrease in size of the primary tumor and metastases up to 20 %; in 25 % (n = 4) of patients, stable disease; and in 25 % (n = 4) of patients, progressing metastases with stable primary tumor. Eleven patients (68.75 %) reported a good quality of life without impaired performance of their daily activities. Side effects were moderate and reversible between the treatment cycles. After one year 25 % of the patients were still alive. CONCLUSION: Transarterial chemoperfusion is a minimally invasive treatment for pancreatic carcinomas and local recurrences with little side-effects and can be delivered on an outpatient basis. It might be indicated as potential neoadjuvant treatment before surgery or as palliative treatment to provide clinical benefits and to improve the quality of life.
Activities of Daily Living↗
[Embolization of symptomatic myomas (UAE): technique, indication and results].
Presentation of indication, technique and results of transarterial uterine artery embolization (UAE) for the treatment of symptomatic myomas. Technical requirements are presented like DSA, catheters, superselective catheterisation and the different embolization materials as polyvinylalcohol (PVA) or microspheres, as well as the follow-up after UAE. The technical success rate of UAE is documented to range between 98 to 100 % and myomatous symptomatology disappears in 85 to 94 % of the cases. A reduction in the size of the myomata after UAE is observed between 48 to 70 %. A resolution of the hemorrhage disappears in 80 to 96 % of the cases immediately. Particulate embolization of the uterine artery is a new minimally invasive therapy in the management of symptomatic leiomyomas with a high efficiency and low rate of major complications. Further studies may prove the longterm results after UAE, the influence on fertility and possible late complications.
Angiography, Digital Subtraction↗
Evaluation of a "no-cost" Internet technology-based system for teleradiology and co-operative work.
The aim of this study was to assess the suitability of a no-cost system based on standard Internet technology components for teleradiology. The system was composed of free software (communication, DICOM viewer, compression) and standard off-the-shelf hardware components. For different image (CR, CT, MR) and network types (LAN and ISDN) the File Transfer, Audio and Video Conference, and Co-operative Work properties were examined and compared with the literature referring to standard complete packages and dedicated teleradiology systems. The main advantages of the no-cost system are: price; ease of use; independence from specific hardware; and potential connection to any possible partner. The performance of the File Transfer and the Audio and Video Conference was comparable to the other system groups with slight disadvantages in the usability. For Co-operative Work the employed "application sharing" technology does not meet the clinical requirements, which applies identically to the standard complete packages. Here the specialized systems prove superior, although they are proprietary. With minimal restraints the evaluated no-cost solution can be used for File Transfer and Conference scenarios. The usage for Co-operative Work with ISDN is not recommended, unless for the purpose of gaining experience or when dealing with small amounts of cases or images.
Computer Systems↗
Double bubble sign.
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Duodenal Obstruction↗
MRI and color-coded duplex sonography: diagnosis of partial priapism.
A case of partial priapism is reported diagnosed by contrast-enhanced MR imaging and color-coded duplex sonography. Follow-up examinations after 4 weeks and 3 months were performed. According to the results of color-coded duplex sonography and MRI, a partial priapism with development from the subacute stage to a fibrous residuum after spontaneous lysis was diagnosed. There are only very few cases of partial priapism reported in the literature and this is the first case report that demonstrates diagnosis and follow-up both by color-coded duplex sonography and contrast-enhanced MR imaging.
Diagnosis, Differential↗