Traumatic injuries of the pelvis and thoracic and lumbar spine: does thin-slice multidetector-row CT increase diagnostic accuracy?

The objective is to evaluate different multidetector-row CT (MDCT) strategies for adequate classification of spinal and pelvic injuries. Seventy intubated patients after multiple trauma underwent conventional radiography (CR) and MDCT. Examinations included the pelvis (P), the lumbar spine (LS) and the thoracic spine (TS). Conventional radiographs, 3-mm (CT5) and 5-mm scans (CT3) and 3-mm and 5-mm scans combined with MPR (CT3R/CT5R) were compared to surgery, autopsy and clinical course. MDCT led to significantly better results than CR (P<0.01). Correlation coefficients were r=1.0 (CT3R), r=0.96 [TS] to r=1.0 [P/LS] (CT5R), r=0.8 [P] to r=1.0 [TS] (CT3), r=0.80 [P] to r=0.86 [TS] (CT5) and r=0.3 [TS] to r=0.69 [P] (CR). Fractures were identified by CT3R in 100% of cases, by CT5R in 95%, by CT3 in 90% [P]-100% [TS], by CT5 in 83.3% [LS]-90% [P] and by CR in 57.1% [TS]-87.2% [P]. Unstable fractures were identified in 100% by CT3R, CT5R and CT3, 85.7% [TS]-100% [P/LS] by CT5 and 57.1% [TS]-80% [P] by CR. Only overlapping thin-slice multiplanar reformation allows for an adequate classification of spinal and pelvic injuries and thus is highly emphasized in patients after severe blunt trauma.

Multidetector-row cardiac CT: diagnostic value of calcium scoring and CT coronary angiography in patients with symptomatic, but atypical, chest pain

The aim of this study was to investigate the accuracy of multidetector-row cardiac CT (MDCT), calcium scoring (Ca-Sc), and MDCT coronary angiography (MD CTA) in the assessment of coronary atherosclerosis. Thirty-eight patients underwent invasive coronary angiography (CA) and MDCT (collimation 4x1 mm, pitch 1.5 mm, TI 500 ms, 120 kV, 300 mAs, and retrospective ECG-gating). Calcium scoring was calculated for the total coronary artery territory and for RCA, LCA, and LCX separately. The MD CTA served to assess the degree and the localization of stenoses. All findings were compared to invasive coronary angiography. Approximately 68.4% (390 of 570) of all coronary segments could be visualized by MDCT. Correlation coefficient for MD CTA and CA amounted to r=0.58, showing distinct differences for the individual segments. Proximal segments generally showed better correlation (range 0.81-0.77) than medial segments (range 0.91-0.20), distal segments (range 0.55-0.04), or side branches (range 0.76-0.00). Patients with hemodynamically relevant (>75%) stenoses were detected by MD CTA with 72.2% sensitivity (13 of 18) and 100% specificity (20 of 20). For Ca-Sc sensitivity ranged between 94.7% (17 of 18) and 66.7% (12 of 18), specificity between 20% (4 of 20) and 80% (16 of 20) respectively, depending on the prevailing cutoff value. Combination of both methods led to 83.3% sensitivity (15 of 18) and 100% specificity (20 of 20), reaching no level of significance as compared with Ca-Sc (p=0.73) or MD CTA (p=0.23) alone. Calcium scoring as a single method showed highest sensitivity in the detection of coronary atherosclerosis but at the expense of low specificity. In patients with no or moderate calcifications, combination with MD CTA helped to distinctly increase specificity and NPV.

Kernspintomographisches Staging des Prostatakarzinoms mittels kombinierter Endorektal-Body-Phased-Array-Spule und histopathologische Korrelation

PURPOSE

Evaluation of the diagnostic value of the combined endorectal body-phased array technique regarding the staging of prostate cancers, especially in the differentiation between stages T2 and T3.

MATERIALS AND METHODS

Forty-two patients with biopsy-proven or clinically suspected prostate cancer were examined on a 1.5 T scanner (Siemens, Symphony) prior to radical prostatectomy. T (2)-weighted TSE (axial, coronal) and T (2)-weighted FSE (axial) sequences were obtained with and without fat suppression. After application of 0.2 mmol/kg body-weight Gd-DTPA, T (1)-weighted GRE sequences were obtained using dynamic MRI. All images were prospectively interpreted by two observers. The MR images were correlated with the histopathological findings of wide-area sections of prostatectomy specimens.

RESULTS

For the detection of extracapsular growth and seminal vesicle infiltration (T2 versus T3) the accuracy was between 94 % and 97 % (sensitivity 100 %, specificity between 87 % and 93 %, observer 1 and 2). In two cases with a histologically proven stadium pT2b, observer 1 had diagnosed stadium pT3a. The results of observer 2 were marginally better in only one case, which was histologically proven to be pT2b and overstaged as pT3a. MRI did not lead to under-staging of a single tumor with regard to the differentiation between T2 and T3. Overall, the staging of the tumor stages (T1 - T4) was correct in 25 of 33 cases (75 %). The dynamic MRI showed no improvement regarding sensitivity (100 %) and specificity (62 %) and achieved a staging accuracy of only 75 %.

CONCLUSION

MRI performed with a combination of a pelvic phased-array coil (PPA) and integrated endorectal coil plays a significant role in the preoperative staging of prostate cancer. However, differentiation between capsular infiltration (T2) and penetration (T3) as well as evaluation of the seminal bladder (T3b) seem to be difficult.

[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.

[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.

[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.

[Sports-related injuries of the spine]

Different sports show different patterns and frequencies of injuries, which are discussed in this paper. About 3% of all sports accidents relate to the spine. These injuries often have far-reaching consequences for the patients. A very early and extensive diagnosis of all changes is decisive for the start of an adequate therapy and thus for the prognosis of the injury. Radiological diagnosis is also of decisive importance for the documentation of late injuries and in the question of rehabilitation. Here special focus is put on MRT and CT diagnostics.A healthy spine of humans is normally able to resist all static and dynamic strains of the usual sports. However, anomalies and dysfunctions of the spine can reduce its capacity to resist strain. The recommendations of sporting activities are given according to the extent of deflection and the expected growth. The importance of radiology in primary diagnosis and in the follow-up due to typical changes like scoliosis, Morbus Scheuerman, spondylolysis and spondylolisthesis is discussed here as well.