Necrotizing pneumonitis caused by postoperative pulmonary torsion

Pulmonary torsion is an adverse event with a reported incidence of 0.089-0.4%. It may occur spontaneously, after trauma but most often as a rare complication after pulmonary surgery. We describe a case of lobar torsion of the left upper lobe after lobectomy of the left lower lobe, which resulted in a necrotizing pneumonitis with fever, hemoptysis and weight loss. A completion pneumonectomy was performed after which the patient recovered well. A review of the literature shows that a delay in diagnosis and treatment of this rare complication can have catastrophic consequences. Surgery is the treatment of choice since sparing of the lobe is hardly ever possible due to the irreversible ischemic changes. Detorsion, instead of resection, may lead to fatal complications. Although infrequent, one should be aware of lobar torsion and the necessity for immediate re-intervention.     

Magnetic resonance imaging and T2 relaxometry of human median nerve at 7 Tesla

Measurements of T2 relaxation times in tissues have provided a unique, noninvasive method to investigate the microenvironment of water molecules in vivo. As more clinical imaging is performed at higher field strengths, tissue relaxation times need to be reassessed in order to optimize tissue contrast. The purpose of this study was to investigate the water proton T2 relaxation time in human median nerve at 7 T. High-resolution images of the wrist were obtained using a home-built dedicated microstrip coil. Gradient echo images provided a good anatomical delineation of the wrist structure, with a clear definition of the median nerve, tendons, bone, and connective tissue within the wrist in an acquisition time of 2 min. Measurements of the T2 relaxation time were performed with a spin echo imaging sequence. The T2 relaxation time of the median nerve was 18.3 +/- 1.9 ms, which is significantly shorter than the T2 measured in previous studies performed at 1.5 T and 3 T. Further, the T2 relaxation time of the median nerve is shorter than the T2 relaxation time of other tissues, such as brain tissue, at the same field strength. Since the T2 relaxation time of water protons is sensitive to the water microenvironment, relaxation measurements and, in general, a more quantitative magnetic resonance imaging approach might help in detecting and investigating diseases of peripheral nervous system, such as compressive and inflammatory neuropathies, in humans.     

Feasibility of pathology-correlated lung imaging for accurate target definition of lung tumors

PURPOSE: To accurately define the gross tumor volume (GTV) and clinical target volume (GTV plus microscopic disease spread) for radiotherapy, the pretreatment imaging findings should be correlated with the histopathologic findings. In this pilot study, we investigated the feasibility of pathology-correlated imaging for lung tumors, taking into account lung deformations after surgery. METHODS AND MATERIALS: High-resolution multislice computed tomography (CT) and positron emission tomography (PET) scans were obtained for 5 patients who had non-small-cell lung cancer (NSCLC) before lobectomy. At the pathologic examination, the involved lung lobes were inflated with formalin, sectioned in parallel slices, and photographed, and microscopic sections were obtained. The GTVs were delineated for CT and autocontoured at the 42% PET level, and both were compared with the histopathologic volumes. The CT data were subsequently reformatted in the direction of the macroscopic sections, and the corresponding fiducial points in both images were compared. Hence, the lung deformations were determined to correct the distances of microscopic spread. RESULTS: In 4 of 5 patients, the GTV(CT) was, on average, 4 cm(3) ( approximately 53%) too large. In contrast, for 1 patient (with lymphangitis carcinomatosa), the GTV(CT) was 16 cm(3) ( approximately 40%) too small. The GTV(PET) was too small for the same patient. Regarding deformations, the volume of the well-inflated lung lobes on pathologic examination was still, on average, only 50% of the lobe volume on CT. Consequently, the observed average maximal distance of microscopic spread (5 mm) might, in vivo, be as large as 9 mm. CONCLUSIONS: Our results have shown that pathology-correlated lung imaging is feasible and can be used to improve target definition. Ignoring deformations of the lung might result in underestimation of the microscopic spread.     

Unicellular or multicellular origin of human granulocyte-macrophage colonies in vitro

The assumption that human granulocyte-macrophage colonies have a unicellular origin and thus are true clones has been directly tested. Cells from seven females heterozygous for the common glucose-6- phosphate dehydrogenase (G-6-PD) gene (GdB) and the variant GdA were cultured in semisolid medium for granulocyte-macrophage colony growth and the enzyme type of individual colonies was determined. When the colony density was less than 20/dish, more than 95% of colonies had either type A or type B G-6-PD, but not both. At colony densities greater than 30/dish, between 15% and 75% of colonies had both enzyme types and therefore arose from more than one cell. These results are consistent with a unicellular origin for the colonies only when they are cultured at low densities. With increasing colony density, there was a greater frequency of colonies with both type A and type B activity, suggesting that accurate enumeration of committed stem cells can only be performed at low colony concentrations.     

The effectiveness and cost evaluation of pain exposure physical therapy and conventional therapy in patients with complex regional pain syndrome type 1. Rationale and design of a randomized controlled trial

ABSTRACT: BACKGROUND: Pain Exposure Physical Therapy is a new treatment option for patients with Complex Regional Pain Syndrome type 1. It has been evaluated in retrospective as well as in prospective studies and proven to be safe and possibly effective. This indicates that Pain Exposure Physical Therapy is now ready for clinical evaluation. The results of an earlier performed pilot study with an n = 1 design, in which 20 patients with Complex Regional Pain Syndrome type 1 were treated with Pain Exposure Physical Therapy, were used for the design and power calculation of the present study. After completion and evaluation of this phase III study, a multi-centre implementation study will be conducted. The aim of this study is to determine whether Pain Exposure Physical Therapy can improve functional outcomes in patients with Complex Regional Pain Syndrome type 1. Methods/design This study is designed as a single-blinded, randomized clinical trial. 62 patients will be randomized with a follow-up of 9 months to demonstrate the expected treatment effect. Complex Regional Pain Syndrome type 1 is diagnosed in accordance with the Bruehl/International Association for the Study of Pain criteria. Conventional therapy in accordance with the Dutch guideline will be compared with Pain Exposure Physical Therapy. Primary outcome measure is the Impairment level SumScore, restricted version. DISCUSSION: This is the first randomized controlled study with single blinding that has ever been planned in patients with Complex Regional Pain Syndrome type 1 and does not focus on a single aspect of the pain syndrome but compares treatment strategies based on completely different pathophysiological and cognitive theories. Trial registration Clinical trials NCT00817128; National Trial Register NTR2090.     

Multislice 1H MRSI of the human brain at 7 T using dynamic B0 and B1 shimming

Proton MR spectroscopic imaging of the human brain at ultra-high field (≥7 T) is challenging due to increased radio frequency power deposition, increased magnetic field B(0) inhomogeneity, and increased radio frequency magnetic field inhomogeneity. In addition, especially for multislice sequences, these effects directly inhibit the potential gains of higher magnetic field and can even cause a reduction in data quality. However, recent developments in dynamic B(0) magnetic field shimming and dynamic multitransmit radio frequency control allow for new acquisition strategies. Therefore, in this work, slice-by-slice B(0) and B(1) shimming was developed to optimize both B(0) magnetic field homogeneity and nutation angle over a large portion of the brain. Together with a low-power water and lipid suppression sequence and pulse-acquire spectroscopic imaging, a multislice MR spectroscopic imaging sequence is shown to be feasible at 7 T. This now allows for multislice metabolic imaging of the human brain with high sensitivity and high chemical shift resolution at ultra-high field.     

Improving SNR and B1 transmit field for an endorectal coil in 7 T MRI and MRS of prostate cancer

Higher magnetic field strengths like 7 T and above are desirable for MR spectroscopy given the increased spectral resolution and signal to noise ratio. At these field strengths, substantial nonuniformities in B(1)(+/-) and radiofrequency power deposition become apparent. In this investigation, we propose an improvement on a conventionally used endorectal coil, through the addition of a second element (stripline). Both elements are used as transceivers. In the center of the prostate, approximately 40% signal to noise ratio increase is achieved. In fact, the signal to noise ratio gain obtained with the quadrature configuration locally can be even greater than 40% when compared to the single loop configuration. This is due to the natural asymmetry of the B(1)(+/-) fields at high frequencies, which causes destructive and constructive interference patterns. Global specific absorption rate is reduced by almost a factor of 2 as expected. Furthermore, approximately a 4-fold decrease in local specific absorption rate is observed when normalized to the B(1) values in the center of the prostate. Because of the 4-fold local specific absorption rate decrease obtained with the dual channel setup for the same reference B(1) value (20 μT at 3.5 cm depth into the prostate) as compared to the single loop, the transmission power B(1) duty cycle can be increased by a factor 4. Consequently, when using the two-element endorectal coil, the radiofrequency power deposition is significantly reduced and radiofrequency intense sequences with adiabatic pulses can be safely applied at 7 T for (1)H magnetic resonance spectroscopy and MRI in the prostate. Altogether, in vivo (1)H magnetic resonance spectroscopic imaging of prostate cancer with a fully adiabatic sequence operated at a minimum B(1)(+) of 20 μT shows insensitivity to the nonuniform transmit field, while remaining within local specific absorption rate guidelines of 10 W/kg.     

7.0?T MRI detection of cerebral microinfarcts in patients with a symptomatic high-grade carotid artery stenosis

In the current study, the presence of cerebral cortical microinfarcts (CMIs) was evaluated in a series of 21 patients with a symptomatic high-grade >50% stenosis of the carotid artery. A T₂-weighted fluid-attenuated inversion recovery sequence and a T₁-weighted turbo field echo sequence of the brain were obtained at 7.0 Tesla magnetic resonance imaging. Primary study endpoint was the number of CMIs and macroinfarcts. In total, 53 cerebral infarcts (35 macroinfarcts; 18 CMIs) were found ipsilateral to the symptomatic carotid artery, in 14 patients (67%). In four of these patients, both CMIs and macroinfarcts were visible. In the contralateral hemisphere, seven infarcts (five macroinfarcts and two CMIs) were found in five patients (24%). In the ipsilateral hemispheres, the number of CMIs and macroinfarcts were significantly correlated (P=0.02). Unpaired comparison of medians showed that the number of CMIs in the ipsilateral hemisphere was significantly higher than the number of CMIs in the contralateral hemisphere (P=0.04). No significant correlation was found between stenosis grade and the number of any infarct. The current study shows that in symptomatic patients with significant extracranial carotid artery stenosis, CMIs are part of the total cerebrovascular burden and these CMIs prevail with a similar pattern as observed macroinfarcts.     

Prognostic factors and therapeutic options of radiotherapy in pediatric brain stem gliomas

BACKGROUND: A retrospective analysis was made to clarify the relationship between prognosis, radiation dose and survival of brain stem gliomas. METHODS: From 1983 to 1995, 22 children with brain stem tumors were treated by radiotherapy in the Veterans General Hospital-Taipei. Twelve patients had pathology proof and the remainder were diagnosed by computerized tomography and/or magnetic resonance imaging. Seven patients had postoperative radiotherapy. Fifteen patients had radiotherapy as primary management, five of whom had adjuvant chemotherapy. All patients received 4000-7060 cGy, either in conventional daily or hyperfractionated twice daily radiotherapy. Survival from date of diagnosis was calculated by the Kaplan-Meier method. Univariate analyses and multivariate analyses were calculated by the log rank test and the Cox proportional hazard model, respectively. RESULTS: Most patients showed improvement following treatment. The overall 2-year survival rate was 55.5% with a median survival of 27.1 months. Two-year survival for patients with primary management of operation and radiotherapy (n = 7), radiotherapy alone (n = 10) and radiotherapy with adjuvant chemotherapy (n = 5) were 66.7, 50 and 53.3%, respectively. In univariate analysis, the study revealed that the growth pattern of tumors and the simultaneous presence of cranial neuropathy and long tract sign were significant prognostic factors (P = 0.017 and 0.036). A trend of better outcome with radiation dose > 6600 cGy and the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme showed significance in multivariate analyses (P = 0.0355). Survival was not significantly affected by age, gender or method of diagnosis. CONCLUSION: Radiotherapy appears to be an effective treatment modality of brain stem tumors. Patients with both cranial neuropathy and long tract signs had a poorer outcome. Hyperfractionated radiotherapy may give better local control and lead to better survival.