Showing papers in "Journal of Medical Imaging and Radiation Oncology in 2007"

Preoperative embolization of hypervascular head and neck tumours.

Abstract: The embolization of vascular tumours of the head and neck has become an important adjunct to the surgical treatment of these tumours. A vascular tumour in the head and neck region in a surgically treatable patient may be a candidate for embolization. Palliative embolization may be the sole treatment for high risk patients. Reducing intraoperative bleeding may shorten surgery time thus decreasing morbidity and mortality. The purpose of this study is to assess the efficacy of embolization as an adjunct to surgery or as a curative measure in the management of hypervascular head and neck tumours. We retrospectively reviewed the records of 46 consecutive patients (27 men and 16 women; mean age, 37.8 years) with 48 hypervascular head and neck tumours that had undergone preoperative transarterial, direct puncture or combined mode of embolization. Diagnosis of tumours was made on the basis of findings of imaging studies. The 46 patients underwent embolization either through transarterial route, by direct puncture technique or both direct puncture and arterial route. The devascularization reached 90-95% with the use of NBCA. The amount of devascularization reached by transarterial particle embolization is a little lesser. One patient (carotid body tumour) developed mild unilateral seventh, ninth and 10th cranial nerve palsy after transarterial embolization, transient hemiparesis was seen in another patient (nasopharyngeal angiofibroma). Both patients improved completely with steroids and had no deficit on follow up. One patient developed delayed glue migration into the middle cerebral artery territory 6 h after the procedure with no reported increase in size of the lesion in the following 5 years. Preoperative embolization of hypervascular tumour of head and neck region appears to be safe and improves the chance of complete removal during surgery with minimal blood loss.

Imaging of ascariasis

Abstract: Ascaris lumbricoides is one of the most common parasitic infestations of the gastrointestinal tract worldwide. During the intestinal phase of the disease, the adult worms usually remain clinically silent, sometimes causing a variety of non-specific abdominal symptoms. When present in large numbers, the worms may get intertwined into a bolus, causing intestinal obstruction, volvulus or even perforation. Occasionally, the adult Ascaris worm may migrate into the Vater's ampulla and enter the bile duct, gall bladder or pancreatic duct, leading to a variety of complications such as biliary colic, gallstone formation, cholecystitis, pyogenic cholangitis, liver abscess and pancreatitis. Imaging plays a significant role in showing the presence of worms and possible complications in intestinal as well as hepatobiliary ascariasis. This pictorial essay aims to illustrate various imaging features of ascariasis and its associated complications.

Post-radiofrequency ablation syndrome after percutaneous radiofrequency of abdominal tumours: one centre experience and review of published works.

Abstract: The aim of this study was to evaluate prospectively post-radiofrequency ablation (RFA) syndrome and to determine its effect on the quality of life in the 15 days after percutaneous RFA treatment. We carried out an internal review board-approved prospective study of the delayed symptoms that occurred after 71 consecutive RFA sessions in 53 patients (12 women and 41 men; age range 45-83 years; mean age 71.6 years) with 45 primary liver tumours, 34 liver metastases, 3 renal cell carcinoma (RCC), 2 residual lesions from RCC after nephrectomy and 1 pancreatic metastases from RCC. Postablation symptoms occurred in 17 of 53 (32%) patients. Six of 17 patients developed low-grade fever (from 37.5 to 38.5 degrees C). Other symptoms included delayed pain (9/17), nausea (7/17), vomiting (3/17), malaise (3/17) and myalgia (1). Postablation syndrome is a common phenomenon after RFA of solid abdominal tumours. Not only in our study but also in the previous ones the occurrence is observed in approximately one-third patients. Patients should be informed that these symptoms are self-limiting after RFA and most patients should be able to resume near-complete preprocedural levels of activity within 10 days after the procedure.

Metastases to the breast: A review of 33 cases

Abstract: The aim of the study was to show the clinical and radiological manifestations of metastases to the breast (MB). From 1987 to 2006, 33 patients with MB were diagnosed at our institution. Their clinical and radiological features were retrospectively evaluated. Of the 33 cases, 31 presented as a palpable breast lump. On mammography, their findings were classified as follows: well-circumscribed masses (11 cases), ill-circumscribed masses (five), focal asymmetric densities (one) and inflammatory skin changes (six). Mammograms were normal in six cases (all of them showed dense breast tissue). Four CT scans showed two well-circumscribed masses and two ill-circumscribed masses. Ultrasonography was available in 18 cases: hypoechoic lesions (15 cases) were more frequent than hyperechoic (one) or isoechoic lesions (two). The appearance on magnetic resonance was similar to primary breast cancer (one case). The most common primary tumours causing MB were haematological malignancies (nine cases) and melanomas (seven). Metastases to the breast showed a wide range of mammographic and ultrasonographic appearances, resembling both benign and malignant lesions. Any patient who presents with a breast lump with a history of cancer should undergo a core-needle biopsy in order to determine the histology of the lump.

Multicentre quality assurance of intensity-modulated radiation therapy plans: A precursor to clinical trials

Abstract: Summary A multicentre planning study comparing intensity-modulated radiation therapy (IMRT) plans for the treatment of a head and neck cancer has been carried out. Three Australian radiotherapy centres, each with a different planning system, were supplied a fully contoured CT dataset and requested to generate an IMRT plan in accordance with the requirements of an IMRT-based radiation therapy oncology group clinical trial. Plan analysis was carried out using software developed specifically for reviewing multicentre clinical trial data. Two out of the three plans failed to meet the prescription requirements with one misinterpreting the prescription and the third failed to meet one of the constraints. Only one plan achieved all of the dose objectives for the critical structures and normal tissues. Although each centre used very similar planning parameters and beam arrangements the resulting plans were quite different. The subjective interpretation and application of the prescription and planning objectives emphasize one of the many difficulties in carrying out multicentre IMRT planning studies. The treatment prescription protocol in a clinical trial must be both lucid and unequivocally stated to avoid misinterpretation. Australian radiotherapy centres must show that they can produce a quality IMRT plan and that they can adhere to protocols for IMRT planning before using it in a clinical trial.

Diagnostic accuracy of shoulder ultrasound performed by a single operator

Abstract: SUMMARY Both diagnostic ultrasound and magnetic resonance imaging (MRI) are used for investigation of the presence and severity of rotator cuff lesions. There is no consensus as to which is the more accurate and cost-effective study. We sought to examine the sensitivity of ultrasound, when used by one experienced radiologist with modern equipment. We compared the ultrasound and surgical results obtained from 68 patients. Ultrasound showed a sensitivity of 89% and specificity of 100% (Positive Predictive Value 100%) for full-thickness tears, and a sensitivity of 79% and specificity of 94% (Positive Predictive Value 87%) for partial-thickness tears. We found that shoulder ultrasound, in the hands of an experienced radiologist with the use of modern high-resolution equipment, is highly sensitive in differentiating complete tears and partial-thickness tears. Our results are similar to the best published results for MRI and given that ultrasound is significantly cheaper and more available, ultrasound by an experienced radiologist should be considered as a primary diagnostic tool for imaging the rotator cuff.

Music therapy as a non-pharmacological anxiolytic for paediatric radiotherapy patients.

Abstract: Outpatient radiotherapy treatment in the paediatric cancer patient can be a traumatic and an anxiety-provoking experience for both the patient and the family. Music therapy has been widely reported to have psychosocial, educational and physical benefits for the paediatric cancer patient. Using individual case reports, this paper shows the successful use of music therapy as a non-pharmacological anxiolytic in the paediatric radiotherapy, outpatient waiting room setting, by providing the patient and the family with a means of communication, self-expression and creativity.

Literature review and suggested protocol for managing ultrasound soft markers for Down syndrome: thickened nuchal fold, echogenic bowel, shortened femur, shortened humerus, pyelectasis and absent or hypoplastic nasal bone.

Abstract: Mid-trimester soft markers have been linked with Down syndrome and other aneuploidies. There are many other prenatal screening tests available with better detection rates for Down syndrome than the mid-trimester ultrasound. Many patients confronted with the diagnosis of a soft marker become anxious and may request a diagnostic test (amniocentesis) despite the associated risk of miscarriage. This is also despite the fact that most fetuses with an isolated soft marker are chromosomally normal. The management of a pregnancy with a soft marker must therefore be planned in a manner designed to minimize patient anxiety. Likelihood ratios can be used to modify a patient's 'prior risk' (based on age or prior screening tests) and create a new risk. This calculation may help identify a subset of patients suitable for further investigation. It has been proposed that 'negative' likelihood ratios can be used to reduce a patient's risk if no soft marker is found at a mid-trimester ultrasound. There remain concerns about this approach and further research is required before this approach enters common practice. The published work surrounding the management of thickened nuchal fold, echogenic bowel, shortened femur, shortened humerus, pyelectasis (renal pelvis dilatation) and hypoplastic nasal bone is reviewed. Each soft marker has different associations and individual management plans for each of these soft markers are presented. Although isolated single umbilical artery is not usually considered a soft marker of aneuploidy, a management plan for this common finding is also included.

Infusion of 50% glucose solution before injection of ethanolamine oleate during balloon‐occluded retrograde transvenous obliteration

Abstract: The feasibility of infusion of 50% glucose solution before balloon-occluded retrograde transvenous obliteration (BRTO) to occlude collateral vessels draining gastric varices other than gastrorenal shunt was evaluated. In five patients with such collateral vessels, 50% glucose solution was infused from the balloon catheter inflated within the gastrorenal shunt. The degree of collateral vessels had decreased when BRTO was carried out so that sclerotic agents sufficiently occupied the gastric varices in all patients. In three patients, embolization of collateral vessels with coils was unnecessary. There were no complications. In conclusion, retrograde infusion of 50% glucose solution assists in effectively carrying out BRTO.

Use of ultrasound in 187 infants with suspected infantile hypertrophic pyloric stenosis.

Abstract: Summary The diagnostic efficacy of ultrasound (US) in the diagnosis of infantile hypertrophic pyloric stenosis (IHPS) was evaluated, with particular attention paid to whether prematurity, age or weight correlate significantly to the sonographic measurements. The medical records of 187 infants with suspected IHPS were reviewed retrospectively. Eighty-seven had an US examination with details of the pylorus. Fifty-nine of these gave a positive diagnosis. The US criteria for a positive diagnosis were pyloric muscle thickness (PMT) ≥3 mm and pyloric muscle length (PML) ≥17 mm. The mean overall PMT was 4.14 mm and mean overall PML was 18.99 mm. Premature infants had a lower mean PML (17.8 mm) than the term infants (PML mean 19.3 mm); however, this was not significant (t-value 1.92, P = 0.062). The sensitivity and specificity of PMT was 91 and 85%, respectively, and of PML 76 and 85%, respectively. The ability of US to diagnose IHPS using our criteria was significant (t-value, PMT 14.93 and PML 6.89; P < 0.0001). There was no significant correlation between age, weight or prematurity and a sonographic diagnosis of IHPS (Pearson’s coefficient <0.3). Therefore, the same US criteria should apply irrespective of prematurity, age or weight. Borderline PMT and PML measurements necessitate repeat US or alternative imaging.

How accurate is the Light index for estimating pneumothorax size

Abstract: In Europe, the Light index is used for estimating the size of pneumothorax. It is based on the proportional relationship between the collapsed lung and the hemithorax. Other methods rely on absolute measurements on radiographs. The aim of this study was to compare the estimated size of pneumothoraces using Light index with that estimated using the CT volumetrics-derived Collins method. This was a secondary analysis of radiographs from a database of pneumothoraces treated conservatively. Radiographs were measured independently by two researchers according to the methods described by Light and Collins. Estimates of size derived by the two methods were compared using bias plot analysis techniques. The primary outcome of interest was agreement between pneumothorax size (as per cent) between the two methods. Sixty-one radiographs (27 patients) were analysed. The median age was 21 years and 76% were men. There was poor agreement between the methods. The average difference was 7.3% with the Light index underestimating the size compared with the Collins method. The 95% limits of agreement were wide (24% underestimation to 17% overestimation of size). The Light index as described does not accurately estimate the size of pneumothorax. New methods if accurate quantification of pneumothoraces is required clinically.

Imaging and intervention of retroperitoneal fibrosis

Abstract: Retroperitoneal fibrosis is a rare condition characterized by the development of fibrous plaques in the retroperitoneal space The fibrous plaques characteristically arise distal to the bifurcation of the abdominal aorta and progress to encase the iliac vessels distally and are defined by the associated encasement of one or both ureters Imaging plays an important role in not only establishing the diagnosis, but also in monitoring disease progression Historically, the radiological diagnosis was made predominantly by intravenous urography and retrograde pyelography More recently, advances in cross-sectional imaging with ultrasound and contrast-enhanced CT have allowed for a more precise diagnosis as well as helping to accurately define the extent of the disease At our institution, we have found ultra-fast MRI to also play a useful role in establishing the diagnosis In particular, magnetic resonance urography using HASTE (half Fourier-acquired single shot turbo spin-echo) sequences allow a safe alternative to intravenous urography, particularly in patients with poor renal function The purpose of this article is to describe the role of the various imaging methods available to the radiologist and to emphasize the important role that the interventional radiologist now plays, not only in obtaining tissue for diagnosis, but also in providing treatment of the disease by percutaneous nephrostomy drainage and subsequent stent placement in select cases

Do kidney sizes in ultrasonography correlate to glomerular filtration rate in healthy children

Abstract: The objective of this study was to determine the correlation between ultrasonographic kidney sizes and glomerular filtration rate (GFR) in healthy children. This was a cross-section study on 116 healthy children. Renal diseases were ruled out by a paediatric nephrologist. Ultra sonography of both kidneys was carried out by an experienced radiologist. The volume was calculated by ellipsoid formula. We defined net volume as kidney volume-sinus fat volume'. The sum of right and left kidney sizes was defined as total sizes. We calculated GFR by means of the Schwartz formula. Correlations between kidney sizes and GFR were studied with Pearson correlation coefficient. The mean age of the children was 8.4+/-3.4. The GFR mean was 108+/-30 (mL/min per 1.73 m2). GFR correlated to total renal volume (r=0.52, P<0.001), total net volume (r=0.53, P<0.001) and total kidney length (r=0.59, P<0.001). Ultrasonographic kidney sizes, especially the kidney length, correlate to GFR in healthy children. Kidney sizes assessment by ultrasonography may play a role in renal function evaluation in children.

Subungual glomus tumour: magnetic resonance imaging findings.

Abstract: SUMMARY The present study aims to present a case of a subungual glomus tumour with literature to the findings on magnetic resonance (MR) imaging. A 51-year-old man consulted his physician because of a pain in the nail bed of his thumb, which he had had for 2 years. A plain radiography and MR examination was performed. Physical examination showed a blue-brown focus beneath the nail and there was deformation. A plain radiography demonstrated no abnormality. T1-weighted spin-echo images showed a well-marginated, oval, slightly hyperintense lesion (4 mm diameter) located in the subungual region. On turbo spin-echo T2-weighted images the lesion was hyperintense with a hypointense rim. T1-weighted spin-echo images after intravenous administration of contrast medium showed strong enhancement. The lesion was completely excised at surgery and the diagnosis of a glomus tumour was established histologically. In conclusion, MR imaging offers excellent diagnostic information about a clinically suspected glomus tumour.

What is a large breast? Measuring and categorizing breast size for tangential breast radiation therapy.

Abstract: Despite consensus in published studies that larger-breasted patients who undergo radiation therapy tend to suffer from more severe acute skin reactions and a more adverse cosmetic outcome, there appears to be no consensus on the definition of a 'large breast'. This paper describes an analysis of breast size that was undertaken on 50 patients and compares this data with other published studies. The desired outcome for the study was to formulate a definition of 'large breast size' that would be appropriate for Australian patients and that could be determined simply and quickly in busy radiation oncology clinics. Analysis suggests that cup and brassiere size may be used to separate breast size into two categories. On the basis of published data and results from this study, it is recommended that patients with a cup size>or=D or a bra size>or=18 could be categorized as having large breasts, with all other patients considered average in size.

Acquired spontaneous intercostal abdominal hernia: case report and a comprehensive review of the world literature.

Abstract: Intercostal hernias develop most often as a result of a blunt or penetrating thoracoabdominal trauma. We know of no prior report of a spontaneously occuring intercostal hernia. This study presents a review of the published literature that deals with this uncommon phenomenon, along with a discussion of our patient's clinical presentation and imaging findings.

Is rural radiation oncology practice quality as good as the big smoke? Results of the Australian radiotherapy single machine unit trial.

Abstract: Summary Radiotherapy utilization rates in rural Australia are suboptimal, with one solution being the building of single machine units (SMUs). One concern raised with such an approach is the quality of care delivered in SMUs. The Australian and Victorian governments have established two SMUs in the state of Victoria, with each SMU operated as a satellite service of a major ‘hub’ site. We report on the planned evaluation of practice quality. Radiation oncologist (RO) clinical practice was externally audited using the Royal Australian and New Zealand College of Radiologists Peer Review Audit instrument. This tool splits RO clinical practice into documentation/quality assurance (QA) criteria and decision-making criteria. Over the four sites, 130 patients were randomly selected for audit. At hub sites, 79.6% of all criteria audited were adequate, compared with 84.4% of criteria audited at SMUs (P = 0.0002). This difference was largely because of better adherence to documentation/QA criteria at the SMU sites. RO decision-making and protocol adherence were routinely very high and consistent with other clinical practice audits. There were no significant differences between hubs and SMUs for adherence to decision-making criteria; however, the few potential deficiencies in patient care identified occurred only at the hub sites. In at least one of these cases, potential suboptimal management was as a direct result of inadequate documentation. This audit found that SMUs provide as high a standard of radiotherapeutic care as larger hub departments. The findings also emphasize the need for all departments to target clinical documentation.

Role of radiotherapy in the management of organ transplant recipients diagnosed with non-melanoma skin cancers

Abstract: Summary Organ transplantation has had a major effect on the lives of thousands of patients worldwide. In Australia and New Zealand, over 13 000 patients have become organ transplant recipients (OTR). Following transplantation, patients require lifelong immunosuppression to prevent organ rejection. The loss of immune surveillance results in OTR experiencing a higher incidence of infection and malignancy in comparison with the general (immunocompetent) population. Non-melanoma skin cancer (NMSC) is the most common malignancy worldwide, arising most often on the sun-exposed head and neck. Organ transplant recipients experience a higher incidence of NMSC when compared with the general population and a higher incidence of squamous cell carcinoma compared with basal cell carcinoma. Organ transplant recipients also develop NMSC at a younger age and experience multiple new NMSC. Australians experience the highest incidence of NMSC in the world with a consequence that NMSC arising in OTR can lead to significant morbidity and even mortality. Radiation oncologists treating patients with skin cancer will almost certainly make recommendations in the setting of NMSC arising in OTR. The aim of this article is to discuss the role of radiotherapy in the management of OTR diagnosed with NMSC. The emphasis will be on the treatment of patients with a high-risk NMSC (e.g. squamous cell carcinoma, Merkel cell carcinoma, unfavourable basal cell carcinoma) because this reflects the most common clinical scenario in which a recommendation of radiotherapy, usually adjuvant, may be considered.

Capillary haemangioma involving the middle and external ear: radiotherapy as a treatment method.

Abstract: Summary Capillary haemangiomas rarely occur in the auditory canal and have mainly been managed with surgical excision or kept on close follow up for development of symptoms. Radiotherapy, as a treatment method, has not been reported previously in the published work. We describe a study of a capillary haemangioma in the auditory canal of a 26-year-old woman who presented with bleeding. She was treated with radiotherapy, after the lesion was found to be unsuitable for surgery and embolization. The patient remains well 5 years after completion of treatment.

Inguinal endometriosis attaching to the round ligament.

Abstract: Summary We report a case of endometriosis in the right inguinal region, attached to the right round ligament in a 28-year-old woman. At the age of 20, laparoscopic left ovarian cystectomy and pelvic adhesiolysis for endometriosis was carried out. She noticed a right tender groin mass 7 months previously, and the tumour size fluctuated with the menstrual cycle. A poorly circumscribed elastic hard mass, measuring 3 cm in diameter, was palpated in her right inguinal region. Magnetic resonance imaging showed a 2.5 cm × 2.5 cm mass in the right inguinal canal and a 5.4 cm × 6.8 cm mass was seen in the left ovary. The mass enlarged during menstruation. The groin mass was removed, in addition to carrying out laparoscopic ovarian cystectomy. At operation, the groin mass was found to be in continuity with the round ligament of extraperitoneal portion. Histological diagnosis of endometriosis was made in both ovarian and inguinal tumours. After surgery, the pain disappeared completely. Worth mentioning is that MRI clearly showed the change of tumour size depending on the menstrual cycle, which aided in arriving at the correct diagnosis of endometriosis in an unusual location.

Metatarsalgia: an ultrasound perspective.

Abstract: Research on metatarsophalangeal joint instability and the plantar plate was conducted from May 2002 to May 2006. Along with plantar plate tears, we found a range of pathologies. This is a pictorial review of our experience.

Colour Doppler ultrasound evaluation of orbital vessels in diabetic retinopathy.

Abstract: The aim of this study was to determine the role of colour Doppler imaging in the retrobulbar vascular circulation in diabetic retinopathy (DR). Maximum (V(max)), end-diastolic (V(min)) and average (V(mean)) velocities of blood flows and pulsatility index and resistivity index (RI) in central retinal artery (CRA), short branches of posterior ciliary artery (PCA) and ophthalmic artery of the 65 diabetic and 22 control eyes were measured. The CRA V(max) level in the control group was significantly higher than in DR groups. The CRA V(mean) level was also significantly higher in the control group than in the mild nonproliferative diabetic retinopathy (NPDR) and the moderate NPDR groups. The CRA RI value was significantly higher in the control group than in the nonretinopathy group. The CRA V(min) and the ophthalmic artery RI values were found significantly higher in the nonretinopathy group than in the moderate NPDR group. There were significant decreases in the some CRA and PCA values as glycated haemoglobin (HbA1c) levels increase in diabetic group. There was a positive correlation between the duration of diabetes and HbA1c levels. This study showed the presence of some dynamic circulatory alterations in the nonretinopathy group with diabetes and DR groups. It was also shown that there is a negative correlation between HbA1c and some orbital vascular velocities.

Normal measurement of orbital structures: implications for the assessment of Graves' ophthalmopathy.

Abstract: Compute tomography anatomy of the orbits is well described, but only a few reports are available on normal measurements of the extraocular muscles (EOM) and globe position (GP). We obtained CT images from patients who were referred to our department for CT of the paranasal sinuses using a standard protocol for evaluation of normal orbital measurements. Our study suggests that optimum results are attained with the use of a coronal scan at a window level and width setting that results in an optimum image at the maximum muscle width for assessment of EOM and an axial scan at the mid-GP for GP and interzygomatic line. Based on our normal values, a right-to-left ratio of more than 1.4 for EOM diameter or 1.2 for GP is indicative of asymmetry. An absolute diameter of EOM > 8 mm and GP < 2 mm are abnormal.

Radiotherapy in the management of recurrent synovial chondromatosis

Abstract: Synovial chondromatosis is a rare, benign condition characterized by the formation of multiple cartilaginous nodules that are generally intra-articular and can lead to chronic pain and limit the function of involved joints. We report on the novel use of radiotherapy that was used to treat a 42-year-old man with rapid recurrences of extensive synovial chondromatosis in the knee refractory to multiple operations. Based on follow-up MRI scans and clinical findings, the disease process was halted with no progression seen over 5 years.

CT evaluation of congenital choanal atresia: our experience and review of the literature.

Abstract: Congenital choanal atresia (CCA) is the developmental failure of the nasal cavity to communicate with the nasopharynx. The aim of this study was to investigate and analyse the CT findings in such cases. Seven patients with CCA were included in our study over a 3-year period (2001-2004). All had a CT scan of the nasal cavity and nasopharynx to establish the diagnosis and to define the extent and type of atresia. The choanal atresia was found to be more commonly bilateral and more of the mixed (membranous-osseous) type. Bilateral CCA in the neonate is a medical emergency that should be treated as early as possible. Computed tomography is a valuable and easily accessible diagnostic tool.

Sarcomatous transformation in diaphyseal aclasis

Abstract: Summary Multiple hereditary exostosis (or diaphyseal aclasis) is a condition characterized by the development of multiple osteochondromas. The tendency for malignant transformation into chondrosarcoma is well known. Malignancy typically arises from the cartilaginous cap of the osteochondroma. Radiographs supplemented by computed tomography have an important role in the diagnosis of this condition. Magnetic resonance imaging shows the features of sarcomatous change and aids in differentiating malignancy from pseudotumours.

Comparison of CT and positron emission tomography/CT coregistered images in planning radical radiotherapy in patients with non-small-cell lung cancer.

Abstract: Summary Imaging with F-18 fluorodeoxyglucose positron emission tomography (PET) significantly improves lung cancer staging, especially when PET and CT information are combined. We describe a method for obtaining CT and PET images at separate acquisitions, which allows coregistration and incorporation of PET information into the radiotherapy (RT) planning process for non-small-cell lung cancer. The influence of PET information on RT planning was analysed for 10 consecutive patients. Computed tomography and PET images were acquired with the patient in an immobilization device, in the treatment position. Using specially written software, PET and CT data were coregistered using fiducial markers and imported into our RT planning system (Cadplan version 6). Treatment plans were prepared with and without access to PET/CT coregistered images and then compared. PET influenced the treatment plan in all cases. In three cases, geographic misses (gross tumour outside planning target volume) would have occurred had PET not been used. In a further three cases, better planning target volume marginal coverage was achieved with PET. In four patients, three with atelectasis, there were significant reductions in V20 (percentage of the total lung volume receiving 20 Gy or more). Use of coregistered PET/CT images significantly altered treatment plans in a majority of cases. This method could be used in routine practice at centres without access to a combined PET/CT scanner .

Usefulness of muscle denervation as an MRI sign of peripheral nerve pathology

Abstract: Peripheral nerve disorders may be classified into compressive or entrapment neuropathies and non-compressive neuropathies. Muscle denervation recognized on MRI may be a useful sign in the diagnosis of peripheral nerve disorders. Acute or subacute denervation results in prolonged T2 relaxation time, producing increased signal in skeletal muscle on short tau inversion-recovery and fat-suppressed T2-weighted images. Chronic denervation produces fatty atrophy of skeletal muscles, resulting in increased muscle signal on T1-weighted images. This review will outline and illustrate the various ways that muscle denervation as seen on MRI may assist in the diagnosis and localization of peripheral nerve disorders.

Persistent trigeminal artery and associated vascular variations

Abstract: SUMMARY Persistent trigeminal artery (PTA) is the most frequent type of persistent primitive carotid-basilar artery anastomoses. Persistent trigeminal artery is usually associated with small or absent posterior communicating artery (Pcom). It may also be associated with hypoplastic vertebral and basilar arteries. Patients may present with symptoms related to hypo-perfusion of posterior circulation or microembolization from carotid artery to posterior circulation. We are presenting a 60-year-old who had recurrent episodes of vertigo and parasthesia, in whom MR angiography revealed a medial, Saltzman type 1 PTA on the left with absent ipsilateral Pcom, duplicated ipsilateral superior cerebellar artery, hypoplastic A1 segment of contralateral anterior cerebral artery (ACA), azygous ACA and hypoplastic ipsilateral vertebral artery.

CT scout view as an essential part of CT reading.

Abstract: Computed tomography scout view is a mode of operating a CT system. It is generally used to prescribe CT slices and to display slice locations rather than for direct diagnosis. However, we found that a careful study of CT scout view can contribute significantly to the diagnosis. We show seven abdominal, two chest and two head CT, where the study of CT scout view allowed diagnoses to be made that were not readily apparent from the axial slices.