Biomedical subjects
Publications and source records attributed to M A Hall-Craggs.
Fibrous hamartoma of infancy is an uncommon, self-limiting benign tumour that presents during the first 2 years of life, developing from subcutaneous fibrous tissue proliferation at almost any site. We describe the results of MRI of a lesion at the wrist. The scans enabled a planned surgical resection with the aim of preventing local recurrence without damaging important neurovascular structures.
Contrast-enhanced MR imaging of the breast has been found to be valuable in the assessment of local recurrence of previously treated breast cancer. We looked specifically at the appearances of the skin and nipple of the treated breast in order to describe the appearances of post-treatment change and recurrence in this region. Thirty-nine women treated for breast cancer had MR imaging of one or both breasts reviewed retrospectively with particular attention to the nipple and skin. The skin and chest wall were assessed for patients with mastectomies. All available histology of the skin and/or nipple, obtained following MR imaging, was reviewed. In patients who did not undergo surgery following MR imaging, clinical follow-up was obtained. Six of 39 cases had nodular enhancing areas seen on MR imaging, which correlated with histology demonstrating tumour recurrence within the skin and/or nipple. Of the remaining 33 patients, changes of linear or diffuse enhancement were seen in the skin and/or nipple of 15 patients. These changes were shown to be benign post-treatment changes at surgery/biopsy in 4 cases or by clinical follow-up in the remainder. In this article we demonstrate differing patterns of contrast enhancement within the skin and nipple in recurrent breast carcinoma vs. post-treatment changes. This suggests that contrast-enhanced MR imaging of the breast may be a useful tool in differentiating tumour recurrence from post-treatment changes within the skin and nipple.
BACKGROUND: Three-dimensional (3D) imaging of delicate, moving soft-tissue body parts is very difficult. Our understanding of the muscles that control lip movements is based largely on histological and cadaveric studies, which provide scant information about dynamic morphology. Our aim was to develop an innovative scanning technique for the imaging and reconstruction of dynamic orofacial morphology by use of 3D and four-dimensional (4D, ie, 3D plus time) ultrasonography. METHODS: Four volunteers (including one patient) underwent ultrasonography with 3D/4D imaging systems. To avoid deformation of the delicate orofacial structures, a water bath with an acoustic window was devised. The orofacial part was immersed in the bath throughout scanning, and a timer was used to synchronize lip movements with the 4D scan. FINDINGS: 4D views showed the functional differences in superficial and deep muscle groups of the lips, and clearly showed the changes occurring with movement of the lips and mouth. In the patient, a pathological layer and its extension corresponding to surface malformation were clearly identified. INTERPRETATION: We have developed a prototype device that has made possible 3D and 4D examination of orofacial anatomy and function. With further refinement of the device and improvement in 4D acquisition timing, this technique may offer a new way of dynamically imaging and quantifying many soft-tissue parts in 3D without deforming structure or disturbing function.
In recent years a variety of minimally invasive therapies have been applied to the treatment of breast lesions. These therapies include thermal treatments (interstitial laser coagulation, focused ultrasound, radiofrequency and cryotherapy), percutaneous excision, and interstitial radiotherapy. Magnetic resonance has been used in these treatments to visualize lesions before, during and after therapy and to guide interventions. "Temperature-sensitive" sequences have shown changes with thermal ablation which broadly correlate with areas of tumour necrosis. Consequently, MR has the potential to monitor treatment at the time of therapy. To date, experience in the treatment of breast cancer has been restricted to small studies. Large controlled studies are required to validate the efficacy and safety of these therapies in malignant disease.
Allogeneic bone marrow transplantation is frequently associated with neurological complications, particularly intracerebral bleeds and infections. Cerebral venous sinus thrombosis has only rarely been reported following allogeneic transplants. We report three cases of cortical venous thrombosis following allografting for acute lymphoblastic leukaemia. Two patients received marrow from HLA-identical siblings and one from an unrelated donor. Two of the patients presented with grand mal seizures and one presented with a headache. No neurological abnormalities were found upon clinical examination and lumbar puncture was normal in all three cases. In two of the patients computed tomography (CT) of the brain was normal and in the third showed non-specific abnormalities. Magnetic resonance imaging (MRI) with MR angiography (MRA) demonstrated cerebral venous sinus thrombosis in all three patients. In conclusion, cerebral venous sinus thrombosis should be considered in the differential diagnosis when neurological symptoms occur following allogeneic bone marrow transplantation. We therefore advocate the use of MRA for unexplained neurological symptoms post-allograft since without it cerebral venous sinus thrombosis may easily be missed.
OBJECTIVES: To measure cerebrospinal fluid (CSF) tau in HIV infected patients with acute neurological episodes and to correlate the findings with the type and severity of neurological disease. METHODS: CSF tau was prospectively measured in 76 consecutive HIV infected patients admitted to a specialist unit at UCL Hospitals, London, for investigation of acute neurological episodes: the results were compared with the clinical diagnoses. RESULTS: 24 patients had HIV associated dementia complex (HADC), 10 had lymphoma (including four with primary CNS lymphoma), 20 had cerebral infections (including five with CMV encephalitis, five with VZV infection, seven with cryptococcal meningitis, two with toxoplasmosis, and one with progressive multifocal leucoencephalopathy); 22 patients had miscellaneous conditions, including nine with self limiting headache/fever. 62 patients (82%) had normal CSF tau concentration and 14 patients (18%) had elevated tau. In those with HADC, there was no correlation between the degree of dementia or atrophy on magnetic resonance imaging and CSF tau. Elevated CSF tau was associated with poor outcome as six of eight patients who died within 4 weeks of lumbar puncture had elevated tau (p = 0.0024, two tailed Fisher's exact test). CONCLUSIONS: CSF tau levels are not elevated in the majority of HIV infected patients presenting with acute neurological episodes. CSF tau levels show no correlation with severity of dementia/atrophy on magnetic resonance imaging. Although elevated CSF tau was observed in some patients with conditions causing cerebral necrosis, the finding did not delineate underlying pathology but was associated with poor outcome.
We report the results of a prospective study of 23 patients in which interstitial laser photocoagulation (ILP) was used to treat an osteoid osteoma. ILP is a technique in which tumour tissue is destroyed by direct heating using low-power laser light energy delivered by thin (400 microm) optical fibres which are introduced percutaneously into the tumour under image guidance. Pain was evaluated before operation and at the latest follow-up using a visual analogue scale with 0 denoting no pain and 10 the worst pain imaginable. The mean follow-up was for 15 months. The results showed that the mean pain score decreased from 7.5 before operation to 0.95 at the latest follow-up. Fourteen patients had no pain and eight had minor discomfort, not requiring analgesia. One patient required a second procedure because placement of the fibre had not been accurate enough and one developed recurrent symptoms eight months after treatment. All patients were satisfied with the operation because of the rapid resolution of pain, the minimally invasive nature of the procedure, and the fact that there was no postoperative restriction of activity.
We compared two methods of estimating the volume of 10 formalin-fixed brains using MRI. MRI was performed and total brain volume was then assessed using two distinct techniques: a stereological point-counting technique based on the Cavalieri principle, and an edge-tracing technique. The total brain volumes obtained using these two techniques were similar and correlated closely with each other (r = 0.97). Both methods could be optimised to a similar degree while maintaining the coefficient of error at an acceptably low level. However, the stereological assessment of brain volume required between 20 min and 30 min per brain, depending on the number of points per sampling grid, compared with 1 h per brain using the planimetric method. Thus, while planimetric and stereological approaches yield very similar results, the stereological method has the advantage of greater speed and, therefore, efficiency.
OBJECTIVE: Magnetic resonance techniques have recently been investigated as tools with which to monitor inflammatory joint disease. Our aim was to use a contrast-enhanced T1-weighted protocol to monitor the short-term changes in knee synovial lining volume in a double-blind, randomized, controlled trial of intra-articular samarium-153 particulate hydroxyapatite (Sm-153 PHYP). METHODS: Twenty-four out-patients with chronic knee synovitis, from a cohort who had been recruited to a long-term clinical efficacy trial, were recruited for this study. Patients received either intra-articular Sm-153 PHYP combined with 40 mg triamcinolone hexacetonide or 40 mg intra-articular triamcinolone hexacetonide alone. Synovial lining volumes were calculated from three-dimensional T1-weighted contrast-enhanced images made before and after contrast enhancement with thresholding and pixel counting, immediately before and 3 months after treatment. RESULTS: Paired pre- and post-treatment magnetic resonance data were obtained for 18/24 (75%) patients. There was no significant difference in mean pre-treatment synovial volume between the two treatment groups (139 vs 127 ml). A mean reduction in synovial lining volume was detected in the Sm-153 PHYP/steroid-treated group (139 to 110 ml, P = 0.07) and in the steroid-treated group (127 to 58 ml, P < 0.001). The reduction was significantly greater in the steroid-treated group (-61% vs -23%, P < 0.05). CONCLUSIONS: Short-term changes in articular synovial lining in response to intra-articular treatment for chronic synovitis may be monitored by magnetic resonance imaging. After 3 months, a greater mean reduction in synovial lining volume had occurred in response to intra-articular steroid alone compared to combined Sm-153 PHYP/steroid injection.
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Central pontine myelinolysis (CPM) is an uncommon complication in sick patients with severe underlying disorders such as chronic alcoholism, malignancy, malnutrition and hyponatraemia. We report two patients with advanced HIV infection who developed CPM. In one case the diagnosis was not suspected in life, in the other the diagnosis was made just before death, on the basis of magnetic resonance (MR) imaging appearances. At post mortem there was a close correlation between the MR abnormalities and the anatomic changes in the pons.
OBJECTIVES: To identify by clinical examination, EEG, MRI, and proton spectroscopy, and neuropsychological assessment the prevalence of signs of CNS involvement in patients infected with HIV, and to relate such findings to the evidence of immunosuppression. METHODS: The design was a cross sectional analysis of a cohort of male patients with infected HIV with an AIDS defining diagnosis or low CD4 count (<350), and seropositive asymptomatic subjects, both groups being followed up in a longitudinal study. Control groups consisted of seronegative subjects from the same genitourinary medicine clinics. RESULTS: This report sets out the cross sectional findings at the seventh visit in the longitudinal study. Patients with AIDS had more signs of neurological dysfunction, poorer performance on a neuropsychological test battery, were more likely to have an abnormal EEG, and to have abnormalities on MRI. They more often had cerebral atrophy, abnormal appearing white matter, and abnormal relaxometry and spectroscopy. There was little evidence of abnormality in seropositive people who had a CD4 count >350 compared with seronegative people from a similar background. CONCLUSIONS: Detailed testing failed to disclose significant CNS impairment without immunosuppression in men infected with HIV. Findings from MRI and magnetic resonance spectroscopy (MRS) correlated with those of the neurological examination and neuropsychological assessment. A combination of such assessments offers a simple surrogate for studies of CNS involvement in HIV disease.
OBJECTIVES: To compare the results of magnetic resonance imaging (MRI) and thallium-201 (201Tl) SPET scanning with laboratory analyses including CSF DNA detection, brain biopsy, and necropsy in the discrimination of cerebral lymphoma and toxoplasmosis in patients with AIDS. METHODS: A retrospective study of 32 patients infected with HIV who had focal CNS lesions on MRI as a result of either lymphoma or toxoplasmosis. RESULTS: 18 patients had lymphoma, 12 had toxoplasmosis, and two had both. Toxoplasma IgG antibodies were detected in only seven patients--four with toxoplasmosis, two with lymphoma, and one with both diagnoses. Epstein-Barr virus DNA was detected in CSF of all six patients with lymphoma and none of two with toxoplasmosis. MRI showed multiple lesions in 23 patients, appearances did not discriminate between lymphoma and toxoplasmosis; nine patients had single lesions, of these eight had lymphoma (p = 0.044, two tailed Fisher's exact test) 201Tl SPET showed accumulation in 17 with lymphoma and six with toxoplasmosis (p = 0.034, two tailed Fisher's exact test). Of nine patients with single lesions on MRI and 201Tl SPET with focal accumulation eight had lymphoma. 201Tl SPET uptake ratios of > or = 2.9 were only seen with lymphoma. CONCLUSION: Knowledge of patients' toxoplasma serostatus does not aid discrimination between lymphoma and toxoplasmosis. Single lesions on MRI with focal accumulation of 201Tl strongly suggest lymphoma. Multiple lesions on MRI with 201Tl SPET uptake ratios > or = 2.9 also suggest lymphoma; uptake ratios less than 2.1 do not aid discrimination. Detection of Epstein-Barr virus DNA in CSF is highly sensitive and specific for cerebral lymphoma.
OBJECTIVE: To investigate the prevalence and extent of cerebral changes in patients with systemic lupus erythematosus (SLE) by magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). METHODS: SLE patients (47 women) and controls (25 women) underwent 1.5T MRI. A semiautomated segmentation technique calculated cerebrospinal fluid (CSF) and brain volumes. Proton MRS of the frontal and parieto-occipital white matter yielded metabolite ratios of N-acetyl groups (NA), choline, and creatine. RESULTS: Compared with the control group, the SLE patients more often had cerebral atrophy on MRI (32% versus 0%), confirmed by an increase in the CSF to intracranial volume ratio. The patients also had old infarcts and hemorrhages (8.5% versus 0%) and more small white matter lesions (23% versus 8% had > 5 such lesions). MRS showed relative reduction of NA peaks. Although no patient was studied when acutely ill, prior neurologic involvement was related to abnormal findings. CONCLUSION: MRI and MRS are helpful in the investigation of cerebral complications of SLE. There are chronic changes which may be ischemic in nature. Their precise cause, consequences, and prevention are current challenges.
The aim of this study was to develop methods of visualising optical fibres on MRI scans for monitoring interstitial laser therapy. Scans were performed on a specialised MRI extremity scanner at 0.17 T. Optical fibres of 0.4 mm diameter used for delivering laser energy were coated with iron particles from a superferromagnetic contrast agent. MR images of the fibres were acquired using gradient echo sequences (TR/TE = 300/10, 1 mm in-plane, 3 mm slice) and assessed for fibre visibility. Coated fibres could be resolved as lines 2 +/- 1 mm wide using the gradient echo sequence. Uncoated fibres were invisible on the sequences used for in vivo therapy monitoring due to partial volume averaging. It is concluded that optical fibre visualisation by MRI may be improved by coating with ferromagnetic particles. Biocompatibility requires further assessment, but direct coating appears to be a promising method for fibre visualisation in MR-guided laser therapy.
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AIM: To identify the magnetic resonance (MR) morphological and enhancement characteristics of the normal and diseased nipple. MATERIALS AND METHODS: The MR appearances of the nipple in 35 patients with known primary breast cancer who went on to mastectomy was reviewed by two radiologists (blinded to the clinical, mammographic and histopathological information) and correlated with histology. The appearance of the contra-lateral nipple in 31 patients was reviewed and compared with that of the affected side. MR was performed at 1.0T using a receive-only double breast coil in 33 patients and a single breast coil in two patients. Three dimensional (3-D) T1-weighted gradient-echo images were made before and immediately after a fast hand injection of gadolinium-DTPA (0.1 mmol/kg). RESULTS: Twenty-six breasts had histopathologically normal nipples and retroareolar tissue, four had evidence of tumour within the nipple and four had retroareolar tumour but with nipple sparing. Fifteen normal nipples were everted and 11 were inverted (flat). All showed superficial linear dermal enhancement above a non-enhancing zone in the nipple areolar complex. Linear or patchy enhancement deep to the non-enhancing zone was seen in four breasts and linear enhancement through the non-enhancing zone was seen in two. The nipple in all four breasts with tumour involvement showed increased thickening/bulkiness and enhancement of the nipple-areolar complex and retroareolar tissue. The four breasts with retroareolar tumour and nipple sparing showed increased thickening and enhancement of the retroareolar tissue only. There was one false positive result on breast MR for retroareolar tumour involvement. In this case the abnormally enhancing retroareolar tissue adjacent to the focal mass was shown to be an area of sclerosing adenosis on histology. The 31 contra-lateral nipples had the characteristic 'normal' appearance and when compared with its normal ipsilateral nipple showed marked symmetry. When compared with its abnormal ipsilateral nipple showed marked asymmetry. CONCLUSION: MR of the breast can show nipple involvement even when clinically unsuspected. This is important for treatment planning of breast cancer, in particular nipple preserving surgery.