Deep endometriosis muscular infiltration of the bowel wall: correlation between MRI and histopathology.

AIM: To assess the correlation between magnetic resonance imaging (MRI) and histopathology for predicting muscular infiltration of endometriosis in the bowel wall in patients undergoing colorectal resection. MATERIALS AND METHODS: All consecutive patients who underwent colorectal surgery for deep endometriosis (DE) with a preoperative MRI in a single tertiary care referral hospital between 2001 and 2019 were included in a prospective cohort. MRI images were revised by a single blinded radiologist. The MRI results regarding the infiltration depth (serosal, muscular, submucosal, or mucosal) and lesion expansion of DE were compared to histopathology. RESULTS: A total of 84 patients were eligible for evaluation. A sensitivity of 89% and positive predictive value of 97% was shown for predicting muscular involvement of the bowel wall. CONCLUSION: This study showed that MRI is valuable in predicting the involvement of the muscular layer of the colorectal wall. Therefore, in patients with symptomatic pelvic bowel endometriosis MRI is a useful tool in guiding the extent of colorectal surgery.

Advanced image analytics predicting clinical outcomes in patients with colorectal liver metastases: A systematic review of the literature.

BACKGROUND: To better select patients with colorectal liver metastases (CRLM) for an optimal selection of treatment strategy (i.e. local, systemic or combined treatment) new prognostic models are warranted. In the last decade, radiomics has emerged as a field to create predictive models based on imaging features. This systematic review aims to investigate the current state and potential of radiomics to predict clinical outcomes in patients with CRLM. METHODS: A comprehensive literature search was conducted in the electronic databases of PubMed, Embase, and Cochrane Library, according to PRISMA guidelines. Original studies reporting on radiomics predicting clinical outcome in patients diagnosed with CRLM were included. Clinical outcomes were defined as response to systemic treatment, recurrence of disease, and survival (overall, progression-free, disease-free). Primary outcome was the predictive performance of radiomics. A narrative synthesis of the results was made. Methodological quality was assessed using the radiomics quality score. RESULTS: In 11 out of 14 included studies, radiomics was predictive for response to treatment, recurrence of disease, survival, or a combination of outcomes. Combining clinical parameters and radiomic features in multivariate modelling often improved the predictive performance. Different types of individual features were found prognostic. Noticeable were the contrary levels of heterogeneous and homogeneous features in patients with good response. The methodological quality as assessed by the radiomics quality score varied considerably between studies. CONCLUSION: Radiomics appears a promising non-invasive method to predict clinical outcome and improve personalized decision-making in patients with CRLM. However, results were contradictory and difficult to compare. Standardized prospective studies are warranted to establish the added value of radiomics in patients with CRLM.

MRI cT1-2 rectal cancer staging accuracy: a population-based study.

BACKGROUND: Adequate MRI-based staging of early rectal cancers is essential for decision-making in an era of organ-conserving treatment approaches. The aim of this population-based study was to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS). METHODS: Patients with cT1-2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value. RESULTS: Of 7382 registered patients with cT1-2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1-2 N1 respectively. CONCLUSION: This Dutch population-based analysis of patients who underwent local excision or TME surgery for cT1-2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.

ANTECEDENTES: Una adecuada estadificación mediante resonancia magnética nuclear (RMN) de los cánceres de recto en estadios precoces es esencial para la toma de decisiones en una era en la existen diferentes opciones de tratamiento preservadoras del recto. El objetivo de este estudio de base poblacional fue determinar la precisión de la estadificación mediante RMN del cáncer de recto precoz en la práctica diaria, ya sea combinada o no con la ecografía endorectal (endorectal ultrasound, ERUS). MÉTODOS: Los pacientes con cáncer de recto en estadio cT1-2 que se sometieron a resección local o resección total del mesorrecto (total mesorectal excision, TME) sin (quimio) radioterapia neoadyuvante fueron seleccionados a partir del registro auditado ColoRectal holandés, entre el 1 de enero de 2011 y el 31 de diciembre de 2018. La precisión de las imágenes se expresó como sensibilidad, especificidad y valores predictivos positivo y negativo (positive- and negative predicting value, PPV / NPV). RESULTADOS: De un total de 7.382 pacientes registrados con cáncer de recto en estadio cT1-2, se incluyeron 5.539 pacientes (5.288 solamente RMN, 251 RMN + ERUS; 1.059 cT1 y 4.480 cT2). Los pacientes pT1 fueron sobreestadificados cuando se utilizó únicamente la RMN en un 54,7% de los casos (792/1.448) y cuando se combinó RMN y ERUS en un 31,0% (36/116). La infraestadificación de pT2 ocurrió en un 8,2% (197/2.388) y en un 27,9% (31/111), respectivamente. La RMN utilizada como única prueba sobreestadificó los casos pN0 en el 17,3% (570/3.303) y el VPP del estadio cN0 fue del 76,3% (2.733/3.583). De los 834 pacientes con estadio pT1N0, potencialmente adecuado para la resección local, 253 pacientes (30,3%) se clasificaron correctamente como cT1N0, y 484 (58,8%) y 97 (11,6%) pacientes se sobreestadificaron como cT2N0 y cT1-2N1, respectivamente. CONCLUSIÓN: Este estudio de base poblacional holandés en pacientes que se sometieron a una resección local o a cirugía TME por cáncer de recto cT1-2 con estadificación preoperatoria mediante RMN, muestra una considerable sobreestadificación, lo que indica las debilidades y oportunidades en las estrategias de preservación del recto.

Risk of spontaneous pneumothorax due to air travel and diving in patients with Birt-Hogg-Dubé syndrome.

BACKGROUND AND OBJECTIVES: Birt-Hogg-Dubé syndrome is an autosomal dominant disorder characterized by skin fibrofolliculomas, lung cysts, spontaneous pneumothorax and renal cell cancer due to germline folliculin (FLCN) mutations (Menko et al. in Lancet Oncol 10(12):1199-1206, 2009). The aim of this study was to evaluate the incidence of spontaneous pneumothorax in patients with BHD during or shortly after air travel and diving. METHODS: A questionnaire was sent to a cohort of 190 BHD patients and the medical files of these patients were evaluated. The diagnosis of BHD was confirmed by FLCN mutations analysis in all patients. We assessed how many spontaneous pneumothoraces (SP) occurred within 1 month after air travel or diving. RESULTS: In total 158 (83.2 %) patients returned the completed questionnaire. A total of 145 patients had a history of air travel. Sixty-one of them had a history of SP (42.1 %), with a mean of 2.48 episodes (range 1-10). Twenty-four (35.8 %) patients had a history of pneumothorax on both sides. Thirteen patients developed SP < 1 month after air travel (9.0 %) and two patients developed a SP < 1 month after diving (3.7 %). We found in this population of BHD patients a pneumothorax risk of 0.63 % per flight and a risk of 0.33 % per episode of diving. Symptoms possible related to SP were perceived in 30 patients (20.7 %) after air travel, respectively in ten patients (18.5 %) after diving. CONCLUSION: Based on the results presented in this retrospective study, exposure of BHD patients to considerable changes in atmospheric pressure associated with flying and diving may be related to an increased risk for developing a symptomatic pneumothorax. Symptoms reported during or shortly after flying and diving might be related to the early phase of pneumothorax. An individualized advice should be given, taking also into account patients' preferences and needs.

Bilateral renal tumour as indicator for birt-hogg-dubé syndrome.

Birt-Hogg-Dubé (BHD) syndrome is a cancer disorder caused by a pathogenic FLCN mutation characterized by fibrofolliculomas, lung cysts, pneumothorax, benign renal cyst, and renal cell carcinoma (RCC). In this case we describe a patient with bilateral renal tumour and a positive familial history for pneumothorax and renal cancer. Based on this clinical presentation, the patient was suspected for BHD syndrome, which was confirmed after molecular testing. We discuss the importance of recognizing this autosomal dominant cancer disorder when a patient is presented at the urologist with a positive family history of chromophobe renal cell cancer or a positive familial history for renal cell cancer and pneumothorax.

Bipolar radiofrequency ablation for symptomatic giant (>10 cm) hepatic cavernous haemangiomas: initial clinical experience.

AIM: To describe initial clinical experience with bipolar radiofrequency ablation (RFA) for symptomatic giant hepatic haemangiomas. MATERIALS AND METHODS: Four consecutive patients with a large-volume, symptomatic hepatic cavernous haemangioma of >10 cm were treated with bipolar RFA during laparotomy with ultrasound guidance. Complications were carefully noted. Clinical and radiological effectiveness were evaluated comparing baseline with 3 and 6 months follow-up of symptom assessments and upper abdominal magnetic resonance imaging (MRI) or computed tomography (CT). RESULTS: RFA was successfully performed for all four giant haemangiomas. No major complications were observed. Peri-procedural shrinking was remarkable and intermediate-term volume reduction ranged from 58-92% after 6 months. Symptom relief after 6 months was complete in two patients and considerable in the other two. CONCLUSION: Preliminary results suggest intra-operative bipolar RFA to be a safe, feasible, and effective technique for treatment of giant symptomatic hepatic cavernous haemangiomas.

Solely inhibin B producing ovarian tumour as a cause of secondary amenorrhoea with hot flushes: case report and review of literature.

In this report, we describe a case of a solely inhibin B producing fibrothecoma presenting with secondary amenorrhoea and hot flushes. Typical laboratory findings were an elevated LH, elevated inhibin B, low FSH and low estrogen. The World Health Organization classification of amenorrhoea was not applicable since the combination of low estrogen and low FSH suggested a central cause, whereas actually there was an ovarian cause. With staging laparotomy, a bilateral borderline tumour was detected in combination with a fibrothecoma. This report underpins the concept of inhibin B being a selective FSH secretion inhibitor of ovarian origin. Furthermore, a literature review on these topics is included.

MR imaging of bladder endometriosis and its relationship with the anterior uterine wall: experience in a tertiary referral centre.

OBJECTIVE: Both the intraperitoneal seeding and the uterine-vesical extension theory have been proposed to explain the pathogenesis of bladder endometriosis. The aim of this study was to describe MR imaging findings of bladder endometriosis and involvement of the anterior uterine wall in a tertiary referral centre for endometriosis in a effort to improve diagnosis and help clarify the pathogenesis. METHODS: In a single-centre, retrospective study (2004-2009), 463 consecutive patients analysed for deep infiltrating endometriosis (DIE) were studied independently by two experienced readers for the presence of bladder endometriosis. MR studies revealing bladder endometriosis were then analysed in consensus for: location, size, signal intensity characteristics, uterine involvement, continuity with adenomyosis and presence of cysts. There was histopathologic correlation in 9 patients who had undergone partial bladder resection. RESULTS: Bladder endometriosis was diagnosed in 32 patients on MR imaging (k=0.85). Most lesions showed heterogeneous isointensity compared to that of muscle on T2-weighed imaging, containing foci of high signal intensity, suggesting cystic ectopic endometrial glands. On T1-weighted imaging lesions showed heterogeneous isointensity with foci or small cysts, demonstrating high signal intensity, indicating hemorrhage, was observed. Uterine involvement was found in 94% of the lesions, with either "continuous" or "hourglass" configurations. Presence of contiguous adenomyosis was found in only 4 lesions. CONCLUSIONS: With MR imaging, uterine involvement in bladder endometriosis is frequently found and in most cases located subserosally, suggesting extensive DIE, favouring the intraperitoneal seeding theory.

Evaluation of MR diffusion-weighted imaging in differentiating endometriosis infiltrating the bowel from colorectal carcinoma.

OBJECTIVE: Endometriosis infiltrating the bowel may be difficult to differentiate from colorectal carcinoma in cases that present with non-specific clinical and imaging features. The aim of this study is to assess the value of MR diffusion-weighted imaging (DWI) in differentiating endometriosis infiltrating the bowel from colorectal carcinoma. METHODS: In 66 patients, MR DWI was added to the standard imaging protocol in patients visiting our outdoor MR clinic for the analysis of suspected or known deep infiltrating endometriosis (DIE). In patients diagnosed with DIE infiltrating the bowel on MR imaging, high b-value diffusion-weighted images were qualitatively assessed by two readers in consensus and compared to high b-value diffusion weighted images in 15 patients evaluated for colorectal carcinoma. In addition, ADC values of lesions were calculated, using b-values of 50, 400 and 800 s/mm(2). RESULTS: A total of 15 patients were diagnosed with DIE infiltrating the bowel on MR imaging. Endometriosis infiltrating the bowel showed low signal intensity on high b-value diffusion-weighted images in all patients, whereas colorectal carcinoma showed high signal intensity on high b-value diffusion-weighted images in all patients. Mean ADC value in endometriosis infiltrating the bowel (0.80 ± 0.06 × 10(-3)mm(2)/s) was significantly lower compared to mean ADC value in colorectal carcinoma (0.86 ± 0.06 × 10(-3 )mm(2)/s), but with considerable overlap between ADC values. CONCLUSION: Only qualitative assessment of MR DWI may be valuable to facilitate differentiation between endometriosis infiltrating the bowel and colorectal carcinoma.

Long-term results of radiofrequency ablation for unresectable colorectal liver metastases: a potentially curative intervention.

OBJECTIVE: The long-term results and prognostic factors of radiofrequency ablation (RFA) for unresectable colorectal liver metastases (CRLM) in a single centre with >10 years of experience were retrospectively analysed. METHODS: A total of 100 patients with unresectable colorectal liver metastases (CRLM) (size 0.2-8.3 cm; mean 2.4 cm) underwent a total of 126 RFA sessions (237 lesions). The mean follow-up time was 29 months (range 6-93 months). Lesion characteristics (size, number and location), procedure characteristics (percutaneous or intra-operative approach) and major and minor complications were carefully noted. Local control, mean survival time and recurrence-free and overall survival were statistically analysed. RESULTS: No direct procedure-related deaths were observed. Major complications were present in eight patients. Local RFA site recurrence was 12.7% (n = 30/237); for tumour diameters of <3 cm, 3-5 cm and >5 cm, recurrence was 5.6% (n = 8/143), 19.5% (n = 15/77) and 41.2% (n = 7/17), respectively. Centrally located lesions recurred more often than peripheral ones, at 21.4% (n = 21/98) vs 6.5% (n = 9/139), respectively, p = 0.009. Including additional treatments for recurring lesions when feasible, lesion-based local control reached 93%. The mean survival time from RFA was 56 (95% confidence interval (CI) 45-67) months. Overall 1-, 3-, 5- and 8-year survival from RFA was 93%, 77%, 36% and 24%, respectively. CONCLUSIONS: RFA for unresectable CRLM is a safe, effective and potentially curative treatment option; the long-term results are comparable with those of previous investigations employing surgical resection. Factors determining success are lesion size, the number of lesions and location.

Magnetic resonance imaging in the evaluation of (deep infiltrating) endometriosis: the value of diffusion-weighted imaging.

PURPOSE: To assess the value of magnetic resonance (MR)diffusion-weighted imaging (DWI) in the evaluation of deep infiltrating endometriosis (DIE). MATERIALS AND METHODS: In a prospective single-center study, DWI was added to the standard MRI protocol in 56 consecutive patients with known or suspected endometriosis. Endometriotic lesions as well as (functional) ovarian cysts were analyzed for location, size, and signal intensity on T1, T2, and DWI. Apparent diffusion coefficient (ADC) values were calculated using b-values of 50, 400, 800,and 1200 s/mm(2). Statistical analysis included the Spearman correlation coefficient, Mann-Whitney U, and Kruskal-Wallis tests. RESULTS: A total of 110 lesions (62 endometrial cysts and 48 DIE) were detected, 60 of which were large enough to analyze. Mean ADC values of endometrial cysts and functional ovarian cysts were 1.10 x 10(-3)/mm(2)/s and 2.14 x 10(-3)/mm(2)/s, respectively. Mean ADC values of DIE retrocervical, infiltrating the colon, and bladder were 0.70 x 10(-3)/mm(2)/s, 0.77 x 10(-3)/mm(2)/s, and 0.79 x 10(-3)/mm(2)/s, respectively. ADC values of DIE did not show a significant difference between varying pelvic locations (P = 0.63). CONCLUSION: Results of our study suggest that ADC values of DIE are consistently low, without significant difference between pelvic locations.

Magnetic resonance imaging in the evaluation of (deep infiltrating) endometriosis: the value of diffusion-weighted imaging.

PURPOSE: To assess the value of magnetic resonance (MR) diffusion-weighted imaging (DWI) in the evaluation of deep infiltrating endometriosis (DIE). MATERIALS AND METHODS: In a prospective single-center study, DWI was added to the standard MRI protocol in 56 consecutive patients with known or suspected endometriosis. Endometriotic lesions as well as (functional) ovarian cysts were analyzed for location, size, and signal intensity on T1, T2, and DWI. Apparent diffusion coefficient (ADC) values were calculated using b-values of 50, 400, 800, and 1200 s/mm(2). Statistical analysis included the Spearman correlation coefficient, Mann-Whitney U, and Kruskal-Wallis tests. RESULTS: A total of 112 lesions (62 endometrial cysts and 48 DIE) were detected, 60 of which were large enough to analyze. Mean ADC values of endometrial cysts and functional ovarian cysts were 1.11 x 10(-3)/mm(2)/s and 2.14 x 10(-3)/mm(2)/s, respectively. Mean ADC values of DIE retrocervical, infiltrating the colon, and bladder were 0.70 x 10(-3)/mm(2)/s, 0.79 x 10(-3)/mm(2)/s, and 0.76 x 10(-3)/mm(2)/s, respectively. ADC values of DIE did not show a significant difference between varying pelvic locations (P = 0.63). CONCLUSION: Results of our study suggest that ADC values of DIE are consistently low, without significant difference between pelvic locations.

Surgical outcome and long-term follow-up after segmental colorectal resection in women with a complete obstruction of the rectosigmoid due to endometriosis.

INTRODUCTION: Intestinal involvement is reported in up to 12% of women with endometriosis. Complete large bowel obstruction is a rare complication of intestinal endometriosis. It is estimated to occur in less than 1% of the cases. OBJECTIVE: The aim of this study is to evaluate the surgical outcome and long-term follow-up after segmental colorectal resection in women with a complete obstruction of the rectosigmoid due to endometriosis. In addition, the diagnostic work-up is described and discussed in view of the current literature. PATIENTS AND METHODS: We present a case series of 5 patients with a complete obstruction of the rectosigmoid due to endometriosis who were finally treated in our hospital within a multidisciplinary endometriosis team. We retrospectively analyzed all patients with this condition who were referred in the period January 2000 to December 2006. RESULTS: All patients (mean age 31.8 years, range 25-43 years) underwent emergency surgery resulting in a diverting colostomy before referral to our hospital. The principal diagnostic tool used was magnetic resonance imaging which demonstrated in all patients multiorgan endometriosis with complete obstruction of the rectosigmoid. Thereafter, all patients underwent a segmental colorectal resection by re-laparotomy. The diagnosis intestinal endometriosis was histologically confirmed in all cases. After surgery no major complications occurred. During a follow-up of 18-36 months, residual symptoms such as chronic constipation, deep dyspareunia and chronic pelvic pain were reported in 2 patients. No recurrences of intestinal endometriosis occurred. CONCLUSION: In our case series, segmental colorectal resection showed a favorable surgical outcome with no major complications. In the long-term follow-up, a limited number of residual symptoms were reported and no recurrences occurred. Intestinal endometriosis as a cause of bowel obstruction is often a diagnostic challenge mimicking a broad spectrum of diseases. It should be included in the differential diagnosis in women of reproductive age presenting with any symptoms of bowel obstruction. Magnetic resonance imaging is recommended as the primary imaging technique in such cases. In our opinion, these patients should be treated in a multidisciplinary setting.

Sources of variation in multi-centre brain MTR histogram studies: body-coil transmission eliminates inter-centre differences.

OBJECT: 1. Identify sources of variation affecting Magnetisation Transfer Ratio (MTR) histogram reproducibility between-centres. 2. Demonstrate complete elimination of inter-centre difference. MATERIALS AND METHODS: Six principle sources of variation were summarised and analysed. These are: the imager coil used for radiofrequency (RF) transmission, imager stability, the shape and other parameters describing the Magnetisation Transfer (MT) pulse, the MT sequence used (including its parameters), the image segmentation methodology, and the histogram generation technique. Transmit field nonuniformity and B1 errors are often the largest factors. PLUMB (Peak Location Uniformity in MTR histograms of the Brain) plots are a convenient way of visualising differences. Five multi-centres studies were undertaken to investigate and minimise differences. RESULTS: Transmission using a body coil, with a close-fitting array of surface coils for reception, gave the best uniformity. Differences between two centres, having MR imagers from different manufacturers, were completely eliminated by using body coil excitation, making a small adjustment to the MT pulse flip angle, and carrying out segmentation at a single centre. Histograms and their peak location and height values were indistinguishable. CONCLUSIONS: Body coil excitation is preferred for multi-centre studies. Analysis (segmentation and histogram generation) should ideally be carried out at a single site.

A standardised method for measuring magnetisation transfer ratio on MR imagers from different manufacturers--the EuroMT sequence.

Magnetisation transfer ratio (MTR) is increasingly used to evaluate neurological disorders, especially those involving demyelination. It shows promise as a surrogate marker of disease progression in treatment trials in multiple sclerosis (MS) but the value measured is highly dependent on pulse sequence parameters, making it hard to include the technique in large multi-centre clinical trials. The variations can be reduced by a normalisation procedure based on the flip angle and timing of the presaturation pulse, but correction for parameters such as saturation pulse shape, amplitude, duration and offset frequency remains problematic. We have defined a standard pulse sequence, to include a standard presaturation pulse and set of parameters, which can be implemented on scanners from both General Electric and Siemens, and has also been used on Phillips scanners. To validate the sequence and parameters, six European centres measured MTR in the frontal white matter of normal volunteers. It was possible to measure MTR values in controls which were consistent to within approximately +/-2.5 percentage units across sites. This degree of precision may be adequate in many situations. The remaining differences between sites and manufacturers are probably caused by B1 errors.

The effect of interferon beta-1b on quantities derived from MT MRI in secondary progressive MS.

BACKGROUND: Magnetization transfer (MT) MRI can provide in vivo markers reflecting the severity of irreversible, MS-related brain damage occurring within and outside T2-visible lesions. OBJECTIVE: To assess the effect of interferon (IFN) beta-1b treatment on the accumulation of brain damage in patients with secondary progressive (SP) MS, measured using MT MRI. METHODS: Eighty-two patients with SPMS from five centers participating in a European, multicenter, double-blind, placebo-controlled trial of IFNbeta-1b in SPMS underwent brain T2-weighted and MT MRI at baseline. Evaluable follow-up data were available for 75 patients at 12 months, 54 at 24 months, and 47 at 36 months. MT MRI scans were postprocessed and analyzed to obtain histograms of MT ratio (MTR) values from the whole brain. A region of interest-based analysis of MTR values from the normal-appearing white matter (NAWM) was also performed. RESULTS: In both the treatment arms, there was a decrease of average brain MTR values from baseline to month 24 (mean change -4.9%) and month 36 (mean change -4.3%). These changes were significant for the placebo group at both timepoints and for the IFNbeta-1b group at month 24 only, with no significant treatment effect. A decrease of NAWM MTR was also observed, with no significant difference between the two treatment arms. CONCLUSION: In this cohort of patients with secondary progressive MS, interferon beta-1b did not show an overall effect on the worsening of magnetization transfer MRI measures, when compared with placebo. The data show that change in magnetization transfer ratio is a promising tool for monitoring disease evolution in secondary progressive MS and that the information obtained from magnetization transfer MRI complements that obtained from MRI measures of lesion load and inflammation.